【作者】 罗涛；

【导师】 屈一新；

【作者基本信息】 北京化工大学 ， 化学工程， 2008， 硕士

【摘要】 邻苯基苯酚是一种应用广泛的精细化工产品,可用于制备杀菌防腐剂、表面活性剂、染料中间体、塑料热稳定剂和阻燃剂等。以环己酮为原料先经缩合脱水得环己酮二聚体（Dimer）,Dimer再脱氢生产邻苯基苯酚的工艺过程是一条过程简单、经济合理的路线,国外已经实现工业化,但我国还没有大型工业化装置。本文研究了以环己酮为原料生产OPP的工艺,重点研究了Dimer脱氢催化剂的制备方法和添加金属钾盐对其性能的影响。首先,本文系统地研究了以硫酸、氧化铝等多种酸性催化剂催化环己酮缩合脱水反应。实验结果表明:以Al₂O₃作为缩合反应的催化剂不但具有较高的活性和选择性而且具有催化剂易分离,产品精制过程简单的优点。环己酮的转化率可达74%,二聚体的选择性为87%。以γ-Al₂O₃为载体,氯铂酸为前驱体,通过等体积浸渍法制备Pt/γ-Al₂O₃脱氢催化剂,并添加钾盐助剂进行改性。重点研究了载体γ-Al₂O₃的性能,载铂量、助剂种类与添加量和催化剂制备条件等因素对催化剂催化性能的影响。研究结果表明:载体γ-Al₂O₃的杂质含量对催化剂的性能具有较大的影响,其SiO₂的含量应低于0.3%,Fe₂O₃的含量应低于0.1%,以360℃为焙烧温度,载铂量以0.5%（载体质量为基准）为宜。在催化剂上K含量相同的情况下以K₂SO₄为助剂的催化剂OPP收率最高,可达93%。采用XRD、NH₃-TPD和CO₂-TPD程序升温脱附法对催化剂表面性质进行研究表明,以K₂SO₄作助剂的催化剂的对产物OPP高选择性和稳定性主要与其较低的表面酸量有关。在T=355℃,LHSV=0.2 h^-1,H₂=40ml/min条件下反应达最佳效果,且在此条件下连续运转240h,Dimer的转化率和OPP收率未发生显著的变化,OPP的平均收率可达92%,催化剂稳定性良好。更多还原

【Abstract】 O-phenylphenol（OPP）is a fine chemical product which is widely used for the preparation of bactericides,preservatives,surfactants, intermediates of dyes,plastic stabilizers and fire retardants.Using cyclohexanone as a starting material,OPP can be prepared by a tow-stage process comprising the condensation of cyclohexanone to its dime and subsequent dehydrogenation of Dimer to OPP.This process is simple, economic and has been industrialized abroad.However,in China such unit has not been available in big and industrial scale.In this thesis the preparation of the OPP from cyclohexanone via the two-stage process was investigated.The study is focused on the preparation method of the dehydrogenation catalyst and the influence of alkali-metal salts on the catalytic performance.Firstly,condensation of cyclohexanone using acidic catalysts such as sulfuric acid and alumina was systematically studied.The result showed that Al₂O₃ owned a high activity and selectivity when it was adopted as the condensation catalyst,the conversion of cyclohexanoe was up to 74%, and the selectivity of Dimer reached 87%.Using Al₂O₃ as a catalyst has the advantages that separation of the catalyst from the liquid product and is easy,subsequent purification of the product is simplified.The Pt/γ-Al₂O₃ dehydrogenation catalyst was prepared by equal-volume impregnation usingγ-Al₂O₃ as the support,chloroplatinic acid as a precursor and K-salts as promoters to improve the catalyst performance.Factors that influence the performance of the dehydrogenation catalyst were investigated including the properties of the support,the amount of platinum supported,the type and amount of the promoters and preparation conditions.The results showed that the impurities in Al₂O₃ support had a significant influence on the catalyst performance.The content of SiO₂ should be lower that 0.3%and Fe₂O₃ should be lower than 0.1%.at 360℃to calcine the catalyst,With the amount of supported Pt of 0.5%（based the quality of the cartier）,and K₂SO₄ as a promoter,the catalyst showed highly activity,selectivity and stability.The yield of OPP amounted 93%.Characterization using XRD, NH₃-TPD and CO₂-TPD revealed that the high OPP yield and stability of the catalyst with K₂SO₄ as a promoter is mainly due to the lower amount of the acidic sites on its surfaces.Optimization of the reaction conditions indicated that at T= 355℃,LHSV=0.2 h^-1,H₂=40ml/min,the catalyst showed its best performance.In the duration of 240h stability test,the average yield of OPP amounted 92%and no significant decrease in the activity was observed,indicating that the catalyst had a good stability.更多还原