微结构的纳米设计膜反应器中的催化

For thermodynamically and kinetically controlled catalytic reactions,the influence of a membrane is discussed. For reactions operating near to the thermodynamic equilibrium,the conversion can be increased if one/all of the products is/are selectively removed in an extractor type membrane reactor. Examples are esterifications,dehydrogenations,and water dissociation using water,hydrogen,and oxygen selective membranes,respectively. For kinetically controlled reactions,i.e. reactions with a very negative free enthalpy,mainly the selectivity can be increased via the control of the partial pressure of the educts by dosing effects using distributor/contactor membrane reactors. Examples are partial oxidations and hydrogenations. In detail,the application of an oxygen transporting perovskite hollow fiber membrane with a nano-designed grain boundary structure in the hydrogen production by thermal water splitting and in the partial oxidation of hydrocarbons as case studies for thermodynamically and kinetically controlled reactions is discussed.     

Simulation and model design of pipe-shell reactor for the direct synthesis of dimethyl ether from syngas

The simulation was made based on the model of pipe-shell reactor that was established by the model of global kinetics of synthesis of dimethyl ether from syngas over a bifunctional catalyst. The results of simulation showed that the selectivity for dimethyl ether （DME） and the conversion of CO were higher but the hot spot was kept below the temperature limit of the pipe-shell reactor. The suitable diameter of the pipe was φ38×2 mm, and the length of the pipe was 5.8 m. The optimal process conditions of the reactor were that the pressure was 5 MPa, the temperature of the cooling water was 240 ℃, and the temperature of the raw gas at inlet of the reactor was 220 ℃. The production of this reactor was 102800 t/y （ton per year） under these conditions.     

膜吸附反应器（MAR）对饮用水系统中病毒的去除

以尺寸与人体肠道病毒相近的f2噬菌体作为模型病毒,本研究采用膜吸附反应器（Membrane adsorption reactor,MAR）,考察膜分离与纳米TiO2耦合工艺对饮用水中病毒的去除效果．两种不同孔径的PVDF（0．20μm）、PAN（0．05μm）平板膜在自来水体系中对f2噬菌体的截留效果分别为1．88～2．56log和4．78～5．95log,大大超过理论计算值,这与膜具有不规则孔型的重叠筛网状结构直接相关．吸附实验结果表明,纳米TiO2对f2噬菌体的吸附在60min内即可达到吸附平衡,符合Freundlich等温吸附模型qe=27．4·Ce1.24．两组MAR系统对f2噬菌体的总去除率分别高达3．88log与6．40log,这主要是由于纳米TiO2的吸附作用,以及运行中在膜表面形成有效的滤饼层．纳米材料与膜系统的耦合既保持了系统对病毒的高效去除,又实现了纳米颗粒的有效分离回收,操作简单、费用低．     

离子液体中脂肪酶催化酯类合成的新进展

作为21世纪最具发展潜力的绿色溶剂,离子液体用于酶促合成的反应介质具有得天独厚的优势.与传统的有机溶剂相比,离子液体能够提高脂肪酶的稳定性和选择性,减少有机合成中的副反应和有毒气体的产生,后处理简单,可重复利用.参考10年来的文献,从脂肪酶催化酯类合成的常用离子液体种类、过程因素及场/反应器强化等方面进行了综述,同时展望了离子液体在未来酯类酶促合成领域的发展趋势.     

Hydrogen production from simulated hot coke oven gas by catalytic reforming over Ni/Mg（Al）O catalysts

Hydrogen production by catalytic reforming of simulated hot coke oven gas (HCOG) with toluene as a model tar compound was investigated in a fixed bed reactor over Ni/Mg(Al)O catalysts. The catalysts were prepared by a homogeneous precipitation method using urea hydrolysis and characterized by ICP, BET, XRD, TPR, TEM and TG. XRD showed that the hydrotalcite type precursor after calcination formed (Ni, Mg)Al₂O₄ spinel and Ni-Mg-O solid solution structure. TPR results suggested that the increase in Ni/Mg molar ratio gave rise to the decrease in the reduction temperature of Ni²⁺ to Ni⁰ on Ni/Mg(Al)O catalysts. The reaction results indicated that toluene and CH₄ could completely be converted to H₂ and CO in the catalytic reforming of the simulated HCOG under atmospheric pressure and the amount of H₂ in the reaction effluent gas was about 4 times more than that in original HCOG. The catalysts with lower Ni/Mg molar ratio showed better catalytic activity and resistance to coking, which may become promising catalysts in the catalytic reforming of HCOG.     

