Biodiesel Production Technology and Development of China

Abstract: The energy crisis contributed to the Development of bio-diesel industry, biodiesel production methods are: direct use and mixing, micro-emulsification, pyrolysis, transesterification. This article describes the Development of bio-diesel industry, the current bio-diesel industry Development problems, and preliminary solutions.

Keywords: Biodiesel; Development status; problems; solution
Energy is the survival and Development of modern society, an important material basis for .20 the 70 years since the energy crisis, caused by burning fossil fuels and a series of ecological crisis, a serious threat to human survival and sustainable development of society in recent years, oil consumption increases and the impact of international politics, oil prices soaring. spike in oil prices to the global economy and personal lives of a serious impact, but also to promote the world's biodiesel industry.

1, bio-diesel production technologies
Biodiesel are direct use and mixing, micro-emulsification, pyrolysis and transesterification. The first two methods is not easy because the oil viscosity is high and volatile, resulting in different degrees of the engine nozzle coking, piston rings and carbon stuck deposition and other issues. vegetable oil and animal fat in the high temperature cracking disadvantage is carried out to be the catalyst, and the reaction difficult to control, expensive equipment; and transesterification ester transfer primarily by the high viscosity of vegetable oils or animal fats into fatty acids, low viscosity ester, prepared by transesterification of biodiesel with a low viscosity, without a lot of energy and other notable features.

1.1 directly or mixed use
Directly mixed with petroleum diesel to natural oils, chemical solvents or alcohol directly to mixed use. Domestic and foreign scholars who will advance and fuel injection pressure of fuel supply adjustment, direct burning of palm oil, sunflower oil, cottonseed oil, big soybean oil, jatropha oil, vegetable oil mixed with diesel oil, good access to power, to achieve rated power. but the use of vegetable oil, cold start problems there, prone to coke combustion chamber, piston ring sticking, oil thickening and other issues.

1.2 Micro-emulsion
Microemulsion is composed of two immiscible liquids mixed with other molecules to form colloidal dispersion of gender systems, transparency, thermodynamic stability, and isotropic, the dispersed phase particle size is between 1-150nm, micro-emulsion method is the use of emulsifier is vegetable oil spread to the lower viscosity of the solvent, thus diluting the vegetable oil to reduce viscosity to meet the requirements as fuel, micro-emulsion composition containing low boiling point components, so you can improve the spray characteristics. but the engine long-term use vegetable oil emulsion carbon fuels and lubricants, viscosity appears to increase and other issues.

1.3 Pyrolysis
Pyrolysis is a substance in the catalyst, caused by the heat generated small molecules bond breaking process, vegetable oil molecular weight, molecular weight decreases the thermal cracking, to reduce the viscosity of purpose. From the polymer structure into simple organic carbon hydrogen compounds, the carbon number distribution and cold start performance and petroleum, diesel is similar but somewhat less stable. thermal cracking process complexity, equipment is large, resulting in product cost is too high, can not achieve the level of industrial production and use.

1.4 Transesterification
Transesterification for biodiesel production is the main method is the use of chemical production, which uses vegetable oil, animal oil with methanol or ethanol and other alcohols in acid or alkaline catalysts and high temperature (2300 �� -2500 ��) under esterification to generate the corresponding fatty acid methyl or ethyl, and then by drying or by washing biodiesel. However, the chemical synthesis of bio-diesel has the following disadvantages: complex process, the alcohol must be excessive, the follow-up process must have the corresponding alcohol recovery, high energy consumption , deep color. Since unsaturated fatty acids in oils under high temperature and perishable, the esterification product of difficult recovery, the high cost of production processes alkali emissions.

To solve these problems, people began to study with the enzymatic synthesis of biodiesel, the oil and alcohols by lipase transesterification to prepare the corresponding fatty acid methyl or ethyl. Enzymatic synthesis of biodiesel has a mild, alcohol with less, non-polluting emissions and so on.

