Modelling of Substitute Natural Gas production via combined gasification and power to fuel

The combination of water electrolysis and solid fuel gasification offers the substitution of Air Separation Unit, the reduction or elimination of water gas shift catalytic system and acid gas removal technology. Subsequently, the direct utilisation of CO2, which otherwise would be emitted during production and its conversion to valuable fuels in combination with energy storage are achieved. Steam gasification and steam-oxygen gasification in different operating conditions and scales are combined with electrolysers with the aim to define optimum efficiencies towards SNG production and reduction of direct CO2 emissions. Modelling and comparison of 6 different cases for steam and steam-oxygen gasification process, gas cleaning and conditioning technologies focusing on tar removal, activated carbon, water gas shift, and acid gas removal technologies with potassium carbonate and MDEA are investigated. Capture ratios are balanced with and without water gas shift reactor according to the requirements of SNG synthesis. The efficiency of gasification and power to SNG ranges between 57.67% and 63.43% for the optimum cases with low pressure steam/oxygen gasification and electrolysers sized according to oxygen demand and according to the oversized electrolysers case respectively. The overall energy conversion resulted in an energy conversion efficiency of 72.83% and 73.51% with the production of steam. (C) 2018 Elsevier Ltd. All rights reserved.