Activity of microporous lignin-derived carbon-based solid catalysts used in biodiesel production

Lignin is utilized as a carbon precursor to produce microporous lignin-derived carbon-based solid acid (MLC-S) ZnCl 2 activation and sulfonation with concentrated sulfuric acid . The effects of reaction conditions, namely the ratio of methanol to oleic acid , carbonization temperature, and catalyst dosage, on the efficiency of the esterification of oleic acid with methanol are investigated. As a carbon-based solid acid, the MLC-S offers high catalytic activity in the esterification , which is a crucial reaction in the synthesis of biodiesel. Compared with nonactivated lignin-derived carbon-based solid acid (LC-S), the highly porous structure of the MLC-S makes its active sites more accessible and ensures its excellent catalytic performance. Under the optimal conditions, the esterification of oleic acid with methanol reaches a conversion of 92.3%. Moreover, after recycling the MLC-S for five times, the extent of the esterification reaction is still as high as 72.9%. Obviously, the synthesized MLC-S has considerable potential for the esterification of oleic acid with methanol and thus for biodiesel production.