CO₂ utilization via a novel anaerobic bioprocess configuration with simulated gas mixture and real stack gas samples

ABSTRACT

CO₂, which is considered to be one of the major causes of climate change, has reached to critical levels in the atmosphere due to tremendous consumption of fossil fuels all over the world. In this study, anaerobic bioconversion of CO₂ into bio-methane using a novel bioprocess configuration (HYBRID bioreactor) was studied under mesophilic conditions. Varying ratios of H₂/CO₂ gas mixture and volumetric feeding rates were investigated and no additional organic matter and trace element were needed throughout the study. The maximum methane production of 19 m³ CH₄/m³ _reactor/d was achieved at a H₂/CO₂ ratio of 4:1 and feeding rate of 24 m³ gas/m³ _reactor/d. It was determined that H₂ conversion rate is about 96%. For demonstration purpose, real stack gas sample from a petrochemical industry was also tested under optimized operational conditions. No inhibitory effect from stack gas mixture was observed. This study provided an environmentally friendly and sustainable solution for industries such as petrochemical industry in order to produce extra energy while capturing their waste CO₂. Thereby, a sustainable and environmentally friendly model solution was presented for industries with high CO₂ emissions.

KEYWORDS:

• Carbon dioxide capture
• carbon dioxide utilization
• hydrogenotrophic methanogen
• bio-methane
• HYBRID bioreactor

Acknowledgements

The data presented in this article were produced within the project below; however it is only the authors of this article who are responsible for the results and discussions made herein. The authors wish to thank Aquaflex Company (Turkey) for the support of supplying bioaqua MBBR rings. The authors wish to thank also Costa, K. and Leigh, A. for the support of figure.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Türkiye Bilimsel ve Teknolojik Araştirma Kurumu (TUBITAK-CAYDAG) [grant number 115Y455]. The authors wish to thank Ege University Scientific Research Project Fon [grant number 15/CSUAM/003] for the financial support of this study.