Hydrogenotrophs-Based Biological Biogas Upgrading Technologies

Abstract

Biogas produced from anaerobic digestion consists of 55–65% methane and 35–45% carbon dioxide, with an additional 1–2% of other impurities. To utilize biogas as renewable energy, a process called biogas upgrading is required. Biogas upgrading is the separation of methane from carbon dioxide and other impurities, and is performed to increase CH4 content to more than 95%, allowing heat to be secured at the natural gas level. The profitability of existing biogas technologies strongly depends on operation and maintenance costs. Conventional biogas upgrading technologies have many issues, such as unstable high-purity methane generation and high energy consumption. However, hydrogenotrophs-based biological biogas upgrading offers an advantage of converting CO2 in biogas directly into CH4 without additional processes. Thus, biological upgrading through applying hydrogenotrophic methanogens for the biological conversion of CO2 and H2 to CH4 receives growing attention due to its simplicity and high technological potential. This review analyzes the recent advance of hydrogenotrophs-based biomethanation processes, addressing their potential impact on public acceptance of biogas plants for the promotion of biogas production.

Co-digestion approach for enhancement of biogas production by mixture of untreated napier grass and industrial hydrolyzed food waste

“…The methane concentration was maintained at a constant level of 65%-80% until the end of the fermentation process. This finding was in line with the previous report that biogas produced from anaerobic digestion is composed of 55%-65% biomethane, 45% carbon dioxide, and 1%-2% other gases (Antukh et al, 2022).…”

Eight Up-Coming Biotech Tools to Combat Climate Crisis

“…Various physico-chemical technologies for such biogas upgrading through CO 2 removal are available. An alternative approach is applied in biogas upgrading, where electrolytically produced H 2 is utilized to microbiologically convert the CO 2 fraction in biogas to CH 4 , yielding >95% of overall carbon conversion to methane [ 123 ]. A direct injection of H 2 into an anaerobic digester, in situ methanation, is one option for this upgrading technique.…”

A MCDA-Based Assessment of Biomethane Generation and Use in Sardinia

“…Qualitative Max [4], [5], [6], [16], [35], [40], [46] I8 Need for further polishing steps n.a. Qualitative Min [5], [6], [7], [9], [16], [35], [36], [40], [41], [42], [46], [47], [48], [49], [50], [51] I9 TRL [unitless] Quantitative Max [1], [5], [6], [8], [36], [41], [42], [50], [52] I10 Possibility of upscaling n.a. Qualitative Max [4], [6], [17], [40], [41], [42], [46], [53], [54], [55], [56] Social I11 Safety n.a.…”