Bio-diesel - an effective renewable alternative fuel to petro-diesel:
Bio-diesel is a renewable alternative fuel generally used in place of petro-diesel in the engines. It is a fuel made from various vegetable oils, vegetable and animal fats etc. Bio-diesel fuels can be used in diesel engines without changing them. It is the fastest growing alternative fuel in many countries. Bio-diesel, a renewable fuel, is safe, biodegradable, and reduces the emissions of most air pollutants.
Most bio-diesel today is made from oil produced from soybean, palm and jatropha seeds. Bio-diesel is most often blended with petroleum diesel in ratios ranging from 2 percent to 20 percent. It can also be used as pure bio-diesel Bio-diesel fuels can be used in regular diesel vehicles without making any changes to the engines. It can also be stored and transported using diesel tanks and equipment.
Bio-diesel and the environment:
(i) Bio-diesel is renewable, nontoxic, and biodegradable. Compared to diesel, bio-diesel is significantly cleaner burning. It produces fewer air pollutants, like particulates, carbon monoxide, hydrocarbons, and air toxics. It does slightly increase emissions of nitrogen oxides, though. Bio-diesel produces less black smoke.
(ii) Regular petro-diesel fuel contains sulfur. Sulfur can cause damage to the environment when it is burned in fuels. New environmental laws will require the amount of sulfur in diesel fuel to be dramatically reduced over the next few years. When sulfur is removed from regular diesel fuel, the fuel doesn't work as well. Adding a small amount of bio-diesel can fix the problem. Bio-diesel has no sulfur, so it can reduce sulfur levels in the nation's diesel fuel supply while making engines run more smoothly.
(iii) Bio-diesel has a higher cetane rating than petro-diesel, which can improve performance and clean up emissions compared to crude petro-diesel.
(iv) Bio-diesel can reduce by as much as 20% the direct (tailpipe) emission of particulates, compared to low-sulfur diesel.
(v) Bio-diesel is biodegradable under ideal conditions and non-toxic.
BIO-DIESEL FROM ALGAE
While a number of bio-feedstock is currently being experimented for bio-diesel production, algae have emerged as one of the most promising sources for bio-diesel production. The current oil crises and fast depleting fossil oil reserves have made it imperative to invest more into research on suitable renewable feedstock such as algae.
It is widely believed that, petroleum had its origins in kerogen, which was converted to an oily substance under conditions of high pressure and temperature. Kerogen is formed from algae, biodegraded organic compounds of plankton, bacteria and plant materials. Several studies have been conducted to simulate petroleum formation by pyrolysis. On the basis of these findings, it can be inferred that algae grown in carbon dioxide rich air can be converted to oily substances. Such an approach can contribute to solving two major problems: (a) air pollution resulting from carbon dioxide evolution, (b) future crises due to a shortage of energy sources.
Therefore, it is believed that, algae are one of the most promising feedstocks for future bio-diesel production. The advantegeous points about algae are their widespread availability, higher oil yields and pressure on cultivated land for production of bio-diesel is reduced.