ENERGY-CYCLE ANALYSIS OF A GASIFICATION-BASED MULTI-PRODUCT SYSTEM WITH CO_2 RECOVERY

摘要

The DOE is investigating CO_2 recovery from fossil-fuel cycles as a greenhouse gas mitigation strategy. Recognizing this, we used life-cycle analysis tools to compare two integrated gasification combined-cycle (IGCC) plant designs based on the Shell entrained-flow gasifier. One option, called the "co-product case," uses high-sulfur Illinois #6 coal to produce electricity and hydrogen (H_2) as energy carriers. At the same time, 90% of the carbon dioxide (CO_2) is recovered for disposal in geological storage or for use, such as enhanced-oil recovery (EOR). The second option, called the "base-case," is a conventional IGCC power plant releasing CO_2 by combustion of the synthesis gas in a gas turbine. The life-cycle analysis task has been aided by use of LCAdvantage~(TM). Process design has been aided by the use of ASPEN simulation for critical design areas. Special attention was paid to the transport issues for the CO_2 product, because transportation technology is a determinant of product specifications, which affect plant design. Separating and purifying the H_2 for fuel cell use should yield an impressive gain in overall process efficiency that can offset the losses in efficiency from recovery and compression of CO_2 to supercritical conditions.