What is biodiesel?
The U.S. Department of Energy defines biodiesel as a form of renewable energy which may be produced from vegetable oils, animal fats or recycled restaurant grease which may be used in diesel vehicles or any other form of machinery which is composed of a diesel engine. Diesel fuel consumption in developing countries have been showed to continuously increase over the past decades and the consumption would only grow as time progresses. This continued use of diesel fuel, a fuel derived from fossil fuels has increased the levels of pollution in the environment as it is a significant contributor of carbon dioxide in the atmosphere. Not only is diesel responsible for high concentrations of carbon dioxide in the atmosphere but it also releases some nitrogen and sulphur compounds, as well as particulate matter into the air. Considering these facts, there is a need to find another source of fuel that can be used in diesel engines which causes little or no damage to the environment.
Biodiesels have been determined to be one of the best possible alternatives to this fossil fuel based derived energy source. Research has indicated that the properties of biodiesel are similar to those of diesel fuel and it may be used in diesel engines with little or no modification whatsoever.
Environmental benefits of biodiesel
The use of biodiesel in place of regular diesel fuel can also lead to a reduction in carbon monoxide emissions, hydrocarbon emissions and particulate matter, which are substances characteristically found in the exhaust emissions of diesel engines. Vegetable oil on its own however, is highly viscous and has a low volatility which can lead to engine damage. Thus, the oil must first undergo a process known as transesterification to facilitate the start of the production of biodiesel. According to studies, vegetable oils are biodegradable, contains little to no sulfur content and the transportation and storage of these oils are easily done and poses no threat to the environment.
The problem..
There is a problem however with the use of vegetable oil as biological feedstock for biofuel production. The problem lies within the use of virgin vegetable oil and its high cost. Studies done have suggested that the use of vegetable oil as feedstock in the production of biodiesel is not an economically feasible option. Furthermore, biodiesel produced from vegetable oil actually costs more that petroleum-based diesel.
How can costs be reduced?
The idea of waste vegetable oil being used instead of the virgin oil was one method aim at reducing the price of the raw material. It is estimated to be half the price of virgin oil.
How is using waste vegetable oils beneficial to the environment?
The use of waste oil also avoids the cost of disposal and treatment and reduces the need to use land for biodiesel-producing crop. This is not only an economic benefit but also an environmental one as there would be reduced contamination of waterways from disposal of oil. Aside from this fact, waste frying oil is readily available. The U.S. records that approximately 2.5 billion pounds of waste fats are annually collected from restaurants and fast-food establishments across the country.
Is this applicable to Trinidad and Tobago?
In the context of Trinidad and Tobago, researchers found that there was approximately 67.3 million liters of edible oil available for consumption in Trinidad and Tobago of which approximately 30% is expected to go towards commercial use. These researchers recognized that the waste oil from commercial places would be a likely major source of feedstock for biodiesel production for the country.
How is biodiesel produced?
Simply put, biodiesel is synthesized by means of a chemical process known as transesterification. This process involves using adding chemical reagents potassium hydroxide and methanol after being heated under reflux to the filtered waste oil and allowing the mixture to settle for a couple days. After which, the bottom layer (glycerol) would be removed, and the remaining layer which is the methyl esters which is the biodiesel layer would be washed several times and then filtered to remove any excess water.
What the challenges faced in biodiesel production?
There are several challenges however when it comes to producing biodiesel from waste oil. Evidence from several studies have indicated that waste oils containing large amounts of free fatty acids are unable to be converted to biodiesel. Studies have also shown that when there was intense cooking for longer periods of time, the free fatty acid and acid values were higher than those restaurants which used their oil for shorter periods of time. Differences in the fatty acid composition was also linked to differences in cooking practices. It was also noted that when oils are exposed to higher temperatures in the presence of oxygen, there are numerous reactions which occur that cause changes in the alteration of the fatty acids in the oil. Additionally, it was observed that when the oil was subject to prolonged use, the saturated fatty acids may react to produce further alkanes, alkenes, carbon dioxide and shorter chain fatty acids.
In conclusion, the abundance of waste oil from restaurants makes it a readily available source, in addition to being a cost effective and environmentally friendly source of biological feedstock. More efforts should thus be put in place to encourage businesses as well as households to recycle their waste oil. Presently, there is one company in Trinidad and Tobago, Ecoimpact, which collects waste vegetable oil and trade it internationally where it is re-used it in the production of alternative fuels. Thus, we are seeing that we have the initial measures in place to start biodiesel production in Trinidad and Tobago. However, a lack of government funding, private investors and the initiative by members of the society has caused us once again to fall behind the world renewable energy technology.
I hope you enjoy reading today's blog and I hope you learnt something. Feel free to leave us your thoughts on the matter in the comments below.
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