Mauro Lafratta


Doctoral Practitioner in Sustainability working with Thames Water Utilities ltd

My research project

In the media

2020
On-demand generation from anaerobic digestion
Featured article on the International Water Association's magazine The Source

Research

Research interests

Research projects

My publications

Highlights

Lafratta, M., Thorpe, R.B., Ouki, S.K., Shana, A., Germain, E., Willcocks, M. and Lee, J., 2020. Dynamic biogas production from anaerobic digestion of sewage sludge for on-demand electricity generation. Bioresource Technologyhttps://doi.org/10.1016/j.biortech.2020.123415

Publications

Mauro Lafratta, Rex B. Thorpe, Sabeha K. Ouki, Achame Shana, Eve Germain, Mark Willcocks, Jacquetta Lee (2020)Dynamic biogas production from anaerobic digestion of sewage sludge for on-demand electricity generation, In: Bioresource Technology310123415 Elsevier

The aim of this work was to study the potentials and benefits of dynamic biogas production from Anaerobic Digestion (AD) of sewage sludge. The biogas production rate was aimed to match the flexible demand for electricity generation and so appropriate feeding regimes were calculated and tested in both pilot and demonstration scale. The results demonstrate that flexibilization capability exists for both conventional AD and advanced AD using Thermal Hydrolysis Process (THP) as pre-treatment. Whilst the former provides lower capability, flexible biogas production was achieved by the latter, as it provides a quick response. In all scenarios, the value of the biogas converted into electricity is higher than with a steady operational regime, increasing by 3.6% on average (up to 5.0%) in conventional and by 4.8% on average (up to 7.1%) with THP. The process has proven scalable up to 18m3 digester capacity in operational conditions like those in full scale.

MAURO LAFRATTA, REX BARRY THORPE, Sabeha K. Ouki, Achame Shana, Eve Germain, Mark Willcocks, JACQUETTA LEE (2021)Demand-Driven Biogas Production from Anaerobic Digestion of Sewage Sludge: Application in Demonstration Scale, In: Waste and biomass valorization

The power system needs flexible electricity generators. Whilst electricity generation from anaerobic digestion (AD) of sewage sludge has traditionally been baseload, transforming the generation capacity into a modern flexible operator is an opportunity to further valorise the resource. This work aims to demonstrate that AD of sewage sludge can support flexible generation and be operated dynamically in a relevant operational environment, to promote full scale implementation. A demonstration scale plant (20 m3 conventional AD reactors) was used to test several feeding regimes designed to return a biogas production rate that matches the demand. Two demand profiles are defined, either by common corporate power purchase agreements or by the main balancing mechanism used by the grid operator in UK. Demand-driven biogas production is demonstrated in this relevant operational environment, and the flexibilisation performance is positive in all scenarios. The value of the biogas increases by up to 2%, which outperforms the results obtained at pilot scale. Additionally, an increase in biogas yield is observed. Whilst transitional imbalances are recorded, they last for few hours and the overall stability is not affected. In conclusion, these trials demonstrate demand-driven biogas production is a feasible operational solution and full-scale implementation is possible.