Techno-economic and sensitivity analysis of biomethane production via landfill biogas upgrading and power-to-gas technology

Power-to-gas system produces synthetic methane through two-step processes: H-2 production via water electrolysis and methanation of CO2. The technology valorizes CO2 as a useful commodity from biogas plants. Biogas upgrading technologies have the capacity to capture CO2 and supply it as a source of carbon to methanation processes hence to produce synthetic methane. In this study, we have carried out a techno-economic assessment of biomethane production and estimation of its production costs via the integration of landfill biogas to methanation process. The study assessed four different scenarios, scenario 1: water-scrubbing, scenario 2: membrane, scenario 3: direct methanation and scenario 4: methanation with membrane. Production costs in case of power-to-gas scenarios 3&4 are competitive with standard upgrading scenarios 1&2 for electricity price below 20 (sic)/MWh. Presence of electrolyzer unit contributes to more than 75% of the total biomethane production costs. Scenarios 1&2 are insensitive to changes in electricity prices as well as to operating time, but scenarios 3&4 are extremely sensitive to both electricity prices variation and operating time. Increase in the plant size and vol% of CH4 in raw biogas presented shorter payback period in case of scenarios 1&2 due to lower specific production costs. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study evaluates the techno-economic aspect of biomethane production through different scenarios and finds that power-to-gas systems are competitive with standard upgrading technologies under certain conditions. The presence of electrolyzer unit significantly contributes to the total biomethane production costs. Different scenarios show varying sensitivity to changes in electricity prices and operating time.