Technical and economic prospects of coal- and biomass-fired integrated gasification facilities equipped with CCS over time

摘要

This study analyses the impacts of technological improvements and increased operating experience on the techno-economic performance of integrated gasification (IG) facilities. The facilities investigated produce electricity (IGCC) or FT-liquids with electricity as by-product (IG-FT). Results suggest that a state-of-the-art (SOTA) coal-fired IGCC without CO_2 capture has electricity production costs of 17/GJ (60MWh) with the potential to decrease to 11 EUR/GJ (40 EUR/MWh) in the long term. Specific direct CO_2 emissions may drop from about 0.71 kgCO_2/kWh to 0.59kgCO_2/kWh. If CO_2 is captured, production costs may increase to 23 EUR/GJ (83 MWh), with the potential to drop to 14GJ (51 EURMWh) in the long term. As a result, CO_2 avoidance costs woulddecrease from 35EUR/t CO_2 to 18EUR^t CO_2. The efficiency penalty due to CCS may decrease from 8.8%pt to 3.7%pt. CO_2 emissions can also be reduced by using torrefied biomass (TOPS) instead of coal. Production costs of a SOTA TOPS-fired IGCC without CO_2 capture are 18-25/GJ (64-92 MWh). In the long term, this may drop to 12EUR/GJ (44/MWh), resulting in CO_2 avoidance costs of 7EUR/t CO_2. The greatest reduction in anthropogenic CO_2 emissions is obtained by using biomass combined with carbon capture and storage (CCS). A SOTA TOPS-fired IGCC with CCS has, depending on the biomass price, production costs of 25-35 EURj/GJ (91-126EUR/MWh) with CO_2 avoidance costs of 19-40 EUR/t CO_2. These values may decrease to 15 EUR/GJ (55EUR/MWh) and 12EUR/t CO_2 avoided in the long term. As carbon from biomass is captured, specific direct CO_2 emissions are negative and estimated at -0.93 kgCO_2/kWh for SOTA and -0.59 kg CO_2/kWh in the long term. Even though more carbon is sequested in the future concepts, specific emissions drop due to an increase in the energetic conversion efficiency of the future facilities. New technologies in IG-FT facilities have a slightly smaller impact on production costs. In the long term, production costs of FT-liquids from coal maydrop from 13/GJ to 9 GJ if CO_2 is vented and from 15EUR/GJ to 10 GJ if CCS is applied. The use of TOPS results in 15-23 EUR/G] (Vent) and 17-24GJ (CCS) for SOTA facilities. These production costs may drop to ll-18GJ (Vent) and 12-19 GJ (CCS) in the longterm. Contrary to the IGCC cases, the coal-fired IG-FT facility shows the lowest CO_2 avoidance costs. The CO_2 emission of coal to FT-liquids with CCS is, however, similar to gasoline/diesel production from crude oil.