Performance study of a methanation process for a syngas obtained from a sorption enhanced gasification process

Synthetic Natural Gas (SNG) produced from renewable sources constitutes a solution for the transition to net-zero emissions for natural gas relying sectors. From the different biomass-to-SNG routes, the gasifi-cation of biomass to produce a syngas that is further converted into SNG has a large potential in a near future. In this work, the methanation process under quasi commercial conditions was demonstrated for a syngas generated from biomass gasification. The influence of process variables like pressure, steam/CO ratio and syngas composition (i.e. content of CO2, CH4 and light hydrocarbons) were analyzed to evaluate the maximum CH4 purity achieved in a commonly used two-step methanation process. Moreover, the need of adding green H2 produced from renewable sources was studied to adjust the H2/CO/CO2 ratio for methanation. A product gas with 78 %vol. CH4 was produced using a commercial Ni-based catalyst, being the conversion of CO2 the limiting factor towards the fulfilment of a higher CH4 content (only 37 % of CO2 conversion was reached in the second methanation reactor at 270 degrees C, 4 bar and 2140 h-1 of gas space velocity). Alternative operating conditions and/or intensified process schemes stand as the most promising alternatives for the conversion of syngas into high purity SNG.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).