Pyrogenic transformation of oil-bearing biomass into biodiesel without lipid extraction

•Biodiesel conversion through a thermo-chemical pathway.•Biodiesel conversion without lipid extraction.•Transformation of oil-bearing biomass into biodiesel via the pseudo-catalytic way.•High tolerance associated with transesterification against impurities.

This study mechanistically investigated the pseudo-catalytic transesterification of oil-bearing biomass through a thermo-chemical pathway. As a case study, all experimental work was conducted with sesame seed and sesame oil. The pseudo-catalytic transesterification occurred in the presence of porous material (silica) since porous material provided reaction space as a micro reactor and drove the heterogeneous reactions between the mobile phase of methanol and the stationary phase of triglycerides (TGs) in sesame. The experimental work verified that the main driving force of pseudo-catalytic transesterification was temperature in the presence of porous material, which led to the direct derivatization of oil-bearing biomass into fatty acid methyl esters (FAMEs). Thermal cracking was observed at temperatures higher than 350 °C and the main experimental parameter initiating this thermal cracking was temperature and time. However, the optimal conditions identified in this study were temperatures lower than 350 °C, where the total yield of FAMEs reached up to 96.4 ± 0.3% of lipid in sesame seed. The introduced technology would be applicable to the production of biodiesel and comprehensive lipid analysis in oil-bearing biomass.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide