| Plasticizers are the largest varieties of production capacity and consumption in plastic processing additives, phthalates accounts for more than90%in the consumption of plasticizers. With the increasing demand for the plasticizers consumption, the consumption of the phthalates are also in the promotion at the same time, and there is a great developmental space. But with the concept of the environmental protection, green, non-toxic, the traditional plasticizers are not suitable for the requirements of environmental protection. it is urgent to development a new kind of plasticizers, and taking one step to catalyze hydrogenation and reduced from phthalic acid ester to cyclohexane two formic acid ester is the most effective and the most efficient way, so it becomes the focus of the current research. cyclohexane two formic acid ester is a kind of low poisonous plasticizer and the substitute of the traditional plasticizersit, it will have a broad application in the future. The traditional precious metal catalyst is the effective catalyst that facilitate benzene hydrogenation into cyclohexane structure, however, because of the high boiling point of the psilocybin of plasticizer, usually it can only use the liquid phase hydrogenation. The activated catalyst Group loss results in high costs in the production of it. This research starts to work with Ni-B catalysts by using of doping second and the third metal as well as load processing, prepared the new hydrogenation catalyst,analyzed and appraised its structure characteristic and the catalytic activity, and studied on the process of catalytic hydrogenation.Adopt three kinds of precious metal catalysts:Pd/C、Rh/C、Ru/C and Raney Ni and investigate their influence for the DOP hydrogenation. Systematically investigated the factors affecting reaction and the dynamics that has shown during the reaction, and construct the apparent dynamic mathematical model based on it. The result shows that Rh/C is an efficient hydrogenation catalyst that is hydrogenated on the DOP ring, and it can transform DOP into DEHCH in the low hydrogen gas pressure. It is particularly important for the safety and operation of tank reactor liquid phase hydrogenation. The reaction temperature has less effect on the hydrogenation speed while hydrogen gas pressure and the amount of catalyst have obvious effect. The apparent reaction dynamics analysis shows that hydrogen concentration absorbed on the catalyst surface is the crucial step. Through the study of the technical parameters, confirm the appropriate process conditions that catalyze DOP hydrogenation for DEHCH:170℃,2.0MPa, response time4.0h. Under those conditions, DEHCH is the only product reaction, and its yield is as high as above99.5%.Use NiCl26H2O、(NH4)6Mo7O24.4H2O as precursor and the COCl2.6H2O as modifier, through dipping, roasting and NaBH4reduction prepared trimetal amorphous CoNiMoB/y-Al2O3catalyst. Through the DOP liquid phase catalysis hydrogenation evaluated the reaction activity. Investigate the impact on catalyst activity from Co doping amounts and NaBH4before reduction. Confirm the optima Co/Ni mole ratio that is1:4,roast at a reasonable temperature before reduction, this is conducive to improve interaction between active component and carrier, and raise the surface dispersion degree of active component, make sure applicable temperature for roasting300℃.The token of XRD and SEM turn out that fresh CoNiMoB/y-Al2O3is amorphous structure and have good thermostability, the structure almost remains unchanged after roasting4.0h at800℃,active component disperses equably on the carrier. Use CoNiMoB/y-Al2O3as catalyst, catalytic hydrogenate on the DOP、DBP、810ester and DOTP, at170℃,hydrogen gas pressure5.0MPa, on the condition of catalyst dosage2.0g, after reacting4.0h, the benzene ring of phthalic acid ester can effectively transform into the corresponding cyclohexane, and the laws of four plasticizers hydrogenation reaction are similar.810-ester has three hydrogenation products:cyclohexane two formic acid ester of two essien, two decanoic ester. When catalytically hydrogenating DOP, there are parts of by-products, the hydrogenation on810-ester from NiMoB/γ-Al2O3shows better catalytic hydrogenation performance. |
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