Transesterification Biodiesel Production: The Chemical Process and Transesterification Definition

In 1853, scientists E. Duffy and J. Patrick started the first transesterification biodiesel production of the oils that were extracted from the vegetables or fats that came from animals. On August 10, 1583, Rudolf Hitler rode the first vehicle powered by the biodiesel, the product that came from transesterification.

What is transesterification?

It is the chemical process of converting vegetable oil into biodiesel. The animal fats and vegetable oils coming from canola, soya, jatropha, algaea, sunflower seeds, among others are used in transesterification definition.

This process utilizes a kind of alcohol like methanol or ethanol, in the existence of a medium like potassium hydroxide or sodium hydroxide, to break down the molecules of the untreated renewable oil into ethyl or methyl esters. This reaction produces a by-product, the glycerol. These ethyl or methyl esters are called biodiesel. Biodiesel has the chemical name of fatty acid alkyl esters.

The main ingredients that are used to produce biodiesel are animal fats or vegetable oils. The vegetable oils, which are the triglycerides that make up the three fatty acid chains, are bound together by glycerol.

Glycerol is the chemical name of "glycerin", a kind of alcohol. If the alcohol methanol is utilized in a chemical reaction, they are able to form "methyl esters". If the alcohol ethanol is used, they are able to form "ethyl esters". These two compounds are types of biodiesel fuels that have diverse chemical combination. In this chemical reaction, glycerin is replaced by alcohol.

During the transeterification process, the glycerin that has been broken down is freed as a byproduct of the process. Glycerin will either float in the surface or sink to the lower level of the vessel, depending on the stage. Centrifuges can separate the glycerin from the mixture. This whole procedure is the process of transesterification.

The biodiesel which is the product of the transesterification mechanism has less thickness, making it the best substitute for diesel. Petroleum is not a component of biodiesel, but the mixture of the two produces biodiesel blend. The positive effects of biodiesel to the environment are many. The biodiesel used as fuel do not emit toxic smoke and is biodegradable.

As soon as the biodiesel and the glycerin are separated, the biodiesel will go through a process of purification. The catalyst and the remaining alcohol are removed. They are dried and are stored for future use.

" To make sure that the biodiesel is clear, colorless, and odorless and without sulfur, a distillation technique may be used ".The byproduct of transesterification or glycerin has a variety of uses. All the products from the transesterification processes are useful, nothing is wasted.

Plants and animal fats are usually made up of triglycerides that are esters which contain three fatty acids and glycerol, the trihydric alcohol. In the process of transesterification of biodiesel, the alcohol that is used is deprotonated by using a base in order for it to be a stronger nucleophile. The methanol or the ethanol is the common alcohol forms that are used in this process. It is clear; the reaction contains only triglyceride and alcohol as their inputs.

The majority of biodiesel chemistry is made from pure vegetable oils which utilizes the base-catalyst method simply because it is the cheapest process for the treatment of pure vegetable oils. This method requires low pressures and temperatures and produces more than 98% in terms of conversion yield. This is done if the starting oil has low moisture and has free fatty acids. But biodiesel created from other methods or sources may need acid catalyst which is definitely much slower.

Using the base-catalyst method, however, posts some problems. The method utilizes high energy. There is a difficulty in the resurgence of glycerol after the chemical reaction. There is a post-reaction treatment needed to take out the catalyst apart from its product – the biodiesel. There are interferences that are called upon by the occurrence of free fatty acid and water that surfaces during the chemical reaction. An acid is developed, together with the heterogeneous systems and catalysts. These catalysts need continuous reactors in order to run. This translates to a lot of dollars needed to produce biodiesel.

" Biodiesel is one of the alternative sources of fuel ". It is natural and produces no pollution. A lot of studies are being conducted to promote the use of this fuel. This fuel can be created through the process of transesterification.