Evangelisti S, Lettieri P, Clift R, Borello D (2014) Distributed generation by energy from waste technology: A life cycle perspective, Process Safety and Environmental Protection
Municipal Solid Waste in general and its organic fraction in particular is a potential renewable and non-seasonal resource. In this work, a life cycle assessment has been performed to evaluate the environmental impacts of two future scenarios using biogas produced from the organic fraction of municipal solid waste (OFMSW) to supply energy to a group of dwellings, respectively comprising distributed generation using solid oxide fuel cell (SOFC) micro-CHP systems and condensing boilers. The London Borough of Greenwich is taken as the reference case study. The system is designed to assess how much energy demand can be met and what is the best way to use the digestible waste for distributed energy purposes. The system is compared with two alternative scenarios fuelled by natural gas: a reference scenario, where the electricity is supplied by the grid and the heat is supplied from condensing boilers, and a fuel cell micro-CHP system. The results show that, although OFMSW alone can only supply between 1% and 4% of the total energy demand of the Borough, a saving of
Elghali L, Clift R, Begg KG, McLaren S (2008) Decision support methodology for complex contexts, PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-ENGINEERING SUSTAINABILITY 161 (1) pp. 7-22 THOMAS TELFORD PUBLISHING
Thambimuthu KV, Tan BKC, Clift R (1980) Mechanisms of steady filtration of gases in packed beds., IN: PROC. INT. SYMP. ON SOLIDS SEPARATION PROCESSES, (DUBLIN, EIRE: APR. 1980), RUGBY, U.K., INST. CHEM. ENGRS., 1980, SESSIO (231 ).)
Correlations for the efficiency of removal of dust from a gas by Brownian diffusion, inertial deposition, gravitational settling, and direct interception in a fixed bed of spherical granular collector particles are applied to predicting the performance of a packed bed filter. The results clarify the difference between filtration of sub-micron particles and particles larger than 1MUm. Filter efficiency is shown to be dependent on operating temperature, with pressure exerting a much weaker effect. (A)
Clift R (1993) Burn or Recycle? An Example of Life Cycle Analysis, Competitive Edge (3) pp. 14-15
Rice G, Clift R, Burns R (1997) LCA software review: Comparison of currently available European LCA software, International Journal of Life Cycle Assessment 2 (1) pp. 53-59
Twelve of the main European LCA software packages currently available are examined with the aim of establishing which are the most appropriate for LCAs on industrial processes. The packages performances are assessed in terms of Volume of Data Windows" environment Network Capabilities Impact Assessment Graphical representation of the inventory results Sensitivity analysis Units Cost User Support Flow Diagrams Burdens allocation Transparency of data Input & output parameters Demo version Quality of data The review concludes with a Specification Table which summarises the facilities available on each software package. The general conclusion from this study is that for industrially based LCAs, there are four packages which may offer advantages over the rest. These are The Boustead Model, The Ecobilan Group's TEAM", PEMS 3.0 and SimaPro 3.1.
Azapagic A, Clift R, Cowell SJ, Lamb J (1996) Environmental management of product system - Application of multiobjective linear programming to life cycle assessment, 1996 ICHEME RESEARCH EVENT - SECOND EUROPEAN CONFERENCE FOR YOUNG RESEARCHERS IN CHEMICAL ENGINEERING, VOLS 1 AND 2 pp. 558-560 INST CHEMICAL ENGINEERS
CLIFT R (1978) Bubbles Drops and particles pp. 121-124 Academic Press
Azapagic A, Clift R (1999) Life cycle assessment and multiobjective optimisation, Journal of Cleaner Production 7 (2) pp. 135-143
Life cycle assessment (LCA) is a method to identify and quantify the environmental performance of a process or a product from "cradle to grave". Its main potential in environmental decision-making lies in providing a quantitative basis for assessing potential improvements in environmental performance of a system throughout the life cycle. This paper introduces the use of multiobjective system optimisation in LCA as a tool for identifying and evaluating the best possible options for environmental management of the product system. A life cycle of a system is optimised on a number of environmental objective functions, defined in terms of the usual LCA burden or impact categories, and a range of environmental optima is found on the Pareto or non-inferior surface. As a result, possibilities for improving the environmental performance of the system are identified. Since system improvements cannot be carried out on the basis of environmental LCA only, it is also shown in this paper that the compromise between environmental and economic performance can be found on the non-inferior surface. The value of multi objective optimisation in system analysis lies in providing a set of alternative options for system improvements rather than a single prescriptive solution, thus enabling the choice of the Best Practicable Environmental Option (BPEO) and Best Available Technique Not Entailing Excessive Cost (BATNEEC). This approach is illustrated by application to a real case study of a system producing five borate products. © 1999 Elsevier Science Ltd. All rights reserved.
CLIFT R (1993) Gas Cleaning at High Temperatures Blackie
Theis TL, Bakshi BR, Clift R, Durham D, Fthenakis VM, Gutowski TG, Isaacs JA, Seager T, Wiesner MR (2012) Erratum: A life cycle framework for the investigation of environmentally benign nanoparticles and products [Phys. Status Solidi RRL 5, No. 9, 312-317 (2011)], Physica Status Solidi - Rapid Research Letters 6 (2)
The name of a further author and contributor to this work, Roland Clift, has been added to the author list of the article in agreement with all co-authors. It had been inadvertently omitted from the original version of the paper. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Levasseur A, Brandão M, Lesage P, Margni M, Pennington D, Clift R, Samson R (2012) Valuing temporary carbon storage, Nature Climate Change 2 (1) pp. 6-8
Cowell SJ, Clift R (1997) Impact assessment for LCAs involving agricultural production, International Journal of Life Cycle Assessment 2 (2) pp. 99-103
LCA has been developed primarily for industrial production systems. Application to agricultural systems requires systematic application of existing methodology and new methodological developments. Conventional approaches can obscure potential options for improving the environmental performance of systems involving agricultural production due to use of restricted system boundaries, incomplete assessment of impacts, and exclusion of ancillaries from the analysis. For use of nutrients such as phosphorus, it is proposed that Impact Assessment should be based on the quantity dispersed after use rather than on the input to the productive system. Eventually, the impacts associated with depletion should be based on technological or thermodynamic assessment of concentration for reuse, but this approach requires further theoretical development.
Clift R (1994) Preface, Powder Technology 78 (2) pp. 107-?
CLIFT R, RAFAILIDIS S (1993) INTERPARTICLE STRESS, FLUID PRESSURE, AND BUBBLE MOTION IN GAS-FLUIDIZED BEDS, CHEMICAL ENGINEERING SCIENCE 48 (9) pp. 1575-1582 PERGAMON-ELSEVIER SCIENCE LTD
Clift R (2001) Clean Technology and Industrial Ecology, In: Harrison RM (eds.), Pollution - Causes, Effects and Control pp. 411-444
The book has been widely adopted for teaching purposes at the undergraduate and postgraduate level.
CLIFT R (1978) Bubbles, Drops, and Particles 111 Academic Press
Koch D, Seville J, Clift R (1996) Dust cake detachment from gas filters, POWDER TECHNOLOGY 86 (1) pp. 21-29 ELSEVIER SCIENCE SA LAUSANNE
Experimental measurements were made of the fraction of cake removed from a polyester needled filter fabric as a function of the force exerted by an impulse tester designed to simulate the conditions experienced in a pulse-jet filter.
Wilson KC, Addie GR, Clift R (1992) Slurry transport using centrifugal pumps,
Topics covered in 'Slurry Transport using Centrifugal Pumps' include a review of fluid and particle mechanics, the principles of slurry flow, force-balance analysis of particle motion and deposition, heterogeneous slurry flow in horizontal pipes, vertical and inclined slurry flow, non-Newtonian slurry flow, the performance and testing of centrifual pumps, the effects of solids on pump performance, wear in pumps and pipelines, components of slurry systems, system design and operability and practical experience with slurry systems. (A.P.)
Clift R, Mitchell CA, Carew AL (2004) The Role of the Professional Engineer and Scientist in Sustainable Development, In: Azapagic A, Perdan S (eds.), Sustainable Development in Practice: Case Studies for Engineers and Scientists pp. 29-55 Wiley
Taking a life cycle approach to addressing economic, environmental and social issues, the book presents a series of new practical case studies drawn from a range of sectors, including mining, energy, food, buildings, transport, waste, and ...
SADD PA, LAMB JA, CLIFT R (1992) THE EFFECT OF SURFACTANTS ON HEAT AND MASS-TRANSFER TO WATER DROPS IN AIR, CHEMICAL ENGINEERING SCIENCE 47 (17-18) pp. 4415-4424 PERGAMON-ELSEVIER SCIENCE LTD
Wright E, Azapagic A, Stevens G, Mellor W, Clift R (2005) Improving recyclability by design: a case study of fibre optic cable, RESOURCES CONSERVATION AND RECYCLING 44 (1) pp. 37-50 ELSEVIER SCIENCE BV
GRACE J, CLIFT R (1974) 2-PHASE THEORY OF FLUIDIZATION, CHEMICAL ENGINEERING SCIENCE 29 (2) pp. 327-334 PERGAMON-ELSEVIER SCIENCE LTD
Clift R, Lloyd S (2008) Nanotechnology: A new organism in the industrial ecosystem?, Journal of Industrial Ecology 12 (3) pp. 259-262
Castell A, Clift R, France C (2004) Extended producer responsibility policy in the european union: A horse or a camel?, Journal of Industrial Ecology 8 (1-2) pp. 4-7
CLIFT R (1970) Proc. Chemeca'70 1
CLIFT R (1971) FORMATION OF GAS CLOUDS IN FLUIDIZED-BEDS, CANADIAN JOURNAL OF CHEMICAL ENGINEERING 49 (6) pp. 876-& CANADIAN SOC CHEMICAL ENGINEERING
Subzwari MP, Clift R, Pyle DL (1978) BUBBLING BEHAVIOUR OF FLUIDIZED BEDS AT ELEVATED PRESSURES., pp. 50-54
The behaviour of cracking catalyst with mean size 60 mu m fluidized by air at pressure from 1 to 7 bars was observed by cinephotography in a two-dimensional column. A series of runs was performed with constant gas superficial velocity. The size and number of bubbles passing through the bed decreased markedly as the pressure was increased, the change being most marked around 4 bars. The decrease in bubble flow rate was accompanied by an increase in the void fraction of the particulate phase. The dominant mechanism of bubble splitting at all pressures was by division from the roof, and the maximum stable bubble size decreased with increasing pressure.
Clift R, Malcolm R, Baumann H, Connell L, Rice G (2005) Eco-labels and electric monks, Journal of Industrial Ecology 9 (3) pp. 4-7
CLIFT R (1993) MASSIMILLA,LEOPOLDO (1930-1993) - OBITUARY, POWDER TECHNOLOGY 76 (3) pp. R5-R6 ELSEVIER SCIENCE SA LAUSANNE
Clift R, Azapagic A, Duff C (2004) Waste Water Management: Identifying Sustainable Processes, In: Azapagic A, Perdan S (eds.), Sustainable Development in Practice: Case Studies for Engineers and Scientists pp. 60-88 Wiley
Taking a life cycle approach to addressing economic, environmental and social issues, the book presents a series of new practical case studies drawn from a range of sectors, including mining, energy, food, buildings, transport, waste, and ...
Clift R Waste Treatment Processes I,
Cederberg C, Persson UM, Neovius K, Molander S, Clift R (2011) Including Carbon Emissions from Deforestation in the Carbon Footprint of Brazilian Beef, ENVIRONMENTAL SCIENCE & TECHNOLOGY 45 (5) pp. 1773-1779 AMER CHEMICAL SOC
Mellor W, Wright E, Clift R, Azapagic A, Stevens G (2002) A mathematical model and decision-support framework for material recovery, recycling and cascaded use, CHEMICAL ENGINEERING SCIENCE 57 (22-23) PII S0009-2509(02)00282-8 pp. 4697-4713 PERGAMON-ELSEVIER SCIENCE LTD
Clift R, Azapagic A, Duff C (2004) Integrated Prevention and Control of Air Pollution: The Case of Nitrogen Oxides, In: Azapagic A, Perdan S (eds.), Sustainable Development in Practice: Case Studies for Engineers and Scientists pp. 85-117 Wiley
Taking a life cycle approach to addressing economic, environmental and social issues, the book presents a series of new practical case studies drawn from a range of sectors, including mining, energy, food, buildings, transport, waste, and ...
Jamieson S, Hilbron R, Rice G, Clift R, Wehrmeyer W (2004) A practical approach to implementing CSR in the electronics industry: Global supply chain management focusing on corporate social responsibility, Electronics Goes Green 2004 (Plus): Driving Forces for Future Electronics, Proceedings pp. 591-596 FRAUNHOFER IRB VERLAG
Arena N, Sinclair P, Lee J, Clift R (2016) Life cycle engineering of production, use and recovery of self-chilling beverage cans, Journal of Cleaner Production
The chill-on-demand system is a new technology designed to provide cooled products on demand, thereby avoiding chilled storage. It uses the cooling effect provided by endothermic desorption of carbon dioxide previously adsorbed onto a bed of activated carbon and has the potential to be applied to any type of product that needs to be cold at the point of consumption. The principles of life cycle engineering have been utilized to evaluate the overall environmental performance of one possible application of this technology: a self-chilling beverage can, with a steel outer can to contain the beverage and an inner aluminium can to contain the adsorbent.
