【作者】 陶祖亮；

【导师】 乔旭； 汤吉海；

【作者基本信息】 南京工业大学 ， 化学工艺， 2004， 硕士

【摘要】 邻、对氯苯甲醛是重要的精细化工中间体,氯化水解法仍然是主要的工业生产方法,但是目前的水解工艺存在收率低、产品质量差、水解催化剂对环境会造成重金属离子污染等问题。此外,采用邻、对氯甲苯分别生产邻、对氯苯甲醛时,因原料价格高而使得生产成本高。为此,本文首先立足开发高收率合成邻、对氯苯甲醛的清洁生产工艺,进而在此基础上对以混合邻、对氯甲苯原料同时制备邻、对氯苯甲醛的新型联产工艺进行探索。针对邻、对氯苄叉二氯的水解是存在水相和有机相的液液两相反应体系的特点,采用相转移催化剂代替浓酸或可溶性的金属盐类等传统水解催化剂,从催化效果和经济性两方面对催化剂进行了筛选,系统研究了催化剂用量、水的用量以及反应温度等因素对水解反应的影响,确定了最优的水解工艺条件,反应的转化率和收率均接近100%。以对氯苯甲醛的合成为对象,考察了水解母液循环套用的可行性,实验结果表明,经3次套用后的水解母液对对氯苯甲醛的收率和反应选择性基本没有影响,从而杜绝了本工艺的废水排放,使水解工艺清洁化。建立了对氯苄叉二氯水解反应的拟一级宏观动力学模型,根据水解反应的实验数据,通过非线性最小二乘拟合得到水解反应的活化能为83.59kJ/mol。模型计算值与实验值吻合较好,为工业反应器的设计提供了依据。研究了将邻、对氯甲苯混合物直接进行氯化、精馏得到的氯化混合物制备邻、对氯苯甲醛的水解工艺,通过在水解反应后期加入一定量的乌洛托品,可使所有侧链氯化物全部转变成相应的醛。采用熔融结晶方法对此混合醛进行分离的初步探索,经过一次结晶得到的晶体中对氯苯甲醛的含量有明显提高。研究结果初步证明了由难分离的邻、对氯甲苯混合物联产易分离的邻、对氯苯甲醛的工艺是可行的,可大大节约分离的能耗,在对邻、对氯苯甲醛熔融结晶分离工艺进一步研究的基础上,该工艺应具有良好的工业化前景。更多还原

【Abstract】 O-chlorobenzaldehyde and p-chlorobenzaldehyde are important fine chemical intermediate products. At present chlorination-hydrolysis method is still the main industrial method, but the yield is low and the product quality is not good enough. Furthermore, the hydrolysis catalyst would cause pollution of metallic ion. Because the prices of raw materials are high and the production cost of o-chlorobenzaldehyde and p-chlorobenzaldehyde from o-chlorotoluene and p-chlorotoluene individually is very high. For these reasons, this research was carried out to find a clean way of producing o-chlorobenzaldehyde and p-chlorobenzaldehyde with high yield and high selectivity firstly, and then the technology of joint process of these two products was preliminarily studied.Because the hydrolysis of o-chlorobenzal chloride or p-chlorobenzal chloride is a liquid-liquid biphase reaction with water and organic reactant, phase-transfer catalysts were used instead of acids or soluble metallic salts. The appropriate PTC was selected in consideration of economic benefit and catalysis effect. The effect of the amount of catalyst, the amount of water and temperature on the reaction rate was investigated systematically and the optimal operation condition was determined. The reaction selectivity and the yield were both nearly 100%. The feasibility of reaction by using recycled mother solution was studied in the hydrolysis production of p-chlorobenzaldehyde. it was confirmed by the experiment that the yield and selectivity little reduced by the reuse of recycled mother solution after 3 times. It has big sense to stop the discharge of waste water and to make the process clean.The apparent kinetic model of hydrolysis reaction of p-chlorobenzal chloride was established. The reaction activity energy was obtained as 83.59kJ/mol. The calculated value and the experimental value coincided well and foundation was provided for designing industrial reactor.The hydrolysis process of the side chain chlorination mixture from p-chlorotoluene and o-chlorotoluene was studied. The whole chlorinated mixture were <WP=5>converted to aldehydes by adding urotropine in the latter period. Then the separation of mixture by melt crystallization was studied primarily. The concentration of p-chlorobenzaldehyde obviously increased in the crystal mass after first crystallization. The results show that the method of converting o-chlorotoluene and p-chlorotoluene difficultly separated to o-chlorobenzaldehyde and p-chlorobenzaldehyde easily separated is feasible, and the separation cost is saved largely. With the further study of melt crystallization of o-chlorobenzaldehyde and p-chlorobenzaldehyde, this technology will have a good industrial perspective.更多还原