Feasibility study on combining anaerobic digestion and biomass gasification to increase the production of biomethane

Syngas biomethanation: state‐of‐the‐art review and perspectives

“…Therefore, the catalytic methanation requires an intensive gas cleaning process of the raw syngas before entering the reactor. Furthermore, an additional water‐gas shift reaction process is often needed in order to correct the ratio of C/H in syngas, which reduces the overall efficiency of the process while increasing the complexity and the cost of operation . The use of biocatalysts in syngas biomethanation is anticipated to result in a more cost‐effective process as these present a higher tolerance to the impurities of syngas and operate at mild temperatures.…”

“…Nonetheless, these technologies are not necessarily alternative as their integration in a combined process seems a promising configuration for achieving a more efficient production of methane. Li et al . studied the feasibility of combining the anaerobic digestion of source‐separated organic waste with the gasification and biomethanation of wood pellets to increase both quality and productivity of biomethane, obtaining a potential increase of 161% in the production of biomethane compared to the stand‐alone anaerobic digestion process.…”

“…Furthermore, an additional water-gas shift reaction process is oft en needed in order to correct the ratio of C/H in syngas, which reduces the overall efficiency of the process while increasing the complexity and the cost of operation. 30 Th e use of biocatalysts in syngas biomethanation is anticipated to result in a more costeff ective process as these present a higher tolerance to the impurities of syngas and operate at mild temperatures. As opposed to the catalytic process, the biological process is not sensitive to the ratio of C/H since the water-gas shift reaction is inherent to the autotrophic metabolism of most microbial groups 31 conducting the biomethanation of syngas.…”

“…Nonetheless, these technologies are not necessarily alternative as their integration in a combined process seems a promising confi guration for achieving a more effi cient production of methane. Li et al 30 studied the feasibility of combining the anaerobic digestion of source-separated organic waste with the gasifi cation and biomethanation of wood pellets to increase both quality and productivity of biomethane, obtaining a potential increase of 161% in the production of biomethane compared to the stand-alone anaerobic digestion process. Similarly, Guiot et al 35 estimated the potential of the conversion of municipal solid waste through anaerobic digestion of the easily digestible organic fraction and syngas biomethanation of the non-digestible organic fraction, resulting in a production of biomethane of about fi ve times higher than the stand-alone anaerobic digestion of municipal solid waste.…”

Modeling of coupling gasification and anaerobic digestion processes for maize bioenergy conversion

“…Literature does not include many works on the possible effect of combined anaerobic digestion and gasification. Li et al [21] modeled a coupled system aimed at biomethane production, while Chen at al. couples a fixed bed gasifier working with corncob and cotton straws and a typical biogas plant for fueling household furnaces in rural scenarios [22].…”