Mesoporous polymeric solid acid as efficient catalyst for (trans)esterification of crude Jatropha curcas oil

•The mesoporous polymeric solid acid possesses large surface area and high acidity.•98% oleic acid conversion was achieved with this robust solid acid.•94% FAMEs content was achieved from one-pot transformation of CJCO with high FFAs.•The catalyst showed superior activity to conventional acidic materials.

Due to the high content of free fatty acids (FFAs), crude Jatropha curcas oil (CJCO) usually requires a two-step process for biodiesel production. In this study, the mesoporous polymeric solid acid consisting of acidic functional ionic liquids and sulfonic acid groups have been synthesized and characterized by XPS, FT-IR, N2 adsorption-desorption, HR-TEM, SEM and TG. The polymeric solid acid possesses abundant mesopores (27.0 nm), high surface area (281.0 m2/g) and high acidity (2.6 mmol g− 1). It shows excellent catalytic performance in esterification of oleic acid with methanol, exhibiting 98% oleic acid conversion, which is more active than commercial resins (i.e., Amberlyst 15 and Nafion NR50). Interestingly, it is also efficient for the simultaneous (trans)esterification of CJCO with a high acid value (15.9 mg KOH/g) to biodiesel without soap formation, giving high FAMEs content of 94%. The obtained catalytic activity was demonstrated to be higher than that of conventional acidic catalysts. Moreover, the polymeric solid acid could keep relatively high catalytic activity after four recycles. Therefore, the mesoporous polymeric solid acid is a promising solid acid catalyst for direct production of biodiesel from renewable and low cost feedstocks with high acid values.

Graphical abstractA mesoporous polymeric solid acid (MPD-SO3H-IL) was prepared and demonstrated to be efficient for simultaneous (trans)esterification of crude Jatropha curcas oil with high free fatty acids to biodiesel in a high FAMEs content of 94%.Figure optionsDownload full-size imageDownload as PowerPoint slide