Hydrogen from wood gasification with CCS – a techno-environmental analysis of production and use as transport fuel

Abstract

The use of biomass as a resource for hydrogen production can contribute to the transition towards carbon neutral or carbon negative energy systems. This paper offers a comprehensive investigation of the technical performance and life cycle environmental footprint of three gasification technologies for H₂ production, using dry biomass (wood) as input. These are compared with H₂ production from reforming of natural gas or biomethane and electrolysis as presented in our previous work. This is followed by an evaluation of the use of H₂ as fuel for passenger cars and trucks. The quantity of biomass required for the production of 1 MW H₂ is calculated with an integrated process simulation approach on the basis of Aspen Plus simulations and real-plant literature data. We observe that all the technologies analysed provide negative CO₂ emissions when coupled with CCS. However, the sorption enhanced reforming and the entrained flow gasifiers are more suited to this scope than the heat pipe reformer, because higher overall CO₂ capture rates can be achieved. As CO₂ is from biogenic sources, the life cycle carbon footprint of the produced H₂ is only slightly positive (without CCS) or negative (with CCS). This negative carbon footprint is not obtained at the cost of important trade-offs with regards to ecosystem quality, human health or resource depletion, with the exception of high forest land use. Fuel cell electric vehicles using hydrogen from biomass (both wood and biomethane) with CCS as fuel turn out to be the most climate friendly among all options, with even possible negative total greenhouse gas emissions. However, limited biomass resources and potential alternative uses need to be considered.