An attributional life cycle assessment has been undertaken considering all the life cycle stages of a self-chilling can: manufacture of each part of the beverage container, its utilization, collection of the used can, and management of the waste by reuse, recycling and landfilling. Activated carbon production is included in detail, to assess its contribution to the overall life cycle. The results are compared with those for conventional aluminium and steel beverage cans stored in two types of retail chiller: a single door refrigerator and a large open-front cooler. A sensitivity analysis explores alternative scenarios for activated carbon production and for recovery of the can components post-use for reuse or recycling. The results highlight the importance of using activated carbon produced from biomass by a process with efficient use of low-carbon electrical energy, energy recovery from waste streams and appropriate air pollution control, and of achieving high rates of recovery, re-use and recycling of the cans after use. The results suggest limited markets into which the product might be introduced, particularly where it would displace inefficient chilled storage in an electricity system with a high proportion of coal-fired generation.
COURY J, THAMBIMUTHU KV, CLIFT R (1987) CAPTURE AND REBOUND OF DUST IN GRANULAR BED GAS FILTERS, POWDER TECHNOLOGY 50 (3) pp. 253-265 ELSEVIER SCIENCE SA
Clift R, Lloyd S (2008) Nanotechnology, Journal of Industrial Ecology 12 3 pp. 259-262 Blackwell Publishing Inc
Clift R (2007) Don't bury your head in the nanostuff, NANOMEDICINE 2 (3) pp. 267-270 FUTURE MEDICINE LTD
Evans PL, Seville JPK, Clift R (1989) Mobilisation of cohesive particles in a novel spouted bed,
A novel spouted bed was developed, suitable for the processing of large light particles subject to substantial cohesion or interparticle attraction. The bed is caused to spin about a vertical axis by the addition of gas through jets at the wall. A torque balance on the bed enables the minimum gas flow rate for rotation to be estimated. (A)
Clift R, Filla M, Massimilla L (1976) Gas and particle motion in jets in fluidized beds, International Journal of Multiphase Flow 2 (5-6) pp. 549-561
Entrainment of solid particles by gas jets discharged downwards through slotted nozzles into bubble-free beds of fluidized particles is considered. The gas flow in the jet is calculated for irrotational flow, using a correlation established previously for slot opening as a function of operating variables. The momentum boundary layer thickness and shear stress at the horizontal interface between jet and particles are then calculated by integral boundary layer analysis. The calculated shear stress distributions are consistent with measurements of the momentum of bed particles caused to saltate by the jet, and explain the dependence of particle movement on the various operating variables. The results provide a direct confirmation of a hypothesis due to Owen on the mechanism of saltation. © 1976.
Clift R (1995) The New Industrial Ecology, In: Castle JE, Kelly MJ (eds.), Advanced materials in the marketplace pp. 129-143 Woodhead Pub Ltd
Clift R (1998) Engineering for the environment: The new model engineer and her role, Process Safety and Environmental Protection 76 (2) pp. 151-160
Although 'Sustainable Development' is invoked in current political and environmental debates, the concept has eluded precise definition. In general terms, 'sustainability' means working within three sets of constraints: techno-economic, environmental and social. Traditionally, engineering has been concerned with techno-economic issues. Explicit recognition of environmental and social issues has led to the way of thinking called Clean Technology, and to the use of more holistic analytical tools including Life Cycle Assessment. Howeover, it is argued here that a paradigm shift is needed in the way engineering skills and knowledge are used, as inputs to deliberative processes which go beyond techno-economic decisions. The need for this new paradigm is illustrated by the waste management sector, which is increasingly seen as needing the skills of the 'New Model' chemical engineer. © Institution of Chemical Engineers.
The following review concentrates on the fundamental processes occurring in fluidised filters. Section II gives a brief summary of filtration in fixed granular beds, to define terms and concepts used in analysis of fluidised filtration. Attention is restricted to 'stationary' filtration, in which the collection medium is the granular material itself, without discussing 'non-stationary' effects caused by structural changes resulting from dust accumulation within the filter. Section III sets out an analysis of filtration in a fluidised bed, derived from conventional models of filtration in fixed beds and reaction in fluidised beds. The interpretation of available experimental results in terms of this model is summarised in Section IV. Section V reviews two variations which have been proposed on a simple configuration of: electrofluidised filters, and rotating fluidised beds. Actual and potential applications of the technique are discussed very briefly in Section VI. (from paper)
Clift R, Shaw H (2012) An Industrial Ecology Approach to the Use of Phosphorus, Proceedia Engineering 46 pp. 39-44
Phosphorus is an abundant resource, even though the most economically attractive reserves are geographically concentrated, so that whether and when production will peak are highly uncertain. However, analysis of the global use of phosphorus primarily in agriculture (including animal husbandry), reveals an exceptionally ?leaky? supply chain: losses, including leaching from soils and animal excreta, amount to some 90% of the inputs. The potential for innovation to improve the efficiency of phosphorus use is therefore enormous, going beyond recovery of phosphorus from waste water to reducing the losses from the whole use system. Drivers to improve the system efficacy include the concerns over distribution and possibly security of supply and also the environmental impacts of phosphorus emissions. Future production, use and price of phosphorus therefore depend as much on changes in food consumption and agricultural practices as on changes in mining and processing.
Evangelisti S, Lettieri P, Borello D, Clift R (2014) Life cycle assessment of energy from waste via anaerobic digestion: A UK case study., Waste Management 34 (1) pp. 226-237
Particularly in the UK, there is potential for use of large-scale anaerobic digestion (AD) plants to treat food waste, possibly along with other organic wastes, to produce biogas. This paper presents the results of a life cycle assessment to compare the environmental impacts of AD with energy and organic fertiliser production against two alternative approaches: incineration with energy production by CHP and landfill with electricity production. In particular the paper investigates the dependency of the results on some specific assumptions and key process parameters. The input Life Cycle Inventory data are specific to the Greater London area, UK. Anaerobic digestion emerges as the best treatment option in terms of total CO2 and total SO2 saved, when energy and organic fertiliser substitute non-renewable electricity, heat and inorganic fertiliser. For photochemical ozone and nutrient enrichment potentials, AD is the second option while incineration is shown to be the most environmentally friendly solution. The robustness of the model is investigated with a sensitivity analysis. The most critical assumption concerns the quantity and quality of the energy substituted by the biogas production. Two key issues affect the development and deployment of future anaerobic digestion plants: maximising the electricity produced by the CHP unit fuelled by biogas and to defining the future energy scenario in which the plant will be embedded.
Clift R (2007) Climate change and energy policy: The importance of sustainability arguments, Energy 32 4 pp. 262 - 268-262 - 268
CLIFT R (1978) Bubbles, Drops, and Particles 172 Academic Press
Azapagic A, Clift R (1999) The application of life cycle assessment to process optimisation, COMPUTERS & CHEMICAL ENGINEERING 23 (10) pp. 1509-1526 PERGAMON-ELSEVIER SCIENCE LTD
Clift R (2000) Engineering for Sustainable Development, Imperial College Engineer 28 pp. 16-18
CARTER B, GHADIRI M, CLIFT R, JURY AW (1987) THE BEHAVIOR OF LARGE JETSAM PARTICLES IN FLUIDIZED-BEDS, POWDER TECHNOLOGY 52 (3) pp. 263-266 ELSEVIER SCIENCE SA LAUSANNE
Clift R, Mellor W, Williams E, Stevens G, Azapagic A (2001) Utility Based Framework for Material and Process Selection in the Integrated Chain Management of Polymers, Journal of Environmental Management and Health 12 (3) pp. 277-285
To model the behaviour of a fabric filter it is essential to be able to predict the amount of cake removed as a result of the force applied to the filter medium by a cleaning pulse. Experimental measurements have been made of the fraction of cake removed as a function of the force exerted by an impulse tester designed to simulate the conditions experienced in a pulse jet filter. These experiments have shown that the force required to remove a given quantity of cake depends upon the areal cake density. The nature of this dependence has been predicted from theoretical consideration of the role of adhesion and cohesion forces, assuming that the cake breaks away in spalls of a regular shape and uniform size.
Clift R, Allwood J (2011) Rethinking the economy, Chemical Engineer (837) pp. 30-31
The industrial energy efficiency in the UK is improved through a government backed closed-loop economy model, which focuses on reducing flows of materials through the economy. In this direction, it is shown that elementary material balances can yield reductions in energy use, outweighing potential savings from improving the energy efficiency of industrial processes. Extending product life represents a reversal of current trends, it requires behavioral change even more than changes in technology or product design. The current approach, in the UK and various other places, is to tax labor rather than use of non-renewable resources, representing economic pressure in diametrically the wrong direction. Closed-loop material use along with industrial symbiosis - co-locating or connecting industries so that a waste or co-product from one becomes an input to another.
Evangelisti S, Tagliaferri C, Lettieri P, Taylor R, Chapman C, Clift R (2014) Life cycle assessment of conventional and two-stage advanced energy-from-waste technologies for municipal solid waste treatment, Journal of Cleaner Production
The EU landfill and Waste Framework directives are driving new approaches to waste management in the UK, away from landfilling and mass-burn incineration, which has been regarded as the main alternative to landfilling. The objective of this study is to compare the environmental impacts of three dual-stage advanced energy-from-waste technologies, i.e. gasification and plasma gas cleaning, fast pyrolysis and combustion and gasification with syngas combustion, with those associated with conventional treatments for municipal solid waste, i.e. landfill with electricity production and incineration with electricity production. Results show that the two-stage gasification and plasma process has a significantly better overall environmental performance than the conventional waste treatment technologies and somewhat better than a more modern incineration plant, exemplified by a plant under commissioning in Lincolnshire in the UK. The benefits of the gasification and plasma process arise primarily from its higher net electrical efficiency.
Clift R, Cowell SJ Life Cycle Assessment for Food Production Systems,
A LINEARIZED STABILITY ANALYSIS OF THE UPPER SURFACE OF A BUBBLE IN A FLUIDIZED BED LEADS TO PREDICTIONS OF INITIAL GROWTH RATES AND MOST SENSITIVE WAVELENGTHS FOR DISTURBANCES OF THE INTERFACE.IT IS SHOWN THAT THE DEGREE OF INSTABILITY IS PRIMARILY A FUNCTION OF THE EFFECTIVE KINEMATIC VISCOSITY OF THE DENSE PHASE, WHILE THE INTERSTITIAL FLUID VELOCITY HAS A COMPARATIVELY MINOR INFLUENCE.THE RESULTS ARE CONSISTENT WITH AVAILABLE EVIDENCE ON THE INCIDENCE OF BUBBLE SPLITTING IN FLUIDIZED SYSTEMS.(A)
CLIFT R, GRACE J (1972) COALESCENCE OF BUBBLE CHAINS IN FLUIDIZED-BEDS, TRANSACTIONS OF THE INSTITUTION OF CHEMICAL ENGINEERS AND THE CHEMICAL ENGINEER 50 (4) pp. 364-& INST CHEMICAL ENGINEERS
Duo W, Kirkby NF, Seville JPK, Clift R (1997) Patchy cleaning of rigid gas filters .1. A probabilistic model, CHEMICAL ENGINEERING SCIENCE 52 (1) pp. 141-151 PERGAMON-ELSEVIER SCIENCE LTD
Clift R, Wright L (2000) Relationships between environmental impacts and added value along the supply chain, TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE 65 (3) pp. 281-295 ELSEVIER SCIENCE INC
Scandrett LA, Clift R (1984) THERMODYNAMIC ASPECTS OF ALKALI COLLECTION IN FLUIDISED BED COMBUSTION OF COAL.,
Recent vapour pressure measurements and calculations of thermodynamic equilibrium conditions suggest that, in gases obtained by pressurised coal combustion, only a few percent of the sodium and potassium should remain as vapour phase chlorides. The bulk of the alkalis are predicted to form sulphate, condensed onto entrained fly ash or present as an aerosol. Filtration of the condensed sulphates may suffice to reduce alkalis to levels acceptable to a gas turbine. Alumino-silicate materials appear to be potential filter media, because collected aerosol should be retained by reaction with the filter medium.
Clift R, Cowell SJ Life Cycle Assessment for Food Production Systems,
This is the first compilation of methods, tools and models that can be used to design products and manufacturing processes that prevent pollution from occurring in the first place, rather than treating the wastes after they are formed.
CLIFT R (1978) Drops, and Particles Academic Press
Clift R (2004) How many lives?, MATERIALS WORLD 12 (7) pp. 23-24 I O M COMMUNICATIONS LTD INST MATERIALS
CLIFT R (1978) Bubbles, Drops, and Particles 97 Academic Press
Clift R, Wright L (2000) Relationships Between Environmental Impacts and Added Value Along the Supply Chain, Technological Forecasting and Social Change 65 (3) pp. 281-295
Geldermann J, Schollenberger H, Rentz O, Huppes G, van Oers L, France C, Nebel B, Clift R, Lipkova A, Saetta S, Desideri U, May T (2007) An integrated scenario analysis for the metal coating sector in Europe, TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE 74 (8) pp. 1482-1507 ELSEVIER SCIENCE INC
Clift R (1999) SETAC Working Groups 1993-1998 Brussels, Belgium, SETAC-Europe News 10 (2)
CLIFT R, GRACE J (1971) BUBBLE COALESCENCE IN FLUIDIZED BEDS - COMPARISON OF 2 THEORIES, AICHE JOURNAL 17 (1) pp. 252-& AMER INST CHEMICAL ENGINEERS
Clift R (2001) Think global; shop local; roll your own, Journal of Industrial Ecology 5 (1) pp. 7-9
Geoffrey Hunt first developed an interest in nanotechnology in late 2002 when planning a visit to Japan to discuss the ethical implications of technological futures, and he put forward a tentative overview of nanotechnological possibilities in a ...
