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Study On Separation Of Glutaric Acid From DBA And Kinetics Of Esterification

Posted on:2008-01-16Degree:MasterType:Thesis
Country:ChinaCandidate:Z B MaoFull Text:PDF
GTID:2121360215460739Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
Mixed dibasic acid (DBA) is byproduct of the production of adipic acid, and the basis of DBA is succinic acid, glutaric acid and adipic acid. Data shows that 50-60 kilograms of DBA are got per 1000 kilograms adipic acid produced. The factories often send DBA to the sewage disposal equipments or bury it in the past. In recent years, some researches on the integrative utilization of mixed dibasic acid are done by domestic institutions. So, it is practically significant to study the separation and utilization of mixed dibasic acid. In this article, the separation of glutaric acid from DBA and the kinetics of esterification are studied.In order to obtain solid-liquid equilibrium data needed in the experiments, equilibrium method and dynamic method were used to determine the solubility of separate system before making certain the separation scheme. The systems are succinic acid-water, glutaric acid-water, adipic acid-water, succinic acid-chloroform, glutaric acid- chloroform, adipic acid- chloroform, glutaric acid-toluene, succinic acid-ethanol, glutaric acid- ethanol and adipic acid- ethanol. Meantime, the separation of glutaric acid from mixed dibasic acid was projected, with chloroform used as solvent and the methods of solvent dissolution, filtration and crystal.With the method of procedural seeking optimum, the dualistic interaction parameters were obtained by putting the experimental data into matlab procedure. Then, the parameters were put into Wilson equation to forecast the solubility of every system. As a result, the average deviation of the values predicted by Wilson model from the experimental valves is 10.29%. Because the average deviation of the values predicted by separate original UNIFAC model from the experimental valves is 49.21%, it is necessary to redefine new groups. In this article, succinic acid, glutaric acid and adipic acid were separately defined as one new group. With the method of procedural seeking optimum, the volume parameters and surface-area parameters of new groups were obtained by putting the experimental data into C++ procedure, and the new interaction parameters are also obtained. Subsequently, the parameters were put into UNIFAC equation to forecast the solubility of every system. Conseqently, the average deviation of the values predicted by modified UNIFAC model from the experimental valves is 6.21%. As for the systems of this article, modified UNIFAC model outgoes Wilson model.In the estirification reaction of this article, gluratic acid and methanol are raw materials; meanwhile, phosphotungstic acid and toluene were separately used as catalyst and azeotropic solvent. The experimental scheme is designed by the method of homogeneous design. The affections of four elements on the yield of dimethyl glutarate are studied, the molecular ratio of methanol to glutaric acid, the amount of catalyst, azeotropic solvent and the reaction time, inclusive. The optimum conditions of the esterification reaction are: the molar ratio of methanol to gluratic acid is 4.0:1, the amount of catalyst is 3.0% by mass of gluratic acid, the amount of azeotropic solvent is 24% by mass of the system and the reaction time is 5h. The highest ratio of esterification is 85.79%. With moving water out or dehydration, each reaction kinetics model of synthesize of dimethyl glutarate was established. It is proved that the macroscopical reaction kinetics accords with third class irreversible reaction under the experimental conditions. The obtained macroscopical kinetics equations are shown as follow:...
Keywords/Search Tags:Succinic acid, Glutaric acid, Adipic acid, Solubility, Group contribution model, Esterification, Kinetics
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