Process for producing biodiesel from acidic raw materials

A process for producing biodiesel from acidic raw materials, characterized in that it comprises:

• a) the use of acidic raw materials and triglycerides in the biodiesel production process;
• b) the integration of the esterification step via acidic and heterogeneous catalysis with the treatment of oils and fats by physical refining and transesterification for the production of biodiesel;
• c) the use of three integration points:
• at the inlet of a first transesterification reactor, at the inlet of a second transesterification reactor and at the inlet of the washing process of the product of the transesterification section;
• d) use of a fixed bed reactor to carry out the esterification step via heterogeneous catalysis;
• e) a transesterification reaction system consisting of three continuous stirred tank reactors in series;
• f) sending the glycerin to a rectifying tower, while the methyl ester is dried and rectified to produce biodiesel;
• and
• g) the methanol-rich stream is rectified to be recycled.