Seville JPK, Clift R (1984) The effect of thin liquid layers on fluidisation characteristics, Powder Technology 37 (1) pp. 117-129
Experiments are reported which show that addition of small quantities of a non-volatile liquid to a material in Geldart's Group B causes its fluidisation behaviour to move through Group A to Group C. It is shown that this behaviour is qualitatively consistent with Molerus' analysis of the role of interparticle forces in determining fluidisation characteristics. Interparticle forces have been estimated by determining the failure point of a bed of solids suspended by upward gas flow. The results lead to a numerical adjustment of Molerus' criterion for the B/A transition, and give some insight into the physical mechanisms causing the difference in behaviour between these two Groups. © 1984.
Azapagic A, Clift R (1999) Allocation of environmental burdens in multiple-function systems, Journal of Cleaner Production 7 (2) pp. 101-119
Allocation of environmental burdens is a recognised methodological problem in Life Cycle Assessment (LCA). It is the process of assigning to each of the functions of a multiple-function system only those environmental burdens and impacts that each function generates. It is argued in this paper that allocation is an artifact of applying LCA to individual products rather than to the whole productive system. To solve this problem, a new "marginal allocation" approach is proposed, based on whole system modelling. Marginal allocation is applicable when marginal changes about some defined state of the product system are to be considered and when the functional outputs can be varied independently. The specific approach developed here is based on representing the system by a model in the Linear Programming (LP) format. The allocation coefficients are equivalent to the marginal values calculated at the solution of the LP model. Marginal values represent a realistic description of the causal relationships between burdens and functional outputs and thus reflect the behaviour of the system. Changes in the system behaviour can also be modelled by LP. The approach is illustrated on three simple examples of multiple-function systems: combined waste treatment, co-production and recycling. © 1999 Elsevier Science Ltd. All rights reserved.
Clift R, Frischknecht R, Huppes G, Tillman A-M, Weidema B (1999) Inventory Enhancement: a summary of the results of the working group on inventory enhancement, SETAC-Europe News 10 (3) pp. 14-20
CLIFT R (1978) Bubbles, Drops, and Particles. 221 Adacemic Press
CLIFT R, GHADIRI M (1986) HIGH-TEMPERATURE HEROICS, CHEMICAL ENGINEER-LONDON (427) pp. 13-13 INST CHEMICAL ENGINEERS
DO HT, CLIFT R, GRACE J (1972) PARTICLE EJECTION AND ENTRAINMENT FROM FLUIDIZED-BEDS, POWDER TECHNOLOGY 6 (4) pp. 195-& ELSEVIER SCIENCE SA
CLIFT R (1990) COMMEMORATIVE ISSUE TO MARK THE RETIREMENT OF WILLIAMS,J.C. AS EDITOR-IN-CHIEF OF POWDER TECHNOLOGY - INTRODUCTION, POWDER TECHNOLOGY 60 (1) pp. R5-R5 ELSEVIER SCIENCE SA LAUSANNE
CLIFT R (1992) 5TH INTERNATIONAL-CONFERENCE - FBC TECHNOLOGY AND THE ENVIRONMENTAL CHALLENGE - RAPPORTEURS REVIEW OF THE PAPERS DEALING WITH EMISSIONS PERFORMANCE, JOURNAL OF THE INSTITUTE OF ENERGY 65 (462) pp. 10-14 INST ENERGY
Clift R, Doig A, Finnveden G (2000) The application of Life Cycle Assessment to Integrated Solid Waste Management - Part 1 - Methodology, PROCESS SAFETY AND ENVIRONMENTAL PROTECTION 78 (B4) pp. 279-287 INST CHEMICAL ENGINEERS
CLIFT R (1992) ON THE FORMULATION OF HYDRODYNAMIC STABILITY-CRITERIA IN FLUIDIZED-BEDS, POWDER TECHNOLOGY 72 (3) pp. 199-199 ELSEVIER SCIENCE SA LAUSANNE
CLIFT R (1978) Bubbles, Drops and Particles 112 Academic Press
Clift R (1966) Fundamental processes in gas filtration., TRANS. INST. ENGRS. AUST. MECH. ENGRS. ME8 (4 , Dec. 1983) pp. 181-191
Some fundamental problems, arising in the filtration of gases by fixed beds of granular collector, are reviewed. Capture gas born particles by the collector normally occurs by the processes of Brownian diffusion, inertial impaction and electrophoretic migration. Prediction of capture rates by theoretical models is discussed. Discusses trajectory calculations for estimating conditions under which a captured particle is retained by collector. Conditions determining cake formation are also included. (from author abstract)
Clift R (2001) Combined Heat and Power: Affordable Warmth and District Heating, Greener Government November pp. 22-22
Clift R (1995) The Concept of Cleaner Technology, Clean Technology 1 (5)
CLIFT R (1983) AN OCCAMIST VIEW OF FLUIDIZED-BED REACTOR MODELING, CHEMICAL ENGINEER-LONDON (388) pp. 29-& INST CHEMICAL ENGINEERS
Weston N, Clift R, Basson L, Pouton A, White N (2008) Assessment of cleaner process options: A case study from petroleum refining, CANADIAN JOURNAL OF CHEMICAL ENGINEERING 86 (3) pp. 302-315 WILEY-BLACKWELL
CLIFT R (1978) Bubbles, Drops and Particles Academic Press
Clift R, Dennison FJ, Azapagic A, Colbourne J (1999) Assessing management options for sludge disposal by applying the environmental tool life cycle assessment, IChemE Environmental Protection Bulletin 59 pp. 10-18
Hoffmann AC, van Santen A, Clift R, Allen RWK (1987) PERFORMANCE OF GAS CYCLONES AT VARYING SOLID LOADINGS., American Institute of Chemical Engineers, National Meeting
The influence of dust loading and gas inlet/outlet dimensions on the performance of four industrial scale (0. 45 m diameter) cyclones has been investigated. All experiments were performed under ambient conditions at an inlet velocity of 15 m/s over a loading range of 0. 5 - 130g solid/m**3 air. Measurements of the pressure drop, gravimetric efficiency and grade-efficiency were made. Strong variations in both pressure drop and separation performance with geometry and solid loading were found. These variations are well described by existing predictive relations. The results are analysed to further elucidate the nature of the observed trends.
Wrisberg N, Clift R (1999) Industrial ecology in Europe: The CHAINET concerted action, Journal of Industrial Ecology 3 (4) pp. 8-9
Clift R (2007) Climate change and energy policy: The importance of sustainability arguments, ENERGY 32 (4) pp. 262-268 PERGAMON-ELSEVIER SCIENCE LTD
Clift R (2006) Wind worries, TCE (779) pp. 74-74 INST CHEMICAL ENGINEERS
DOGANOGLU Y, JOG V, THAMBIMUTHU KV, CLIFT R (1978) REMOVAL OF FINE PARTICULATES FROM GASES IN FLUIDIZED-BEDS, TRANSACTIONS OF THE INSTITUTION OF CHEMICAL ENGINEERS 56 (4) pp. 239-248 INST CHEMICAL ENGINEERS
Sinclair P, Cowell S, Löfsted R, Clift R (2007) A case study in participatory environmental systems assessment with the use of multimedia materials and quantitative LCA, Journal of Environmental Assessment Policy and Management 9 (4) pp. 399-421
While participation in environmental decision-making is widely recognised and valued in democratic countries as beneficial, its format and scope have not always been the source of agreement. The use of environmental systems assessment (ESA) offers the opportunity for structuring knowledge and decision-making systematically and appropriately to decision makers' concerns, to enable lay publics to participate in development of policy and implementation in public sector initiatives. In order to perform participatory ESA, effective means of involving lay people are required. This paper describes the development and testing of an innovative interactive multimedia package (WOMBLE), written for non-experts to enable them to use the expert tool WISARD, a quantitative life cycle assessment package, to enable involvement in developing and assessing options for management of Municipal Solid Waste (MSW). It was shown that this combination of tools can reduce the time needed to achieve effective communication, learning and active engagement. © Imperial College Press.
Thambimuthu KV, Tan BKC, Clift R (1980) MECHANISMS OF STEADY FILTRATION OF GASES IN PACKED BEDS., Institution of Chemical Engineers Symposium Series (59)
Correlations for the efficiency of removal of dust from a gas by Brownian diffusion, inertial deposition, gravitational settling, and direct interception in a fixed bed of spherical granular collector particles are applied to predicting the performance of a packed bed filter. The results clarify the difference between filtration of sub-micron particles and particles larger than 1 mu m. Filter efficiency is shown to be dependent on operating temperature, with pressure exerting a much weaker effect.
Rathbone RR, Ghadiri M, Clift R (1989) Measurement of particle velocities and associated stresses on immersed surfaces in fluidized beds,
To diagnose the processes causing metal wastage from immersed surfaces in fluidized beds, a miniaturized probe was developed for simultaneous measurement of the transient normal and tangential components of particle velocity and stress against a surface. In a two-dimensional bed, high shear stresses are generated by oblique impact of particles in bubble wakes. The associated particle velocities correspond closely with estimates from video records, and are consistent with current understanding of particle motion in fluidized beds. Taken together, the results suggest that metal wastage results from a combination of impact and abrasion. (A)
Elghali L, Clift R, Sinclair P, Panoutsou C, Bauen A (2007) Developing a sustainability framework for the assessment of bioenergy systems, ENERGY POLICY 35 (12) pp. 6075-6083 ELSEVIER SCI LTD
Clift R, Grace JR (1985) CONTINUOUS BUBBLING AND SLUGGING., Fluidization pp. 73-132
Gas-fluidized beds are commonly operated in a regime in which the rising particle-lean regions are dispersed in a 'continuous phase' of fluidized particles. The continuous phase is variously termed the dense, particulate, or emulsion phase, while the rising voids are termed bubbles if their diameter is less than that of the bed itself and slugs if their dimensions approach the diameter D or width of the containing column. Bubbling and slugging have been subjected to more research effort, experimental and theoretical, than any of the other regimes which have been recognized. The more important and useful findings are summarized. Refs.
Zhang S, Bi XT, Clift R (2013) A Life Cycle Assessment of integrated dairy farm-greenhouse systems in British Columbia., Bioresource Technology 150 pp. 496-505
The purpose of this study was to evaluate the anticipated environmental benefits from integrating a dairy farm and a greenhouse; the integration is based on anaerobic digestion of manures to produce biogas energy, biogenic CO2, and digested slurry. A full Life Cycle Assessment (LCA) has been conducted on six modeled cases applicable in British Columbia, to evaluate non-renewable energy consumption, climate change, acidification, eutrophication, respiratory effects and human toxicity. Compared to conventional practice, an integrated system has the potential to nearly halve eutrophication and respiratory effects caused by inorganic emissions and to reduce non-renewable energy consumption, climate change, and acidification by 65-90%, while respiratory effects caused by organic emissions become negative as co-products substitute for other materials. Co-digestion of other livestock manures, greenhouse plant waste, or food and food processing waste with dairy manure can further improve the performance of the integrated system.
CLIFT R, CLIFT DHM (1981) CONTINUOUS MEASUREMENT OF THE DENSITY OF FLOWING SLURRIES, INTERNATIONAL JOURNAL OF MULTIPHASE FLOW 7 (5) pp. 555-561 PERGAMON-ELSEVIER SCIENCE LTD
ABDELGHANI M, PETRIE JG, SEVILLE JPK, CLIFT R, ADAMS MJ (1991) MECHANICAL-PROPERTIES OF COHESIVE PARTICULATE SOLIDS, POWDER TECHNOLOGY 65 (1-3) pp. 113-123 ELSEVIER SCIENCE SA LAUSANNE
Cowell SJ, Clift R (2000) Methodology for assessing soil quantity and quality in life cycle assessment, Journal of Cleaner Production 8 (4) pp. 321-331
Changes resulting from economic activities in the quantity and quality of soil in a system under analysis are important considerations in a life cycle assessment (LCA) study because they affect the safeguard subjects of resources and future agricultural productivity. In the approach proposed here, soil is treated as an ancillary which may leave the system in a form different from that at entry. Relevant factors describing possible changes in the soil include: soil mass, nutrients, weeds and weed seeds, pathogens, nutrients, salts, pH, organic matter, and soil texture and structure. Many of the factors can be included by modelling the effects of infrequent activities benefitting the crop(s) under analysis. Three additional factors require separate assessment: changes in the mass of soil, its organic matter content, and soil compaction. Taken together, these approaches provide an integrated assessment method capable of accounting for the overall impacts of agricultural production on soil.
Azapagic A, Clift R, ØK ? w?.3·ê-º-109-?#·¹Æàn°?i?--é¤Õµ¤¯ë¢»¹áóÈhÚb?;Õ, Material flow 38 (7) pp. 105-108 A??v>
Clift R, Udo de Haes HA, Bensahel JF, Fussler CR, Griesshammer R, Jensen AA (1994) Guidelines for the Application of Life Cycle Assessment in the EU Ecolabelling Programme,
Clift R (2004) Sustainability - Game or reality?, PROCESS SAFETY AND ENVIRONMENTAL PROTECTION 82 (B5) pp. 381-382 INST CHEMICAL ENGINEERS
Clift R (1994) Editorial, Powder Technology 80 (1)
Wright M, Allen D, Clift R, Sas H (1997) Measuring Corporate Environmental Performance : The ICI Environmental Burden System, Journal of Industrial Ecology 1 (4) pp. 117-127
The Imperial Chemical Industries (ICI) group has developed a method, called the "environmental burden system," to rank the potential environmental impacts of its emissions and wastes. The method uses potency factors to characterize the potential environmental impacts of wastes and emissions in ten major impact categories. When compared to the more traditional approach of reporting the total mass of emissions and wastes, the environmental burden approach provides a more meaningful picture of the potential impact of emissions; it helps identify the most harmful wastes and emissions; it provides the public with a better understanding of the potential impact of company operations; and it helps communicate the effectiveness of waste and emission reduction programs.
