乙苯脱氢制苯乙烯反应器的技术进展

乙苯脱氢是工业生产苯乙烯的主要方法,传统生产方法有等温脱氢工艺和绝热脱氢工艺,分别采用等温列管式反应器和绝热轴向反应器,随着装置高效化和大型化的要求,负压脱氢工艺开发成功,反应器采用低阻力径向反应器,基本上为所有新建装置所采用。20世纪90年代我国开发了独特的轴径向反应器,首次应用于苯乙烯工业,形成了自主的负压脱氢制苯乙烯技术。     

延长乙苯脱氢催化剂GS-11使用周期的工业应用

介绍了两级负压绝热脱氢反应工艺的流程、乙苯脱氢反应原理、乙苯脱氢催化剂GS-11的物理性质,分析了导致催化剂活性下降的因素,以某厂苯乙烯装置为研究对象,在一定的生产负荷、水油比及反应压力的条件下,对反应转化率的两级负荷分配进行优化,找到了催化剂使用的最优转化率,延长了乙苯脱氢催化剂GS-11使用周期,预期使用寿命40个月以上。     

信息与动态

乙苯脱氢制苯乙烯国产化技术进展　　乙苯负压脱氢制苯乙烯的核心技术是乙苯负压脱氢制苯乙烯反应器 ,国际上主要有UOP/鲁姆斯技术和巴杰尔 /菲纳技术 ,都采用负压脱氢工艺和径向反应器技术。我国华东理工大学开发的乙苯负压脱氢反应器采用轴径向反应器技术和气 气快速混合技术两大关键技术 ,突破了技术垄断 ,形成了自主知识产权。轴径向反应器是在床层顶部采用催化剂自封式结构、以使径向床的顶部造成轴径向二维流动的新颖径向反应器。与传统的径向反应器相比 ,这种催化剂自封式结构取消了催化床上部的机械密封区 ,简化了径向床结构 ,有…     

三段乙苯负压脱氢制苯乙烯的工艺分析

介绍了三段中间再热式乙苯负压脱氢工艺、轴径向反应器及其在抚顺石化分公司的运行情况,建立了反应器模型,并对不同负荷工况条件下的生产进行了模拟,各反应器的转化率和选择性模拟计算值与实际分析值相吻合,该反应器模型可用于脱氢工艺分析并指导工业生产.     

苯乙烯装置中尾气压缩机机组的选型简介

在苯乙烯装置中,采用目前应用最为广泛,技术最为成熟的乙苯负压绝热脱氢工艺,其中包含脱氢过程,而脱氢反应的负压操作条件,则由装置的关键设备尾气压缩机产生。尾气压缩机无论国产还是进口,较多选用无油双螺杆压缩机,蒸汽轮机驱动。且压缩机、汽轮机公用一套润滑控制油系统。     

国内化学工程文献摘要

国内化学工程文献摘要９４００１乙苯脱氢径向反应器的模拟计算－盖旭东、佟泽民（北京石油化工专科学校），石油化工设计，１９９２，９（４）：１２。本文通过建立乙苯脱氢径向反应器的一维和二维模型，逐一说明各因素对乙苯脱氢反应过程的影响，并提出适宜的操作条件。...     

基于径向基函数神经网络的乙苯催化脱氢转化率的软测量应用

针对乙苯催化脱氢过程的特点,选用历史生产数据即乙苯进料、一反温度、二反温度、二反出口压力、水比、脱氢选择性,利用改进的径向基函数神经网络（RBFNN）来构建乙苯催化脱氢过程模型,通过企业实际生产数据对该网络进行测试,其结果表明该模型可真实模拟实际乙苯脱氢生产过程,为后续乙苯催化脱氢系统实施先进控制优化技术奠定了基础.     

苯乙烯装置脱氢催化剂性能分析

乙苯脱氢催化剂是苯乙烯生产装置的核心硬件之一,其活性、寿命、操作条件等自身性能对一套装置的实际生产有着很大程度的影响.本文借天津大沽500,000 t/a苯乙烯装置更换脱氢催化剂之际,从进料流量、反应温度、反应压力、乙苯进料组分、乙苯转化率、苯乙烯选择性、副产物、废气等方面简要分析了催化剂的各项技术指标,供相关技术人员参考.     

