新戊二醇的制法

新戊二醇的制法在装有强碱性阴离子交换剂（作催化剂用）的反应器中，异丁醛与甲醛（用甲醇作溶剂）反应来制备新戊二醇。例如，在反应器中装入ＷｏｆａｔｉｔＳＢＷ交换剂，然后输入Ｍｅ２ＣＨＣＨＯ和ＨＣＨＯ的水溶液，反应后，得新戊二醇，转化率为９９％，选择性亦为...     

丙烯氨氧化合成丙烯腈流化床反应器的模型拟合

基于反应动力学实验结果,分析考察了丙烯氨氧化反应的动力学行为,提出了关于反应转化率与目的产物收率的幂函数形式的拟合模型,藉此对某厂丙烯腈工业流化床反应器的操作数据进行了关联,在考虑反应器中气－固流动影响的前提下,建立了丙烯腈反应器的下述宏观数学模型：反应转化率Ｘ＝０．８３２５ｕ－０．１０５８Ｒ－０．０１６４ＮＨ３Ｒ０．２５０９Ｏ２ｅｘｐ（－０．７４５９＋３５９．７９／Ｔ）丙烯腈单收ＹＡＮ＝０．０８９６ｕ０．０３４２Ｒ０．２３３３ＮＨ３（５．８２４５ｅｘｐＲ１．１３３７Ｏ２－Ｒ４．７４４５Ｏ２）ｅｘｐ（－２．０６５１＋５２２．９８／Ｔ）模型拟合的相对误差小于１０％．     

沸石膜反应器苯脱氢反应性能

采用管式沸石膜反应器,研究了乙苯脱氢反应生成苯乙烯的性能。考察了不同渗透分离性能的沸石膜对乙苯脱氢反应的影响和不同沸石膜反应器上乙苯脱氢反应的规律。结果表明,与固定床操作条件下相比,沸石膜反应器乙苯转化率可提高近10％－16％,苯乙烯选择性可提高3％－5％。渗透分离性能是决定沸石膜提高脱氢反应性能的最重要因素,H2渗透量越大、H2／C3H8分离系数越高,对反应越有利。渗透分离性能相近但类型不同的沸石膜对乙苯脱氢反应性能有差异,其中Fe-ZSM-5沸石膜反应性能较好,这是杂原子Fe进入沸石骨架后引起的。反应后膜的渗透分离性能略有变化。     

合成2,6-二甲基苯胺的催化剂及工艺条件研究

通过实验筛选出该反应的催化剂为Ｖ２Ｏ５ － Ｃｒ２Ｏ３ － Ａｌ２Ｏ３ ,确定了浸渍法制备的浸渍液质量分数为１３－２％ ,催化剂中主催化剂Ｖ２Ｏ５ 的最佳质量分数为１０ ％ ,最佳改性金属氧化物为Ｃｒ２Ｏ３及最适宜比例为ｎ（Ｖ２Ｏ５）∶ｎ（Ｃｒ２Ｏ３） ＝１０∶１ 。通过工艺条件考察,筛选出最佳工艺条件为：反应温度３７０ ℃,原料配比ｎ（Ｃ７Ｈ７ＮＨ２）∶ｎ（ＣＨ３ＯＨ）∶ｎ（Ｈ２Ｏ）＝ １∶３∶１,液时空速０－５／ｈ,原料中加入水可明显提高目的产物选择性。反应转化率为７４－２９ ％ ,目的产物选择性为５１－２４ ％ 。     

Li_2O·MnO_2-Ag-YSZ氧泵型反应器中NEMCA效应的研究

本文对Ｌｉ２Ｏ·ＭｎＯ２－Ａｇ－ＹＳＺ氧泵型催化膜反应器中甲烷氧化偶联反应的ＮＥＭＣＡ效应进行了研究。考察了稳态电流和反应温度对ＮＥＭＣＡ效应的影响,考察了反应气中甲烷含量、反应温度对发生ＮＥＭＣＡ效应时的交换电流密度的影响,比较了传递体系和联合体系的交换电流密度与活性过电位的关系。结果表明：高甲烷含量、低反应温度和反应气中引入极少量的Ｏ２,可降低三相界面的交换电流密度,有利于ＮＥＭＣＡ效应的发生     

乙烷-氧-水氧化裂解制乙烯反应的研究

研究了不同反应体系组成的乙烷造反然的反应性能,考究了乙烷－氧－水反应体系氧化裂解制乙烯的反应条件。结果表明,在不同反应体系中,以Ｃ２Ｈ６－Ｏ２－Ｈ２Ｏ氧化裂解制乙烯反应性能最佳,８００℃的乙烷转化率为８５．１％,乙烯选择性为６８．１％,乙烯收率可达５８％,Ｃ２Ｈ６－Ｏ２－Ｈ２Ｏ氧化裂解帛乙烯体系最佳工艺参数;反应温度为８５０℃,原料气组成为５０．５％,Ｃ２Ｈ６＋２５．２％Ｏ２＋２４．３％Ｈ２Ｏ停留     

光催化氧化法处理活性染料水溶液

在开放的光催化反应器中,以紫外光为光源,ＴｉＯ２ 为催化剂,考察了催化剂用量、反应液的起始质量浓度、反应液的起始ｐＨ 及Ｈ２Ｏ２ 的加入等因素对光催化氧化反应的影响。结果表明,在一定的光强度下,催化剂的投加量存在一最佳范围（２ ～４ ｇ／Ｌ） ;加入Ｈ２Ｏ２ 可加快染料分子的脱色速度,但对染料废水的ＣＯＤｃｒ的去除影响不大。同时,也考察了活性艳黄Ｘ－ ６Ｇ、活性艳蓝Ｘ－ ＢＲ 及活性艳红Ｘ－ ３Ｂ的ＣＯＤｃｒ的去除情况,反应７５ ｍｉｎ ,可以使上述３ 种染料的ＣＯＤｃｒ的去除率均达６０ ％ 以上。     

哌嗪合成中催化剂的研究

以Ｎ－β－羟乙基乙二胺为原料合成哌嗪，研制出一种高活性和选择性铜／载体型催化剂，并探讨了催化剂组成等因素对反应的影响，在Ｃｕ－Ｃｕ－Ｍｎ／γ－Ａｌ２Ｏ３催化剂和氢气的存在下，于１８０℃下反应２ｈ，原则料转化率达９８％以上，哌嗪收率为８８％。     

四羰基钴钠的合成及红外光谱研究

在常温常压下，用Ｎａ２Ｓ２Ｏ３／Ｆｅ－Ｍｎ粉为联合活化剂，将一氧化碳通入ＣｏＣｌ２／ＣＨ３ＯＨ溶液，制备了Ｎａ［Ｃｏ－（ＣＯ）４］，３ｈ后转化率可达９０％以上。选择性接近１００％。ＩＲ分析发现产物溶液在１９０４ｃｍ－１左右有一强的特征吸收峰，证实了［Ｃｏ（ＣＯ）４］－离子的存在。研究了反应条件对产率的影响，讨论了合成羰基钴钠的反应机理。     

先锋褐煤CO／H2O超临界萃取研究

在不同ＣＯ初压、不同催化剂作用下，以ＣＯ／Ｈ２Ｏ为溶剂对云南先锋褐煤进行超临界萃取，对萃取物的族组成进行了＾１Ｈ，＾１３Ｃ－ＮＭＲ分析。结果表明：萃取产率和转化率随ＣＯ初压增大而增加；ＣＯ和Ｈ２Ｏ可发生变换反应生成中间态活泼氢，从而具有较哟的供氢能力，使萃取产率和转化率提高；碱金属的氢氧化物及碳酸盐对ＣＯ／Ｈ２Ｏ变换反应有较强的催化作用；萃取物的油组分以单环芳香结构为主，具有较高的Ｈ／Ｃ比和较多的     

Water Gas Shift Reaction in a Membrane Reactor Using a High Hydrogen Permselective Silica Membrane

