First Generation Biofuels

Biofuels are introduced as the renewable energy resource. Biofuels are borne with high potential to minimize the greenhouse gas emission compare to the fossil fuels. The feedstock is used for first generation biofuels production can be also used as the food crops. Sun flower, Jatropha, soy bean, pram, sugar cane, wheat, sugar potato and beat are examples for plants that have been used. A part including seeds, fruits or whole food plant can be used for biofuel production. Bioalcohol, biodiesel, green diesel, biogas are produced as the first generation biofuels.

Bioalcohol: It is produced from the sugar and starch rich food crops. Sugar is fermented into alcohol by microorganisms and enzymes. Bioalcohol includes methanol, ethanol and propanol.

Cereal grains are crushed to release starch. Then these starches are subjected to process called hydrolysis to convert the cellulosic biomass into fermentable sugar. Yeast is added and the solution is heated. Invertase acts as the catalyst and breaks down the sucrose into glucose and fructose. Then these glucose and fructose reacts with another catalyst, zymase to produce ethanol. Since the ethanol contain large fraction of water, the distillation process is used to remove water and increase the concentration of ethanol compare to the initial solution. The mixture of ethanol and water is heated. As the boiling point of ethanol is lower than the water, it is converted into vapor phase. Then ethanol is condensed and separated from the water. Ethanol can be used directly in the gasoline engines.

Biodiesel: it is produced from the transesterification of alcohol and oil which is extracted from the crop plants.  A mixture of methanol or ethanol and biomass containing fatty acids are mixed and reacted together in the presence of NaOH as the catalyst. Biodiesel is similar in the composition to fossil diesel. Biodiesel are fatty acid methyl or ethyl esters. Animal flat, sun flower, soy bean, pram, vegetable oil, algae are used as the raw materials for biodiesel production. Biodiesel can be used in directly in petroleum engine of mixture of biodiesel and petroleum engine can be used.

Green diesel: It is produced by using refinery methods. Large molecules found in vegetable oil are break down into small hydrocarbon chains at elevated temperature and elevated pressure in the presence of catalysts.

Biogas: It is produced through the digestion of biomass in an anaerobic digester by anaerobic microorganisms. Whole crop plants or a part of the plant, residues of crop plant and residues of other biofuel production can be used as the feedstock for anaerobic director. Here biomass is converted into methane which combustible gas. It can be directly used in vehicle engines or cooking ovens. The residue form the anaerobic digester can be further processed and used as a biofuel or can be applied as a fertilizer for agriculture.

·        Use of first generation biofuel has advantages over fossil fuels as follows.

1)    Greenhouse gas mitigation: Biofuels are burned more cleanly than fossil fuels which result in leaving small quantity of greenhouse gas emission. Use of biodiesel in vehicle is able to reduce the greenhouse gas emission by 20-60%.

2)    Renewable energy source: Biofuels can be replenished within short time period. Fossil fuel is limited in the supply. It takes millions of years to generate fossil fuel to generate in the underground. So fossil fuel cannot replenish within short time period. Therefore biofuels are one of the best solutions for limited fossil fuels.

3)    Provide employment for rural communities: Preparation of land, sawing, harvesting and processing of biofuels give opportunity form rural people to earn considerable income.

4)    Economic security: The countries where the fossils fuels were not generated as a natural resources have to export crude oils and other associated products from Middle East countries. So these countries have to pay extremely high prices for purchase crude oil and transport them into their country. The processing crude oil into fossil fuels such as diesel and gasoline is also costly. Therefore as countries can grow crops for biofuel production within their countries, it saves money of them.

·        Although biofuels are renewable energy source, it also has certain negative consequences on society, environment and economic as follows:

1)    Threat to food security: The use of food crops for biofuel generation cause the increase of the price of food and animal feed. The lands available for agriculture and fertilizers are used for the growing crops for biofuels. Thereby it reduces the agricultural production in the world. The world food supply is restricted for the developed countered for their consumption and biofuel production while poor country surfing from long time starving.

2)    High production cost: More money has to be pumped into preparation of lands, planting crops, application of fertilizers and pesticides, harvestings and processing.it can be manual or mechanical. The use of machines is more effective and cheap even though its capital cost is high.

3)    Contribution to greenhouse gas emission is considerable: Even though the burning of biofuel is more clean, use of machines for preparation of lands, sawing, harvesting is contributed to the greenhouse gas emission.

4)    The price of the biofuel is expensive: Due to the high production cost, the biofuels cannot be sold at reasonable price. Therefore most of people still rely on fossil fuels.

5)    Reduce biodiversity: Growing crops for biofuel generation is often monoculture. So it has relatively low biodiversity.  Forested areas have to be cleared to be growing food crops. So it disrupts the food webs and reduces the regional biodiversity. With the growing of crops, animals, microorganisms and plants pests can be introduced. There is high probability to spread those pests into natural ecosystems and displace the native species. The scientists tend to introduce genetically modified plant spices which are insect pest resistant and increase in energy content for biofuel production. Those GMO can spread into natural ecosystems and cross with wild species. It may cause genetic degradation.