Biodiesel production process by homogeneous/heterogeneous catalytic system using an acid-base catalyst

The transesterification of triglycerides contained in waste oilseed fruits with methanol has been studiedin heterogeneous/homogeneous systems using acid and base catalysts. The acid catalysts (strong acidcatalysts: USY, BEA, FAU-X, and weak acid catalysts: MCM-41 and ITQ-6 with Si/Al =∞) were preparedby hydrothermal synthesis procedures. In order to obtain acid–base catalysts, potassium was loadedon different materials by ionic exchange (obtaining K-MCM-41, K-ITQ-6,). XRD, ICP-MS, IR after CO andCO2 adsorption, thermal analyses and N2 adsorption/desorption techniques have been used for catalystscharacterization. The highest triglycerides conversion and biodiesel yield values were achieved by K-ITQ-6 catalysts, after 24 h of reaction at 180 ◦C. Deactivation of this catalyst occurs for potassium leaching, butits regeneration and reuse are feasible and easy to perform. A possible continuous biodiesel productionprocess has been proposed