Process for recovery of glycerol from biodiesel production streams

A process for treating a glycerol solution comprising fatty acid soaps obtained in a biodiesel production process, the process comprising the following steps:

• i. acidifying the glycerol solution with a concentrated acid under agitation to a pH in the range of from 0.5 to 2.5 and at a temperature of from 65 to 100° C., and allowing the mixture to phase separate into a first phase comprising free fatty acids;
• a second phase comprising a glycerol solution, and a third phase comprising salt and water;
• and
• ii. gravimetrically removing the free fatty acid phase and the salt phase from the glycerol solution, to obtain a glycerol enriched phase, and
• iii. adding a diluent to obtain a diluted glycerol enriched phase;
• iv. neutralizing the diluted glycerol enriched phase by addition of a base to obtain an aqueous phase comprising salts, and a glycerol enriched, neutralized and diluted phase, and
• v. gravimetrically separating the aqueous phase and the glycerol enriched, neutralized and diluted phase.