A membrane reactor (MR) for the water gas shift (WGS) reaction was developed by integrating a highly hydrogen permselective silica membrane. The membrane was prepared using an extended counter-diffusion chemical vapor deposition (CVD) method. A tetramethylorthosilicate (TMOS) silica source was fed from one side of the membrane support and oxygen gas fed from the other. The dense silica film was deposited on a porous support by pressurizing the side that TMOS is supplied. A high hydrogen permselective silica membrane was obtained by this method. A commercial Pt catalyst was used in the WGS reaction. Efficacy of the silica membrane toward the WGS reaction was investigated as a function of temperature (523-623 K), steam/carbon monoxide (S/C) ratio (1-3), differential pressure (0-100 kPa), and gas hourly space velocity (GHSV; 1800-5400 h^?1). The CO conversion in the MR was higher than that for a fixed bed reactor (FBR) under all experimental conditions, and was also higher than the thermodynamic equilibrium conversion under almost all experimental conditions. This was due to the selective abstraction of hydrogen from the product stream by the silica membrane. At an S/C of 1.0, the CO conversion in the MR was superior to that in a FBR by 16.8%.     

Upgrading of Simulated Syngas by Using a Nanoporous Silica Membrane Reactor

The permeance properties of a nanoporous silica membrane were first evaluated in a laboratory‐scale porous silica membrane reactor (MR). The results indicated that CO, CO₂, and N₂ inhibited H₂ permeation. Increased H₂ permeability and selectivity were obtained when gas was transferred from the lumen side to the shell side. This was therefore selected as a suitable permeation direction. On this basis, upgrading of simulated syngas was experimentally investigated as a function of temperature (150 – 300 °C), feed pressure (up to 0.4 MPa), and gas hourly space velocity (GHSV), by using a nanoporous silica MR in the presence of a Cu/ZnO/Al₂O₃ catalyst. The CO conversion obtained with the MR was significantly higher than that with a packed‐bed reactor (PBR) and broke the thermodynamic equilibrium of a PBR at 275 – 300 °C and a GHSV of 2665 h^–1. The use of a low GHSV and high feed pressure improved the CO conversion and led to the recovery of more H₂.     

Mathematical Modeling and Optimization of Combined Steam and Dry Reforming of Methane Process in Catalytic Fluidized Bed Membrane Reactor

Mathematical modeling of the methane-combined reforming process (steam methane reforming–dry reforming methane) was performed in a fluidized bed membrane reactor. The model characterizes multiple phases and regions considering low-density phase, high-density phase, membrane, and free board regions that allow study of reactor performance. It is demonstrated that the combined effect of membrane and reaction coupling provides opportunities to overcome equilibrium limits and helps to achieve higher conversion. Additionally, the influence of key parameters on reactor performance including reactor temperature, reactor pressure, steam to methane feed ratio (S/C), and carbon dioxide to methane feed ratio (CO₂/C) were investigated in the multi-objective genetic algorithm to find the optimal operating conditions. Finally, the process of steam reforming was simulated in selected optimal conditions and the results are compared to those of the combined reforming process. Comparison reveals the superiority of the combined reforming process in terms of methane conversion, catalyst activity, and outlet H₂/CO ratio in the syngas product in being close to unity.     

Effect of incipient removal of hydrogen through palladium membrane on the conversion of methane steam reforming: Experimental and modeling

This paper presents a mathematical model based on the reaction rate expressions to describe the displacement of methane conversion in the steam reforming. The effect of several parameters including weight hourly space velocity (WHSV), load-to-surface ratio, reaction pressure, hydrogen partial pressure in permeate side and reaction temperature were investigated. Simulation and experimental results showed that a conversion higher than 80% could be achieved in a palladium membrane reactor at reaction temperature of 500 °C relative to 850 °C in a conventional fixed bed reactor (FBR). Besides, the yield of CO (<2%) in membrane reactor was much lower than that (>50%) in the FBR, which indicated the significant depression of CO production in use of membrane reactor.     

CFD analysis of water gas shift membrane reactor

Fuel cell based modular power generation can be achieved by miniaturization and process intensification of equipments in the process. Fuel cells require hydrogen rich gas which can be generated through reforming and water gas shift reaction. The water gas shift reactor being kinetically limited occupies more volume to achieve the required CO conversion. A membrane reactor integrates the reaction and hydrogen separation stages and hence reduces the volume requirement. Computational Fluid Dynamics offers virtual prototyping of the reactor and thus helps in design, optimization and scale up of reactors. In this study customized User Defined Functions (UDFs) were developed to analyze the performance of low temperature water gas shift membrane reactor. The models were validated using literature data for the parameters – synthesis gas compositions, time factor, sweep flow rate and steam to CO ratio. The effect of all these parameters on the reactor was analyzed for CO conversion, H₂ recovery, DaPe, concentration polarization, concentration profiles and conversion index. The simulations have showed that the UDFs developed were capable of simulating the membrane reactor and this can be used for the design and optimization of the membrane reactor for any process conditions.     