CLIFT R, GRACE J, WEBER ME (1974) STABILITY OF BUBBLES IN FLUIDIZED-BEDS, INDUSTRIAL & ENGINEERING CHEMISTRY FUNDAMENTALS 13 (1) pp. 45-51 AMER CHEMICAL SOC
Clift R, Azapagic A System Analysis and Allocation in Multiple-Input Waste Treatment Processes,
Clift R, Ransome T (2002) The Supply, Use and Waste Management of Domestic Clothes Washing: A CHAINET Case Study, In: Wrisberg N, Haes HAUD (eds.), Analytical Tools for Environmental Design and Management in a Systems Perspective pp. 205-230 Springer
The aim of this book is to link demand and supply ofenvironmental information in the field of Life Cycle Management.
Hart A, Clift R, Riddlestone S, Buntin J (2005) Use of life cycle assessment to develop industrial ecologies - A case study graphics paper, Process Safety and Environmental Protection 83 (4 B) pp. 359-363
Printer and letter quality paper represents a high-value component of the waste from commercial premises. Around large cities, exemplified by London, the paper flows are sufficiently large to sustain a dedicated logistics network and plant to recover and recycle graphics-quality paper. Analysis of the fibre flows around the supply system for paper recovery and recycling shows that, given the present low proportion of recycled fibre graphics paper used in the UK, other sources of fibre are not needed to maintain the supply and quality of the recycled material. Life Cycle Assessment (LCA) of the recycling system shows that its environmental performance is dominated by energy use and greenhouse-warming emissions. Although the detailed results depend on how waste fibre and biomass are otherwise used, this emerges as a case in which recycling really does give environmental benefits. LCA also enables possible changes in the system for recovering and reprocessing paper to be examined, leading to new concepts for more sustainable local management of resource flows. © 2005 Institution of Chemical Engineers.
Dowling A, Clift R, Grobert N, Hutton D, Oliver R, O'Neill O, Pethica J, Pidgeon N, Porritt J, Ryan J, Seaton A, Tendler S, Welland M, Whatmore R (2003) Nanotechnology under the microscope, NANOTECHNOLOGY 14 (9) IOP PUBLISHING LTD
Godfrey MA, Kwasowski P, Clift R, Marks V (1993) Assessment of the suitability of commercially available SpA affinity solid phases for the purification of murine monoclonal antibodies at process scale., J Immunol Methods 160 (1) pp. 97-105
Eight commercially available staphylococcal protein A (SpA) affinity chromatography solid phases were evaluated in order to establish their potential for the large-scale purification of a murine monoclonal antibody (MAb, mIgG1). The antibody was produced in-house, serum-free, in a hollow fibre bioreactor. Solid phases were tested for the effects of salt concentration, pH, and the presence of MAb on ligand leakage and flow rate. These effects were compared using the solid phases in stirred-tank (roller-mixing) and flow-through (packed-bed) modes of operation. Ligand leakage in the absence of MAb was generally at its lowest when the solid phases were used in a flow-through mode. In this mode of operation increasing the inorganic salt concentration and pH of the washing/adsorption buffer from 150 mM at pH 8.6, to 3 M at pH 8.9, typically produced a 10% increase in MAb capacity of the solid phases (20% for Sepharose CL-4B). However, contamination of the purified antibodies was also greatly increased due to an elevated level of background ligand leakage from the matrices. Residual contaminating levels of SpA in affinity purified MAbs were lowest with a low salt (NaCl, 150 mM) glycine (1 M) adsorption/washing buffer. Maximal antibody capacity was achieved for all matrices on frontal analysis (breakthrough curves), as opposed to a pulse mode of use. The largest capacity was found for Prosep A 'high capacity' (12-15 mg/ml column volume), where capacity approached its experimentally determined theoretical capacity (C/Co = 0.5) regardless of its mode of use. The relatively high MAb capacity of Prosep A 'high capacity' was further reflected in a superior dynamic isotherm. Frontal analysis, however, generally resulted in a greater SpA contamination of the purified MAbs. Under these conditions the lowest levels of SpA contamination were found for the Prosep A 'high capacity', and Repligen solid phases (12 ppm) on purifying 12.8 and 4.3 mg of MAb respectively. For the large scale downstream processing of a MAb for therapeutic applications, Prosep A 'high capacity', would appear to be the most appropriate of the solid phases tested.
Clift R (2003) An introduction to life cycle assessment, IB Revija (Ljubliana) XXXVII (4) pp. 70-79
Munoz I, Canals LMI, Clift R (2008) Consider a Spherical Man - A Simple Model to Include Human Excretion in Life Cycle Assessment of Food Products, JOURNAL OF INDUSTRIAL ECOLOGY 12 (4) pp. 521-538 WILEY-BLACKWELL
Brandão M, Clift R, Milà i Canals L, Basson L (2010) A Life-Cycle Approach to Characterising Environmental and
Economic Impacts of Multifunctional Land-Use Systems: An
Integrated Assessment in the UK, Sustainability 2 (12) pp. 3747-3776
An integrated environmental and economic assessment of land use for food,
energy and timber in the UK has been performed using environmental Life Cycle
Assessment (LCA) and economic Life Cycle Costing (LCC), to explore complementary
sustainability aspects of alternative land uses. The environmental assessment includes
impacts on climate change, ecosystem services and biodiversity, all of which include soil
carbon emissions. The systems explored include all processes from cradle to farm ?gate?.
The crops assessed were wheat and oilseed rape (under both organic and conventional
farming systems), Scots Pine, and willow and Miscanthus. Food crops, particularly
conventional food crops, are shown to have the highest climate-changing emissions per ha,
whereas energy and forestry crops show negative net emissions. To a lesser extent, the
same situation applies to impacts on ecosystems and biodiversity, with carbon storage in
biomass playing a larger role than carbon in soils. The energy and forestry crops in this
study show an overall beneficial environmental impact, in particular due to soil carbon
sequestration, making these land uses the lowest contributors to climate change.
Combining this with the non-renewable CO2 emissions displaced will mean that energy
crops have an even lower impact. Economically, conventional food crops present the
highest costs per ha, followed by organic food crops, energy and forestry crops. Integrating
the results from LCA and LCC shows that the climate impacts per monetary unit of all land
uses are dominated by soil management and, in the case of food production, also by
fertilisation. Taxes or incentives such as ?carbon charging? will encourage changes in
practice in these areas to improve the sustainability of land management, mainly by
building up Soil Organic Carbon (SOC).
Theis TL, Bakshi BR, Clift R, Durham D, Fthenakis VM, Gutowski TG, Isaacs JA, Seager T, Wiesner MR (2012) A life cycle framework for the investigation of environmentally benign nanoparticles and products (vol 5, pg 312, 2011), PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS 6 (2) pp. 98-98
Sievert and Loeffler have recently presented data on the cleaning behaviour of a range of non-woven fabrics when subjected both to reverse gas flow and to mechanically induced acceleration. In common with other workers in the field they suggest that, for reverse flow, cleaning is easier if the deposited cake mass is greater; i.e. the pressure drop required across the filter in order to release the cake, and the reverse gas flowrate through it, are both reduced for thicker cakes. In this short paper Sievert and Loeffler's results show that the stress which must be imposed on the cake in order to detach it, is independent of cake loading and that this level is consistent with the stress required to detach the cake by mechanically induced acceleration.
A new generation of gas filter media is becoming available, based on rigidly bonded ceramic granules or fibres, and suitable for high temperature duty. This papers outlines the main considerations in selecting and applying such a medium. Pressure drop through a 'virgin' medium is readily predictable from simple tests at ambient conditions. Behaviour on 'conditioning' over many cycles of filtration and cleaning can be determined by a simple 'coupon test', which shows the range of filter velocities which can be used and the cleaning action needed. Low density media have some advantages, and this paper concentrates on one such medium which has been found to have good performance: Cerafil 12H10, formed as a bonded mat of synthetic ceramic fibres. It is currently supplied as cylindrical candles, but other geometries are under development. Experience in using Cerafil to filter gases generated by a pyrolytic incinerator treating contaminated soil is outlined.
Clift R, Doig A The Environmental Implications of Recovering Energy from Waste,
CLIFT R (1978) Bubbles, Drops and Particles pp. 30-141 Academic Press
Clift R (1983) FUNDAMENTAL PROCESSES IN GAS FILTRATION., 1
Clift R, Doig A (1995) Developing Life Cycle Inventories for Waste Management, HMSO
Clift R (2007) Climate change and energy policy: The importance of sustainability arguments, Energy 32 4 pp. 262 - 268-262 - 268
Mayers K, Peagam R, France C, Basson L, Clift R (2011) Redesigning the Camel The European WEEE Directive, JOURNAL OF INDUSTRIAL ECOLOGY 15 (1) pp. 4-8 WILEY-BLACKWELL
Dennison FJ, Sindall D, Azapagic A, Clift R, Colbourne JS (1999) Assessing sludge disposal options using LCA, Environmental Protection Bulletin (59) pp. 10-18
Clift R (2012) Integrated waste management: environmental assessment and planning, Ambiente Rischio Comunicazione (2) pp. 74-89
Clift R, Basson L, Cobbledick D (2009) Accounting for carbon, TCE (819) pp. 35-37 INST CHEMICAL ENGINEERS
Clift R, Cowell SJ, Doig A A Case study of LCI by Allocation & System Extension: Straw,
Clift R Rapporteur's Report on Session 1: Waste Treatment Processes,
The EC Directive on Integrated Pollution Prevention and Control (IPPC), now to be implemented in the UK under the Pollution Prevention and Control Act (1999), will widen the range of issues to be considered by enforcing authorities when determining the Best Available Techniques (BAT) for an installation. IPPC requires integrated control of emissions to air, water and land, the efficient use of energy and raw materials and the avoidance or reduction of impacts caused by disposal of wastes. This paper demonstrates that adopting a life cycle approach for the assessment of candidate techniques can fulfil these new requirements when choosing BAT. The glass manufacturing industry is used as a case study to show that the methodology can be used to assess both primary (in-process) and secondary (end-of-pipe) techniques for pollution prevention and control. General conclusions are drawn regarding the use of life cycle approaches to support the assessment of BAT, limitations in the current methodology and the requirements for future research. © Institution of Chemical Engineers.
Zhang S, Bi XT, Clift R (2013) A Life Cycle Assessment of integrated dairy farm-greenhouse systems in British Columbia, Bioresource Technology 150 pp. 496-505
The purpose of this study was to evaluate the anticipated environmental benefits from integrating a dairy farm and a greenhouse; the integration is based on anaerobic digestion of manures to produce biogas energy, biogenic CO2, and digested slurry. A full Life Cycle Assessment (LCA) has been conducted on six modeled cases applicable in British Columbia, to evaluate non-renewable energy consumption, climate change, acidification, eutrophication, respiratory effects and human toxicity. Compared to conventional practice, an integrated system has the potential to nearly halve eutrophication and respiratory effects caused by inorganic emissions and to reduce non-renewable energy consumption, climate change, and acidification by 65-90%, while respiratory effects caused by organic emissions become negative as co-products substitute for other materials. Co-digestion of other livestock manures, greenhouse plant waste, or food and food processing waste with dairy manure can further improve the performance of the integrated system. © 2013 Elsevier Ltd.
CLIFT R (1992) PROFLIGATE ENVIRONMENTALISM, CHEMICAL ENGINEER-LONDON (513) pp. 3-3 INST CHEMICAL ENGINEERS
CLIFT R (1978) Bubbles. Drops and Particles 30 Academic Press
Tate AHJ, Seville JPK, Singh A, Clift R (1986) On-line non-sampling determination of the size and concentration of particles entrained in a gas., IN: GAS CLEANING AT HIGH TEMPERATURE SYMP., (GUILDFORD, U.K.: SEP. 16-18, 1986), RUGBY, U.K., INST. CHEM. ENGRS, 1986, PAPER (99 ))
A new approach is proposed for direct measurement of the aerodynamic diameter of particles entrained in a gas. A probe, which can be a pitot static tube, is inserted into the flow. The velocity of each particle approaching the stagnation point is measured, for example by laser Doppler anemometry using a single optical fibre within the probe. The particle size distribution and concentration can be built up from a succession of single particle measurements. The instrument could be used to measure the efficiency of gas cleaning equipment, or to detect surges in particle size or concentration.
