Biodiesel production alternative fuel

Cardoso, A. L., S. C. G. Neves M. J. da Silva (2009) Kinetic study of alcoholysis of the fatty acids catalyzed by tin chloride (II) An alternative catalyst for biodiesel production. Energy Fuels, 23,1718-1722,ISSN 0887-0624. 

The first biodiesel initiatives were reported in 1981 in South Africa and in 1982 in Austria, Germany and New Zealand. Since then, the production of this alternative fuel has seen enormous developments, particularly in Europe, where it reached 5.7 millions tons in 2007. It is expected to increase further to fulfill the recent decision of the European Parliament to substitute 10% of transport fuels with biofuels by 2020. According to assessments of the European Community, to reach this target, the production of bioethanol, biodiesel and second-generation biofuels should reach 36 Mtep (tep = tonnes equivalents petrol) in 2020. 

Biodiesel is presently making the transition in many countries of the world from a research curiosity to an accepted alternative to petroleum-based fuel. Europe is the leading region for the production and use of biodiesel, with an estimated 2001 output of 757-million L. Biodiesel production in the United States in 2001 was estimated at 79.5-million L. Production and consumption are rapidly increasing worldwide, with estimates of combined US and European output in 2003 at around 1,628 million liters (144). Present and anticipated use constitutes but a fraction of... 

One impediment to the cultivation of jatropha for the production of bio-fuel is that it would threaten the growing of food crops and the technology of commercial biodiesel production plant is not yet readily available on the market. However, the area of land that would be brought under jatropha cultivation during the initial years would not yield adequate quantities of seeds for a trans-esterification unit to operate economically. Farmers, on the other hand, would not go in for jatropha cultivation on a commercial basis without being assured of a reliable market. Clearly, it is necessary to find alternative uses for the oil in its natural form (i.e., without trans-esterification), for which a large quantity of the oil can be used for soap making. 

The energy balance for the production of an alternative fuel can be enhanced if the byproducts are used to produce some of the energy required to produce the fuel. For example, if the soybean meal or the glycerin were burned to provide process heat for the conversion of soybean oil to biodiesel, this would improve the overall energy balance. Currently, the economic value of these byproducts is higher for use as animal feed and other products than for use as fuel. 

The annual biofuel production was about 40 billion 1 in 2006, 90 % of which was bioethanol, the rest in the form biodiesel. Some properties of these alternative fuels are described in the next paragraphs. 

Hundred years after the discovery of Rudolph Diesel s motor, scientists evaluate the possibility to obtain alternative fuels, similar to Diesel fuel. It is well known that several fuels are chemical materials normally employed in simple and complex chemical processes. Biodiesel is comprised of esters that are derived from the transesterification of oils and fats with alcohols and has emerged in recent years as a great potential complementary resource to petroleum-based fuels and derivatives. Rudolf Diesel predicted that the use of vegetable oils for engine fuels may seem insignificant during his time but could become as significant as petroleum and coal-tar products in the future [10],... 

The use of methanol offers the best results in the trans-esterification of oils and fats. Compared with other alcohols, methanol requires shorter reaction times and smaller catalyst amounts and alcohol/oil molar ratios [10,12,15,16,51,52]. These advantages lead to reduced consumption of steam, heat, water, and electricity, and use of smaller processing equipment to produce the same amount of biodiesel. Biodiesel applications continue to expand. Thus, in addition to its use as fuel, biodiesel has been employed in the synthesis of resins, polymers, emulsifiers, and lubricants [53-64]. Concerning the range of applications, new biodiesel production processes should be considered as alternatives to the production based on methanol. Currently, methanol is primarily produced from fossil matter. Due to its high toxicity, methanol may cause cancer and blindness in humans, if they are overexposed to it. Methanol traces are not desired in food and other products for human consumption [15]. In contrast, ethanol emerges as an excellent alternative to methanol as it is mainly produced from biomass, is easily metabolized by humans, and generates stable fatty acid esters. Additionally, fatty acid ester production with ethanol requires shorter reaction times and smaller amounts of alcohol and catalyst compared to the other alcohols, except methanol, used in transesterification processes [11,15,16]. 

As an alternative to fossil fuels, vegetable and animal fats can be used as efficient alternatives. Apart from the preparation of food and feed, vegetable oil and animal fats have a potential market for biodiesel production. Using the biorefinery concept, fat and oils provide a large platform in the synthesis of glycerol, fatty acid methyl esters, soaps, paints, candles, bioplastics, lubricants, and many other value-added products. 

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