Kinetic analysis and fuel characterization with hydrocarbon distribution in pyro-oil produced from co-pyrolysis of rice husk and low-density polyethylene

Abstract

The expansion of the human population, urbanization, environmental damage, and energy demand have depleted the fossil fuel supply. As a result, the primary problems of the current global socioeconomic restructuring require substantial and long-term alternative energy resources. This study studies the synergistic potential of co-pyrolysis, a promising thermochemical conversion process, to produce hydrocarbon-rich fuel from a blend of low-density polyethylene (LDPE) and rice husk biomass. The thermal behavior of the blended feedstock at different weight ratios was investigated using TGA. For pyrolysis experiments, several mixes of waste plastics (80, 60, and 50 wt%) were combined with biomass and pyrolyzed in a semi-batch reactor under optimal conditions (550 °C temperature, 10 °C/min heating rate, and 200 mL/min N₂ flow rate). The fuel characteristics of co-pyrolyzed fuel were assessed using ASTM techniques. The physicochemical parameters of the co-pyrolyzed fuel were characterized using experimental investigations, which included its energy content, elemental composition, density, viscosity, and stability. The results show that pyrolyzing LDPE and rice husk together produces a hydrocarbon-rich fuel with good combustion properties. The fuel has higher energy content and lower viscosity than individual feedstocks, making it a feasible alternative to traditional petroleum-based fuels. FTIR and NMR investigations indicated the presence of a variety of functional groups, most notably aromatic compounds, acids, phenols, water, esters, and ethers. Furthermore, NMR study indicated that adding waste plastics enhances aromatic content while decreasing paraffinic chemicals. Furthermore, a GC-MS examination revealed a considerable rise in hydrocarbons and decreased oxygen-rich compounds when waste plastic LDPE was added to the blend.