高压脉冲放电降解水溶液中4-氯酚过程的数学模型（Ⅰ）氧气放电形成臭氧的速率计算

采用电子碰撞理论计算了点-面式高压脉冲电晕放电过程中的臭氧产生速率.研究发现，臭氧形成速率是电场中能量大于等于6.0eV的电子形成速率的2倍.脉冲电压峰值和放电频率与臭氧生成速率均几乎有线性关系.放电电极直径比电极间距对臭氧生成速率的影响更加显著.     

冶炼烟气处理新技术——SO_2的非定态转化理论研究

本文对Boreskov和Matros提出的绝热式非定态SO_2转化器的基本特性进行了系统的理论研究。考察了冶炼烟气的SO_2浓度和气速对操作性能的影响,确定了适宜的换向周期和气体停留时间。针对我国冶炼烟气的特点,提出了串气的并串联非定态两转两吸工艺,该工艺可在现有的定态转化器上实现,出口尾气SO_2含量小于150ppm。     

乙苯脱氢反应器的灵敏度分析

以6万吨/年乙苯脱氧反应器的开发为背景,对乙苯脱氢绝热反应器和列管式反应器分别进行了灵敏度分析,包括各种工程因素和一些难测的参数设计值与实际值存在偏差对反应结果的影响。     

低分子量聚己二酸乙二醇酯制备过程中的缩聚反应动力学

以己二酸和乙二醇为原料、经酯化及缩聚过程合成的数均分子量1 000~4 000聚己二酸乙二醇酯(PEA)是生产聚氨酯的主要原料之一。实验考察了制备低分子量PEA的缩聚过程中催化剂种类、催化剂用量、反应温度等对合成的PEA羧基浓度、分子量等的影响。结果发现钛酸异丙酯催化活性最好,其较佳用量为25~50 mg/kg,较佳的反应温度为220~250℃。建立了基于有外加催化剂存在下酯化和缩聚反应均为2级反应的动力学模型,并根据不同反应温度、催化剂用量时的动力学实验数据,利用遗传算法得到了低分子量PEA合成缩聚过程反应动力学参数,模型计算值和实验值的相对误差在9%之内。     

多相催化微观动力学与催化剂理性设计

微观动力学研究包含微观动力学分析和催化反应综合两个组成部分,是揭示多相催化反应机理和筛选固体催化剂的重要手段。密度泛函理论的进展和应用使得动力学分析能够半定量地描述复杂过程的反应动力学,并确定标识催化反应活性的描述符及其最优范围。催化反应综合可以在大量候选催化材料中筛选出具有更高活性、选择性、稳定性和更加廉价的多组分催化剂。密度泛函理论计算与微观动力学研究相结合为理性催化剂设计提供了一条崭新的途径。     

Cu-ZnO-Al_2O_3催化剂上甘油氢解制1,2-丙二醇的反应动力学(英文)

A series of Cu-ZnO-Al2O3 catalysts with various metal compositions of Cu/Zn/Al were prepared by the co-precipitation method,and screened for glycerol hydrogenolysis to propylene glycol.The catalyst with a Cu/Zn/Al molar ratio of 1:1:0.5 exhibited the best performance for glycerol hydrogenolysis,and thus selected for kinetic investigation.Under elimination of external and internal diffusion limitation,kinetic experiments were performed in an isothermal fixed-bed reactor at a hydrogen pressure range of 3.0-5.0 MPa and a temperature range of 493-513 K. Based on a dehydration-hydrogenation two-step hydrogenolysis mechanism,a two-site Langmuir-Hinshelwood kinetic model taking into account competitive adsorption of glycerol,acetol and propylene glycol was proposed and successfully fitted to the experimental data.The average relative errors between observed and predicted outlet concentrations of glycerol and propylene glycol were 6.3%and 7.6%,respectively.The kinetic and adsorption parameters were estimated by using the fourth-order Runge-Kutta method together with the Rosenbrock algorithm.The activation energies for dehydration and hydrogenation reactions were 86.56 and 57.80 kJ·mol-1,respectively.     

丙烷脱氢Cr_2O_3/Al_2O_3催化剂烧焦再生过程的模型化与模拟(英文)

A heterogeneous model is developed for the regeneration of the Cr2O3/Al2O3 catalyst for the propane dehydrogenation process by considering the internal mass transfer and external mass/heat transfer during the coke combustion. Simulation shows that under practical operating conditions, multi-steady states exist for the catalyst pellets and the catalyst temperature is sensitive to gas temperature. However, at increased mass flow rate or lowered oxygen concentration, multi-steady states will not appear. Under the strong influences of film diffusion, the coke in the packed bed reactor will first be exhausted at the inlet, while if the film diffusion resistance is decreased, the position of first coke exhaustion moves toward the outlet of the reactor.     

密闭体系中乳酸的固相缩聚

研究在真空密闭、存在脱水剂的条件下聚乳酸固相缩聚工艺的可行性,得到了分子量达25万的聚乳酸;实验研究了催化剂浓度,预聚体粒度和反应时间对缩聚过程的影响,表明降解副反应仍然是控制聚乳酸最终分子量的重要因素。     

4-CBA在Pd/AC上加氢表观动力学研究

在实验室间歇高压釜中对Pd/AC催化剂上对苯二甲酸(TA)加氢精制过程的对羧基苯甲醛(4-CBA)加氢反应进行了研究.考察了氢分压、反应温度、催化剂颗粒大小对4-CBA消逝速率的影响,结果表明,在高于0.35 MPa时,氢分压对4-CBA加氢反应的速率影响很小,而温度和催化剂颗粒大小对加氢反应速率的影响显著.同时,工业条件下的TA加氢精制过程存在着严重的内外扩散.采用幂函数动力学模型方程,利用Matlab拟合得到了接近工业反应温度下的表观动力学方程.