25-08-2017, 09:32 PM
Recent Trends and Applications of Bio Diesel
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Abstract
In current scenario, populations continue to increase, It will meets energy demands has become an increasing concern for world scenario and one such solution is to utilize Biodiesel as an alternative fuel is explored, along with his desirable fuel characteristics. The technological requirements for process and production of Biodiesel being comparatively less cumbersome and its ability to fuel an existing diesel vehicle with no or minor modifications also make it a promising alternate fuel and it is discussed. This report also covers attributes like emissions, feed stocks, production method, latest trends and the advantages and disadvantages of the Biodiesel. Pollution reduction is now major issue for changing world situations and it is discussed how exactly Biodiesel meet with the solution.
INTRODUCTION
India imported about 2/3rd of its petroleum requirements last year, which involved a cost of approximately Rs. 80,000 crores in foreign exchange. Even 5% replacement of petroleum fuel by bio-fuels can help India save Rs.4000 crores per year in foreign exchange. It is utmost important that the options for substitution of petroleum fuels be explored to control this rapidly growing import bill. With the stock of fossil fuels diminishing throughout the world and demand for energy based comforts and mobility ever increasing, time is ripe that we strike a balance between energy security and energy usage. Moreover having uplifted to such a sphere of engineering excellence, reverting back to the ages of the bull carts will prove next to impossible thereby compelling us to search for a variety of alternative fuels to derive energy to cater to our needs. Several sources of energy, especially for driving the automotives are being developed and tested. This report presents detailed information on Biodiesel together with its emission benefits. The prospect of Biodiesel as an alternative to conventional fuels like gasoline and diesel and the experience of other countries are also mentioned.
BIODIESEL
Biodiesel is the name for a variety of ester-based oxygenated fuels derived from natural, renewable biological sources such as vegetable oils. Biodiesel operates in compression ignition engines like petroleum diesel thereby requiring no essential engine modifications. Moreover it can maintain the payload capacity and range of conventional diesel. Biodiesel fuel can be made from new or used vegetable oils and animal fats. Unlike fossil diesel, pure Biodiesel is biodegradable, nontoxic and essentially free of sulphur and aromatics. The concept of using vegetable oil as a fuel dates back to 1895 when Dr. Rudolf Diesel developed the first diesel engine to run on vegetable oil. 2.1 Production Vegetable oils can be chemically reacted with an alcohol (methanol or ethanol is the usual choice) to produce chemical compounds known as esters. Biodiesel is the name given to these esters when they are proposed for use as fuel. Currently Biodiesel is produced by a process called transesterification where the vegetable oil or animal fat is first filtered, then processed with alkali to remove free fatty acids. It is then mixed with an alcohol (usually methanol or ethanol) and a catalyst (usually sodium or potassium hydroxide). This transesterification process can also be carried out in presence of acid catalyst. The only problem with acid catalyzed process is that it is very slow. Generally base catalyzed process takes about 2 hours for completion while acid catalyzed process is much slower than this at about 700 C.
Characteristics of Biodiesel
Density of Biodiesel is same as that of, Tat
M.E et al. (2000), conventional diesel. Biodiesel as
automotive fuel has similar properties to petrodiesel
and as such can be directly used in existing diesel
engines with no or minor modifications. It can be
used alone or mixed in any ratio with petrodiesel.
The viscosity of Biodiesel is higher, Geller D.P et
al. (2000), than that of conventional diesel. The
most common blend is B20, a mix of 20% Biodiesel
with 80% petroleum diesel. Biodiesel has 11%
oxygen by weight and essentially contains no
sulphur or aromatics. This extra oxygen contain
results in complete combustion of fuel. The use of
Biodiesel in a conventional diesel engine results in
substantial reduction of unburned hydrocarbons,
carbon monoxide and particulate matter. Emissions
of nitrogen dioxides are either slightly reduced or
slightly increased depending on the duty cycle or
testing methods. Biodiesel eliminates the sulphur
fraction (as there is no sulphur in the fuel), while the
soluble or hydrogen fraction stays the same or is
increased.
CONCLUSION
The Biodiesel program on the national level is achieved and will have a very positive impact on the upliftment of the rural economy and has very large employment generating potential. It also fulfils strategic needs of a country like India, which has large dependence on the imported crude. Bio-diesel is an attested and proven low emission fuel, which is accepted world over by engine manufacturers, is safe to handle and require no separate infrastructure for its distribution and marketing. Biodiesel is a viable alternative to petroleum diesel and has successfully introduced in several countries in the world. Price of Biodiesel is higher than that of conventional diesel; government should give subsidy to promote production of Biodiesel. So, government need to give about Rs.20 subsidy per kg of Biodiesel produced. Since, prices of vegetable oils are relatively high in Asia.