A comprehensive review of life cycle assessment (LCA) of microalgal and lignocellulosic bioenergy products from thermochemical processes.

Microalgal biomass is a renewable energy source and is considered as a crucial solution in the increasing energy demand and greenhouse gas emissions. Through various thermochemical conversion processes such as torrefaction, pyrolysis, liquefaction, and gasification, biomass can be converted to different bioenergy products. However, the production of these bioenergy products through the aforesaid thermochemical processes entails raw material consumption, energy consumption, and environmental impact. A multitude of studies has been conducted to evaluate the environmental impact of bioenergy products for specific thermochemical processes on a specific biomass feedstock using life cycle assessment. This study aims to comprehensively review the life cycle assessment of bioenergy products from microalgal biomass together with lignocellulosic biomass and through different thermochemical processes. The study identifies the current challenges and potential future works of bioenergy production from different thermochemical processes in the perspective of a life cycle assessment framework.