抚顺石化公司3万吨／年苯乙烯装置改造设计

以我国第一套乙苯负压脱氢工艺装置的技术特点及化塑厂乙苯（正压）扩能改造为负压脱氢工艺的结果,说明我国在苯乙烯生产工艺方面向前跨了一大步。     

抚顺石化公司3万吨/年苯乙烯装置改造设计

以我国第一套乙苯负压脱氢工艺装置的技术特点及化塑厂乙苯( 正压) 扩能改造为负压脱氢工艺的结果,说明我国在苯乙烯生产工艺方面向前跨了一大步。     

Hydrocracking: An improved Kinetic Model and Reactor Modeling

Stangeland's kinetic model for predicting hydrocracker yields was modified to explicitly account for the mass balance closure in each individual hydrocracking reaction and for the effect of hydrogen partial pressure on the hydrocracking reaction rate. This improved kinetic model has two additional parameters. The model was applied to the modeling of a fixed bed reactor for mild hydrocracking of vacuum gas oils in the framework of the Aspen Plus® process simulator. The kinetic parameters were regressed using the algorithm of Levenberg-Marquardt such that the mass balance in each individual hydrocracking reaction is satisfied. The reactor model assumed gas-liquid equilibrium and was used to quantify the effect upon conversion of the operating variables--liquid hourly spatial velocity, reactor pressure, and hydrogen-to-feed ratio--showing that both the kinetic and reactor models predict the appropriate trends compared to the reference data. The practical implications of explicitly introducing the mass balance closure for each hydrocracking reaction in the kinetic model are discussed.     

Hydrocracking: An improved Kinetic Model and Reactor Modeling

Stangeland's kinetic model for predicting hydrocracker yields was modified to explicitly account for the mass balance closure in each individual hydrocracking reaction and for the effect of hydrogen partial pressure on the hydrocracking reaction rate. This improved kinetic model has two additional parameters. The model was applied to the modeling of a fixed bed reactor for mild hydrocracking of vacuum gas oils in the framework of the Aspen Plus® process simulator. The kinetic parameters were regressed using the algorithm of Levenberg-Marquardt such that the mass balance in each individual hydrocracking reaction is satisfied. The reactor model assumed gas-liquid equilibrium and was used to quantify the effect upon conversion of the operating variables--liquid hourly spatial velocity, reactor pressure, and hydrogen-to-feed ratio--showing that both the kinetic and reactor models predict the appropriate trends compared to the reference data. The practical implications of explicitly introducing the mass balance closure for each hydrocracking reaction in the kinetic model are discussed.     

氯醇化管道反应新工艺的压降和传质的研究

氯醇化管道反应新工艺是环氧丙烷生产过程中关键步骤，该反应属气液非均相系统，但装有Ｋｅｎｉｃｓ型静态混合构件的管道反应器用于气液系统还缺乏大量的基础数据。研究以Ｎ２－Ｈ２Ｏ２作为实验系统，测定了不同工况下压降和氧含量，并应用一心均相模型救是了相应的摩擦系数和传质系数。     

Vapour–liquid slip in a parallel-plate electrochemical fluorination reactor

A mathematical model was used to study the effect of slip between the gas and liquid phases on the performance of an electrochemical fluorination reactor. The model incorporates two-phase flow with differential material, energy and pressure balances. The effect of slip on the temperature, pressure, gas fraction and current distribution in the reactor is presented under relatively severe operating conditions. In addition, the effect of slip on the cell voltage, current efficiency and energy usage is shown at different flow rates over a wide current range. It was found that slip of the gas past the liquid is insignificant under normal operating conditions, but it is significant at high cell currents and low flow rates. Under these more severe operating conditions, slip significantly reduces the cell voltage, and hence the energy usage, since less gas resides in the reactor.     

Selective Hydrogenation of 1‐Butene Rich Cuts: the Impact of the Intraparticle Diffusion Limitations on the Selectivity

The impact of intraparticle diffusion limitations on the selectivity of an industrial reactor for selective hydrogenation of 1‐butyne and 1,3‐butadiene contained in 1‐butene rich cuts was evaluated. To this end, a simple model of a trickle‐bed reactor was employed and actual process operating conditions were chosen. A kinetic model was chosen whose parameters correspond to a commercial catalyst. These parameters were calculated from experiments conducted under industrial operating conditions. The complex diffusion and reaction phenomena occurring inside catalyst pellets placed at different depths of the reactor are comprehensively described. 1‐Butene losses in the range 20–30 %, which are usual in commercial plants, were predicted. It was concluded that the operating pressure is crucial for enhancing process selectivity.     