PATERSON AHJ, CLIFT R (1987) LIQUID HOLDUP MEASUREMENTS IN TURBULENT BED CONTACTORS BY A TRACER TECHNIQUE, CANADIAN JOURNAL OF CHEMICAL ENGINEERING 65 (1) pp. 10-17 CANADIAN SOC CHEMICAL ENGINEERING
Clift R (1994) UNTITLED, POWDER TECHNOLOGY 80 (1) pp. R5-R5
ELSEVIER SCIENCE SA LAUSANNE
Azapagic A, Clift R (1998) Linear programming as a tool in life cycle assessment, International Journal of Life Cycle Assessment 3 (6) pp. 305-316
Linear Programming (LP) is a powerful mathematical technique that can be used as a tool in Life Cycle Assessment (LCA). In the Inventory and Impact Assessment phases, in addition to calculating the environmental impacts and burdens, it can be used for solving the problem of allocation in multiple- output systems. In the Improvement Assessment phase, it provides a systematic approach to identifying possibilities for system improvements by optimising the system on different environmental objective functions, defined as burdens or impacts. Ultimately, if the environmental impacts are aggregated to a single environmental impact function in the Valuation phase, LP optimisation can identify the overall environmental optimum of the system. However, the aggregation of impacts is not necessary: the system can be optimised on different environmental burdens or impacts simultaneously by using Multiobjective LP. As a result, a range of environmental optima is found offering a number of alternative options for system improvements and enabling the choice of the Best Practicable Environmental Option (BPEO). If, in addition, economic and social criteria are introduced in the model, LP can be used to identify the best compromise solution in a system with conflicting objectives. This approach is illustrated by a real case study of the borate products system.
Morris K, Allen RWK, Clift R (1986) ADHESION OF CAKES TO FILTER MEDIA., 1
To model the behaviour of a fabric filter it is essential to be able to predict the amount of cake removed as a result of the force applied to the filter medium by a cleaning pulse. Experimental measurements have been made of the fraction of cake removed as a function of the force exerted by an impulse tester designed to simulate the conditions experienced in a pulse jet filter. The nature of this dependence has been predicted from theoretical consideration of the role of adhesion and cohesion forces, assuming that the cake breaks away in spalls of a regular shape and uniform size. These concepts have allowed the construction of a 'characteristic curve' which describes the behaviour of a given cake and fabric combination.
Clift R, Azapagic A System Analysis and Allocation in Multi-input Waste Treatment Processes,
Davis J, Geyer R, Clift R, Jackson T, Azapagic A (2002) A time series material flow analysis of the UK steel sector, STEEL IN SUSTAINABLE CONSTRUCTION: IISI WORLD CONFERENCE 2002, CONFERENCE PROCEEDINGS pp. 267-272 INT IRON AND STEEL INST
Clift R, Earl G (1998) How important is environmental performance? A case study measuring the environmental preferences of business-to-business consumers, Journal of Sustainable Product Design 6 pp. 18-27
Hunton-Clarke L, Wehrmeyer W, Clift R, McKeown P, King H (2002) Employee participation in environmental initiatives: Facilitating more environmentally conscious decision-making in innovation, Greener Management International (40) pp. 45-56
In recent years society as a whole has become more aware and concerned about environmental issues. In light of increasingly stringent legislation and the more critical eyes of external stakeholders, companies have come to realise the heightened need for their actions to be seen as environmentally responsible. The innovation process provides companies with an excellent opportunity to influence the environmental impacts associated with their products. However, merely providing product developers with new processes and a toolbox of available ecodesign tools is rarely sufficient to facilitate more environmentally conscious decision-making in innovation. This paper proposes that employee participation within the development of new initiatives will aid the implementation of those initiatives. It highlights the first results from a study undertaken at Unilever seeking to initiate employee participation within initiatives for environmentally conscious innovation by ascertaining the attitudes of employees involved in the product innovation process regarding environmental responsibility and its integration into innovation.
Clift R (1991) Editorial, Powder Technology 64 (1-2)
ABDELGHANI M, PETRIE JG, SEVILLE JPK, CLIFT R, ADAMS MJ (1990) MECHANICAL-PROPERTIES OF POWDER COMPACTS - A NEW EXPERIMENTAL-TECHNIQUE TO INVESTIGATE SCALING EFFECTS IN FRACTURE, 2 WORLD CONGRESS : PARTICLE TECHNOLOGY, PTS 1-5 pp. A116-A123 FINE PARTICLE SOC
Clift R (1991) Editorial, Powder Technology 65 (1-3)
Agnew J, Clift R, Darton R, Guy K, Lefroy G (2003) Commentary on the visions, CHEMICAL ENGINEERING: VISIONS OF THE WORLD pp. 117-125
ELSEVIER SCIENCE BV
CLIFT R, SEVILLE JPK, MOORE SC, CHAVARIE C (1987) COMMENTS ON BUOYANCY IN FLUIDIZED-BEDS, CHEMICAL ENGINEERING SCIENCE 42 (1) pp. 191-194 PERGAMON-ELSEVIER SCIENCE LTD
Clift R, Cowell SJ Farming for the Future - an Environmental Perspective,
Biswas G, Clift R, Davis G, Ehrenfeld J, Förster R, Jolliet O, Knoepfel I, Luterbacher U, Russell D, Hunkeler D (1998) Identification, categorization and life cycle validation, International Journal of Life Cycle Assessment 3 (4) pp. 184-190
Indicators which reflect environmental, economic, health and safety issues, have been categorized as microecometrics and macroecometrics. The former, generally flow based measures, have been developed for local, firm- wide or product based assessments. Microecometrics include materials intensity, energy consumption and emissions data, often from life cycle perspectives. They are, generally, intensive and are scaled with respect to unit of production, GDP or per capita, though other normalization factors have been proposed. In contrast macroecometrics tend to be extensive and represent global conditions such as temperatures and environmental concentrations. Ecometrics are subjective and reflect the dominant value of the individual, family unit, stakeholder group or firm. As such overaggregating or reducing the number of ecometrics for given applications, such as the rating of investments or access to credit, presents potential conflicts. Furthermore, while eco-indicators used for internal corporate reporting should not, necessarily, be validated, those microecometrics which involve external reporting, or multiple stakeholders, are arbitrary if not derived from, or based on, comprehensive life cycle approaches. This paper summarizes ECOMETRICS'98, a workshop held in Lausanne, Switzerland in January 19-20, 1998. It discusses ecometric needs of various users including consumers, designers, private sector decision makers as well as politicians and policy makers. A discussion regarding appropriate microecometrics for industrial sectors including chemical, pharmaceutical, insurance, finance, electronics, manufacturing and consumer products is also summarized.
CLIFT R (1993) SPECIALIZATION MUST BE THE FUTURE, CHEMICAL ENGINEER-LONDON (538) pp. 4-4 INST CHEMICAL ENGINEERS
CLIFT R (1978) Bubbles Drops, and Particles pp. 97-141 Academic Press, Inc.
Evangelisti S, Tagliaferri C, Clift R, Lettieri P, Taylor R, Chapman C (2015) Life cycle assessment of conventional and two-stage advanced energy-from-waste technologies for municipal solid waste treatment, Journal of Cleaner Production 100 pp. 212-223
© 2015 Elsevier Ltd. All rights reserved.The EU landfill and Waste Framework directives are driving new approaches to waste management in the UK, away from landfilling and mass-burn incineration, which has been regarded as the main alternative to landfilling. The objective of this study is to compare the environmental impacts of three dual-stage advanced energy-from-waste technologies, i.e. gasification and plasma gas cleaning, fast pyrolysis and combustion and gasification with syngas combustion, with those associated with conventional treatments for municipal solid waste, i.e. landfill with electricity production and incineration with electricity production. Results show that the two-stage gasification and plasma process has a significantly better overall environmental performance than the conventional waste treatment technologies and somewhat better than a more modern incineration plant, exemplified by a plant under commissioning in Lincolnshire in the UK. The benefits of the gasification and plasma process arise primarily from its higher net electrical efficiency.
Ghadiri M, Seville JPK, Clift R (1985) A high-temperature agglomerating filter., IN: POWTECH '85 PARTICLE TECHNOLOGY, (BIRMINGHAM, U.K.: MAR. 5-7, 1985), RUGBY, U.K., INST. CHEM. ENGRS., 1985, PAPER 7 (41 ))
The development of the fluidized bed as a continuously renewable gas filter was reviewed with special reference to work in which the performance was enhanced by addition of a liquid retention aid. Preliminary experiments designed to show the potential of the device for hot gas cleaning in combined cycle power generation were briefly described. (A)
Seville JPK, Tüzün U, Clift R (1997) Processing of Particulate Solids, Springer
This book has been written to meet their needs.
Clift R, Cowell SJ, Hogan SB (1997) Positioning and Applications of LCA, In: Udo de Haes HA, Wrisberg N (eds.), Life Cycle Assessment: State of the Art and Research Priorities pp. 33-57
Davidson JF, Clift R, Harrison D (1985) Fluidization, Academic Press, London
CLIFT R, GAUVIN WH (1971) MOTION OF PARTICLES IN TURBULENT GAS STREAMS, BRITISH CHEMICAL ENGINEERING 16 (2-3) pp. 229-&
CLIFT R, GHADIRI M, HOFFMAN AC (1991) A CRITIQUE OF 2 MODELS FOR CYCLONE PERFORMANCE, AICHE JOURNAL 37 (2) pp. 285-289 AMER INST CHEMICAL ENGINEERS
Davis J, Geyer R, Ley J, He J, Clift R, Kwan A, Sansom M, Jackson T (2007) Time-dependent material flow analysis of iron and steel in the UK. Part 2. Scrap generation and recycling, Resources, Conservation and Recycling 51 (1) pp. 118-140
This paper presents an analysis of the use of iron and steel in the UK and explores how much of the iron and steel is recycled when it becomes obsolete after use. The first part of this paper series investigated production and consumption trends of iron and steel in the UK, whereas this paper focuses on scrap generation and recycling. Information on the amounts of iron and steel going into different groups of goods, together with values for their estimated lifetimes, have enabled modelling of the annual release of iron and steel from the use phase in the form of end-of-life scrap. This is an application to material flow accounting of the theory of residence time distributions used routinely in chemical reaction engineering. By comparing modelled generation of scrap with actual scrap consumption in the UK, we obtain estimates of loss or accumulation of iron and steel scrap in the UK. The model indicates that as much as 30% of the scrap that was potentially available in 2001 as end-of-life scrap has either been accumulated within the economic system or lost to landfill. © 2006 Elsevier B.V. All rights reserved.
Arena U, Mastellone ML, Perugini F, Clift R (2004) Environmental assessment of paper waste management options by means of LCA methodology, INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 43 (18) pp. 5702-5714 AMER CHEMICAL SOC
Kronenberg J, Clift R (2004) Industrial ecology in Poland, Journal of Industrial Ecology 8 (4) pp. 13-17
Shiels S, Garner D, Clift R (2002) Using life-cycle assessment to inform the nuclear debate, NUCLEAR ENERGY-JOURNAL OF THE BRITISH NUCLEAR ENERGY SOCIETY 41 (6) pp. 375-381 BRITISH NUCLEAR ENERGY SOC
Henein H, Guthrie RIL, Clift R (1974) CONTACTING PROBLEMS ASSOCIATED WITH ALUMINIUM AND FERRO-ALLOY., pp. 29-43
Water model experiments are described in which spheres of various diameters and specific gravities were dropped from typical industrial heights into water. Maximum penetration distances, trajectories and retention times were measured and compared with theoretical predictions based on transient fluid flow. The relative importance of steady drag, added mass and history forces were demonstrated. Results indicate that immersion times are extremely short ( similar 1 second) for aluminum additions and low density ferro-alloys. High density ferro-alloys remain immersed considerably longer and penetrate much deeper.
Evangelisti S, Lettieri P, Borello D, Clift R (2014) Life cycle assessment of energy from waste via anaerobic digestion: A UK case study, Waste Management 34 (1) pp. 226-237
Particularly in the UK, there is potential for use of large-scale anaerobic digestion (AD) plants to treat food waste, possibly along with other organic wastes, to produce biogas. This paper presents the results of a life cycle assessment to compare the environmental impacts of AD with energy and organic fertiliser production against two alternative approaches: incineration with energy production by CHP and landfill with electricity production. In particular the paper investigates the dependency of the results on some specific assumptions and key process parameters. The input Life Cycle Inventory data are specific to the Greater London area, UK. Anaerobic digestion emerges as the best treatment option in terms of total CO2 and total SO2 saved, when energy and organic fertiliser substitute non-renewable electricity, heat and inorganic fertiliser. For photochemical ozone and nutrient enrichment potentials, AD is the second option while incineration is shown to be the most environmentally friendly solution. The robustness of the model is investigated with a sensitivity analysis. The most critical assumption concerns the quantity and quality of the energy substituted by the biogas production. Two key issues affect the development and deployment of future anaerobic digestion plants: maximising the electricity produced by the CHP unit fuelled by biogas and to defining the future energy scenario in which the plant will be embedded. © 2013 Elsevier Ltd.
