Sorption-enhanced gasification of municipal solid waste for hydrogen production: a comparative techno-economic analysis using limestone, dolomite and doped limestone
Mónica P. S. Santos, Dawid P. Hanak
Abstract
Abstract Sorption-enhanced gasification has been shown as a viable low-carbon alternative to conventional gasification, as it enables simultaneous gasification with in-situ CO 2 capture to enhance the production of H 2 . CaO-based sorbents have been a preferred choice due to their low cost and wide availability. This work assessed the technical and economic viability of sorption-enhanced gasification using natural limestone, doped limestone with seawater and dolomite. The techno-economic performance of the sorption-enhanced gasification using different sorbents was compared with that of conventional gasification. Regarding the thermodynamic performance, dolomite presented the worst performance (46.0% of H 2 production efficiency), whereas doped limestone presented the highest H 2 production efficiency (50.0%). The use of dolomite also resulted in the highest levelised cost of hydrogen (5.4 €/kg against 5.0 €/kg when limestone is used as sorbent), which translates into a CO 2 avoided cost ranging between 114.9 €/tCO 2 (natural limestone) and 130.4 €/tCO 2 (dolomite). Although doped limestone has shown a CO 2 avoided cost of 117.7 €/tCO 2 , this can be reduced if the production cost of doped limestone is lower than 42.6 €/t. The production costs of new sorbents for CO 2 capture and H 2 production need to be similar to that of natural limestone to become an attractive alternative to natural limestone.