A new two-impinging-streams heterogeneous reactor

The characteristics of a new heterogeneous reactor of the “two impinging streams” type, suitable for gas-solid heat and mass-transfer operations, were investigated. The operating limits of the reactor, with respect to gas and solid particles mass flow rate and pressure drop, were determined; scale-up criteria with respect to the hydrodynamics of the reactor were also established. It has been found that, under certain conditions, the introduction of solid particles into the gas stream lowers the pressure drop on the reactor. In addition, the maximal pumping energy per kg of solids transported through the reactor by the air is much lower than in a fluidized-bed-type reactor. A stochastic model based on Markov processes was developed which closely describes the behavior of the solid particles in the reactor. A technique based on this model was employed for determining the residence time distribution of the particles in the reactor.     

催化精馏法合成2-羟丙基甲醚

研究了用催化精馏工艺由环氧丙烷和甲醇合成2-羟丙基甲醚的方法。建立了动力学模型。通过ASPEN PLUS对体系物性数据进行模拟估算。并通过过程模拟和实验对催化精馏塔的工艺条件进行了研究,主要讨论了不同操作压力下的单位催化剂的最大处理量、进行醇烷比（摩尔比,下同）、回流量L与进料关键组分流量FPO之比（摩尔比,下同）对选择性影响,确定了催化精馏塔的工艺操作条件。     

Deposition uniformities on a wafer and in a trench for tungsten silicide LPCVD in a single-wafer reactor

A transient model of a single-wafer reactor in axisymmetric, stagnation point flow is used to study the effects of operating conditions on film thickness uniformity and composition uniformity across the wafer during low pressure chemical vapor deposition of tungsten silicide. Orthogonal collocation on finite elements is used to solve the transient model equations; continuity, momentum, energy and chemical species balances. A feature scale model for simultaneous Knudsen transport and heterogeneous reactions is used to predict film thickness in infinite trenches. Boundary conditions for the feature scale model are established using the reactor scale model. The use of a combined reactor scale and feature scale model is demonstrated to select deposition conditions which provide both good interwafer uniformity and good intrafeature uniformity. Film thickness and composition uniformity on a wafer are predicted using a model for a single-wafer reactor. Significant differences in step coverage predicted using partial pressures in the feed stream and partial pressures at the wafer surface were observed. Step coverage differences between the wafer center and the wafer edge were also significant under the operating conditions used in this study. Uniformities of interwafer and intrafeature step coverages inceased as either the wafer temperature or the partial pressure ratio of dichlorosilane to tungsten silicide in the feed was decreased.     

Drying Characteristics and Kinetics of Vacuum Microwave–Dried Potato Slices

Vacuum microwave dehydration characteristics and drying kinetics of potato slices were evaluated using a laboratory-scale dryer. The test materials were placed on a rotating tray to allow uniform exposure to the microwave field. The effect of drying conditions on the drying characteristics was investigated. As expected, higher drying rates were obtained with higher microwave power and lower vacuum levels. The effect of vacuum pressure on drying rate was not as significant as that of microwave power. The Henderson & Pabis model provided better simulation of the drying curves for potato slices. Empirical models are presented for the drying rate constant as a function of the microwave power and vacuum pressure for potato slices under the range of operating conditions tested.     

SOME ASPECTS OF THEORETICAL COMPARISON OF FISCHER-TROPSCH REACTORS

The reactor systems used for the Fischer-Tropsch synthesis, fixed bed, fluidized bed and slurry bed, are compared on the basis of space time yield (STY) and level of conversion obtainable under the same set of feed and operating conditions. The slurry bed and fluidized bed reactor were compared on the basis of a first order reaction model. The performance of these two reactors was found to be comparable at low values of WHSV, but at higher values of WHSV, the fluidized bed reactor gave higher conversions and STY. A power law kinetic expression was used to compare the performance of the slurry bed and fixed bed reactors. Higher conversions and STY were obtained from the fixed bed with varying WHSV. This may be due to the omission of the intra and inter phase mass transfer resistances in the modelling of the fixed bed reactor.