Clift R (2000) Special topic issue - Sustainable development, PROCESS SAFETY AND ENVIRONMENTAL PROTECTION 78 (B4) pp. 235-235 INST CHEMICAL ENGINEERS
Wilson KC, Clift R, Sellgren A (2002) Operating points for pipelines carrying concentrated heterogeneous slurries, POWDER TECHNOLOGY 123 (1) PII S0032-5910(01)00423-5 pp. 19-24 ELSEVIER SCIENCE SA
Clift R, O'Brien M, Doig A Social and Environmental Life Cycle Assessment,
GRACE J, KROCHMAL L, CLIFT R, FARKAS EJ (1971) EXPANSION OF LIQUIDS AND FLUIDISED BEDS IN SLUG FLOW, CHEMICAL ENGINEERING SCIENCE 26 (5) pp. 617-& PERGAMON-ELSEVIER SCIENCE LTD
Levasseur A, Brandao M, Lesage P, Margni M, Pennington D, Clift R, Samson R (2012) COMMENTARY: Valuing temporary carbon storage, NATURE CLIMATE CHANGE 2 (1) pp. 6-8
Azapagic A, Clift R (1999) Life cycle assessment as a tool for improving process performance: A case study on boron products, International Journal of Life Cycle Assessment 4 (3) pp. 133-142
This paper explores the use of LCA as a tool for process environmental management, thereby moving the focus from product to process oriented analysis. The emphasis is on Improvement Assessment in which the 'hot spots' in the system are targeted for maximum environmental improvements. In this context, it is useful to use multiobjective optimisation which renders valuation unnecessary. The approach is illustrated by the case study of the system processing boron ores to make five different products. The results of Inventory Analysis and Impact Assessment are presented and discussed. In Improvement Assessment, a number of improvement options are identified and evaluated, using system optimisation. It is shown that the site environmental performance can be improved over current operation by an average of 20% over the whole life cycle. Thus the study demonstrates that the optimisation approach to environmental process management may assist in identifying optimal ways to operate a process or plant from 'cradle to grave'. This may help the process industries not only to comply with legislation but also provide a framework for taking a more proactive approach to environmental management leading to more sustainable industrial operations and practices.
LEGROS R, CLIFT R, MILLINGTON CA (1995) DEVELOPMENT OF A MOBILIZATION TECHNIQUE FOR FIBROUS MATERIALS, POWDER TECHNOLOGY 85 (2) pp. 105-114 ELSEVIER SCIENCE SA LAUSANNE
Vermeylen S, Martin G, Clift R (2008) Intellectual Property Rights Systems and the Assemblage of Local Knowledge Systems, International Journal of Cultural Property 15 02 pp. 201-221-201-221
Malcolm R, Clift R (2002) Barriers to industrial ecology: The strange case of "The Tombesi Bypass", Journal of Industrial Ecology 6 (1) pp. 4-7
MACCUAIG N, SEVILLE JPK, GILBOY WB, CLIFT R (1985) APPLICATION OF GAMMA-RAY TOMOGRAPHY TO GAS-FLUIDIZED BEDS, APPLIED OPTICS 24 (23) pp. 4083-4085 OPTICAL SOC AMER
Koch D, Cheung W, Seville JPK, Clift R (1992) Effects of dust properties on gas cleaning using rigid ceramic filters, Filtration and Separation 29 (4)
Coupons of rigid ceramic filtration media have been conditioned using fine gasifier char and calcium carbonate dusts and both the cake resistance and the stress needed to detach the cake from the medium have been measured. For gasifier char, cake resistance appears to be independent of face velocity and proportional to areas cake loading, while cake removal stress is approximately independent of loading. For calcium carbonate, broadening the size distribution increases the cake resistance but slightly reduces the cake removal stress. Increases in particle size and cake void fraction decrease both cake resistance and cake removal stress. However, since increase in particle size seems often to be accompanied by decrease in cake void fraction, the range of commonly-observed cake resistivities and removal stresses is narrower than might otherwise be expected. © 1992.
AZAPAGIC A, CLIFT R (1995) WHOLE SYSTEM MODELLING AND LIFE CYCLE ASSESSMENT, 1995 ICHEME RESEARCH EVENT - FIRST EUROPEAN CONFERENCE FOR YOUNG RESEARCHERS IN CHEMICAL ENGINEERING, VOLS 1 AND 2 pp. 429-431 INST CHEMICAL ENGINEERS
CLIFT R (1995) CLEAN TECHNOLOGY - AN INTRODUCTION, JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY 62 (4) pp. 321-326 JOHN WILEY & SONS LTD
Clift R, Dennison FJ, Azapagic A, Clayton CRI (1999) Life cycle assessment: comparing strategic options for the mains infrastructure, Water Science and Technology 39 (10-11) pp. 315-319
Clift R (2005) Precaution and sustainability, TCE (764) pp. 20-22 INST CHEMICAL ENGINEERS
GARCIA A, GRACE J, CLIFT R (1973) BEHAVIOR OF GAS BUBBLES IN FLUIDIZED-BEDS, AICHE JOURNAL 19 (2) pp. 369-370 AMER INST CHEMICAL ENGINEERS
Burningham K, Barnett J, Carr A, Clift R, Wehrmeyer W (2007) Industrial constructions of publics and public knowledge: a qualitative investigation of practice in the UK chemicals industry, Public Understanding of Science 16 (1) pp. 23-43
While the rhetoric of public engagement is increasingly commonplace within industry, there has been little research that examines how lay knowledge is conceptualized and whether it is really used within companies. Using the chemicals sector as an example, this paper explores how companies conceive of publics and "public knowledge," and how this relates to modes of engagement/communication with them. Drawing on qualitative empirical research in four companies, we demonstrate that the public for industry are primarily conceived as "consumers" and "neighbours," having concerns that should be allayed rather than as groups with knowledge meriting engagement. We conclude by highlighting the dissonance between current advocacy of engagement and the discourses and practices prevalent within industry, and highlight the need for more realistic strategies for industry/public engagement.
Clift R (1998) A role for tribology in life cycle design, TRIBOLOGY FOR ENERGY CONSERVATION 34 pp. 3-9 ELSEVIER SCIENCE BV
CLIFT R (1991) A critique of two models for cyclone performance, AlChE J. 37 pp. 285-289
Clift R (1997) The ECTEL Trials, Journal of Industrial Ecology 1 2 pp. 3-5 MIT Press
Clift R Clean Technology and the Future Process of Process Engineering,
Clift R, Morris N (2002) Engineering with a human face, Engineering Management Journal 12 (5) pp. 226-230
Rafailidis SV, Clift R (1991) Study of the influence of bubble formation at the distributor on fluidized bed behavior, AIChE Symposium Series 87 (281) pp. 47-57
To investigate the effect of distributor characteristics on bubble motion in a fluidized bed, a simulation has been performed in which the motion of each bubble in the bed is calculated using the model of Clift and Grace. Calculations have been carried out for a 0.3m square combustor, for which experimental measurements are to be published. The results show that standpipe distributors lead to localized areas of bubbling inside the bed, which become more diffuse when the number of bubble generation sites is increased. No significant distributor effects have been found on the bubble frequency or rise velocity, except very close to the distributor. It appears that, under some circumstances, increasing the number of bubble generation sites in the distributor could help to alleviate wastage of heat transfer surfaces.
CLIFT R (1995) MASSIMILLA,LEOPOLDO (1930-1993) - OBITUARY, POWDER TECHNOLOGY 82 (3) pp. 215-216 ELSEVIER SCIENCE SA LAUSANNE
CLIFT R (1991) POWDER TECHNOLOGY, POWDER TECHNOLOGY 65 (1-3) pp. R9-R9 ELSEVIER SCIENCE SA LAUSANNE
CLIFT R (1993) AN OCCAMIST REVIEW OF FLUIDIZED-BED MODELING, FLUID-PARTICLE PROCESSES: FUNDAMENTALS AND APPLICATIONS 89 (296) pp. 1-17 AMER INST CHEMICAL ENGINEERS
Clift R (1983) FUNDAMENTAL PROCESSES IN GAS FILTRATION., Transactions of the Institution of Engineers, Australia. Mechanical engineering ME8 (4) pp. 181-191
Some fundamental problems, arising in the filtration of gases by fixed beds of granular collector, are reviewed. Capture of gas-borne particles by the collector normally occurs mainly by the processes of Brownian diffusion, inertial impaction and electrophoretic migration. Diffusional and electrophoretic capture are controlled by processes occurring close to the surface of the collector, and theoretical models are reasonably successful in predicting capture rates. Theoretical estimates for inertial impaction are much less reliable, and reasons for this are discussed. Retention of a particle by the collector is governed by a balance between particle kinetic energy and adhesion energy; trajectory calculations can be used to estimate conditions under which a captured particle is retained by the collector.
Grace JR, Clift R (1974) On the two-phase theory of fluidization, Chemical Engineering Science 29 (2) pp. 327-334
The distribution of gas flow between bubbles and the dense phase in a fludized bed is considered. By deriving general equations for gas and solids continuity in a freely-bubbling fluidized bed, the possible contributions to the invisible gas flow are formulated. It is shown that the gross assumptions inherent in "two-phase theories" of fluidization are not justified. Measurements of visible bubble flow and bubble volume fraction can give nothing more than estimates for the gas flow through the two phases. © 1974.
This research compares and contrasts the physical and chemical characteristics of incinerator sewage sludge ash (ISSA) and pyrolysis sewage sludge char (PSSC) for the purposes of recovering phosphorus as a P-rich fertiliser. Interest in P recovery from PSSC is likely to increase as pyrolysis is becoming viewed as a more economical method of sewage sludge thermal treatment compared to incineration. The P contents of ISSA and PSSC are 7.2?7.5% and 5.6%, respectively. Relative to the sludge, P concentrations are increased about 8-fold in ISSA, compared to roughly 3-fold in PSSC. Both PSSC and ISSA contain whitlockite, an unusual form of calcium phosphate, with PSSC containing more whitlockite than ISSA. Acid leaching experiments indicate that a liquid/solid ratio of 10 with 30 min contact time is optimal to release PO4-P into leachate for both ISSA and PSSC. The proportion of P extracted from PSSC is higher due to its higher whitlockite content. Heavy metals are less soluble from PSSC because they are more strongly incorporated in the particles. The results suggest there is potential for the development of a process to recover P from PSSC.
Zhang S, Bi XT, Clift R (2014) Life cycle analysis of a biogas-centred integrated dairy farm-greenhouse system in British Columbia, Process Safety and Environmental Protection
This study investigates the potential integration of a dairy farm and a greenhouse into an eco-industrial system to promote waste-to-energy and waste-to-material exchanges. Natural gas consumption is substituted by renewable biogas generated from anaerobic digestion (AD) of the dairy manure; CO2 for plant enrichment in greenhouses is supplied by biogas combustion and the digestate (digestion residue) from digesters is used as animal bedding, plant growing media and liquid fertilizers. A life cycle analysis (LCA) was conducted to quantify the environmental impacts of the eco-industrial system in comparison to the conventional agriculture practices. The results show that the integrated system reduces non-renewable energy consumption, climate change impact, acidification, respiratory effects from organic emissions, and human toxicity by more than 40%. If the digestate surplus is treated as a waste, the integrated system shows an increase in eutrophication and respiratory effects from inorganic emissions while all the analyzed impacts are reduced if the digestate can be used for substituting chemical fertilizers. © 2014 The Institution of Chemical Engineers.
GRACE JR, CLIFT R (1974) ON THE TWO-PHASE THEORY OF FLUIDIZATION., Chemical Engineering Science 29 (2)
THE DISTRIBUTION OF GAS FLOW BETWEEN BUBBLES AND THE DENSE PHASE IN A FLUIDIZED BED IS CONSIDERED.BY DERIVING GENERAL EQUATIONS FOR GAS AND SOLIDS CONTINUITY IN A FREELY-BUBBLING FLUIDIZED BED, THE POSSIBLE CONTRIBUTIONS TO THE INVISIBLE GAS FLOW ARE FORMULATED.IT IS SHOWN THAT THE GROSS ASSUMPTIONS INHERENT IN 'TWO-PHASE THEORIES' OF FLUIDIZATION ARE NOT JUSTIFIED.MEASUREMENTS OF VISIBLE BUBBLE FLOW AND BUBBLE VOLUME FRACTION CAN GIVE NOTHING MORE THAN ROUGH ESTIMATES FOR THE GAS FLOW THROUGH THE TWO PHASES.(A)
Clift R (2002) The Hydrogen Saga: Why the Energy Future could be in Iceland, Town and Country Planning (December) pp. 315-317
Clift R, Grace JR (1985) Continuous bubbling and slugging.,
Effort in the areas of bubbling and slugging in gas fluidized beds is reviewed and the major achievements summarized. Properties of single bubbles, behaviour of interacting bubbles, properties of freely bubbling beds and slugs and freely slugging beds are discussed. (P.J.B.)
Clift R, Mulugetta Y (2007) A plea for common sense (and biomass), TCE (796) pp. 24-26 INST CHEMICAL ENGINEERS
DUO W, KIRKBY NF, SEVILLE JPK, CLIFT R (1995) ALTERATION WITH REACTION PROGRESS OF THE RATE-LIMITING STEP FOR SOLID-GAS REACTIONS OF CA-COMPOUNDS WITH HCL, CHEMICAL ENGINEERING SCIENCE 50 (13) pp. 2017-2027 PERGAMON-ELSEVIER SCIENCE LTD
Clift R, Burningham K, Lofstedt R (1995) Environmental Perspectives and Environmental Assessment, In: Guerrier Y (eds.), Values and the environment: A Social Science Perspective pp. 19-31 Wiley
This book examines the multitude of ways in which we value the environment from a social science perspective.
