Thermal Conversion of Microalgae into Biochar: A Review on Processes, Properties, and Applications

Abstract Global energy consumption has drastically increased over the years due to population growth and industrialization. This has prompted an exploration for clean and renewable energy alternatives. Microalgae are widely recognized as a promising third‐generation energy source because they have the capability to generate biofuels, including biochar. The utilization of microalgal biomass has been gaining traction because of their advantages, such as fast growth, a high rate of production, and high carbon‐fixing efficiency. Thermochemical methods like hydrothermal carbonization, torrefaction, and pyrolysis can be employed to harness energy from microalgae. The different thermochemical methods employed for converting microalgal biomass into biochar have been discussed, as well as the factors affecting these methods. In addition, a dedicated section covered the components and properties of the generated biochar, including its thermal and surface properties. Furthermore, the economic analysis of the production of biochar from microalgae as well as the applications of microalgae‐derived biochar were presented and discussed, along with suggestions for further research.