Abstract
There is a growing interest in biogas upgrading processes based on the use of hydrogenotrophic methanogens. Hydrogenotrophic methanogens utilize H2 and CO2 in converting them into CH4. In this work, a new approach for CO2 conversion to CH4 and biogas upgrading has been developed based on magnesium ribbon and anaerobic granular sludge under mild aqueous conditions; with CO2 as the sole carbon source, Mg(0) oxidizes and generates H2 that is utilized by hydrogenotrophic methanogens in anaerobic granular sludge. The Mg concentration (2 g/L) contributed to high H2 production during the first day; subsequently H2 gradually decreased/utilised with a simultaneous CH4 increase (days 1–4). Results show that 2 g/L Mg(0) in anaerobic granular sludge can generate 60 % CH4 after 7 days. In this system, the daily regulation of pH to 6 can increase the CH4 to 71.4 % after 7 days, while biogas can be converted to 92 % CH4 after 9 days. At these conditions, Nesquehonite (MgCO3·3H2O) is formed at the outer surface of Mg(0) which prevents the H2 released from Mg(0). However, Nesquehonite (MgCO3·3H2O) can be potentially used as construction materials. Therefore, a new process is reported to convert CO2 to CH4 and Nesquehonite based on Mg(0) and anaerobic granular sludge under mild aqueous conditions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.