Experimental Evaluation of Dehydrogenations Using Catalytic Membrane Processes

Abstract

Many industrially important dehydrogenation reactions are operated under conditions where the equilibrium conversion is limited by the production of hydrogen. Ceramic membrane reactors offer the potential for increased conversion at existing operating temperatures or reduced operating temperature for the same conversion level by removal of product hydrogen.

This paper reports the results of recent efforts to develop catalytic membrane reactors for the dehydrogenation of ethylbenzene to styrene. The focus of this study was to compare the performance of a hybrid reactor, consisting of a packed bed followed by a membrane reactor, with that of a traditional two-stage packed-bed reactor under industrially relevant conditions. The hybrid configuration mimics the simplest implementation of a ceramic membrane reactor, simulating the use of the membrane reactor as an add on stage to the existing reactor train.

A benchscale system has been developed that is capable of experimentally simulating the industrial operation. Features of this system include syringe pumps from which an ethylbenzene liquid hourly space velocity of 0.4 hr^?1 is attainable with a water:ethylbenzene molar ratio of 9, a 7-zone furnace in which isothermal catalyst bed temperature profiles within ± 1°C are achieved, and two dual FID/TCD on-line gas chromatographs for simultaneous analysis of the entire spectrum of compounds in the permeate and reject effluents from the reactor with 30 minute analysis turnaround time. The membrane module incorporates a four-point thermocouple in the catalyst bed to insure isothermal operation and three single-point thermocouples on the permeate side for monitoring purposes.

Results obtained with this system showed a 4% yield enhancement to styrene in the hybrid reactor compared to the traditional two-stage packed bed. This enhancement was achieved with no loss in styrene selectivity. Carbon deposition on the membrane was observed during reaction which rapidly reduced the permeability from 70 m³/m²/hr/atm for the fresh membrane to a value of 2 m³/m²/hr/atm under reaction conditions. This 2 m³/m²/hr/atm permeability was a steady state value representing a dynamic equilibrium between coke formation from organic compounds and coke removal due to the presence of steam in the reaction mixture and was constant for run times in excess of 100 hours.     

Membrane pilot reactor applied to selective oxidation reactions

The partial oxidation of butane to maleic anhydride was studied in a conventional fixed bed as well as a novel reactor configuration consisting of a porous metallic membrane immersed in a gas–solid fluid bed. The diameter of both reactors was at a commercial scale greater than 30 mm. A range of gas flow rates, temperatures and butane concentrations were tested. Maleic anhydride yield was generally higher in the membrane reactor due to higher butane conversion. Maleic productivity in the fixed bed equalled that observed in the membrane reactor when the gas–solid fluid bed was maintained at a higher temperature of as much as 30 °C. The butane feed rate to the membrane reactor was limited by hot spots. These hot spots were unanticipated and underscore the importance of increasing heat transfer in order to commercialize this technology.     

酶膜反应器控制系统的研制

提出了实现连续酶化反应的控制方案,利用单片机实时检测反应所需温度、pH值和体积,实现自动控制以满足连续酶化反应的要求。试验结果表明转化率和产物的产率均得到提高,该方法具有推广价值。     

Membrane reactors for hydrogen production

Fuel cell powered vehicles with on board reforming need compact and lightweight components. A membrane reactor, that combines hydrogen permeable membranes with a methanol steam reformer promises considerable weight and space savings. Its dense metal membranes produce high purity hydrogen over a wide range of pressure and load. The selective removal of hydrogen yields methanol- and CO-conversions that are higher than the equilibrium conversion in a conventional reactor. Results with three different metal membranes in a membrane reactor for steam reforming of methanol are presented. A mathematical model accurately describes the measured performance of the membrane reactor and allows predictions for other values of the process parameters.