The role of biomass resources in a 100 percent renewable energy system in Denmark

When?

Thursday 19 January 2012, 13.00 hrs to 14.00 hrs

Where?

45A AZ 04

Open to:

Staff, Students, Public

Speaker:

Henrik Wenzel Professor, Institut for Kemi-, Bio- og Miljøteknologi, Syddansk Universitet, Denmark

Admission information:

No charge

 In the fossil free society, global warming may still be a key concern due to agricultural or forestry based greenhouse gas emissions, but other concerns and constraints can be expected to supplement our perspective on sustainability. Concerns for nature and biodiversity and constraints on arable land, carbon, water, phosphorus and scarce metals like rare earth elements may become key sustainability concerns in a fossil free society. Some roads towards sustainability may prove to imply even tougher challenges than today’s fossil based society. An exercise of ‘back-casting’ technological development pathways from future targets can be a way to ensure timely care and avoid blind alleys on the road, especially when facing, as we do, resource constraints and the need for prioritizing resources.

Due to our demand for carbon, biomass and arable land may constitute dominating constraints in the fossil free society. In a fossil free energy and transport system, carbon and thus biomass has a key role to play. We need carbon for 1) chemical and material feedstock, 2) energy dense fuels for mobility like aviation, long distance road and sea transportation, and 3) a storable fuel to buffer our wind and solar power supply of electricity. These three main roles of carbon and biomass, together with the development in our average diets towards more meat on the menu, set the framework conditions for prioritizing the use of biomass and land in the fossil free society. A recent Danish research program (www.ceesa.dk) has done technology back-casting from a target of a fossil free and 100% renewable society & energy system in Denmark. Even though Denmark has a very high agricultural production relative to World average, and thus has relatively large residual biomass resources such as manure and straw residues, biomass and carbon constitute the key constraints of the designed systems. To avoid huge biomass imports or huge reductions in food/feed production due to conversion of agriculture to energy crops, it was proven necessary to prioritize biomass for the electricity sector and to upgrade biogenic carbon by hydrogenation and carbon capture and recycling. In the designed systems, part of the wind power provides hydrogen through electrolysis. Biomass is gasified and hydrogenated to methanol or aviation fuels and CO2 is captured and hydrogenated further to fuels again. In this way, the system designs succeed in keeping biomass demand below national Danish biomass residual resources with no use of agricultural land. Economic modeling proved the system design to provide a net benefit compared to reference fossil based systems.

Henrik Wenzel Presentation (934.12KB - Requires Adobe Reader)