Green and economical transesterification of castor oil for biodiesel production via a novel bentonite based Li2SiO3-LiAlO2 composite: Process technology & production feasibility

In our work, a highly efficient Li2SiO3-LiAlO2 composite was designed via a simple solid-state reaction using bentonite as raw material and successfully applied to the transesterification of castor oil with methanol for biodiesel production. The preparation processes for the bentonite-based Li2SiO3-LiAlO2 composite (Li/Bent) were optimized, and the prepared Li/Bent catalyst was characterized using a variety of experimental techniques. The maximum oil conversion to biodiesel of 97.16 % was obtained under reaction temperature of 65 degrees C, reaction time of 90 min, catalyst amount of 4 wt%, and methanol/oil molar ratio of 15:1. The possible mechanisms of the reaction process were revealed. The preliminary analysis of technical feasibility for the production showed that the production of castor oil biodiesel catalyzed by Li/Bent had competitive advantages in terms of market demand, industrial policy, process technology, environmental impact and economic benefits. The high efficiency and good stability of the catalyst reflect the technical advantages of the process. According to the study of environmental factor and process mass index, the synthesis process of biodiesel generated low waste, which was a green and environment-friendly process. Finally, the economic evaluation showed that the biodiesel production from castor oil catalyzed by Li/Bent catalyst was a cost-effective and low risk process.