Dissertation > Industrial Technology > Chemical Industry > Basic Organic Chemistry Industry > The production of aromatic compounds > Aromatic sulfur compounds > Aromatic sulfonic acid and its derivatives

Preparation of DSD Acid by Catalytic Transfer Reduction Using Aqueous Formate

Author JiangZuo
Tutor ZhangGuoLiang
School Tianjin University
Course Biomedical Engineering
Keywords DNS DSD Sodium Reduction DADB Raney-Ni Inactivation
CLC TQ247.5
Type Master's thesis
Year 2010
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4,4 ' - diamino -2, 2' - disulfonic acid ( DSD acid ) is a the bifunctional dye intermediates , widely used in detergent , textile industry, plastics , photographic and paper industry . This paper presents a pass with sodium formate catalytic reduction of 4,4 ' - dinitro -2, 2' - disulfonic acid ( DNS ) Preparation of DSD acid method . The method is characterized DNS catalytic hydrogenation at atmospheric pressure , low equipment requirements , and to overcome the labor-intensive traditional iron reduction , environmental pollution and other issues . The main research contents include: 1 , commonly used in industry Pd / C ( 5 % ) and Raney-Ni catalytic hydrogenation catalyst as the sodium formate catalytic transfer reduction DNS catalyst were investigated their usage and activity on the DNS restore the conversion rate and selectivity . The experimental results show that the Pd / C ( 5 % ) of sodium formate passed restore the catalytic activity is too high , resulting in a large number of byproducts 4,4 ' - diaminobenzidine benzyl -2,2 ' - disulfonic acid ( DADB ) generated . Using Raney-Ni catalyst passivation can effectively inhibit the generation of impurities in the benzyl group , thus also greatly improved the selectivity of the DNS . By single factor experiment and orthogonal experiment to study the impact of various factors on the DNS -reduction reaction , to determine the optimum conditions : passivation Raney-Ni catalyst , the reaction temperature was 80 ° C , the amount of catalyst 0.10 g ( 10%) of the DNS mass ratio of raw materials DNS : sodium formate = 1:8.5 ( mol ratio ) , and the reaction pH value of 5.1 , the use of positive dropwise slow dropwise addition, the raw material liquid . Under these conditions , the DSD acid yield reached more than 96% for the industrial production of new methods and experimental evidence . 3, the experimental verification of the passivation treatment of the Raney-Ni although there is good selectivity , but the repeated use of the performance is not satisfactory , the paper analyzes the Raney-Ni catalyst deactivation was mainly due to a reduction in the number of surface active center . 4 , the preliminary design of a sodium formate Catalytic transfer reduction DNS preparation DSD acid process wastewater treatment process , i.e. by evaporation, sulfuric acid , distillation and other operations to achieve the reuse of formic acid, acetic acid , reducing the production cost for wastewater treatment subsequent experiments a theoretical basis .

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