Enhancing bioenergy production from food waste by in situ biomethanation: Effect of the hydrogen injection point

This study explores the potential to reduce carbon arising from anaerobic digestion of food waste by the addition of externally sourced hydrogen gas to aid the biological conversion of internally generated carbon dioxide to biomethane. Moreover, this manuscript assayed the efficiency of hydrogen and carbon dioxide conversion to biomethane by identifying suitable injection points. AbstractThe increasing rate of food waste (FW) generation around the world is a growing environmental concern, notwithstanding, its valorisation through anaerobic digestion (AD) makes it a potential resource. Moreover, there is a growing demand to optimise the biomethane from AD for gas-to-grid (GtG) and vehicular applications. This has spurred researches on hydrogen gas (H2) injection into AD systems to enhance the biological conversion of H2 and carbon dioxide (CO2) to methane (CH4), a process known as biomethanation. A simplistic approach for biomethanation is to add H2 directly into working AD reactors (in situ biomethanation). However, a competition for the injected H2 towards other biological reactions besides H2/CO2 conversion to CH4 could follow, thus, reducing the efficiency of the system. Hence, this study was conducted to understand how different H2 injection points would affect H2/CO2 conversion to CH4 during FW in situ biomethanation, to identify an optimal injection point. Experiments were designed using H2 equivalent to 5% of the head-space of the AD reactor at three injection points r...
Source: Food and Energy Security - Category: Food Science Authors: Tags: ORIGINAL RESEARCH Source Type: research