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Study On The Synthesis Process Technology Of Cyclohexanol/Cyclohexanone From Catalytic Oxidation Of Cyclohexane With TDMPPCo

Posted on:2015-02-10Degree:MasterType:Thesis
Country:ChinaCandidate:L Y TanFull Text:PDF
GTID:2251330431952389Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
The mixture of cyclohexanol and cyclohexanone is an important chemical rawmaterial. The research on production process improvement of cyclohexanol andcyclohexanone has been praised by scientists’ attention. At present, synthesis ofcyclohexanol and cyclohexanone of biomimetic catalytic oxidation of cyclohexane withmetal porphyrin complexes as catalysts is one of the hot spot of researches. Thereinto, thecatalyst of tetraphenyl metal porphyrins can embody the higher catalytic activity, andimprove the one-way conversion rate of cyclohexane and the selectivity of cyclohexanoland cyclohexanone.Firstly, the process conditions of catalytic oxidation of cyclohexane with tetra (3,4-2methyl phenyl) metal porphyrin with Co2+(hereinafter referred to as TDMPPCo) wereoptimized. By L9(34) orthogonal test, the optimum process conditions of biomimeticcatalytic oxidation of cyclohexane has been determined. The process conditions are asfollows: reaction temperature is145℃, reaction pressure is1.0MPa, catalyst dosage is4.010-6g g-1, reaction time is90min. Under these conditions, the conversion rate ofcyclohexane is5.60%, the selectivity of cyclohexanol and cyclohexanone is up to93.82%.The appropriate separation methods of unreacted cyclohexane from the oxidation liquidunder these conditions is azeotropic distillation of adding water, it can inhibit theesterification reaction of cyclohexanol and by-products of organic acid in oxidation liquidof cyclohexane, and improve the production rate of cyclohexanol and cyclohexanone.In order to eliminate the influence of organic acid which is produced in the processof catalytic oxidation of cyclohexane with TDMPPCo to the quality of the refinedcyclohexanol/cyclohexanone, the removal conditions of organic acids in the oxidationliquid of cyclohexane has been examined. Water extraction method is used to remove theorganic acids, and the best conditions of removing organic acids by orthogonal test have been confirmed. The conditions are as follows: the extraction temperature is70℃, theoperation time is2min, the volume ratio of water and oxidation liquid of cyclohexane is2/3(ml/ml), and removing rate of organic acid is57%. After the wastewater of extraction oforganic acid concentrated, the concentrated wastewater can be directly oxidized to preparedibasic acid which it is in nitric acid of60%without catalyst and the weight ratio (massratio of concentrated wastewater and nitrate) is3:8, and the content of adipic acid is morethan78%.The feasibility of nitric acid oxidation for the products of catalytic oxidation ofcyclohexane with TDMPPCo directly used to prepare adipic acid has been confirmed. Theprocess conditions of the production of adipic acid of a two-step cyclohexane oxidation areoptimized by the orthogonal experiment. The conditions are as follows: reactiontemperature is65-95℃, nitrate concentration is55%, mass ratio of oxidizing acid with0.4%of Cu2+and400×10-6g·g-1of VO3ˉas catalyst and raw materials for oxiding is1:5.2,reaction time is180min. In these conditions, the content of adipic acid is more than85%,and the content of dibasic acid is95%. Esters content in the product of cyclohexaneoxidation has influenced on the quality of the product of nitric acid oxidation reaction, andthe best way to reduce esters content in the products of nitric acid oxidation is to controlester content in the raw material.
Keywords/Search Tags:metal porphyrins, cyclohexane, cyclohexanol/cyclohexanone, adipic acid
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