共查询到18条相似文献,搜索用时 62 毫秒
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采用固定床积分反应器,研究了自制的负载型钯系催化剂上CO气相催化偶联主、副反应的宏观动力学模型.所采用的催化剂是经过模式1000 h连续运转、性能稳定的φ1.5 mm×(3~5)mm圆柱状催化剂.在适宜的反应条件下测定了动力学实验数据,并采用一维拟均相模型建立了微分方程组.使用了幂函数宏观动力学模型,采用Runge-Kutta法解微分方程组,并用单纯形法确定动力学模型参数,同时进行了残差分析和统计检验.结果表明,所得的动力学模型与实验数据吻合良好,可以为草酸二乙酯合成反应器设计和放大提供依据. 相似文献
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采用流程模拟软件PRO/II,对一氧化碳与亚硝酸乙酯合成草酸二乙酯工艺过程进行模拟。建立了工业过程设计详细流程,提供了模拟使用的主要物性参数、动力学模型及流程数据及其来源。流程模拟计算结果与实际生产数据吻合证明了模拟的可靠性。模拟考察了一氧化氮再生反应设计转化率对主要过程参数,如循环比、放空气中一氧化氮含量及乙醇补充量的影响。结果表明提高再生过程一氧化氮设计转化率,可以降低循环比,提高偶联过程CO的转化率,但亚硝酸乙酯利用率下降,乙醇补充量需相应提高。再生反应器较为适宜设计条件为:一氧化氮再生转化率为(92±2)%,压力为101.3~150kPa及温度为(308±2)K。 相似文献
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介绍一氧化碳常压气相催化偶联合成草酸二乙酯的基本原理、工艺流程、原材料及产品的规格、公用工程及消耗定额,分析该工艺的特点以及经济和社会效益.该工艺环境友好、技术先进,可供国内化肥企业开发新产品参考. 相似文献
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CO常压气相催化偶联法合成草酸酯新工艺 总被引:1,自引:0,他引:1
介绍一氧化碳常压气相催化偶联合成草酸二乙酯的基本原理、工艺流程、原材料及产品的规格、公用工程及消耗定额 ,分析该工艺的特点以及经济和社会效益。该工艺环境友好、技术先进 ,可供国内化肥企业开发新产品参考 相似文献
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一氧化碳气相催化偶联制草酸二乙酯的动力学研究 总被引:1,自引:0,他引:1
在固定床反应器内,测定了一氧化碳气相催化偶联制草酸二乙酯的动力学数据,建立了相应的幂函数型动力学方程式中k符合Arrhenius关系,k=32.3exp(-2.12×10~4/RT),检验结果表明:模型的置信度在99%以上。 相似文献
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一氧化碳偶联再生反应动力学研究 总被引:8,自引:1,他引:7
采用常压连续流动气液反应器,测定了CO气相偶联亚硝酸乙酯再生反应的宏观动力学数据,建立了相应的宏观动力学模型R_A=K_(pNO)反应的活化能E_a=19.46kJ/mol,指前因子A=0.341mol/(m~3·Pa·s).根据气液反应双膜理论,对反应过程进行了分析和参数计算.结果表明,再生反应为一级快反应,反应区在液膜内,反应速率主要受液膜传质控制.求出“本征”反应的活化能为E_a=22.86kJ/mol,指前因子A=1.741×10~8s~(-1). 相似文献
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研究了反应精馏合成草酸二乙酯的工艺条件,在自行设计的反应精馏塔内考察了挟带剂种类及用量、塔釜温度、进料速度、回流进料比对酯化反应的影响。环己烷为较适宜的挟带剂,确定了最佳工艺条件:塔釜温度为110℃,进料速度0.8 mL/min,回流比3。在最佳工艺条件下草酯二乙酯的酯化率达到92.16%。 相似文献
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This study focused on the performances and kinetics of the transesterification reaction of diethyl oxalate with methanol to prepare ethyl methyl oxalate via microreactor technology. The conversion of 79.8% of diethyl oxalate (DEO) and the selectivity of 65.9% of ethyl methyl oxalate (EMO) was obtained under the following optimized conditions: the mole ratio of methanol to diethyl oxalate was 3.3:1, the temperature was 35°C, the K2CO3 catalyst concentration was 15 mg/mL, and the residence time was 2.30 minutes. In the temperature range of 25°C to 38°C, the simplified dynamic model was found to obtain the reaction order (α = 2.30), frequency factor (k0 = 2.377 × 105), and apparent activation energy (E = 31.86 kJ/mol). The macroscopic dynamic equation was derived from the experimental result of the transesterification reaction of two feedstocks, which can be obtained through a series of calculations. 相似文献
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CO与亚硝酸甲酯(MN)氧化偶联制草酸二甲酯(DMO)是合成气制乙二醇过程的关键步骤,现有工业装置存在效率低的问题。采用包括副反应(生成碳酸二甲酯和甲酸甲酯)动力学的动力学模型和二维两相反应器模型,对CO氧化偶联的移热式固定床反应器进行建模,研究了换热方式及操作条件对反应器性能和安全性的影响。结果表明,以温度的二阶导数作为飞温的判据是灵敏和可靠的。与常规的逆流和恒温移热方式相比,并流移热使反应器形成更为均匀的温度分布,有利于提高反应器产能。增加入口MN含量会升高反应器MN转化率和热点温度;但是,由于CO、NO和反应物MN之间存在竞争吸附,增加入口CO和NO含量会导致MN转化率和热点温度降低,所以增加入口压力导致MN转化率降低。且热点温度对MN和NO的含量更为敏感,应严格控制入口MN和NO的含量。采用遗传算法进行反应器工况寻优,确定了最优的反应条件,可提高单台反应器对应的乙二醇(EG)年产能至12万吨。 相似文献
