Cost benefit and environmental impact assessment of compressed biogas (CBG) production from industrial, agricultural, and community organic waste from India

Worldwide methane production by anaerobic digestion (AD) from organic waste has been expanded for greenhouse gas emission reduction by replacing fossil-fuel needs to facilitate sustainable energy supply. India also launched Sustainable Alternative Towards Affordable Transportation (SATAT) policy to promote compressed biogas (CBG) production through anaerobic digestion of organic waste. However, it is vital to understand productivity, raw material availability, and raw material quality to produce biogas at profit margin lucrative for business. The present work depicts biogas production from 11 organic feedstocks from community, industrial, and agricultural waste through 25 m(3) demo-scale biogas plant. All materials were analysed for moisture, total solids, organic matter, carbon, nitrogen, C:N (carbon:nitrogen) ratio, and volatile solids, to optimize process parameters. Average 423 Nm(3) biogas yield with 57% methane was obtained with average hydraulic retention time (HRT) of 60 days. The design, operation, and cost-benefit analysis of a 5 tons per day (TPD) CBG plant were carried out by integrating two digesters with pressure swing technology (PSA) for biogas purification, which resulted in 14% IRR and 3.6-year payback period after 10 years of operation. The 1500-tons/year CBG production can replace gasoline demand of 2070 kL/year while reducing CO2 emission of 41,218.6 tons/year through replacing gasoline and synthetic fertilizer (urea) by organic biogas slurry as by-product and preventing open dumping of organic waste.

Automated summary

Methane production through anaerobic digestion of organic waste can replace fossil fuels for sustainable energy supply and greenhouse gas emission reduction. Optimizing the process parameters can result in high biogas yield from different sources of organic waste. The design and cost-benefit analysis of a compressed biogas plant show acceptable investment returns and payback period. Large-scale production of compressed biogas can replace gasoline demand and reduce CO2 emissions.