Fossil fuels have been the prime source of energy for domestic, transportation and industrial purposes for more than a century. The rapidly-increasing consumption and consequent depletion of the fossil fuel reserves clearly show that the end of the fossil fuel era is not very far. For developing countries like India, rising world prices of crude oil and petroleum is a cause of serious concern. India imports almost 70 per cent of its requirement of crude oil and in future it is likely to increase to 85 per cent.
This is high time to ponder over and to find an alternative to the fossil fuels. The green fuel biodiesel is one such alternative to partly replace the petroleum crude and be the fuel of the future.
Rudolf Diesel’s prime model, a single 10-feet (3m) iron cylinder with a fly wheel at its base, ran on its own power for the first time in Augsburg, Germany on August 10, 1893.
In remembrance of this event, August 10 has been declared the International Biodiesel Day. Rudolf Diesel demonstrated a diesel engine run on peanut oil (vegetable oil) at the world fair in Paris, France in 1900.
Biodiesel is a nontoxic; biodegradable diesel fuel made from vegetable oils, animal fats and used or recycled oils and fats. Biodiesel could be an excellent renewable fuel for diesel engines. It is derived from vegetable oils that are chemically converted into biodiesel.
The chemical process is called Transesterification. The process was developed as early as in 1853 by scientists E Duffy and J Patrick. Transesterification is the process of using methyl alcohol in the presence of a catalyst such as sodium hydroxide or potassium hydroxide to chemically break the molecule of the raw renewable oil into methyl ester (biodiesel) of the renewable oil with glycerol as a byproduct. Biodiesel, when used as a pure fuel, is known as B100. However, it is often blended with petroleum-based diesel fuel, and when this is done, the blend is designated “BXX” where XX is the percentage of biodiesel in the blend. For example, B20 is a blend of 20 per cent biodiesel and 80 per cent petroleum diesel fuel. Biodiesel can be used in the pure form, or blended in any amount with diesel fuel for use in compression ignition engines.
The total fossil energy efficiency ratio (i.e., total fuel energy/total fossil energy used in production, manufacture, transportation and distribution) for diesel fuel and biodiesel shows that biodiesel is four times as efficient as diesel fuel in utilising fossil energy (3.215 for biodiesel vs. 0.8337 for diesel).
ADVANTAGES OF BIODIESEl:
A higher flashpoint of biodiesel makes it safer to store and transport.
The higher the cetane number, the greater the probability of ignition and combustion process being initiated leading to higher engine performance.
Regular petrodiesel fuel particulates are carcinogenic. Using biodiesel fuel or blending it with regular diesel fuel can reduce the production of these carcinogenic emissions. It reduces CO, sulphates, unburnt hydrocarbons, polycyclic aromatic hydrocarbons (PAH s), particulates and NOx emissions as compared to diesel emissions.
Biodiesel can even make engines smell better. An engine powered by biodiesel actually smells like French fries! Biodiesel fuel is a good lubricant, which helps engines last longer. Biodiesel is a renewable and environment-friendly fuel. Biodiesel use helps reduce greenhouse gases. The overall ozone forming potential of biodiesel is 50 per cent less than the diesel fuel.
Biodiesel has the highest energy balance of any transportation fuel. Biodiesel degrades in the environment as fast as sugar and is 10 times less toxic than table salt. Biodiesel buses are in use in Europe and in the mid-western United States. In India successful test-run drives have been done by using biodiesel produced from Jatropha Curcas (Ratanjyot in Hindi and Baigaba in Odia). The Shatabdi train was run from Delhi to Amritsar using B5 (5% biodiesel) blend and no problem was observed during the run. Other non-edible oils like Karanja, Mahula, Neem, Kusum, etc., can also be converted into biodiesel. In India, it is a usual practice to produce biodiesel from non-edible oils.
Rapeseed and soybean oils are mostly used to produce biodiesel in the USA.
The Mercedes Benz C 220 CDI vehicle was run in various States of India using 100 per cent biodiesel by CSMCRI, Bhavnagar without any problem with a mileage of 13.5 km per litre, which is comparable with fossil fuel.
In July 2002, the Planning Commission constituted a committee for development of bio-fuels, which recommended creation of a Biodiesel Mission to coordinate the initiative and enterprise of individuals, communities, oil companies, industries, businessmen as well as Government. In October 2005, the Union Ministry of Petroleum and Natural Gas announced the biodiesel policy from January 2006.
The public-sector oil marketing companies, Indian Oil, Hindustan Petroleum and Bharat Petroleum, would purchase biodiesel from private operators at Rs 26.50 a litre. The purchase price has reportedly come from the estimates of the Planning Commission and twenty purchase centres would be set up in 15 States by the oil companies. A cell has been created as the Biodiesel Board to coordinate Jatropha cultivation and biodiesel production with a target of up to 500,000 tonnes of biodiesel per year.
There is an urgent demand for the plantation of Jatropha Curcas which can not only mitigate the unemployment problem but also solve any fuel crisis in future.
(Dr Senapati works at the Department of Chemistry, Trident Academy of Technology, Bhubaneswar)