Clift R (2005) Bioenergy and its potential in the UK, UK Power 1 pp. 49-51
SEVILLE JPK, CLIFT R (1984) THE EFFECT OF THIN LIQUID LAYERS ON FLUIDIZATION CHARACTERISTICS, POWDER TECHNOLOGY 37 (JAN-) pp. 117-129 ELSEVIER SCIENCE SA LAUSANNE
AZAPAGIC A, CLIFT R (1995) LIFE-CYCLE ASSESSMENT AND LINEAR-PROGRAMMING - ENVIRONMENTAL OPTIMIZATION OF PRODUCT SYSTEM, COMPUTERS & CHEMICAL ENGINEERING 19 pp. S229-S234 PERGAMON-ELSEVIER SCIENCE LTD
SCANDRETT LA, CLIFT R (1984) THE THERMODYNAMICS OF ALKALI REMOVAL FROM COAL-DERIVED GASES, JOURNAL OF THE INSTITUTE OF ENERGY 57 (433) pp. 391-397 INST ENERGY
Clift R, Azapagic A, Cowell S, Doig A, Hogan S, Solberg-Johansen B (1996) Allocation in Life Cycle Inventory Analysis, Report for Groupe des Sages, DGXI Brussels
Clift R (1995) Greenpeace life cycle appeal, CHEMICAL ENGINEER-LONDON (600) pp. 3-3 INST CHEMICAL ENGINEERS
Solberg-Johansen B, Clift R, Jeapes A (1997) Irradiating the environment: Radiological impacts in life cycle assessment, International Journal of Life Cycle Assessment 2 (1) pp. 16-19
One of the main shortcomings of Life Cycle Assessment (LCA) when applied to the Nuclear Fuel Cycle, is that there is currently no recognised procedure to deal with radionuclide emissions in the Impact Assessment stage. A framework which considers both human and environmental impacts is required and a methodology which is compatible with the other impact assessment approaches in LCA must be developed. It is important that the discussion is not only restricted to concepts, but that a working methodology is developed which can be readily applied by LCA practitioners. A provisional method is available for assessing radiological impacts on human health, but no consideration has been given to potential effects on the environment. A methodology is proposed in this paper which assesses irradiation of the environment using Environmental Increments (EI) as the quality standard. This approach is based on the same principles as for the Ecotoxicity classification group, and it represents a working methodology which can be continuously improved as knowledge in the area increases.
Clift R, Udo de Haes HA, Bensahel JF, Fussler CR, Griesshammer R, Jensen AA (1995) Research Needs in Life Cycle Assessment for the EU Ecolabelling Programme, final report of the second phase, Groupe de Sages, Commission of the European Union
GHADIRI M, CLIFT R (1980) JET PENETRATION INTO A FLUIDIZED-BED AT HIGH-TEMPERATURE, INDUSTRIAL & ENGINEERING CHEMISTRY FUNDAMENTALS 19 (4) pp. 440-440 AMER CHEMICAL SOC
Clift R, Doig A Applying Life Cycle Thinking to Solid Waste Management,
Clift R (1994) UNTITLED - REPLY, PROCESS ENGINEERING 75 (6) pp. 17-17
MILLER FREEMAN TECHNICAL LTD
Clift R, Longley AJ (1994) Introduction to Clean Technology, In: Kirkwood RC, Longley AJ (eds.), Clean Technology and the Environment pp. 174-198 Springer
This important book describes the concept of `clean technology' as an approach for protecting the environment by preventing the pollution at source, minimising waste and reducing energy use.
JOHNSSON JE, CLIFT R, GRACE JR (1974) PREDICTION OF BUBBLE DISTRIBUTIONS IN FREELY-BUBBLING TWO-DIMENSIONAL FLUIDIZED BEDS., MULTI-PHASE FLOW SYSTEMS, I.CHEM.E.SYMP.SERIES 38 1 , PAPER B5
THE MODEL PROPOSED BY CLIFT AND GRACE TO DESCRIBE THE MOTION OF INTERACTING BUBBLES IN A FLUIDIZED BED IS EXTENDED TO APPLY TO FREELY-BUBBLING BEDS.THE MODELR REQUIRES AS A BOUNDARY CONDITION THE SIZE, POSITION AND FREQUENCY OF BUBBLES AT SOME LOW REFERENCE LEVEL IN THE BED.THE MOTION AND COALESCENCE OF BUBBLES IN THE BED IS THEN CALCULATED TO GIVE PREDICTIONS OF BUBBLE FREQUENCY, SIZE AND SPATIAL DISTRIBUTIONS AT ANY HEIGHT ABOVE THE REFERENCE LEVEL.IT IS SHOWN THAT THE PREDICTIONS AGREE CLOSELY WITH MEASUREMENTS OF THESE PARAMETERS IN TWO-DIMENSIONAL BEDS EVEN THOUGH THE MODEL REQUIRES NO FITTED PARAMETERS.(A)
Clift R, Petrie JG (1995) Life Cycle Assessment, Mining and Environment Research Network Research Bulletin and Newsletter 7 pp. 9-11
CLIFT R, GAUVIN WH (1971) MOTION OF ENTRAINED PARTICLES IN GAS STREAMS, CANADIAN JOURNAL OF CHEMICAL ENGINEERING 49 (4) pp. 439-& CANADIAN SOC CHEMICAL ENGINEERING
Jorgensen KM, Azapagic A, Clift R, Ericson SO, Lofstedt R (1997) Life cycle assessment of a circulating fluidised bed combustion process utilising forest residues as a fuel, 1997 JUBILEE RESEARCH EVENT, VOLS 1 AND 2 pp. 53-56 INST CHEMICAL ENGINEERS
Mungkung RT, de Haes HAU, Clift R (2006) Potentials and limitations of life cycle assessment in setting ecolabelling criteria: A case study of Thai shrimp aquaculture product, INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT 11 (1) pp. 55-59 ECOMED PUBLISHERS
Clift R, Sim S, King H, Chenoweth JL, Christie IP, Clavreul J, Mueller C, Posthuma L, Boulay A, Chaplin-Kramer R, Chatterton J, DeClerck F, Druckman A, France CM, Franco A, Gerten D, Goedkoop M, Hauschild M, Huijbregts M, Koellner T, Lambin E, Lee J, Mair SJ, Marshall S, McLachlan M, Milà i Canals L, Mitchell C, Price E, Rockström J, Suckling JR, Murphy RJ (2017) The Challenges of Applying Planetary Boundaries as a Basis for Strategic Decision-Making in Companies with Global Supply Chains, Sustainability 9 (2)
The Planetary Boundaries (PB) framework represents a significant advance in specifying the ecological constraints on human development. However, to enable decision-makers in business and public policy to respect these constraints in strategic planning, the PB framework needs to be developed to generate practical tools. With this objective in mind, we analyse the recent literature and highlight three major scientific and technical challenges in operationalizing the PB approach in decision-making: first, identification of thresholds or boundaries with associated metrics for different geographical scales; second, the need to frame approaches to allocate fair shares in the ?safe operating space? bounded by the PBs across the value chain and; third, the need for international bodies to co-ordinate the implementation of the measures needed to respect the Planetary Boundaries. For the first two of these challenges, we consider how they might be addressed for four PBs: climate change, freshwater use, biosphere integrity and chemical pollution and other novel entities. Four key opportunities are identified: (1) development of a common system of metrics that can be applied consistently at and across different scales; (2) setting ?distance from boundary? measures that can be applied at different scales; (3) development of global, preferably open-source, databases and models; and (4) advancing understanding of the interactions between the different PBs. Addressing the scientific and technical challenges in operationalizing the planetary boundaries needs be complemented with progress in addressing the equity and ethical issues in allocating the safe operating space between companies and sectors.
The contemporary interest in urban cultivation in the global North as a component of sustainable food production warrants assessment of both its quantitative and qualitative roles. This exploratory study weighs the nutritional, ecological, and social sustainability contributions of urban agriculture by examining three cases?a community garden in the core of New York, a community farm on the edge of London, and an agricultural park on the periphery of San Francisco. Our field analysis of these sites, confirmed by generic estimates, shows very low food outputs relative to the populations of their catchment areas; the great share of urban food will continue to come from multiple foodsheds beyond urban peripheries, often far beyond. Cultivation is a more appropriate designation than agriculture for urban food growing because its sustainability benefits are more social than agronomic or ecological. A major potential benefit lies in enhancing the ecological knowledge of urbanites, including an appreciation of the role that organic food may play in promoting both sustainability and health. This study illustrates how benefits differ according to local conditions, including population density and demographics, operational scale, soil quality, and access to labor and consumers. Recognizing the real benefits, including the promotion of sustainable diets, could enable urban food growing to be developed as a component of regional foodsheds to improve the sustainability and resilience of food supply, and to further the process of public co-production of new forms of urban conviviality and wellbeing.
Every year in Europe refrigerant gases with a greenhouse-warming equivalent of more than 30 Mt CO2 are emitted from retail refrigerators. Furthermore, the effective efficiency of such refrigerators is far below that achievable under ideal (e.g. optimal-load; minimum access) operation. In this work the design of an alternative on-demand cooling unit is presented. The unit is based on the cooling effect provided by desorption of carbon dioxide previously adsorbed onto a bed of graphite-bonded activated carbon: in this paper, a case study of a self-chilling beverage can is used to demonstrate the technology. The high compaction of the activated carbon, and the presence of graphite, enhances the heat transfer properties of the adsorbent, thus enhancing the efficiency of cooling. Furthermore, potential exists for the use of activated carbon and CO2 from waste sources. This paper provides an overview of the design basis and environmental advantages of the unit, and experimental and simulation studies on the thermal dynamics of the cooling process. Particular attention is given to the effective thermal conductivity of the activated carbon bed. The results indicate that adequate on-demand cooling can be achieved within a portable unit. However, scope exists for enhancing the heat transfer within the cooling chamber through design and bed composition alterations. Recommendations for improved unit design are presented.
The earlier in the development of a process a design change is made, the lower the cost and the higher the impact on the final performance. This applies equally to environmental and technical performance, but in practice the environmental aspects often receive less attention. To maximise sustainability, it is important to review all of these aspects through each stage, not just after the design. Tools that integrate environmental goals into the design process would enable the design of more environmentally friendly processes at a lower cost. This paper brings together approaches based on Life Cycle Assessment (LCA) including comparisons of design changes, hotspot analysis, identification of key impact categories, environmental break-even analysis, and decision analysis using ternary diagrams that give detailed guidance for design while not requiring high quality data. The tools include hotspot analysis to reveal which unit operations dominate the impacts and therefore should be the focus of further detailed process development. This approach enables the best variants to be identified so that the basic design can be improved to reduce all significant environmental impacts. The tools are illustrated by a case study on the development of a novel process with several variants: thermal cracking of mixed plastic waste to produce a heavy hydrocarbon product that can displace crude oil, naphtha, or refinery wax or be used as a fuel. The results justified continuing with the development by confirming that the novel process is likely to be a better environmental option than landfill or incineration. The general approach embodied in the toolkit should be applicable in the development of any new process, particularly one producing multiple products.
The Construction sector is characterised by complex supply networks delivering unique
end products over short time scales. Sustainability has increased in importance but continues to
be difficult to implement in this sector; thus, new approaches and practices are needed. This paper
reports an empirical investigation into the value of the UN Sustainable Development Goals (SDGs),
especially Sustainable Consumption and Production (SDG12), when used as a framework for action
by organisations to drive change towards sustainability in global supply networks. Through inductive
research, two different and contrasting approaches to improving the sustainability of supply networks
have been revealed. One approach focuses on the ?bottom up? ethical approach typified by the
Forest Stewardship Council (FSC) certification of timber products, and the other on ?top-down?
regulations exemplified by the UK Modern Slavery Act. In an industry noted for complex supply
networks and characterised by adversarial relationships, the findings suggest that, in the long term,
promoting shared values aligned with transparent, third-party monitoring will be more effective
than imposing standards through legislation and regulation in supporting sustainable consumption
This study focuses on British Sustainability-inspired Business Startups (SiBS) from two sectors of the creative industry: fashion clothing and gifts. These two sectors are some of those that motivate most entrepreneurship, by using distinct elements of business models to attract their consumers. While price and style have led consumers to look for products with short lifespans, reducing sustainability impact is a growing concern in the fashion clothing and gifts sectors, what motivates some sustainable initiatives to be taken in place. However, although some sustainable initiatives have emerged, there is no clear understanding of how they are based in the business drivers or in the business models, and if these initiatives are contributing to startups to succeed.
This research aims to provide new understanding of the role of sustainability in the business startups from the fashion clothing and gifts sectors which offer manufactured green products. In order to narrow the presenting study, specific research questions are: What are the drivers of SiBS and do they differ from generic-mainstream startups? What business models are adopted by SiBS, how and why? and What are the factors affecting the longevity of the startups investigated and why?
Case study method was chosen to allow in-depth investigation and analyses of multiple variables in each startup investigated. Then, qualitative data from each startup was collected by different sources: interviews, direct observation and documentation. The use of multiple sources of evidence allowed triangulation between data collected. Fifteen British startups were examined, covering generic-mainstream and SiBS, business lifetimes up to ten years, and two sectors in the experimental group (fashion clothing, with four startups; and gifts, with six startups) and one sector in the control group (energy, with five startups). Data analysis consisted of within-case study and multi-case study. In-depth investigation provided richness of information from each startup and the identification of similarities and differences between groups of startups investigated.
Accordingly, the findings of this research suggest that: Regarding business drivers, startups in the gifts and fashion clothing sectors are more motivated by lifestyle and less motivated by money than energy firms; Also, SiBS are driven by the founder?s motivation when aiming to incorporate sustainability aspects into their business activities, while generic- mainstream startups are driven by money with focus on profits; Regarding business models,
SiBS prioritise environmental and social issues as main elements of their business models; Furthermore, business models do not really change throughout the growth of startups; Regarding business longevity, most startups in the gifts and fashion clothing sectors do not have clear financial strategies but this is commonly clear in the energy firms.
