| With the increasing of acute crisis of global energy, bioenergy as an ideal renewable energy, more and more attention is paid around the world. Biodiesel is an environment-friendly "green energy", an ideal alternative to petroleum diesel, which has great strategic significance for relieving two major problems of energy shortage and environmental pollution that the world is facing. The theoretical and experimental research was carried out about the reaction system of biodiesel produed from Jatropha oil. The optimization of technical condition, thermodynamics and dynamics of system were studied deeply. At the basis of analysis by synthesis, the equipment of pilot-scale production of 300-500t/y of biodiesel was designed and the research of pilot-scale production was carried out. The foundation of production of large-scale is layed for biodiesel from Jatropha Curcas oil and other materials.1) For the lack of basic thermodynamic data of producing biodiesel from Jatropha oil in reaction system. The estimation methods of physical properties is established which based on group bond contribution, as well as, the query system of physical property data based on VB programming is established. The essential data is provided for the research of thermodynamics, the optimization of technical condition of preparing system of biodiesel from Jatropha Curcas oil, as well as the design of the equipment of pilot-scale production.2) The central composite rotating was used to design experiment and response surface methodology was used to optimizing technolgy of reducing acid continuous gas-phase esterification reaction for Jatropha Curcas oil of high acid values. The relative error of verification test is 0.66%in the condition of optimization. The result demonstrates that it is reliable and accurate, the process conditions of continuous reducing acid by gas-phase esterification reaction for Jatropha Curcas oil of high acid values optimized by response surface method.The equilibrium properties of liquid-vapor which was composed of methanol and water in the presence of Jatropha Curcas oil fatty acid methyl ester shows that, the boiling point of the system is rising along with increasing acid value of Jatropha Curcas oil in liquid-liquid system of methanol and water. The mole fraction of methanol in the liquid phase is also increasing in liquid phase but the mole fraction of methanol in the gas phase is decreasing. The average deviation of temperature for methanol-water in the presence of different acid value of jatropha Curcas oil is 0.12%associated with Wilson equation, as well as, the average deviation of the vapor phase composition is 0.16%. These result sated the calculation results of Wilson model is in good agree with the experimental data. Through theoretical calculations, the AHθof esterification reaction is less than zero between methanol with mixed fatty acids from jatropha Curcas oil at a temperature in the range of 50 ℃ to 100 ℃, the standard Gibbs free energy is less than zero indicates that the esterification reaction within the above temperature range may occur spontaneously. In this temperature range the equilibrium constant is substantially constant, it indicates that the esterification reaction is essentially thermal equilibrium, as well as the temperature had little effect on the equilibrium.The suggestion on optimization about the continuous reducing acid by gas-phase esterification reaction for Jatropha Curcas oil of high acid values is followed:the reaction temperature need is increased when the acid values is verry higher of reaction material, and it may is reduced step by step along with the achieve of esterification reaction. Thus it is realized for the purpose of improving of the efficiency of drop acid and economy of energy consumption.The reaearch of kinetic shows that, under optimal technical conditions of the rate of methanol vapor is 5.94L-min-1and the amount of p-toluenesulfonic acid catalyst is 5.0%, the kinetic equation of reducing acid continuous gas-phase esterification reaction for Jatropha Curcas oil of3) The optimization of technical condition, thermodynamics and dynamics of preparing biodiese by continuous transesterification under ultrasonic assistant and pressure were studied in the paper, the optimal technical conditions is followed:6.71:1 ratio of methnol to oil,55.7 ℃ of temperature,1.36%of catalyst dosage,0.26Wcm-2 of power density of ultrasonic and 0.35MPa of pressure. The relative error of verification test is-0.53%in this condition of optimization. The result demonstrates that it is reliable and accurate, the process conditions of preparing biodiese by continuous transesterification under ultrasonic assistant and pressure optimized by response surface method.The result of thermodynamic show that biodiesel and methanol, glycerol and methanol are completely miscible respectively, while glycerin and biodiesel Jatropha Curcas oil are partially miscible. And biodiesel is slightly greater solubility in glycerol than glycerol in biodiesel. With Aspen Plus simulation software, experimental data is correlated by NRTL model and UNIQUAC model. The model parameters could be obtained at different temperatures under different systems. After the model parameters of NRTL and UNIQUAC was adjusted, the quaternary system of Jatropha Curcas oil-biodiesel-methanol-glycerine equilibrium was predicted through using AspenPlus soft. The results shows, the adjusted NRTL model parameters could be used to predict the quaternary system equilibrium.The result of thermodynamic indicates that the reaction material must be fully mixed in the beginning of the reaction, in order to make the speed of transesterification conduction rapidly in two phases. Thus the theoretical foundation could be provided that the invigorating effect of ultrasonic assistant in continuous transesterification under pressure.The reaearch of kinetic shows that, under the optimal process conditions of 6.71:1 ratio of methnol to oil,55.7 ℃ of temperature,1.36%of catalyst dosage,0.26Wcm-2 of power density of ultrasonic and 0.35MPa of pressure, the kinetic equation of preparing biodiese by continuous transesterification under ultrasonic assistant and pressure in the range of 40 ℃ to 60 ℃ is followed:4) The saturated vapor pressure of eight major fatty acid methyl esters in biodiesel from Jatropha Curcas oil was estimated according to riedel equation. The saturated of various vapor pressure fatty acid methyl esters is increased with increasing of temperature. At the same temperature, the saturated vapor pressure is decreased with increasing of saturated fatty acid carbon chain, at the same time, the unsaturated carbon of the fatty acid methyl ester is more, and the saturated vapor pressure is higher. This result provides a theoretical basis for the rectification of boidiesel through distillation methyl esters by cyclic gas. The experiment results show that 5 L-min"1 of the flow rate of N2 would be more appropriate way in this experimental condition. The purity of biodiesel product could be over 99% through operation of egmented heterotherm in the range of 160 ℃ to 260 ℃.5) The pilot-scale production of biodiesel from Jatropha Curcas oil shows that this system could realize achieved continuous production and continuous recycling of methanol, the conversion rate of raw materials is up to about 98%. The trait of production has all reached the national standards of BD100except for oxidation stability. From the point of view of energy consumption, the energy consumption is lower in the phase of the preparation of biodiesel (power consumption is 80 to 90kW·h/t), but the high energy consumption of biodiesel is existed in purification (power consumption is 700 to 750kW·h/t). It is necessary to carry out further improvements of refining process.The research results of this paper can provide a reliable theoretical basis for the design of technology and production system in large-scale production of biodiesel from Jatropha Curcas oil.
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