Hi fellas, I was drawn back into this work of ours amidst the crash of 'Unity Group' a network marketing company believed to have been promoted by political leaders and government officials at high posts. I thought it was better to pour light on the topic that was causing much controversy. So here goes the Op-Ed, 'Prospects of Jatropha oil as Diesel Substitute', though it didn't got published on paper.
Recent doom of the Unity Group has highlighted several aspects of the company and its so called fairy plans to make it seem a financially feasible one. One of the prospects of high returns as pointed out by the group is its investment in farming a shrub ‘Jatropha Curcas’ and subsequent marketing of its oil as petroleum diesel substitute. It is contextual to bring upon facts about this shrub and oil with reference to the National Research Project Titled ‘Study on the use of Jatropha Oil: A Possible Solution to the Present Fuel Crisis 2009’ undertaken by Department of Industrial Engineering, Thapathali Campus and sponsorship of Alternative Energy Promotion Center and Nepal Oil Corporation, Government of Nepal in the year 2009. The project was carried out by nine of the then students of Industrial Engineering under the supervision of Associate Professor Er. Om Bahadur Shrestha.
· Jatropha – Botanical Details.
Jatropha is a perennial small tree, 3 to 6 meters tall found in tropical and sub-tropical regions of Nepal, up to an altitude of 1400 meters. It is known by different local names in different parts of Nepal such as ‘ratanjot’, ‘baghandi’, ‘sano kadam’, ‘nimtel’, etc. With more than two hundred species of Jatropha in the world, the species found in Nepal are limited to only three namely, Jatropha curcas L., Jatropha glandulifera Roxba and Jatropha gossypifolia L. Among the three species, Jatropha curcas L. is the most abundantly grown one. A single plant in average produces about 5-10 kilograms of seeds per year and lives for about fifty years. One kg of dried seed has been found to yield 200 ml of oil.
· Jatropha Oil- Chemical Property
Jatropha oil commonly refereed to as biodiesel chemically consists of hydrated mono alky esters of fatty acids. The main chemical properties of it to be considered before using it as a fuel in diesel engines are Kinematic Viscosity, Flash Point, Acid Number and Cetane Index. These properties of pure Biodiesel and its 10 and 20 percentage blend with diesel (commonly called B10, B20) were tested at Shreeram Institute of Industrial Research, Delhi India.
Pure Jatropha oil has been found to have much higher kinematic viscosity value than the diesel. Fuel viscosity controls the characteristics of the injection from the fuel injector (droplet size, spray characteristics etc.) inside the engine. Conventional engines are designed to operate on Diesel, a low viscosity fuel so it is out of question that Jatropha oil alone be used in the existing engines with out any significant modifications. However B10 and B20 samples showed only negligible rise in kinematic viscosity as compared to diesel.
Flash points are concerned with ignition temperature of the fuel inside the engine. Pure Jatropha oil has been found to have high flash point and its blends with diesel have show a drastic increase in the flash point as compared to pure diesel.
Increased flash point in B10 and B20 mixture pose no harm in engine operation. Instead B10 and B20 fuels are safer to store and transport than diesel which has a very low flash point.
Acid number is concerned with the corrosiveness of the fuel. Pure Jatropha oil has been found to have high acid number and is bound to corrode the rubber sealing in the piston ring of the engine. Cetane index measures the ignition quality of the fuel. Higher the Cetane index, better the fuel. Pure Jatropha oil has been found to have lower Cetane index than diesel have but its B10 and B20 blends show negligible changes in Cetane index compared to pure diesel.
· Engine Performance
Satisfactory results have been found in running three different engines during the research period. Two stationary engine viz. a diesel generator and a diesel pumps have shown similar results as of diesel while blending 10% and 20% Jatropha oil in the diesel in terms of average fuel consumption and power output. Road tests done on a Toyota Land Cruiser showed smaller increase in mileage when fuelled with B10 and B20 mixture than when fuelled with diesel.
· Emission Characteristics
The emission tests of stationary engine fueled with B10 and B20 conducted at the Department of Automobile Engineering, Thapathali Campus has shown some encouraging results. Bio diesel blends show significant decrease in Light Absorption Coefficient Value (K Value), a parameter used by government of Nepal to determine the pollution levels of diesel engines. B10 mixture exhibited a Light Absorption Coefficient Value of 2.1 which is 30% lower than the standard value prescribed by the government to pass the emission test of diesel engines.
The research has concluded that up to 20% of Jatropha oil can be readily mixed in petroleum diesel without any modification in the engine and without any compromise in the mileage and engine performance. Instead this can reduce the pollution levels of the exhaust by up to 30 %. The economic viability study of the Jatropha oil done during the project shows that with mass productions of the Jatropha seed through extensive farming, per liter of the oil costs about rupees 50 at today’s price. It is worth noting that even 20 % replacement of the diesel fuel can save a significant amount of our outgoing foreign currency, lessening our dependency to third country for petroleum products. Still it is to be noted that higher blends of Jatropha oil definitely need engine modification and much research is needed before thinking about their use. Complete substitution of diesel by Jatropha is still a daydream for the time being.
· J
Bibliography
· R Report on ‘Study on the use of Jatropha Oil: A Possible Solution to the Present Fuel Crisis 2009’, Institute of Engineering, Thapathali Campus, Tribhuvan University
· Indian Standard Specification for diesel fuel (HSD and LDO), IS: 1460-2000
· D. Ramesh and A. Sampathrajan, Investigations on Performance and Emission
· Characteristics of Diesel Engine with Jatropha Bio diesel and Its Blends, Agricultural Engineering International: The CIGR Ejournal Manuscript EE 07 013, Vol. X, March, 2008
Increased flash point in B10 and B20 mixture pose no harm in engine operation. Instead B10 and B20 fuels are safer to store and transport than diesel which has a very low flash point.
