Production of Bio-CNG from sugarcane bagasse: Commercialization potential assessment in Indian context

Bio-CNG (compressed natural gas) is being actively promoted in India as a cleaner transportation fuel while also providing a sustainable option for agricultural waste management. This work assesses the commercialization potential of Bio-CNG production from sugarcane bagasse by performing a detailed techno-economic and life cycle assessment (LCA). The process under consideration uses hydrodynamic cavitation as pretreatment followed by anaerobic digestion based bagasse valorization and biogas upgradation using water scrubbing. Experimental data for cavitation and anaerobic digestion are combined with process simulation data for upgradation and compression. Process design and economics methods are used to perform techno-economic assessment (TEA) for plants producing 5 and 10 TPD Bio-CNG. For LCA, 1 kg of Bio-CNG is used as a functional unit. Inventory data were obtained from experiments, process simulation, and Ecoinvent® database v 3.3. The Bio-CNG production cost for a 5 TPD plant was $ 1.29 /kg (₹ 96/kg) which decreased to $ 1.18/kg (₹ 87/kg) for a 10 TPD plant. For a 5 TPD plant, the production cost could potentially reduce to $ 0.51 /kg (₹ 37/kg) if bagasse and electricity were available for free. The total climate change impact for 1 kg of Bio-CNG was 1.55 kg CO₂ eq., and the electricity source significantly contributed to the total impact. Considering the source of CNG used in the transport sector in India, Bio-CNG provided a net benefit (reduction) of 3.96 kg CO₂ eq. per kg Bio-CNG.