Since the discovery of coal and petroleum, mankind has never stumbled in the path of success until today where there is severe decrease in oil reserves and increase in petroleum prices worldwide. But man with a will to succeed has carried out a major breakthrough to quench his need for energy-the discovery of biofuel. Biofuel are the fuels derived from organic sources which obtain their energy from carbon fixation. With the added advantage of producing less pollution as compared to conventional petroleum they are also sustainable. The ongoing research divides biofuel into 2 generations based upon their discovery and stage of development. But biofuel faces the controversy of being too competitive with live feedstock before being a major fuel source for the world.
First generation biofuel
These biofuel comprising bioalcohol, green diesel, biogas, biodiesel and solid biofuel are obtained directly from plant and animal products like vegetable oil, starch and sugar.
Bioalcohol forms the major bulk of biodiesel used over the world and can be obtained from the fermentation of a wide variety of organic materials. While corn and sugarcane form a major part of these crops; wheat, molasses and sugar beets also add up to the list. The major disadvantage of using corn and sugarcane as a source of biofuel lies in their utility as food-stock and the highly expensive extraction procedure involved. Sugarcane though has enabled countries like Brazil to become independent in terms of energy requirement, it is still not that prospective for majority of the places in the world. Apart from few, sugarcane is simply not sufficient to handle the teeming demand of the world!
Soy has been used as a biofuel for several years as jet fuel and biodiesel. The fact that soybean forms a staple diet of many vegetarians around the world; scientists are reluctant to utilize it for commercial fuel production.
Biodiesel is obtained from a variety of plants such as Jatropha, rapeseed and Camelina and also from animal fat by implementing a method known as Trans-esterification. Pure biodiesel (B100) constitutes the lowest emitting diesel fuel in market today. Jatropha in addition to not being a food crop in contrast to soy, corn and sugarcane replenishes the fertility of the soil and is only grown in dry areas. Rapeseed, obtained from commonly found Canola plant, despite being cheaper, cleaner than petroleum requires a larger area under cultivation thus hindering its utility in the longer run. Animal fat too is somewhat feasible in comparison to both of these but isn't much efficient as a fuel source.
Methane one of the major constituents of biogas has the potential to become one of the most commercially popular biofuel. It is easily available from landfills around the world due to the action of microorganisms. Being cleaner as compared to others it forms one of the front-runners of public transport system in many countries around the world like Sweden where an entire fleet of bus already runs on methane.
Second generation biofuel
These are currently under research and comprise Algal fuel, cellulosic ethanol, biomethanol, biohydrogen diesel and the mixed alcohols. These are advanced and use sustainable feedstock for their production.
Cellulosic ethanol is produced from inedible wastes or nonfood crops and thus prevents diversion of food away from the environmental food chain. The sustainability, abundance of cellulose combined with it being the cleanest burning material makes it one of the best biofuel. Thus cellulose which can be obtained from all kinds of plant waste can be expected to be the major source powering the world economy in the next decade or so.
Algal fuels are obtained from seaweeds and pond scums which grow in water very fast. This solves two major problems of energy sources affecting the first generation biofuel- competition with food crops on land and slow rate of growth thus making it a good prospective long term alternative. By photosynthesis they store up to 50% of their body weight as fat which can be converted into fuel for their conversion to ethanol. The fast rate of growth leads to the problem of overcrowding which scientists say can be controlled over the next decade or so. Thus this makes the second most important second generation biofuel.
Other second generation biofuel are currently under research but have shown huge potential as successors to petroleum being more cleaner, energy efficient, sustainable and reliable.
About Author / Additional Info:
Maitree Baral holds a Masters in Bioinformatics and shows profound interest in sharing and discussing various aspects of biology.