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CFD modeling of gas flow in porous medium and catalytic coupling reaction from carbon monoxide to diethyl oxalate in fixed-bed reactors 总被引:4,自引:0,他引:4
A comprehensive two-dimensional heterogeneous reactor model was developed to simulate the flow behavior and catalytic coupling reaction of carbon monoxide (CO)–diethyl oxalate (DEO) in a fixed-bed reactor. The two-temperature porous medium model, which was revised from a one-temperature porous medium model, as well as one equation turbulent model, and exponent-function kinetic model was constructed for the turbulent velocity scale comparing with laminar flow and simulation of the catalytic coupling reaction. The simulation results were in good agreement with the actual data collected from certain pilot-plant fixed bed reactors in China. Based on the validated approach and models, the distributions of reaction parameters such as temperature and component concentrations in the reactor were analyzed. The simulations were then carried out to understand the effects of operating conditions on the reactor performance which showed that the conduction oil temperature in the reactor jacket and the CO concentration are the key impact factors for the reactor performance. 相似文献
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Synthesis of diethyl carbonate from ethanol through different routes: A thermodynamic and comparative analysis 下载免费PDF全文
In this study, thermodynamic analysis of various possible synthesis routes of diethyl carbonates (DEC), a benign organic carbonate, was carried out and a comparative analysis was performed. Chemical equilibrium constants at standard conditions were calculated using Gibbs free energy of the system. The Benson group contribution method was used to estimate standard heat of formation and standard entropy change of some raw materials/components like dimethyl carbonate. Variation of heat capacity (Cp) with temperature was estimated for different components from the Rozicka‐Domalski model. Variation of chemical equilibrium constants with temperature and pressure was studied for various routes. Synthesis of DEC from ethylene carbonate (EC) was also found to be better considering equilibrium constants at room temperature. The CO2 route was found to be the most unfavourable route for DEC synthesis due to stability of CO2 molecules. Moreover, DEC synthesis through the urea route was found to be best at high temperatures since the equilibrium constants were found to increase exponentially. Experiments were conducted for DEC synthesis using the EC route at two temperatures. Activity coefficients were calculated using the UNIFAC model. Experimentally and theoretically determined chemical equilibrium constant values were found to be similar. PRO/II was also used to minimize Gibbs free energy of the system and estimate the equilibrium constants and the results were comparable with those obtained by the equilibrium constant method and the trend was found to be the same for both the methods. 相似文献
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