Biodiesel is an environmentally friendly fuel to power cars and trucks that run on diesel engine. This natural biofuel can be gotten from different natural plant sources but we shall focus on biodiesel extracted from soybean. Soybean is a leguminous crop that is high in protein and other essential nutritional components such as isoflavones, lecithin, minerals and healthy fats. However, one other novel component of soybean is soy oil which can be industrially extracted to give soy biodiesel. Biodiesel from soybean is known as soy methyl ester. It is an eco-friendly biofuel that has found increased use in diesel engines. Soybean can also be processed to give other oils such as hydraulic oils, ink, solvents and grease.
There are three common processing methods of extracting biodiesel from soybean. These methods are:
1. Continuous Pressing
2. Hydraulic Pressing
3. Solvent Extraction
We shall now examine these methods individually.
Continuous Pressing: This is a process that is carried out at high temperatures by using a screw press to extract the oil. This method gives between 4% and 6% of biodiesel oil.
Hydraulic or Batch Pressing: Hydraulic pressing is carried out at elevated temperatures. It is an intermittent operation carried out in a mechanical or a hydraulic press after the soybean have been formed into flakes and properly conditioned through heat treatment. This method is the oldest known method of processing oil seeds
Solvent Extraction: Solvent extraction process uses hexane to extract or leach oil from flaked oilseeds. It is the most commonly used method of oil extraction around the world.
Important Facts About Biodiesel
Biodiesel is an eco-friendly renewable fuel gotten from animal or plant fat. It is used in diesel engine with little or even no modification at all. Biodiesel can be blended with petroleum diesel in varying proportions. For instance, biodiesel blended with 98% petroleum diesel is referred to as B2 while those blended with 50% petroleum diesel is referred to as B50 and so on. This environmentally friendly fuel can also be used in its very pure form and this is referred to as B100.
Biodiesel is no-toxic, biodegradable and renewable. It also burns cleaner compared to petroleum diesel( emits up to 40% less greenhouse gases compared to petroleum diesel. When biodiesel is added to petroleum diesel, it increases the lubricity of the fuel thereby reducing wear and tear of engine parts and making engine components last longer.
fats and oils are industrially converted into biodiesel by a process known as transesterification. Transesterification is a process where alcohol catalytically(facilitated by a catalyst) breaks down fats and oils into methyl esters. methyl esters are the biodiesel gotten from this process.
Biodeisel is finding increasing use across the world especially as we try to find solutions to climate change. Europe tends to have a higher concentration of biodiesel plants which may be due to the large demand for diesel across the continent compared to other places on the globe. In the US, soybean has remained the main source of biodiesel. However, if current demand for renewable fuels are to be met, then other sources must be exploited such as used vegetable oil, palm oil and cotton seed oil.