Energy, Environmental, and Economic Analyses of Design Concepts for the Co-Production of Fuels and Chemicals with Electricity via Co-Gasification of Coal and Biomass.

摘要

The overall objective of this project was to quantify the energy, environmental, and economic performance of industrial facilities that would coproduce electricity and transportation fuels or chemicals from a mixture of coal and biomass via co-gasification in a single pressurized, oxygen-blown, entrained-flow gasifier, with capture and storage of CO(sub 2) (CCS). The work sought to identify plant designs with promising (Nth plant) economics, superior environmental footprints, and the potential to be deployed at scale as a means for simultaneously achieving enhanced energy security and deep reductions in U.S. GHG emissions in the coming decades. Designs included systems using primarily already-commercialized component technologies, which may have the potential for near-term deployment at scale, as well as systems incorporating some advanced technologies at various stages of R&D. All of the coproduction designs have the common attribute of producing some electricity and also of capturing CO(sub 2) for storage. For each of the co-product pairs detailed process mass and energy simulations (using Aspen Plus software) were developed for a set of alternative process configurations, on the basis of which lifecycle greenhouse gas emissions, Nth plant economic performance, and other characteristics were evaluated for each configuration. In developing each set of process configurations, focused attention was given to understanding the influence of biomass input fraction and electricity output fraction. Self-consistent evaluations were also carried out for gasification-based reference systems producing only electricity from coal, including integrated gasification combined cycle (IGCC) and integrated gasification solid-oxide fuel cell (IGFC) systems. The reason biomass is considered as a co-feed with coal in cases when gasoline or olefins are co-produced with electricity is to help reduce lifecycle greenhouse gas (GHG) emissions for these systems. Storing biomass-derived CO(sub 2) underground represents negative CO(sub 2) emissions if the biomass is grown sustainably (i.e., if one ton of new biomass growth replaces each ton consumed), and this offsets positive CO(sub 2) emissions associated with the coal used in these systems. Different coal: biomass input ratios will produce different net lifecycle greenhouse gas (GHG) emissions for these systems, which is the reason that attention in our analysis was given to the impact of the biomass input fraction.