【作者】 唐凤金；

【导师】 曹贵平；

【作者基本信息】 华东理工大学 ， 化学工程， 2011， 硕士

【摘要】 DSD酸(4,4’-二氨基二苯乙烯-2,2’-二磺酸)是一种应用广泛的工业中间体,主要用于合成直接染料、荧光增白剂和防蛀剂等。它是由DNS(4,4’-二硝基二苯乙烯.2,2’-二磺酸)加氢还原制得,在加氢过程中,除了会生成目的产物DSD之外,还会发生C=C双键加氢生成-C-C-和.C=C-断裂生成-CHO等副反应,产生杂质。目前,工业上合成DSD酸的方法有多种,传统的铁粉还原法由于产生大量的铁泥,亟需进行工艺改进。具有环境友好、三废少等优点的催化加氢法得到了人们的广泛重视。本文以工业石油焦为原料,经破碎、筛分、焙烧、浸渍、活化、水洗及干燥等工艺过程制备了具有不同比表面积和孔隙结构的活性炭。考察了制备过程中碱炭比和活化温度等因素对活性炭性能的影响,为催化剂的制备提供了不同比表面积和孔隙结构的载体。本文还以自制的活性炭及其它商售活性炭为载体制备了Pd/C催化剂,以丙烯酸为模型加氢体系,考察了Pd/C催化剂对碳碳双键的加氢性能。进一步地,制备了适用于DNS加氢催化的掺杂Pd-M/C(M=Fe、Co、Ni、Cu)催化剂,考察了过渡金属(Fe、Co、Ni、Cu)的加入对于Pd/C催化剂选择性的影响。结果表明,适量的加入铜系、铁系和镍系助剂都可以提高Pd/C催化剂对于DNS加氢体系的选择性。其中当M的λ为0.050时,DSD的选择性达97.83%。另外本文还考察了反应温度、氢气压力及搅拌转速等因素对DNS加氢过程的影响,优化了反应的工艺条件,使催化剂能保持较高活性及选择性。更多还原

【Abstract】 DSD acid (4,4’-diaminostilbene-2,2’-disulfonic acid) is an important immediate, which is widely used in producing direct dyes, fluorescent brighteners and mothproof agents.It is prepared from DNS(4,4’-dianitrostilbene-2,2’-disulfonic acid), in the process of DNS hydrogenation, side reactions, i.e. saturation of-C=C-double bond to-C-C-and cleavage of-C=C-to-CHO groups, go easily with the main reaction for hydrogenation of-NO2 group to-NH2 group. There are several ways for DSD production. Traditional method to prepare DSD is Bechamp method using Fe powder, which is a well known and thoroughly studied process but results in high pollution of a large amount of ferron slurry. The catalytic hydrogenation process is a environmental friendly method for DSD preparation, this method has received enough attention from researchers.In this paper, different specific surface areas and pore structure of active carbons, soursing from industry petrol coke, were prepared through crushing, screening, baking, impregnation, activation, washing and drying process. The effects of the ratio of alkali to coke and temperature on the performance of carbon were investigated in the preparation process, and this work provided many carries for catalyst preparation.This article also prepared Pd/C catalysts with self-made and other industrial active carbon as the carrier, the hydrogenation of acrylic acid which was as the model system was provied to investigate the catalyst performance of-C=C-double bond to-C-C-. Forthemore, Pd-M/C (M=Fe,Co,Ni,Cu) catalysts were also prepared for the catalytic hydrogenation of DNS. In this research, the effects of modifiers (Fe, Co, Ni, Cu) on the selective hydrogenation of DNS were studied. The results showed that the modifiers could significantly improve the selectivity of DNS to DSD. When theλof M was 0.050, the selectivity of DSD reached 97.83%. Additionally, the reaction conditions such as reaction temperature, hydrogen pressure, agitation speed and other factors on DNS hydrogenation were optimized; the life of catalyst was studied in the optimum reaction conditions, the catalyst maintained a stable activity and selectivity.更多还原