Production of antioxidant additives and biochar pellets from the Co-pyrolysis of agricultural biomass: A review

One of the panaceas to mitigating the menace of environmental degradation and global warming is the adoption of bioenergy; a probable alternative to fossil fuels. The thermochemical process is a viable approach that converts biomass into biofuel. However, bio-oil produced from biomass pyrolysis still lacks the fuel qualities required to satisfy the American Society for Testing and Materials requirements for petroleum products. This therefore necessitates the adoption of a better alternative, co-pyrolysis. This mild energy consumption technology has helped lower production costs, alleviated some waste management problems, and increased the variety and quality of pyrolysis product applications. With a little adjustment, bio-oil generated by co-pyrolysis can be converted to crude oil. Through co-pyrolysis, agricultural biomass presents an exciting prospect to produce essential antioxidant compounds and biochar pellets while addressing waste management and sustainability concerns. Biochar, one of the major by-products of co-pyrolysis serves as a stable carbon sink, aiding with carbon sequestration and climate change mitigation. Moreover, biochar pellets, as a biofuel, provide a greener alternative to fossil fuels due to their high energy density and minimal emissions. The co-pyrolysis process not only converts agricultural waste into economically useful products but also contributes to environmental sustainability and socio-economic growth. Albeit the imminent challenge is the cost of upgrading bio-oil for commercial purposes, which is one of the major obstacles to its widespread usage. This work offers an overview of agricultural biomass types, the co-pyrolysis process, key influencing factors, byproduct characteristics, bio-oil as an antioxidant additive, and biochar pellets.