Biodiesel is gaining importance as an alternative fuel all over the world. Thanks to the rise in oil prices and the often-occurring rifts between the middle-east oil giants and other countries, petroleum-based products are becoming too expensive to the over-consumptive western world. Biofuel is a sustainable and long-standing renewable alternative to this issue. But what is the future of biodiesel? Can animal fat form a good source of biodiesel?
Animal-fat based biodiesel: Animal-fat based biodiesel has long been ignored or sidelined in the biofuel industry. It has been given step motherly treatment compared to plant-oil based biodiesel and has been termed as a lesser-quality option. But according to scientific studies both animal fat and plant based oil contain the same chemical constituents and differ only in the proportion of the constituents. Both plant oils and animal fat (like tallow) are biodegradable, non-toxic and safe for use in diesel engines. Both reduce unburned hydrocarbons, carbon monoxide, particulates and also lubricate the engines well.
Livestock as fuel stock: When livestock is used as fuel stock, there are a few shortcomings. Many manufacturers knew about this and abstained from using animal fat in biodiesel. But with the advancement of technology, it has been proved that tallow is a slightly better ingredient than vegetable oil in biodiesel production. Some manufacturers did not adequately manage the chemistry or downstream refining of the biofuel produced and this resulted in low quality biodiesel from beef tallow. Things have changed and now we have high-quality, animal-fat based biodiesel that complies with ASTM and EN standards.
There are several reasons why tallow is better compared to plant oil based biodiesel. Below are a few:
1. Cheaper than plant oils: Soybean oil, which is extensively used in biodiesel production, costs higher than animal fat. Owing to the high demand of the oil, soybean oil price has skyrocketed tremendously so much so that manufacturers find it difficult to balance between production costs and biodiesel rates. With such increased prices, fuel producers find animal fat as a better alternative to soybean oil.
2. High cetane number: Cetane number is something which measures the ignition quality of a fuel. The higher the cetane number, the better for the vehicle. Petroleum-based diesel has a cetane number of 40 to 52. While soybean-oil based diesel has a cetane value between 46 and 52, animal-fat based biodiesel’s cetane value is between 56 and 60. Higher cetane value results in improved fuel combustion and therefore, better vehicle performance. Tallow biodiesel is better in this way.
3. More lubrication: Animal-fat based biodiesel lubricates the engine parts better than its plant-oil based fuel. With protective compounds, the fuel reduces engine wear and tear, and offers it a longer lifetime.
4. Lower combustion: With higher cetane levels, tallow biodiesel comes with reduced emissions of nitrogen oxides, particulate matter and pollutants. This makes tallow biodiesel a greener and better alternative to vegetable-oil based or petroleum based fuel.
However, there is one strong negative point against animal-fat based biodiesel and that is its poor winter performance. Since tallow is solid only at room temperature, it can lead to poor quality ignition in winter. This is a drawback compared to plant-oil based fuels which are active all time of the year. Yet extensive testing has shown that blends like B5 show no change even in cold weather conditions.