Links to download http://www.hi138.com 1.4.1 free paper acid, alkali catalyzed transesterification
Acid catalyzed transesterification catalyst used more concentrated sulfuric acid, phosphoric acid and sulfuric acid are cheap, abundant resources, is the most common esterification catalysts. Acid catalyzed transesterification process yields, but the response was slow, difficult separation and easy to produce waste. Base-catalyzed transesterification reaction rate much faster than acid catalyzed more common inorganic base catalyst sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate etc., sodium methoxide is used to make biodiesel very high activity of alkaline catalyst, soluble in fatty acids, esters into full; However, if the oils containing water, methanol and sodium activity will be greatly reduced. hydroxide and methanol and sodium hydroxide relative to the price to be cheaper. In addition, the use of liquid acid or alkali as a catalyst, in the post-processing will emit large amounts of water, causing environmental pollution; and solid acid as catalyst, the product easy to separate, not only reduce costs, streamline processes, and environmental protection has become the focus of attention. now industry often natural oils as raw material to produce bio diesel. Because almost all natural fats contain a certain amount of free fatty acids, fatty acid ester is not conducive to the exchange there. Simple alkali catalyzed transesterification of fatty acid methyl esters produced big losses, too low, the general to join the acid catalyst, the raw material pre-esterification, and then add the base catalyst for transesterification.

1.4.2 Enzymatic transesterification
Traditional acid base catalysis exist complex process of biodiesel, alcohol consumed in large quantities, the product of difficult recovery, environment pollution and other shortcomings. Enzymatic biodiesel has a mild, a small amount of alcohol, the product easy to collect, clean emissions and so on. Enzymatic transesterification of biodiesel generally use the fixed bed reactor, and for the multi-stage reactor. In order to inhibit the toxic effects of methanol on the enzyme, the general three-step flow method. but it catalyzed transesterification enzyme price is high because the reaction too long, the reaction yield is low, the current application is limited.

2, the status of bio-diesel industry
2.1 The development of biodiesel in China
2001-2003 is the development of biodiesel in China before the initial phase of .2001 Shangqiu oil chemical plant in China only has a biodiesel production plant, but has not been the normal production of .2001 in September and bio by the Hainan is China's first investment in energy companies a biodiesel production plant in Hebei Wu'an formally put into operation, the restaurant waste oil plant, oil processing oil after the feet and legs, and Pistacia soap oil as raw material, designed annual production capacity of 1 million tons of biodiesel. By 2003 By the end of a total of 5 companies of biodiesel production, the annual production capacity of 9 million tons, annual output of 4-5 million tonnes, mostly raw materials and food catering companies recycling waste oil-based. To promote bio-diesel industry in China Development, Chinese Academy of Engineering in January 17, 2003 meeting "to discuss the development of bio-diesel plant materials will be." participants experts pointed out that large, stable, affordable supply of raw materials of plant bio-diesel industry, China's sustained and healthy development. plus the second half of 2003, the international crude oil prices continued to rise, and promote China's rapid development of biodiesel industry, biodiesel industry .2005 by the end of 8 enterprises, with annual production capacity of 20 tons, an increase of more than 1 times .2005 February 28, the Tenth National People's Congress passed the <<Renewable Energy Law ">, President Hu Jintao signed by the Laws be published in January 1, 2006 part of the formal implementation of large-scale biological .2006 Diesel projects have completed and commissioned the same year on June 30, China Biodiesel International Holdings Limited London Stock Exchange AIM market in the UK successfully listed. in the last two years, the domestic biodiesel industry's rapid expansion, supply of raw materials, large-scale bio- enterprises operating rate of diesel shortage expected.

2.2 The development of pure biodiesel industry issues and solutions in
Bio-diesel industry the main problem is high costs. Therefore, the use of cheap raw materials, bio-diesel production process to improve the conversion rate is to reduce the cost of the main aspects of bio-diesel, biodiesel can also determine the key practical.

In addition, the Researchers also conducted a series of lower cost of biodiesel: First of all, biodiesel raw materials, ways to open up the source, choose the cheaper raw materials: �� the production of food and catering waste oil and waste oil, swill oil as raw material; �� animal and plant oil plant oil soap foot feet and raw materials; �� more use of non-edible oils and fats as raw materials, such as jatropha, tung son, Bunge, tallow and other sub-tree oil. Secondly, in terms of production technology for different raw materials of different technology, so that production costs decrease. Finally, the national policy support. countries for modest financial subsidies and tax incentives to make biodiesel production more competitive; while developing bio-diesel development plan, great efforts to cultivate bio-diesel is the consumer market .


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