Forest residues gasification integrated with electrolysis for production of SNG – modelling and assessment

Book chapter, 2018

This study investigates opportunities for integrating an electrolysis unit with a biomass gasifier for production of synthetic natural gas (SNG). Gasification is a key technology for production of biofuels and chemicals from lignocellulosic biomass, for which an increased demand is expected in the future. H2produced through an electrolyser can be used to increase the output of a gasifier by reaction with CO2to form CH4. Four integrated flowsheet configurations are evaluated with respect to system energy efficiency and process operating revenue. The system energy efficiencies are in the range of 0.55 – 0.8, and the maximum value of operating revenues is 0.245 $/kWhdry biomass. The results show that feeding the Sabatier reactor with the full product gas flow coming from the methanation unit, and separating the unreacted CO2afterwards, is the most attractive configuration with respect to operating revenue.