Important differences in outlook between different groups and types of business startups (generic-mainstream and SiBS) investigated in this study lead to the conclusion that: The awareness of two financial aspects (financial literacy and financial importance) provide an opportunity to increase chances of success in the early days of SiBS; The dissemination of the types of business models innovation for sustainability may motivate the development of more sustainable practices into the SiBS operations; And the emphasis on sustainability in business startups, either as through the business drivers or the business models adopted, is a central and long-term strategy that may increase the significance, the number and the importance of SiBS.
Following the boom of shale gas production in the
USA and the decrease in the US gas prices, increasing interest
in shale gas is developing in many countries holding shale
reserves and exploration is already taking place in some EU
countries, including the UK. Any commercial development of
shale gas in Europe requires a broad environmental assessment,
recognizing the different European conditions and
This study focuses on the UK situation and estimates
the environmental impacts of shale gas using lifecycle
assessment (LCA); the burdens of shale gas production
in the UK are compared with the burdens of the current UK
natural gas mix. The main focus is on the analysis of water
impacts, but a broad range of other impact categories are also
considered. A sensitivity analysis is performed on the most
environmentally criticized operations in shale gas production,
including flowback disposal and emission control, by considering
a range of possible process options.
Results and discussion
Improper waste water management
and direct disposal or spills of waste water to river can lead
to high water and human ecotoxicity. Mining of the sand and
withdrawal of the water used in fracking fluids determine the
main impacts on water use and degradation. However, the
water degradation of the conventional natural gas supply to
the UK is shown to be even higher than that of shale gas. For
the global warming potential (GWP), the handling methods of
the emissions associated with the hydraulic fracturing influence
the results only when emissions are vented. Finally, the
estimated ultimate recovery of the well has the greatest impact
on the results as well as the flowback ratio and flowback
This paper provides insights to better understand
the future development of shale gas in the UK. Adequate
waste water management and emission handling significantly
reduce the environmental impacts of shale gas production.
Policy makers should consider that shale gas at the same time
increases the water consumption and decreases the water degradation
when compared with the gas mix supply.
Furthermore, the environmental impacts of shale gas should
be considered according to the low productivity that force the
drilling and exploitation of a high number of wells.
By means of the life cycle assessment methodology, the purpose of this study is to assess the environmental
impact when biomethane from organic waste produced at residential level is used to supply
energy to a group of dwellings in the distributed generation paradigm. Three different Combined Heat
and Power systems, such as fuel cells, Stirling engine and micro gas turbine, installed at household level
are assessed in two different settings: one in Northern Europe (UK) and one in Southern Europe (Italy).
Different operating strategies are investigated for each technology. Moreover, marginal electricity production
technologies are analysed to assess their influence on the results. This study has demonstrated
that the type of bio-methane fed micro-CHP technology employed has a significantly different environmental
impact: fuel cells are the most environmentally friendly solution in every category analysed;
Stirling engines, although can supply heat to the largest number of dwellings are the least environmentally
friendly technology. However, key factors investigated in the model presented in this paper influence
the decision making on the type of technology adopted and the operating strategy to be
Liquefied natural gas (LNG) is expected to become
an important component of the UK?s energy supply because
the national hydrocarbon reserves on the continental shelf
have started diminishing. However, use of any carbon-based
fuel runs counter to mitigation of greenhouse gas emissions
(GHGs). Hence, a broad environmental assessment to analyse
the import of LNG to the UK is required.
A cradle to gate life cycle assessment has been carried
out of a specific but representative case: LNG imported to
the UK fromQatar. The analysis covers the supply chain, from
gas extraction through to distribution to the end-user, assuming
state-of-the-art facilities and ships. A sensitivity analysis
was also conducted on key parameters including the energy
requirements of the liquefaction and vaporisation processes,
fuel for propulsion, shipping distance, tanker volume and
composition of raw gas.
Results and discussion
All environmental indicators of the
CML methodology were analysed. The processes of liquefaction,
LNG transport and evaporation determine more than 50% of the cradle to gate global warming potential (GWP).
When 1% of the total gas delivered is vented as methane
emissions leakage throughout the supply chain, the GWP increases
by 15% compared to the GWP of the base scenario.
The variation of the GWP increases to 78% compared to the
base scenario when 5% of the delivered gas is considered to be
lost as vented emissions. For all the scenarios analysed, more
than 75% of the total acidification potential (AP) is due to the
sweetening of the natural gas before liquefaction. Direct emissions
from transport always determine between 25 and 49%of
the total eutrophication potential (EP) whereas the operation
and maintenance of the sending ports strongly influences the
fresh water aquatic ecotoxicity potential (FAETP).
The study highlights long-distance transport of
LNG and natural gas processing, including sweetening, liquefaction
and vaporisation, as the key operations that strongly
affect the life cycle impacts. Those cannot be considered negligible
when the environmental burdens of the LNG supply
chain are considered. Furthermore, the effect of possible fugitive
methane emissions along the supply chain are critical for
the impact of operations such as extraction, liquefaction, storage
before transport, transport itself and evaporation.
Bioenergy has an important role to play in helping the UK meet its carbon target in 2050
and the European Renewable Energy Directive objectives for 2030. There are however uncertainties
associated with the use of bioenergy, and whether or how much it contributes to
green-house gas emission reductions. In order to help identifying environmental benefits
and burdens associated with biomass use for energy production, an attributional life cycle
assessment has been carried out of a biomass-fired CHP plant: the Heathrow Airport energy
centre. This facility burns woodchips sourced from nearby forests providing 2 MWe of electricity
and 8 MWth of thermal energy which delivers heat and cooling to Heathrow Terminal
2 and low temperature hot water to Terminal 5. A hot spot analysis is conducted to identify
the process steps with the largest environmental impact, starting from the harvesting of the
forest residue to the disposal of the boiler ash. A scenario analysis is performed to compare
the impacts of the biomass plant against fossil alternatives and to identify which renewable
energy sources, between biomass and MSW, should be prioritised for development and
investment. The results show a reduction in GHG emissions from using biomass, with further
benefits if the bottom ash is collected and re-used as a soil conditioner for land-farming
or forestry. The paper also discusses the treatment of biogenic carbon in the assessment.
Under some circumstances, electric vehicles (EVs) can reduce overall environmental impacts
by displacing internal combustion engine vehicles (ICEVs) and by enabling more intermittent
renewable energy sources (RES) by charging with surplus power in periods of low demand.
However, the net effects on greenhouse gas (GHG) emissions of adding EVs into a national
or regional electricity system are complex and, for a system with significant RES, are affected
by the presence of storage capacity, such as pumped hydro storage (PHS). This article
takes the Portuguese electricity system as a specific example, characterized by relatively
high capacities of wind generation and PHS. The interactions between EVs and PHS are
explored, using life cycle assessment to compare changes in GHG emissions for different
scenarios with a fleet replacement model to describe the introduction of EVs. Where there
is sufficient storage capacity to ensure that RES capacity is exploited without curtailment,
as in Portugal, any additional demand, such as introduction of EVs, must be met by the next
marginal technology. Whether this represents an average increase or decrease in GHG
emissions depends on the carbon intensity of the marginal generating technology and on
the fuel efficiency of the ICEVs displaced by the EVs, so that detailed analysis is needed
for any specific energy system, allowing for future technological improvements. A simple
way to represent these trade-offs is proposed as a basis for supporting strategic policies on
introduction of EVs.
Screening social life cycle assessment (S-LCA) can be applied to identify the social hotspots associated with a production activity or supply chain. The objective of this paper is to explore how the quality of the results of a screening S-LCA can be improved, illustrated by a case study of sugarcane production in Brazil, an activity which has been criticized for its records on social sustainability due to issues such as poor working conditions for field workers and treatment of migrant workers.
Cradle-to-gate production of sugarcane in Brazil has been modeled using input-output analysis. The associated social impacts have been modeled using the framework of the Social Hotspots Database (SHDB), which is one of the first databases providing information on social risks along supply chains. The results from the SHDB were complemented with results from a systematic analysis of relevant literature. Content analysis was applied to 38 publications in English relevant to the social impacts of sugarcane production in Brazil, including peer-reviewed articles, ?gray literature,? non-governmental organization reports, and conference presentations. Qualitative data analysis software NVivo 8 was used to facilitate the analysis of the publications. A deductive category system was established based on the subcategories recommended in the UNEP/SETAC social life cycle assessment guidelines. Social impacts were further aggregated and analyzed by social themes and impact categories.
Results and discussion
The social impacts of the sugarcane life cycle in Brazil arise almost exclusively within the Brazilian sugarcane sector itself. Fifteen social themes are identified as hotspots in the SHDB, and nine of them are also identified by content analysis. Health and safety and labor rights and decent work are the impact categories with the highest risks. Besides negative impacts, content analysis is capable of identifying several positive impacts related to sugarcane production. Due to the use of aggregated country-level data, social impacts of manual and mechanical harvesting of sugarcane cannot be differentiated in SHDB; however, this can be achieved by content analysis.
SHDB is effective for identifying social impacts at the country level, but the data are inevitably aggregated and only show averages across different technologies and geographical areas; therefore, the database is of limited value in distinguishing between alternative operations and locations. Content analysis can facilitate foreground data collection by differentiating operations and identifying both negative and positive impacts at the level of individual activities. We recommend that S-LCA databases can be integrated with results of content analysis to improve the richness?representativity and specificity?of results from a screening S-LCA, to differentiate between alternative production routes and processes.
It is well accepted that the technical, financial and environmental performance of a chemical process is largely determined during design. Therefore, the development of tools that integrate environmental considerations would enable the design of more environmentally friendly processes at a lower cost. This research investigates how Life Cycle Assessment (LCA) can be applied at any stage in the design process to produce useful information for design, not just after the plant is operating, which is the norm for LCA. The tools have been applied to the development of a novel process (the RT7000): thermal cracking of mixed plastic waste to produce several hydrocarbon products with the potential to displace crude oil, naphtha, or refinery wax or be used as a fuel.
To allow LCA to guide the design process, a toolkit methodology was developed including comparisons of design changes, hotspot analysis, identification of key impact categories, environmental break-even analysis, and decision analysis using ternary diagrams. The results of applying these tools justified continuing with the development by confirming that the novel process is likely to be a better environmental option than landfill or incineration.
At the later stages of design, advanced tools such as process simulations become attractive and allow a more accurate estimation of material and energy flows. A simulation of the RT7000 in Aspen Plus® was developed that provided data for a wide range of feed compositions. The RT7000 continued to have lower environmental impact to incineration offering a saving equivalent to 969-1305 kgCO2/tonne plastic processed. It was also ascertained that variation in feed composition does influence environmental performance, but not enough to affect the outcomes of decision making.
The general approaches used in this work to assess the RT7000 should be applicable to the development of any new process. Benefits and insights similar to those obtained in the case study can realistically be expected when these methodologies are applied to any new processes. Therefore the results have been published in the Journal of Cleaner Production (Gear et al., 2018)
Phosphorus (P) is an essential non-substitutable nutrient for all living organisms, but it is also a dwindling non-renewable resource. Approximately two-thirds of the world?s supply of phosphate rock is located in China, Morocco, and the USA. Phosphate rock is included in the EU list of ?critical raw materials? and is ranked 20th in an index of commodity price volatility. P recovery from waste water can help alleviate reliance on imported phosphate and reduce vulnerability to fluctuating prices. This project explored the options for P recovery from wastes produced across Thames Water?s waste water treatment plants (WWTPs), the main foci being sludge dewatering liquors and incineration/pyrolysis residues.
The research focussed specifically on the Slough WWTP and the operation of a newly installed Ostara system for recovery of P as struvite from dewatering liquors. The Ostara process is designed to operate with centrate PO4-P concentrations above 100 mg/l; to obtain these concentrations chemical coagulant dosing in the enhanced biological nutrient removal process must be reduced. Centrate monitoring following this change showed that Fe concentrations must measure consistently below 1.5 mg/l for PO4-P concentrations to remain steadily above 100mg/l. Following these changes onsite, operational savings and revenue can be produced onsite. Significant operational and maintenance savings totalling to £113K can be made in the first year of operation of the P recovery system in Slough WWTP. Sale of P rich struvite fertiliser produces annual revenue of £20K. Moving beyond the local benefits of P recovery, national benefits of P recovery were quantified. In a national context, a total of 28±1 kt P/year can be recovered from all WWTP waste streams, reducing P fertiliser imports by 36±1%. P recovery from WWTP influent and incinerated sewage sludge ash would reduce P losses to water bodies by 22±2%.
Sewage sludge may be incinerated, producing incinerated sewage sludge ash (ISSA), or alternatively pyrolysed to produce sewage sludge char (PSSC). The possibility of recovering P from these residual solids was also investigated. PSSC samples contained significantly more nitrogen and lower heavy metal concentrations than ISSA samples due to the process conditions. The % P extractions from both ISSA and PSSC plateaus at 0.6M and 0.8M H2SO4 acid concentrations, respectively, due to the formation of gypsum on the particles, so that further increase in acid concentrations does not increase P recovery.
The knowledge gained through this research has been used to improve the understanding and efficiency of the P recovery system at Slough WWTP. The information learned about pyrolysis residues will be used by Thames Water to develop a novel P recovery process from PSSC. Combined, these findings can impact the industry by creating incentives and inform policies regarding P recovery.
How can we design more sustainable industrial and urban systems that reduce environmental impacts while supporting a high quality of life for everyone? What progress has been made towards reducing resource use and waste, and what are the prospects for more resilient, material-efficient economies? What are the environmental and social impacts of global supply chains and how can they be measured and improved?