Microwave-driven oleic acid esterification over chlorosulfonic acid-treated hydroxyapatite: synergism for intensified biodiesel production.

Treating hydroxyapatite (HAP) with sulfonic acid without structural destruction remains challenging owing to the sensitivity of HAP to acidic pH. In this work, natural derived HAP was prepared using natural phosphate a dissolution/precipitation process. Notwithstanding the challenge, the prepared HAP was treated with three concentrations of chlorosulfonic acid in dichloromethane to prepare HAP-S1, HAP-S2 and HAP-S3 depending on the acid content under carefully controlled conditions.

Biodiesel production from rapeseed oil and low free fatty acid waste cooking oil using a cesium modified natural phosphate catalyst.

The present study focuses on the catalytic activity of cesium modified natural phosphate in biodiesel production from rapeseed oil and low free fatty acids (FFA) used in cooking oil. The catalyst was prepared by impregnation of cesium chloride (CsCl) on the natural phosphate followed by calcination up to 800 °C. The phosphate based catalyst was thermally, structurally, morphologically, and texturally characterized in order to determinate the relationship between its physicochemical properties and its catalytic activity.