Energy Savings and Element Utilization of Coal-Based Polygeneration Systems Producing Power and Fischer–Tropsch Synfuels

Abstract

This study employed simulation software to model the coal-based polygeneration systems (PGSs). The carbon-utilization ratios (η C ), hydrogen-utilization ratios (η H ), and energy-saving ratios (ESRs) were used to quantitatively analyze the performance of various coal-based PGSs. This analysis was based on two parameters: the unreacted gas circulation ratio (r) and the ratio of synfuel energy output to power output (λ). The results indicate that both r and λ a ect the η C , η H , and ESR values. Increasing r was found to increase element utilization and ESRs, and a better performance was achieved when a water-gas shift (WGS) reactor was utilized. The highest η C , η H , and ESR values obtained were 29.08, 37.89, and 17.68%, respectively. Increasing λ was also found to increase element utilization and ESRs. When λ 4 and both unreacted-gas circulation and the WGS reactor were employed, the highest element-utilization ratios (η C 19.59%, η H 37.78%) and ESR (19.78%) were achieved. In the corresponding case where a WGS reactor was not used, the η H value signi cantly improved over the range λ 0.0-2.0.