| Title |
Biogas upgrading using Clostridium autoethanogenum for value-added products |
| ID_Doc |
13260 |
| Authors |
Heffernan, JK; Lai, CY; Gonzalez-Garcia, RA; Nielsen, LK; Guo, JH; Marcellin, E |
| Title |
Biogas upgrading using Clostridium autoethanogenum for value-added products |
| Year |
2023 |
| Published |
|
| DOI |
10.1016/j.cej.2022.138950 |
| Abstract |
Biogas production from anaerobic digestion is a well-established bioprocess for energy generation, nutrient re-covery, and valorisation of waste resources. Typical biogas contains 60 % methane and 40 % carbon dioxide (CH4/CO2 of 1.5). Removing or altering carbon dioxide content facilitates biogas use as biomethane due to its impact on the calorific value. Technologies that effectively remove carbon dioxide to convert biogas to bio-methane could play a central role in transforming waste resources. This is important as the world transitions into a low carbon and circular economy. Gas fermentation utilising acetogens and renewable H2 offers an under -explored biological alternative for biogas upgrading. To demonstrate the use of gas fermentation for biogas upgrading, we used Clostridium autoethanogenum to ferment CO2 from synthetic biogas supplemented with H2 to produce ethanol and acetate (2.8 +/- 0.1 and 3.9 +/- 0.1 g/L, respectively). The bioprocess was able to enrich the biogas (CH4/CO2 of 2.20 +/- 0.05) and transform the CO2 into valuable fuels and chemicals in a one-step process. Strikingly,-50 % of the off-gas was inert, meaning there is potential for optimising acetogenic fermentation to achieve complete valorisation of CO2 from waste streams. Increasing the gas to liquid mass transfer of H2 improved the culture's growth rate and stability, but biomass and ethanol titres remained unaffected during chemostat operation. This represents a step towards upgrading biogas and other low-grade CO2 waste streams by utilising renewable hydrogen and gas fermentation as a sustainable platform technology. |
| Author Keywords |
Biogas upgrading; Sustainable bioproduction; Industrial biomanufacturing; Acetogens; Gas fermentation |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000870517200004 |
| WoS Category |
Engineering, Environmental; Engineering, Chemical |
| Research Area |
Engineering |
| PDF |
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