Chemistry Biodiesel Essay

Submitted By robstar1997
Words: 1167
Pages: 5

6/7/2013

Introduction With the accumulating amount of the consumption of non-renewable fossil fuels, the amplified amount of pollution in the atmosphere and the enhancement of the greenhouse effect, one of modern society’s greatest challenges to find is an unconventional resource other than to burning these fossil fuels. A safe and economical alternative to the use of oils and petroleum can be found in the use of biodiesel. Biodiesel is a domesticated fuel designed for the use within diesel engines. It is manufactured from the use of agronomic co-products and by-products; these may consist of all natural oils and even greases. The reasons I believe that biodiesel is the best alternative compared to the ever decreasing amount of today’s petroleum and diesel fuels are that of:
As biodiesel is made of all agricultural and renewable by-products, it is safe in terms of the environmental considerations. But only has a slight decrease in both the energy density and all the other energy components compared to diesel. But on that note, biodiesel acquires a component in its molecular structure known as the ether group (meaning to contain oxygen atoms) which helps the process of combusting the burning of fuel more efficiently causing less harmful gases to arise from the gas pipes.
Provided your car runs on the use of diesel fuel, (given that it acquires a new fuel filter model) no modification will be required to use any Biodiesel, from B2-B100 (the number indicates the percentage of biodiesel to that of ordinary diesel fuel) as it has an almost identical molecular structure to that of diesel.
Biodiesel is easy to produce/find fuel, and although it is slightly more expensive per gallon than that of diesel, along with it being able to be reused, there are large amounts of biodiesel being processed around the world, including a large processing site for the creation of biodiesel in the Perth metro area.

The Components of Biodiesel
As stated in the introduction, Biodiesel contains soybean oil, all natural oils (vegetable oil etc.), and natural greases along with some animal fats. Biodiesel can also be blended with regular diesel for an increase in the fuels energy capacity. A blend in which many car manufacturers use in this day and age is that of B20, (20% Biodiesel, 80% regular diesel) which may not be using a lot of Biodiesel, but at the same time is saving a moderate amount of regular fuel and releasing much cleaner gas fumes into the airways.
The reason Biodiesel can run in a diesel fuelled engine is because of the similarities that the two hold in both their molecular structures, shown below.
Biodiesel molecular structure
A typical molecule of biodiesel looks like the structure below. Mostly it is a long chain of carbon atoms, with hydrogen atoms attached, and at one end is what we call an ester functional group (shown in blue). (http://www.goshen.edu/chemistry/files/2010/10/biodiesel-molecule.jpg)

Regular Diesel molecular structure:
Notice that regular diesel also has the long chain of carbon and hydrogen atoms, but doesn’t have the ester group shown in blue above. (http://www.goshen.edu/chemistry/files/2010/10/diesel-molecule.jpg)

But Biodiesel is not just found in the ground, it is made in a process called transesterification. To do this, we must begin with the component of vegetable oil. Below is what a regular vegetable oil molecular structure looks like: (http://www.goshen.edu/chemistry/files/2010/10/veggy-oil-molecule.jpg )

As it can be seen, the molecular structure of vegetable oil is almost identical to that of biodiesel, except only three times as large. (Fact: Vegetable oil used to fuel engines before other oils and fuels had come into place, but due to its large molecular structure, it turned into a thick gel when the temperature lowered. Converting it into biodiesel makes it a smaller molecule, closer to the size of regular…