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With the increasing depletion of oil resources, the aggravation of environmental pollution and vehicle diesel acceleration of the trend, the countries in the world to speed up the pace of development of alternative fossil fuels. In this situation, environmental protection, renewable biofuel technology came into being. As biodiesel and petroleum diesel is very similar nature, can replace petroleum diesel, the new clean and green renewable liquid biofuels, and has a huge potential and broad market prospects. Bio-diesel (biodiesel), also known as fatty acid methyl esters (Fatty Acid Ester) is the use of vegetable oils or animal fats renewable resource system taken out of the new clean fuel alternative to fossil fuels, mainly composed of palmitic acid, stearic acid , oleic acid, linoleic acid and other long chain saturated and unsaturated fatty acids with methanol or ethanol and the like formed by the ester compound. Currently, the industry mostly uses the bio-diesel in an acid or alkali catalyst method, although the method is technically more mature, but this method there are higher requirements on the raw materials, the reaction time is relatively long, the process is more due to the saponification reaction occurred after leaving complex catalyst service life limit, product separation difficulties and shortcomings, need to find a new method for the preparation of biodiesel. Jatropha (the Jatropha curcas.L), also known as Jatropha, smelly tung tree, tung oil tree, Jatropha curcas, hibiscus, black soap tree, genus the Euphorbiaceae (Euphorbiaceae) the Jatropha (J.atropha),. Deciduous shrub or small tree, the seed oil content, oil yield up to 50%, one of China's four major woody oil plants (tallow, tea, Jatropha and walnut). Jatropha oil is toxic and can not eat, the traditional multi-chemical aspects, such as the production of paint, hardened oil, soap. Present, the main raw material for the production of bio-diesel waste oil, edible oil, thus limiting the large-scale development of bio-diesel. Jatropha oil production from biodiesel, expanding the source of raw materials for biodiesel, to meet the needs of large-scale development of biodiesel, but also to avoid the development of bio-diesel and human competition for edible oil situation. Jatropha oil as raw material, without adding any catalyst, the use of subcritical water - two-step supercritical methanol biodiesel Jatropha oil, the first step in the sub-critical water hydrolysis of fatty acids, the second step of the fatty acids in the supercritical methanol esterified fatty acid methyl ester, namely, biodiesel. The papers detailed study of the reactions in each step of the reaction temperature, reaction time, reaction pressure and the ratio of raw materials and other factors on the preparation of biodiesel. The test results using the acid value analysis, and the use of ultra-high performance liquid chromatography analysis. Draw Jatropha oil in subcritical water hydrolysis reaction conditions as follows: reaction temperature of 290 ° C, oil-water volume ratio of 1:3, the reaction time is 40min, the conversion rate of 98.9%. Hydrolysis reaction dynamics analysis, come to this hydrolysis reaction reaction order of 0.78, the activation energy is 55.34 kJ / mol, the reaction kinetics model for -dcA/dt = 7254.96e55.34/RTC A 0.78 . Jatropha oil fatty acids in supercritical methanol esterification reaction, first the single factor analysis method were analyzed according to the test results of the analysis, the use of L9 (34) orthogonal table, reaction temperature, reaction time and the ratio of fatty acids with methanol volume three factors and three levels of orthogonal experiment, the results of orthogonal test range and variance analysis, come to this esterification reaction conditions as follows: reaction temperature of 290 ° C, reaction time 30min, fatty acids and methanol volume ratio of 1: 2, and the optimum conditions optimized the verification test, the conversion rate of 99.02%. Esterification reaction dynamics analysis, come to this esterification reaction order of 1.45, the activation energy is 66.79 kJ / mol kinetic model: -dcA/dt = 5.65 × 105e66.79/RTcA1 .45. The author concludes the determination of performance indicators of Jatropha oil and its biodiesel and biodiesel In addition to the moisture content and acid value indicators, other indicators have reached the biodiesel in China national standards.
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