Potential of biogas generation from mango industrial waste Shanika R. Musser, Sri Suhartini*, Lynsey Melville
Universitas Brawijaya, Birmingham City University
Abstract
Agro-industries in Indonesia generate significant amounts of mango industrial waste (MIW), which consists of the mango seed, peel, and wastewater. Biogas, a mixture of primarily methane and carbon dioxide, can be generated from MIW via anaerobic digestion (AD) to produce renewable energy. The objective of this research is to understand the potential of biogas generation from MIW of two mango varieties - podang and madu. First, each MIW component was characterized in various analyses: lignocellulosic content, proximate analysis, ultimate analysis, calorific value, and TS/VS. Then a biochemical methane potential (BMP) test was performed on the individual components of MIW (mono-digestion) and on various mixtures of the MIW components (co-digestion). The BMP test was performed using the novel gas density BMP (GD-BMP) method, a low-cost measuring technique that relies on gas volume and weight to approximate methane content. Results indicate that BMP was highest for the co-digestion of podang seeds and peels at a 1:1 ratio, with an average BMP of 125.8 mL/g VS substrate. These results may indicate a synergistic relationship between podang seeds and peels. However, inhibition from a low pH was observed for all test groups, with an average pH of 6.17 prior to the BMP test and an average pH of 4.26 after the BMP test. This could be attributed to the highly acidic nature of MIW and the accumulation of volatile fatty acids in the reactor. Therefore, it is advised that future research investigate the co-digestion of MIW with high pH substrates. This information is critical to the sustainability of mango agro-industries in Indonesia and the development of the larger bioeconomy.
