间歇结晶过程的分析

本文概要地介绍了用于研究在间歇悬浮结晶器中的结晶动力学和晶体粒度分布（CSD）的实验技术和数据分析的新进展,讨论了包括最大CSD的特征化、累积CSD方法、热响应技术、最大允许成长速率在内的几个简单而有用的方法。     

高效液相色谱法测定去乙酰基-7-氨基头孢烷酸的含量

建立了一种高效液相色谱法测定去乙酰基-7-氨基头孢烷酸含量的方法,采用迪马公司的C18色谱柱（4.6mm×250mm,5μm）,以0.01mol/L醋酸钠（pH=4.25）为流动相,流速为1.0mL/min,检测波长为254nm,柱温为25℃,样品池温度为4℃,线性范围为60～300μg/mL,r=0.9999,平均回收率为99.36%。     

7-氨基-3-去乙酰氧基头孢酸

7-氨基-3-去乙酰氧基头孢酸(7-ADCA)是一种重要的医药中间体，主要用于合成头孢氨苄、头孢拉定和头孢羟氨苄等药物。据估计，每年我国7-ADCA的总需求量为550t，而产量只有200t，其余全部进口，因此，7-ADCA被列入国家急需发展的重点医药中间体之一。文中概述了7-ADCA的性质、用途、合成工艺、国内生产、市场状况等。     

蛋氨酸CO2酸化半间歇反应结晶动力学研究

针对海因法合成蛋氨酸工艺，利用间歇动态法、以蛋氨酸钾为原料研究了CO₂酸化条件下蛋氨酸的反应结晶过程，建立结晶动力学模型。通过矩量变化法求解粒数衡算方程，利用最小二乘法对数据多元线性回归得到结晶动力学参数。结果表明：晶体生长类型为粒度无关生长，晶体生长活化能为21.01 kJ·mol^-1,成核与生长速率方程中过饱和度的指数分别为0.62和1.52,晶体聚结对结晶过程的影响不可忽略。气体表观速率、搅拌速率对晶体成核与聚结均有明显影响。高过饱和度与高搅拌转速不利于晶体平均粒径的增加。     

7-氨基-3-去乙酰氧基头孢烷酸合成工艺的研究

7-氨基-3-去乙酰氧基头孢烷酸是一种重要的头孢抗菌素医药中间体。讨论了青霉素G钾盐的氧化剂及扩环重排反应中的催化剂、扩环条件及头孢G酸的后处理,以优化其合成工艺。     

反应结晶过程研究（Ⅰ）——激光法研究结晶热力学与反应动力学

采用激光测量装置研究了普鲁卡因青霉素在不同温度，不同浓度，不同ｐＨ值的氯化钠水溶液中的溶解与超溶解特性，以及其生成反应的反应动力学，为系统研究普鲁卡因青霉素反应结晶过程提供了一定的热力学和反应动力学基础。     

两步酶法制备去乙酰基7-氨基头孢烯酸

以生产头孢菌素C(CPC)过程中的副产物去乙酰头孢菌素C(DCPC)为原料,用固定化D-氨基酸氧化酶(DAAO)和固定化戊二酰基酰化酶(GA),连续两步进行酶裂解,制备了去乙酰基7-氨基头孢烯酸(D-7-ACA),总收率72%。滴加浓度为1 mol/L的过氧化氢可使去乙酰基戊二酰基7-ACA(D-G l-7-ACA)的收率提高6%。提高氧气流速和改善搅拌形式可以加快DAAO酶反应速度,使中间产物残留减少3%。高纯度的去乙酰头孢菌素C钠盐(DCPCNa)可以提高该两步酶法反应的收率和产品质量,延长酶的使用寿命。     

间歇冷却结晶过程的模拟

The general mathematical model for batch cooling crystallization was established based on the population balance equation considering the change of slurry volume, and simulated with crystallization thermodynamics,kinetics and mass balance employing bed voidage. In the system of vitamin C-water-ethanol, reliability of this model was verified by comparison between simulation results and experimental data. The effects of operation parameters on product quality can be systematically investigated by modeling simulation.     

间歇反应精馏过程的模拟及其刚性问题

本文修正了Boston等人用于间歇精馏过程的数学模型,使之能适用于间歇反应精馏过程;提出了用解离法完成间歇反应精馏过程模拟的计算步骤;比较了SIRK,GEAR和EPISODE等软件在间歇精馏过程刚性微分方程数学模型积分中的有效性;并以醋酸丁酯用乙醇转移酯化反应精馏过程为例说明了方法的应用。     

酶法7-ACA结晶过程研究

头孢菌素C钠盐(CPCNa)在D-氨基酸氧化酶(DAO)和戊二酰-7-ACA酰化酶(GAC)双酶催化反应下得到7-氨基头孢烷酸(7-ACA).在7-ACA结晶时,通过对比添加0.1‰阳离子型高聚物聚四胺辅助结晶和普通结晶方法,发现聚四胺可有效使晶体聚结成球状,大大提高了结晶后过滤速度、7-ACA含量和质量以及7-ACA成品稳定性.同时,对聚四胺的加入量进行了优化.     

Statistical simulation of aluminum agglomeration during combustion of heterogeneous condensed mixtures

A statistical model of aluminum agglomeration during combustion of solid composite rocket propellants is considered; the model describes the process dynamics, beginning from propellant heating in the combustion wave and ending by separation of agglomerates from the burning surface. An algorithm of computing the agglomeration process by the Monte Carlo method is proposed. A series of computations of aluminum agglomeration is performed; the density distribution functions for agglomerate sizes are derived; the dependence of the mean-mass size of agglomerates on the mean-mass size of ammonium-perchlorate particles is determined. The model proposed predicts power dependences of the mean-mass size of agglomerates on pressure and burning rate, which agrees with available experimental data.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 2, pp. 62–74, March–April, 2005.     

