Enhanced biomass-to-liquid (BTL) conversion process through high temperature co-electrolysis in a solid oxide electrolysis cell (SOEC)

A novel process design of a plant integrating a dimethyl ether (DME) synthesis unit with a woody biomass gasifier and a high-temperature co-electrolysis unit is proposed and analysed in this study. The plant foresees a two-stage gasifier that produces a CO2-rich syngas, which is further upgraded to a product gas with a higher energy content through a high temperature co-electrolysis section consisting of a solid oxide electrolysis cell (SOEC) module. The energy system analysis of the whole process was developed, also taking into account the kinetic mechanisms for the syngas conversion to DME in a catalytic reactor. The calculated biomass-to-liquid (BTL) plant efficiency is 69.5% (LHV) with specific productivity of 0.86 kg(DME)/kg(biomass). This is a productivity two-fold higher than what achieved in conventional BTL plants operating without the electrochemical enhancement step. (C) 2014 Elsevier Ltd. All rights reserved.