Economic and environmental analyses of coal and biomass to liquid fuels

Abstract

We analyzed the economic feasibility and environmental benefits of an alternative technology that converts coal and biomass to liquid fuels (CBTL), using West Virginia as a real case scenario. A mixed integer linear programming model was developed to analyze the economic feasibility. A cradle-to-grave life cycle assessment (LCA) model was also developed to analyze the environmental benefits. Sensitivity analyses on required selling price (RSP) and greenhouse gas (GHG) emissions of CBTL fuels were conducted according to feedstock availability and price, biomass to coal mix ratio, conversion rate, internal rate of return (IRR), capital cost, operational and maintenance cost. The results showed the price of coal had a more dominant effect on RSP than that of biomass. Different mix ratios and conversion rates led to RSP ranging from $104.3 – $157.9/bbl. LCA results indicated that GHG emissions ranged from 80.62 kg CO2 eq to 101.46 kg CO2 eq/1000 MJ of liquid fuel at various biomass to coal mix ratios and conversion rates if carbon capture and storage (CCS) was applied. Most of the water and fossil energy were consumed in the conversion process. Compared to petroleum-derived-liquid fuels, the reduction in GHG emissions could be between −2.7% and 16.2% with CBTL substitution.