Benefits of Bio-Diesel

Bio-diesel is the only 'drop in fuel' replacement for existing fuel types. In a mineral blend bio-diesel does and in not require any modifications to be made to the vehicle and in a 95.5 blend actually improves fuel efficiency. Using vegetable and animal oils, either pure or used, means, that not only is the main raw material renewable, it also contributes to environmental issues by using up residual oils and the new crops absorb CO2 gases created while burning the fuel in a diesel engine. By adding bio-diesel to mineral oil supplies, we will be able to extend the existing fossil fuel reserves.

BIODEGRABILITY

Bio-diesel has desired degradation attributes, which makes it a fuel of choice by environmentally conscious people. The studies at the University of ldaho compared the biodegradation of bio-diesel in an aqueous solution to diesel fuel and dextrose sugar. Bio-diesel samples degraded more rapidly than dextrose and were 95 per cent degraded at the end of 28 days. The diesel fuel was 40 per cent degraded after 28 days.

NONTOXICITY

Impact on human health is a significant criterion when considering the suitability of the fuel for commercial applications. It has been found that bio-diesel is less toxic than diesel fuel. The acute oral LD 50 (lethal dose) is greater than 17.4 g/kg body weight. By comparison table salt is nearly ten times more toxic.

EMISSION REDUCTION

The use of bio-diesel in a conventional diesel engine results in substantial reduction of unburnt hydrocarbons, CO and particulate matter. The use of bio-diesel reduces the solid carbon fraction of particulate matter (since oxygen in bio-diesel enables more complete combustion of carbon dioxide) and eliminates sulphur fractions in the fuel.

FLASH POINT

The flash point of the fuel is the temperature at which the fuel will ignite when exposed to a spark or a flame. Specific testing at the South West research Institute has concluded that the flash point of bio-diesel blends increases as the percentage of bio-diesel increases. Therefore, pure bio-diesel and the blends of bio-diesel with petroleum diesel are safer to store, handle and use than conventional diesel fuel. Neat bio-diesel has flash point over 300 F, well above the flash point of petroleum base diesel fuels.

HEALTH EFFECTS

Evidence does exit which indicates that diesel particulate matter is a potential carcinogen. In 1988, the National Institute of Occupational Safety and Health recommended that whole diesel exhaust be regarded as a potential occupational carcinogen, as defined in the Cancer Policy of the Occupational Safety and Health Administration. The use of bio-diesel decreases most regulated emissions. Research result indicates that the particulate matter, hydrocarbon and CO are significantly reduced. In addition to reducing the overall levels of pollutants and carbon, the compounds that are prevalent in the bio-diesel and diesel fuels are different. Bio-diesel exhaust has less harmful impact on human health than petro-diesel. Bio-diesel emissions have decreased levels of all target polycyclic aromatic hydrocarbons (PAH) and nitrited PAH compounds as compared to petroleum diesel exhaust. PAH and P-PAH compounds have been identified as potential cancer causing compounds.

The Environmental Protection Agency (EPA) has announced that long-term exposure to diesel exhaust will likely cause lung cancer. However, bio-diesel, a fuel usually made from soybean oil, can reduce targeted cancer-causing compounds by up to 90 per cent. The findings are the result of two years of independent studies on bio-diesel as fuel completed the Health Effects Testing Requirements of the Clean Air Act. To date, bio-diesel is the only fuel to have completed the tests.

EPA studied diesel vehicle built prior to the mid-1990s. Although current diesel technology is much cleaner than older models, the life of a diesel engine can exceed 20 years, so older vehicles are likely to operate for years to come. Bio-diesel use helps lower emissions from these vehicles.

Advantages of Bio-diesel

High Cetane number makes less noise and smooth running of engine.

It is an oxygenated fuel with higher oxygen content and gives better emission than conventional diesel.

It is an ideal synergistic partner for oxidation catalytic converter for improving efficiency.

More than 100 species of plants have been identified as source neem, karanja, jatropha etc.

Technical/Environmental Advantages

Very low sulphur content.

No Aromatics.

No net carbon dioxide emissions.

99.6 per cent bio degradability within 21 days.

Renewable source.

Socio-Economical

Rural development.

Employment generation.

Waste/arid land utilization.

Alternative fuel in diesel scarcity regions.

Bio-diesel as Transport Fuel

Bio-diesel as alternate fuel has great potential to supplement the growing demand of auto fuels.

Basically these are alkyl esters prepared by treating the vegetable oil with alcohol to produce corresponding esters,

Can be blended with diesel at any level to produce bio diesel blend for automotive application.

Can be used in diesel engine without any major modifications.

It is biodegradable, non-toxic and free of sulphur and aromatic compounds.

Potential of Bio-diesel in India

India has vast tracts of degraded lands, mostly in areas with adverse agro climatic conditions, where hardy tree borne oil seeds species like jatropha, karanja and mahua can be grown easily. Even 30 million hectares of plantation for bio-diesel can completely replace the current use of fossil fuels. Wasteland development would require an investment of about Rs 1,000 crore per year for 20 years to make India self sufficient.

The main bottleneck towards better utilization of these resources have been-

Lack of sufficient appreciation of its value.
Lack of appropriate organization to handle the job.
Scattered distribution of trees or absence of systematic plantations.
Large size of working capital required during the short collection periods.
Requirements of large labor force during the brief fruiting period.
Low wages paid to seed collectors.