Integrated process design for sorption-enhanced steam reforming of biogas and sorption-enhanced DME synthesis: a techno-economic study

This work integrates two intensified processes, the sorption-enhanced steam reforming (SESR) of biogas and sorption-enhanced dimethyl ether synthesis (SEDMES), offering a route for the efficient production of bio-dimethyl-ether (bio-DME). A full process simulation was developed in Aspen Plus, integrating a 40 MW SESR unit with a SEDMES system. Optimisation of the bio-DME plant increased the cold gas efficiency from 64% to 74% and the overall DME yield from 39% to 45%. A base-case configuration was established and improved through three integration strategies: (i) heat recovery, (ii) recycling of unconverted gases, and (iii) steam integration through the regeneration of the SEDMES adsorbent. The levelised cost of DME (LCODME) for the optimised system is estimated at ∼1 €/kg DME, which is lower than costs reported for alternative power-to-X DME routes. The net present value analysis indicates that plant profitability becomes positive for DME selling prices above ∼1000 €/t. This study demonstrates that intensifying both hydrogen production and DME synthesis enables a technically and economically attractive pathway for bio-DME production from biogas.