An overview on thermochemical conversion and potential evaluation of biofuels derived from agricultural wastes

Abstract

Amongst the advanced biomass conversion technologies, thermochemical processes have potential applicability, becoming the key technologies to support a new waste management strategy by optimizing it. This review relies on thermochemical conversion processes including pyrolysis, gasification, and hydrothermal liquefaction for turning agricultural wastes into biofuels (bio-oil, biochar, and syngas), explicitly addressing their technological principles, implementation prospects, and operating parameters. The feasibility of thermochemical conversion technologies is considered from economic and environmental viewpoints along with life cycle assessment analysis. This paper sheds light on multiple agricultural wastes analyzed for biofuel production through thermochemical conversion. The differences between the characteristics of the identical agricultural waste samples and different agricultural waste samples are exhibited here, which vary due to their geographical location of cultivation and the various growing conditions. Furthermore, a thorough review of the literature regarding the characterization techniques for feedstock, the characterization methods for the generated biofuels, and their proper utilization in various applications are also covered.

Keywords

• Pyrolysis
• Gasification
• Hydrothermal liquefaction
• Bio-oil
• Biochar
• Syngas