海藻酸钠-壳聚糖微胶囊作为肠道内生化微反应器的研究

基因工程技术的发展使蛋白、多肽类高值生化药物的大规模生产得以实现并用于临床^[1].但目前存在产物分离、纯化工艺复杂、成本高等问题.因此,研制一种无需分离纯化、低成本的肠道内生化微反应器作为基因工程药物释放系统具有实际应用意义(例如将基因工程微生物包埋在具有半透性高分子膜的微胶囊中,口服后微囊化活细胞在肠道内生长并分泌有治疗作用的基因工程药物而达到治疗目的^[2]).本文以酵母菌Pichia pastoris GS115为模型菌株,以海藻酸钠-壳聚糖(A lginate-chitosan,AC)微胶囊为载体,考察了AC微囊化酵母菌在模拟胃肠液中的形态、膨胀性能、酵母菌存活率及小鼠口服后肠道黏膜粘附性能,初步证明AC微囊化基因工程酵母菌作为肠道生化微反应器是可行的.     

Ba0.5Sr0.5Co0.8Fe0.2O3-δ透氧膜反应器在丙烷氧化脱氢反应中的应用

工业上一般采用丙烷热裂解脱氢反应生产丙烯. 该反应通常在高温(＞700 ℃)下进行,催化剂容易积碳. 而且,由于反应受到热力学平衡的限制,丙烯的选择性也不很高. 近年来,以廉价空气和丙烷为原料的丙烷氧化脱氢(PODH)反应为丙烯的生产提供了另外一条途径,且已引起广泛的关注. 在PODH反应中,一般认为晶格氧(O2-)参与丙烷的选择氧化,而其它氧物种(O-,O-2等)导致丙烷的完全氧化[1]. 钙钛矿结构的混合导体透氧膜是同时具有氧离子导电性和电子导电性的一类材料. 在高温下,当膜两侧存在氧浓度梯度时,氧以氧离子的形式通过氧缺陷进行传导,同时以电子的反向传输来完成传输回路[2]. 这种透氧机理使得混合导体透氧膜在理论上对烷烃氧化反应具有一定的催化活性. 作为膜反应器材料,这类混合导体透氧膜已成功地应用于甲烷部分氧化(POM)反应[3]. 但迄今为止,还没有文献报道这种膜反应器在PODH反应中的应用. 组成为Ba0.5Sr0.5Co0.8Fe0.2O3-δ的钙钛矿膜材料是本研究组开发的一类具有高透氧量、高稳定性的新型透氧膜材料. 本文尝试将该材料制备的膜反应器用于PODH反应,同时研究了PODH反应对膜透氧量的影响.     

简化化学反应计算的当地自适应建表方法在PMSR中的应用

本文描述了一种减少化学反应计算时间的有效方法－当地自适应建表方法,对之做了改进,并计算了配对混合搅拌反应器（ＰＭＳＲ）的甲烷／空气非预混燃烧问题。结果表明在各种参数条件下,这种方法都能在保证精度的条件下节省两到三个量级的计算时间。     

增湿活化反应器内气—液滴—固三相流场的数值模拟

本文给出了气—液滴—固三相流体的双流体模型下的各控制方程组。颗粒动理学方法模拟颗粒相湍动能。模型中考虑了气、液滴和固相的相互作用以及液滴与固相的非弹性作用造成的能量传递和耗散。模型预测在增湿活化反应器内相速度和浓度等参数空间分布,以及操作参数、结构布置等对相速度等参数的影响。     

层状双金属氢氧化物晶粒尺寸的控制

旋转液膜反应器;层状双金属氢氧化物晶粒尺寸的控制