Flue-to-Fuel: Biomediated carbon capture and utilization of dilute CO2 gas streams to biomethane

20 March 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Capturing anthropogenic carbon dioxide (CO2) and utilizing it as a feedstock for chemical production has been identified as an essential step towards mitigating climate change. The most dominant CO2 emissions originate from flue gases that contain diluted concentrations of CO2 emitted from combustion and industrial processes. Conventional capture technologies such as amine scrubbing are impeded by their high energy demand due to the thermodynamically low driving force for desorbing CO2. A new concept is here presented that exploits the robustness of microbial catalysts to simultaneously desorb the CO2 from an amine-based absorbent and convert the captured CO2 to biomethane (CH4) in a single step by the use of renewable hydrogen. The concept combines carbon capture with that of power-to-methane, to hereby abate CO2 emissions and use the captured CO2 as a resource. Experimental results of the conceptual design in batch reactors demonstrated high microbial biocompatibility with amine methyl diethanolamine (MDEA). The biocompatibility was examined in the range of 0 – 500 mM MDEA, and the system demonstrated almost full bioavailability of the absorbed CO2 until 120 mM of MDEA. Within this range, the CH4 productivity ranged from 40.7 - 63.6 NmLCH4 L-1culture h-1 from synthetically absorbed CO2 with a maximum conversion 1.77 times higher than traditional biomethanation with gaseous CO2. Conversion of raw flue gas from a biogas engine resulted in only a slight decrease in conversion efficiency compared to that of pure gasses, which demonstrated that the concept has high robustness to the impurities and oxygen present in raw flue gas.


Carbon capture and utilization
amine scrubbing
flue gas


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.