Methylester and Glycerin Production

EMi Group 's commitment on the construction of Biodiesel plants is based on a very specialized technical knowledge of the Biofuels production processes; in this article you will find a more detailed understanding about the process of Methylester and Glycerin Production.

Transesterification

The transesterification reaction is accomplished in continuous, using reactors in series operating under mild conditions.
The raw material is dried in flash chamber and then is continuously fed to the first reaction loop. Catalyst is continuously dosed. The Methanol is fed to the reaction unit in a proper excess.
The separate glycerin is rich in soap and is directly sent to the glycerin treatment.
The light phase outgoing from the head of the first reaction loop is transferred to the second reaction loop after the addition of fresh methanol and catalyst.
The light phase coming from the top of the second reactor is transferred to the third reactor with addition of methanol and catalyst. The third transesterification reactor is a stirred vessel.
The glycerin separated at the bottom of the second separator, relatively rich in methanol and catalyst, is recycled to the transesterification unit.
The reaction mixture leaving from the third reactor containing the product (Methylester), the excess of methanol and the glycerin (reaction by-product) and a limited amount of soaps is sent to the Methylester purification section.

Methylester / Glycerin Separation

The reaction mixture coming from the third reactor is transferred to a gravity separator after a partial flash of the contained methanol; it is then to the vent condensation section.
The methanol is condensed in the exchanger and sent directly to the dry methanol holding tank from where it is recycled into the process.
The settled glycerin containing glycerin, part of the excess of methanol and almost the total amount of soaps is sent to the hold up tank and then is finally sent to glycerin treatment unit.
The Methylester phase is washed with water added up with citric acid.
The washed Methylester is sent to the Final Methylester/Glycerin centrifugation

Final Methylester / Glycerin Centrifugation

The washed methylester is partially heated before entering the centrifugal separator.
The water/glycerin phase coming from centrifugal separator is sent to glycerin treatment.
The Methylester coming from the centrifugal separator, free of glycerin, catalyst and soap has to be dried to remove the remaining water and methanol and is sent to Methylester Purification Section.

Methylester Purification/ Flash of Methanol

The Methylester is heated before going to the final methanol flash drum where the contained water and methanol are removed.
The Methylester coming from the flash drum is transferred to storage.
The wet methanol evaporated inside the flash drum is condensed and sent to the methanol rectification unit.

Vent Condensation and Recovery Unit

This unit consists of a vent header and a scrubbing system.
The unit is designed in order to condense all emergency vents from the upstream production unit.