The alarming rise in global greenhouse gas emissions, surpassing 36 billion tons in 2022, necessitates urgent measures for sustainable CO2 utilization. Traditional methods like carbon capture and chemical conversion pose challenges, prompting interest in microbial CO2 conversion to biofuels for economic and environmental benefits.

This study delves into the impact of switchgrass and poultry litter biochars, produced at different temperatures, on Clostridium strains’ ability (P7, P11, P21) to convert CO2 into C2–C6 alcohols and acids. Results reveal that SGB350 enhances alcohol production, while PLB350 promotes acid formation, showcasing the potential of biochar in boosting the process’s feasibility.

The shift towards higher alcohol production holds promise, as these alcohols are more compatible with gasoline, opening avenues for jet fuels and biodiesel. The research emphasizes the potential of converting waste gases, such as those from ethanol facilities, into value-added products like ethanol, butanol, and hexanol.

While acknowledging the thermodynamic preference for C4 and C6 products, the study highlights the influence of strain-specific factors on product profiles. Clostridial strains like P11, P7, and P21 demonstrate varied capabilities, with P21 excelling in butanol and hexanol production with SGB350.

Biochar, rich in minerals and trace metals, proves beneficial in enhancing microbial fermentation. Its porous structure facilitates cell attachment, and the study emphasizes its potential as an affordable nutrient source for CO2 fermentation, showcasing diverse applications in sustainable practices.

The research not only explores the capabilities of Clostridium strains in converting CO2 but also emphasizes the role of biochar as a sustainable tool to enhance microbial activity. This study contributes to the ongoing efforts to develop cost-effective and environmentally friendly technologies for mitigating the global carbon footprint.