Conversion of biomass to biochar using top‐lit updraft technology: a review

Abstract

AbstractThe demand for biochar has increased over time due to its wide range of applications in various industries. Biochar, which is the solid product of the thermochemical conversion of biomass, has been synthesized using different reactor‐based technologies. One such technology is top‐lit updraft (TLUD) technology. This study is a review of published literature that discusses trends in the utilization of the TLUD technology, focusing on biochar production. This study also evaluated the principles of TLUD technology. The properties and applications of TLUD‐based biochar were also discussed. In comparison with other technologies, TLUD technology is characterized by higher thermal efficiency, simplicity of starting the fuel, low smoke emission, and high biochar yield. It was observed that the use of TLUD technology resulted in the production of high‐quality biochar with a variety of characteristics, which has been utilized as an adsorbent for wastewater treatment, in the agricultural sector to increase soil nutrients, and as a solid fuel. The concept of semi‐batch‐fed TLUD technology was also introduced in this study to enhance the efficiency and output of the batch‐fed TLUD configuration that has been in use. Some knowledge gaps in the study could be addressed by future studies on the use of this technology. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd.