Transesterification of soybean oil to biodiesel using cement as a solid base catalyst

This work studies the recycling of cement as a catalyst in the production of biodiesel by transesterification of soybean oil with methanol. Literature survey showed that cement has never been studied as a solid catalyst in the transesterification of triglyceride. Concrete is a composite construction material composed of cement, aggregate, water, and chemical admixtures. In these composite, Portland cement was supposed to be an efficacious catalyst for biodiesel production. Therefore, the catalytic effects of calcination temperature, oil/alcohol ratio (mol/mol), and catalyst amount (wt% of oil) of hydrated cement were discussed. Finally, the waste concrete catalyst was successfully used in the transesterification reaction of soybean oil according to catalytic property of the cement catalyst.

► Waste concrete catalyst was also successfully tested in transesterification reaction of soybean oil.
► Cement was main active composition of concrete catalyst.
► Thermal decomposition is an efficient method to separate coarse aggregate from concrete and can be easy to practice in industry.