Abstract
Biomass valorization through thermochemical pathways is an appropriate option to generate bioenergy, reducing the reliance on petroleum-based fuels and minimizing their adverse environmental impacts. Biomass waste accumulates abundantly worldwide and is typically managed through landfilling and incineration, posing threats to the environment. Alternatively, biomass waste can be converted into valuable products through thermochemical techniques. This review provides an overview on the categories of biomass and the most widely utilized thermochemical pathways for its conversion, including pyrolysis, gasification, liquefaction, and combustion. Additionally, the characteristics and conditions of the processes, configuration of the utilized reactors, the main products, bio-oil catalytic upgrading, advanced upgrading techniques, and commercial-scale thermochemical plants are discussed. Moreover, it summarizes the main findings of the notable studies that investigated the thermal degradation of various biomass types. Furthermore, it highlights the role of artificial intelligence (AI) in forecasting bioenergy production from lignocellulosic biomass. Finally, the main challenges in the thermochemical valorization of biomass, which necessitate further research, are identified.