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1,4 cyclohexanediamine (1,4-diaminecyclohexane, DACH) referred to as widely used in the polyurethane industry , it is very important fine chemical intermediates , and so far , by the study of the catalytic hydrogenation of p-phenylene diamine very less. In this paper, under the conditions of water as solvent , using Raney nickel catalytic hydrogenation process of synthesis of 1,4 - cyclohexanediamine system , including qualitative phenylenediamine hydrogenation reaction products , reaction thermodynamics and kinetics analysis , catalyst Preparation of the hydrogenation reaction conditions optimization work . The specific reaction is phenylenediamine 5g materials with concentrated sulfuric acid molar ratio of 1:1.16 , deionized water, 50ml based , the optimum conditions of the hydrogenation reaction conversion rate as follows : temperature 80 ° C , pressure 3 MPa , time 8h, catalyst 3ml, 30.781% selectivity . Group contribution method using a thermodynamic analysis of the entire reaction system ; intrinsic kinetic model for the dynamics, the text in the exclusion conditions within rumored transfer resistance established for -dC phenylenediamine / dt = 1.0289 106exp (-41294/RT) C -phenylenediamine PH20.12. First orthogonal experimental paraphenylenediamine hydrogenation reaction conversion rate studies, intended to change the process conditions to obtain a high selectivity in a high conversion rate of 1,4 - cyclohexanediamine . Thus reducing the temperature to extend the reaction time to improve selectivity , wherein DACH highest selectivity is 70 ° C , 5MPa, 36h , can reach 55.003% . Also comparison study the reaction system when the solvent is ethanol , fixed phenylenediamine 5g , with concentrated sulfuric acid molar ratio of 1:1.16 , and then through the orthogonal experiment with ethanol as a solvent when the reaction conversion rate BEST conditions: temperature 80 ° C , the pressure 4MPa , the reaction time was 8H catalyst 4ml , the conversion rate can reach 99% or more , the selectivity was 43.736% . Raney nickel system applied also studied literature the deactivation of the catalyst , its activity has been some recovery and regeneration by alcohol washing .
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