带电硬哑铃流体的分子热力学

Chemical potentials of charged hard-dumbbell fluids are obtained by Monte Carlo simulations using Widom‘s test-particle method, corresponding compressibility factors are achieved by integration of chemical potentials at different densities. A molecular thermodynamic model is also developed for these charged hard-dumbbell fluids where the residual Helmholtz function is composed of two terms: a reference term responsible for the charged hard spheres and a bonding contribution measuring the sticky interactions between positive and negative hard ions.Model predictions are in good agreement with simulation results.     

丙烯聚合的Monte Carlo模拟(Ⅰ)活性杂质对丙烯聚合的影响

A comprehensive mechanism for propylene polymerization was proposed by considering the effects of main impurities in the material on propylene polymerization. According to the proposed mechanism, Monte Carlo simulation was employed to investigate the polymerization kinetics in order to determine the effects of the main impurities on the polymerization. Significant influences of the main impurities on the rate, number-average degree and controlling capability of hydrogen of the polymerization were analyzed.     

丙烯聚合的Monte Carlo模拟(Ⅰ)活性杂质对丙烯聚合的影响

1 INTRODUCTION Polypropylene is a popular thermoplastic polymer, and produced via bulk polymerization in petroleum chemical industry. The molecular configuration of polypropylene and the characteristics of polymer can be controlled by the catalyst and polymerization method. Furthermore, other factors, such as impurities in the material and polymerization conditions, also influence the industrial production. Catalyst influences the rate and the quality of polymer, is a key factor of the in…     

树脂吸附法处理7-ADCA生产中的废水研究

采用大孔树脂和离子交换树脂串联吸附的方法对7-ADcA生产废水进行处理,考察了各种吸附剂对处理结果的影响。实验结果表明：在吸附速率2．0Bv／h、解析速率0．8Bv／h、60％丙酮水溶液为解析剂的条件下,以HT-1600大孔树脂先行处理废水,之后在吸附速率2．5Bv／h、解析速率0．8BV／h、0．5％稀碱为解析剂条件下,以HT-008离子交换树脂处理废水中COD值,平均去除率达88．9％。     

普鲁卡因青霉素的结晶动力学

通过对用生死函数表征粒子聚结和破裂的粒数衡算模型,采用新的分析计算方法来研究普鲁卡因青霉素反应结晶过程中粒子的聚结和破裂对过程的影响机理;采用ＭＳＭＰＲ结晶实验获得了普鲁卡因青霉素反应结晶的结晶动力学。     

Effects of kinetics coefficients on ternary phase separation during the wet spinning process

A new Monte Carlo diffusion model is employed to simulate the phase separation of the ternary system during wet spinning process. Our results illustrate the thermodynamics parameters are the primary factors in morphology determination during the phase separation process. Meanwhile by varying kinetic parameters different fiber structures ranging from dust-like, finger-like to sponge-like morphologies are obtained. The morphological patterns are discussed in relation to the rate of particle exchange and the phase diagram. On the basis of the systematical simulation experiments we propose how the competition between segment–solvent and solvent–nonsolvent exchange determines the ultimate fiber morphologies in spinning solution.© 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

表面活性剂对丁二酸冷却结晶中聚结的抑制

借助聚焦光束反射测量仪(FBRM)和颗粒录影显微镜(PVM)对丁二酸冷却结晶过程中的聚结现象进行研究,通过加晶种实验和不加晶种实验初步推断大小颗粒的共存及颗粒间的相互结合力是形成聚结需要考虑的两个因素。在此基础上,将3种类型的表面活性剂十六烷基三甲基溴化铵(CTAB)、十二烷基苯磺酸钠(SDBS)和吐温80(Tween80)加入到丁二酸冷却结晶系统,考察了表面活性剂对结晶过程中颗粒聚结的抑制作用。晶体形貌变化表明,所选的表面活性剂均能吸附于晶体表面,且可大大降低聚结,可推测表面吸附产生的机械隔离能够降低晶体间的相互结合力,并促使结晶产品的粒度更为均匀。这一研究证明添加表面活性剂可降低结晶过程的聚结程度。     

重要的半合成头孢菌素中间体--7-ADCA

7-氨基-3-去乙酰氧基头孢烷酸(7-ADCA)是以青霉素G为原料,经氧化、扩环重排、裂解3步反应制得.目前用于裂解反应的固定化酰化酶技术日益成熟,因而化学法裂解的生产工艺已逐渐被淘汰.世界上主要生产厂家有荷兰GIST公司、美国TEVA公司、意大利DOBFA公司、台湾骏祥公司和印度LUPIN公司等.国内华北制药倍达公司开发了酶法生产7-ADCA的工艺,并建立了250t/a的生产能力,产品质量与进口产品相当.我国7-AD-CA年需求量约900t,而生产能力不足300t/a.国内企业应改进回收工艺、降低生产成本、实现规模化生产,以改变市场依赖进口的局面.     

应用固定化青霉素酰化酶IPA-750制备7-ADCA的工艺研究

详细讨论了头孢G酸 (扩环酸 )在固定化青霉素酰化酶 (IPA 75 0 )催化裂解下转化为 7 ADCA的工艺。在 0 0 5mol/L的硼酸缓冲液中 ,通过改变酶促反应过程中底物浓度、pH值、温度 ,筛选出了优惠反应条件 :底物浓度 6 % ,pH8 0 ,温度 2 8～ 30℃。在优惠反应条件下进行批次反应 ,4 0 0～ 4 5 0批 ,转化率≥ 97% ,收率≥ 95 %。