Diesel Industry Injects Green Power

　　Proposed by China Petrochemical Co., Ltd. and drafted by Research Institute of Petrochemical Technology, the first national standard of biodiesel in China, Biodiesel for Diesel Fuel Blending, entered the approval process. The original biodiesel standards in China are all enterprise standards. The index setting and specific requirements of these standards are often formulated by enterprises according to their respective R&D, production and process levels, lacking common requirements. Some enterprises also directly adopt the standard of mineral diesel to produce biodiesel, but the composition and properties of biodiesel and mineral diesel are different, so controlling the quality of biodiesel with the standard of mineral diesel will cause many problems.
　　
　　Biodiesel is a real green energy, and the industrialization of biodiesel in China is in its infancy, facing many problems. Among them, there must be a basic answer to what requirements biodiesel needs to meet, which is exactly the question to be answered in "Biodiesel for Diesel Fuel Blending".
　　
　　In recent years, the international crude oil price has been soaring all the way, which is accompanied by the rapid economic growth and rising crude oil consumption in China. According to some sources, it is conservatively estimated that the national diesel shortage has reached 50 million tons every year. In the market, demand is the driving force. As early as when the international crude oil price just showed signs of rising, some domestic enterprises began to research and develop economic and environmental-friendly raw materials, so biodiesel began to move to the foreground.
　　
　　Biodiesel industry is easily accepted by the market because of its high technical maturity and good compatibility with existing oil transportation and distribution facilities. Although it can’t completely replace petrochemical diesel, it is still strongly supported because of its various advantages.
　　
　　However, although the technical path is feasible and countries such as Europe and America have been developing and encouraging the use of biodiesel, the industrialization of biodiesel in China, which is in its infancy, is also facing many problems. The national standard "Biodiesel for Diesel Fuel Blending" is trying to solve these problems, which will be of great significance to promote the industrialization of biodiesel.
　　
　　National standard of biodiesel: stand on tiptoe to reach it.
　　
　　According to Professor Zhang Yongguang, the drafter of the national standard of Biodiesel for Diesel Fuel Blending and director of the fuel oil products and additives research office of the Research Institute of Petrochemical Technology, the national standard of biodiesel in China includes 17 technical requirements and limits, namely, density: 0.82 ~ 0.90 kg/m3; The minimum value of kinematic viscosity is 1.9mm2/s and the maximum value is 6.0mm2/s; Flash point above 130℃; Cold filter points are reported; Set two indicators for sulfur content, namely, no more than 0.05% and 0.005%; 10% of the residual carbon of the steam residue is not more than 0.3%; Sulfate ash content is not more than 0.02%; Water content 0.05%; No mechanical impurities are allowed; Copper corrosion is not greater than grade 1; Cetane number is not less than 49; The oxidation stability is not less than 6.0; The acid value is not more than 0.80; Free glycerol does not exceed 0.02%; Total glycerol does not exceed 0.24%; 90% recovery temperature does not exceed 360℃. These requirements take into account that the use of biodiesel in China is mainly blended with ordinary mineral diesel in the proportion of 5% ~ 20% as a component fuel. If 100% biodiesel is used, it is necessary to formulate another standard or adjust the index requirements of this standard.
　　
　　In terms of the number of indicators, there are more than 10 differences between China’s biodiesel standards and developed countries, and the specific limits are also different. Zhang Yongguang explained that the main reason is that the raw materials of biodiesel in Europe and America are mainly oil crops. Simply taking their indicators will limit the raw materials of biodiesel in China, and some indicators are not in line with China’s situation. China’s national standard for biodiesel is a relatively high standard. According to the reality of most biodiesel production enterprises in China, it is necessary to stand on tiptoe to reach the standard.
