Bio-methane and bio-methanol co-production from biogas: A profitability analysis to explore new sustainable chemical processes

Abstract

Herein a potential synergy between biogas upgrading and CO2 conversion to bio-methanol is investigated. This novel idea arises as an alternative path to the traditional biogas – to – bio-methane route which involves CO2 separation. In this work a techno-economic analysis of the process was performed to study the profitability for potential investors. A total of 15 scenarios were analysed. Different biogas plant sizes were examined as baseline scenarios: 100, 250, 500, and 1000 m3/h. Furthermore the potential effect of governmental incentives through bio-methane subsidies (feed-in tariffs and investment percentage) was studied. Finally a sensitivity analysis was developed to study the effect of key parameters. The results of the baseline scenarios demonstrated that not profitable results can be obtained without subsidies. Bio-methane subsidies as feed-in tariffs proved to be effective for the 500 and 1000 m3/h plant sizes. For a feed-in tariff subsidy of 40 €/MW, 500 m3/h biogas production plants are remarkably profitable (net present value equal to 3106 k€). Concerning 1000 m3/h biogas production plants, 20 €/MW of subsidies as feed-in tariffs gives similar net present value result. Our results point out that only big biogas production can produce bio-methanol at profitable margins under 90–100% of investment subsidied. The sensitivity analysis showed that electricity, natural gas and bio-methanol price can affect considerably to the overall profitability, converting predicted positive cases in negative scenarios