(2025) Biochar_Use of defatted cottonseed-derived biochar for biodiesel production: a closed-loop approach

Park G.; Park J.; Kim J.Y.; Lee D.; Kwon E.E.

(Springer) Biochar ISSN: 25247867 Vol.7 Issue.1 Article No.4 DOI: 10.1007/s42773-024-00394-3

This study aimed to enhance the economic viability and sustainability of the cotton industry by converting cottonseed into energy. Cottonseed was subjected to lipid extraction for biodiesel production, and a pyrolysis test was conducted under N₂ and CO₂ conditions to valorise defatted cottonseed. Under CO₂ conditions, the increase in CO concentration was due to homogeneous reaction of CO₂ with volatile matters. Biochar, a pyrolytic product of defatted cottonseed, was used as a catalyst for thermally induced transesterification, and showed high performance in biodiesel conversion efficiency due to its abundant alkaline earth metals and meso-/macro-pores. For example, transesterification using silica at 250 ˚C yielded only 1.6 wt.% biodiesel, whereas using biochar at the same temperature resulted in a significantly higher biodiesel yield of 83.5 wt.%. This study experimentally proved that 7,900 tons (304 million MJ) of biodiesel could be produced annually, surpassing the diesel fuel requirement (145 million MJ) for cotton cultivation. These results indicate the potential to fully replace fossil fuels in the cotton industry. © The Author(s) 2025.; Oil was extracted from cottonseed, and the defatted cottonseed was used in pyrolysis to produce syngas and biochar. Biochar demonstrated catalytic properties in thermally induced transesterification of cottonseed extracts into biodiesel. Biochar outperformed conventional silica, providing a biodiesel yield of 83.5 wt.% at 250 ˚C (silica: 1.6 wt.%). © The Author(s) 2025.

This work was supported by a grant from the National Research Foundation of Korea (NRF), funded by the Korean government (MSIT) (NRF-2022R1C1C1011570 and NRF-2023R1A2C3003011).