| Epichlorohydrin (EPCH) is an important organic material, which has been widely used in many fields such as chemical industry, light industry, medicine and electric appliance. At present, EPCH is mainly produced by the two traditional methods including chloropropylene process and propenyl acetate process, which are high energy-consuming, environmental unfriendly and heavily dependent on petroleum industry. With the shortage of petroleum reserve and the rapid development of bio-products, glycerol, as one of the by-products of biodiesel production, has become an inexpensive and renewable material. A novel glycerol hydrochlorination process has been presented in this paper.The EPCH preparation technology from glycerol has been investigated systematically, which includes the research on hydrochlorination reaction, saponification reaction and also their separation technology involved. The main contents are listed as follows:(1) The analysis methods have been established, which can be applied to the samples for all the epichlorohydrin preparation process in this paper.(2) The thermodynamics for the binary system of EPCH-water has been studied. The liquid-liquid equilibrium (LLE) data from 293.15K to 353.15K and vapor-liquid equilibrium (VLE) data at 101.3KPa have been determined, respectively. The LLE and VLE experimental data have been correlated satisfactorily by UNIQUAC and NRTL simultaneously. Both of the two equations can be used for the simulation of extraction and distillation process.(3) The characteristics of the hydrochlorination reaction have been investigated and the factors which influence hydrochlorination process have also been discussed. The experimental results have shown that acetic acid and hexanedioic acid are suitable catalysts for hydrochlorination reaction and the appropriate mass concentration of catalyst is 5～6w/%. For the hydrochlorination reaction process, the yield of dichloropropanol(DCH) can be above 91%, the appropriate temperature is 100～120℃, and water-carrying agent can not increase the reaction yield. The kinetic model has been set up, and then the kinetic data of hydrochlorination reaction has been determined. According to the kinetic parameters obtained in this study, the kinetic equations are obtained as followed: Kinetic equation for hydrochlorination reaction catalyzed by acetic acid: Kinetic equation for hydrochlorination reaction catalyzed by hexanedioic acid:(4) The continuous hydrochlorination process has been studied systematically. The influence of temperature and space time on the reaction rate and yield are discussed. Kinetic equation for the CSTR has been correlated. On the basis of the laboratory research and theoretical analysis, pilot plant test of hydrochlorination has been carried out in three tanks-in-series reactor, the maximum yield of DCH has reached 89.3%. A calculation procedure for the hydrochlorination process of three tanks-in-series reactor has been proposed, and the results of calculations agree well with the experimental results.(5) The separation process for the hydrochlorination reaction solution, including mother liquor and condensate, has also been investigated in this paper. According to the composition of the reaction mixtures, cross-current extraction has been applied to separate DCH from the condensate, and the vacuum distillation has been used to purify DCH from the mother liquor. Octanol has been chosen as the appropriate extraction reagent, and the extraction ratio of DCH has reached about 98.4% by three-stage extraction under optimization operating conditions. The suitable operation pressure of vacuum distillation is between 20 and 40mmHg, the yield of distillation is over 96%, and the concentration of DCH is above 98%.(6)The reaction process of preparation EPCH from DCH has been investigated and the kinetic data of saponification reaction and hydrolysis reaction have been determined by conductivity method and titration method respectively. The result has shown that both saponification reaction and hydrolysis reaction are second order reactions and the saponification rate is much faster than hydrolysis rate. Based on the kinetic data, the kinetic parameters of the two reactions have been calculated, and the kinetic equations have been obtained as follows: Kinetic equation of saponification reaction: Kinetic equation of hydrolysis reaction:A calculation procedure for the saponification process of DCH has been proposed based on the kinetic equation, and the results of calculations agree well with the experimental results.(7) The continuous saponification process has been investigated. The EPCH has been prepared in a tube reactor coupling with a reaction distillation column, and the influence of temperature, space time and material proportion on the reaction rate and yield have been discussed. The optimization operating conditions of saponification process are:the reaction temperature in tube reactor is 50℃, space time is 5s, nNaOH:nDCH is 1.05, nvapor:nDCH is between 3.8 and 4.2. The saponification production has been purified by distillation, the product EPCH obtained has met the national standard.An environmental friendly circular process of EPCH has been brought forward in this paper. This research provides foundation for exploitation and design of large-scale industrial equipment to achieve economical production of EPCH in the future.
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