Sorption-enhanced gasification of municipal solid waste for hydrogen production: a comparative techno-economic...

Sorption-enhanced gasification has been shown as a viable low-carbon alternative to conventional gasification, as it enables simultaneous gasification with in-situ CO₂ capture to enhance the production of H₂. 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 H₂ production efficiency), whereas doped limestone presented the highest H₂ 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 CO₂ avoided cost ranging between 114.9 €/tCO₂ (natural limestone) and 130.4 €/tCO₂ (dolomite). Although doped limestone has shown a CO₂ avoided cost of 117.7 €/tCO₂, this can be reduced if the production cost of doped limestone is lower than 42.6 €/t. The production costs of new sorbents for CO₂ capture and H₂ production need to be similar to that of natural limestone to become an attractive alternative to natural limestone.

The online version contains supplementary material available at 10.1007/s13399-022-02926-y.