　　
　　When making biodiesel standards, Chinese enterprises mostly refer to the indicators and specific requirements stipulated by foreign biodiesel standards. For some items that are not stipulated in the national standard of biodiesel in China, Zhang Yongguang explained that high concentrations of monoglyceride, diglyceride and triethylene glycol can produce injector deposits, which may affect the low-temperature operation performance and cause filter blockage. In the process of standard formulation, after analyzing the samples of Chinese enterprises, it is found that these three indicators are far less than the limits stipulated by European standards. At the same time, as blended biodiesel, monoglyceride, diglyceride and triethylene glycol can also play the role of lubricating additives in diesel, so these three indexes are not limited in Chinese standards. Residual metals can lead to engine deposition and wear, and pump and injector failure, which increases the smoke emission of diesel vehicles and makes it difficult to start. Monovalent metals and divalent metals can be introduced into the reaction by the catalyst of transesterification. Because the metal elements have been separated from biodiesel in the post-treatment, their content in biodiesel is generally small, so it is unnecessary to limit the metal content. Phosphorus can destroy the catalytic converter used in emission control system, and its content must be kept low. Because the phosphorus content of biodiesel in China is far less than that of biodiesel in Europe and America, the standard of biodiesel in China does not require phosphorus content. Iodine value is the number of grams of iodine consumed when reacting with 100 grams of oil under specified conditions. Biodiesel with high iodine value is unstable and easy to oxidize. However, the iodine value is only a rough estimate of the stability of biodiesel, so the iodine value is not required in China’s biodiesel standards.The methanol content in biodiesel is one of the unreacted residues in the production of biodiesel. The methanol content of biodiesel after treatment is generally low, and there is no equipment for detecting the methanol content of biodiesel in China at present, so the methanol content requirement is not included in the standard for the time being. The content of methyl ester reflects the degree of transesterification, and the EU standard requires no less than 96.5%. All the biodiesel samples taken in the process of standard formulation in China meet this requirement, so the Chinese standard does not require it.
　　
　　While people enjoy the convenience brought by automobiles, they also have to endure the environmental pollution and energy pressure caused by the development of automobile industry. Under the background of global warming and rising oil prices, finding alternative energy sources has become a common topic for the development of global automobile industry.
　　
　　Some experts pointed out that vigorously developing biomass energy to replace the increasingly scarce fossil energy is one of the directions of future energy development. In China, biodiesel is becoming a new field of biomass energy development. Focus on biomass energy: the industrialization of biodiesel is heating up.
　　
　　Biodiesel is a fatty acid monoalkyl ester prepared by transesterification of animal and vegetable oils with alcohols (such as methanol or ethanol). The raw materials of biodiesel mainly come from oil crops, oil trees and fruits, oil aquatic plants, animal fat, waste catering oil and so on. The commonly used oil crops are mainly soybeans and rapeseed, the fruits of oil trees are mainly oil palm and Pistacia chinensis, and oil aquatic plants mainly refer to engineering microalgae. These animal and vegetable oils and fats react with low-carbon alcohols such as methanol or ethanol in the presence of acid or alkaline catalyst and at a high temperature of 230~250℃ to produce fatty acid methyl ester or ethyl ester, which is then washed and dried to obtain biodiesel.
　　
　　Biodiesel was born in Germany in 1988. In 2005, the 15 member States of the European Union produced more than 2 million tons of biodiesel, accounting for 90% of the world’s total biodiesel. Germany is currently the country with the largest biodiesel production in the world.
　　
　　China began to produce biodiesel in 2001. At present, there are dozens of enterprises producing biodiesel in China, with an annual output of over 100,000 tons. China’s biodiesel is rich in raw materials. According to Chu Fuxiang, vice president of the Chinese Academy of Forestry, there are more than 600 common woody oil plants in China, with a total area of over 6.66 million hectares and an annual output of more than 2 million tons of seeds. Among them, there are dozens of kinds of seeds whose oil content reaches or approaches 50%, mainly including Jatropha curcas, Pistacia chinensis, light bark, Xanthoceras sorbifolia and so on. According to a study by the Bioenergy Research Center of Tianjin University, there is only one waste oil resource in China, with an annual output of 401,000 tons. The research and production of biodiesel in China is relatively late, but it has made rapid progress. From the distribution, selection, cultivation and genetic improvement of oil plants to the processing technology and equipment manufacturing, it has been industrialized. Companies in Hainan, Sichuan and Fujian have successively developed biodiesel production technologies with independent intellectual property rights, and successively built biodiesel production plants with a scale of over 10,000 tons. In 2005, the national special agricultural and forestry bioengineering project determined that the annual production capacity of biodiesel in China would reach 2 million tons by 2010 and 15 million tons by 2020.