费托合成铁基催化剂浆态床反应性能的研究

为了获得工艺参数对铁基催化剂费托合成产品分布的影响规律,在浆态床反应器中考察了反应温度、反应压力、氢碳比、空速对铁基催化剂费托合成反应性能的影响。结果表明,温度升高时,催化剂活性、CO_2和CH_4选择性均升高,产物向轻组分分布;压力增大时,催化剂活性和CO_2选择性升高,CH_4选择性下降,产物向重组分分布;随氢碳比的增加,催化剂活性和CH_4选择性升高,CO_2选择性下降,C_(5+)呈下降趋势;随空速增加,催化剂的活性和CO_2选择性下降,CH_4选择性上升,C_(5+)向轻质烃分布。选择合适的工艺条件,可有效改善铁基催化剂的费托合成反应性能,控制碳链长度和产物的分布,提高费托合成反应的经济性。     

A systematic generation of reactor designs: I. Isothermal conditions

A new method is proposed for systematic generation of conceptual design of reactor networks. Given feed compositions and a kinetic model, the objective is to find the optimal mixing structure and feed distribution. The method aims at finding the optimal sequence and sizes of ideal reactors and the optimal addition of extra feed streams along the reactor path. The total reaction time is calculated so as to maximize the space time yield subject to a minimum yield of the key product component. The method does not have any limitations with respect to the number of components or reactions. A new model formulation is proposed that comprises both CSTR and PFR model equations and the design problem is formulated as an optimal control problem. In this paper, only isothermal conditions are considered.     

Optimal temperature policy in a riser reactor

The nature of the optimal axial temperature distribution in a riser reactor to maximise the yield of the intermediate B, in the reaction sequence A→B→C was investigated by way of the selective oxidation of naphthalene to phthalic anhydride. For this case, imposition of an axial profile could not improve the yield over that obtainable by operating at the optimum isothermal temperature. This result appears to be general, and suggests that optimal yields could be obtained by operation at the optimum isothermal temperature, which should prove easier to implement in practice than a specified temperature distribution.     

CFB提升管等效反应器网络模型

对气固循环流化床（CFB）提升管内的非均相流动行为进行了计算流体力学（CFD）模拟。基于CFD时均流场数据与信息,搭建了用于描述提升管内非理想流动过程的等效反应器网络（ERN）模型。在ERN模型建立过程中提出了反应器网络的6个拓扑结构参数和一个等效判据,并系统地分析了等效反应器网络结构六参数的性质与确定方法,从而形成了一套CFB提升管流动模型建模方法。     

Tube-wall reactor modelling for multiple reaction networks with non-linear kinetics and volume change

Tube-wall reactors are gaining importance for highly exothermic and fast chemical reactions because of their simple construction and improved temperature control. A generalized mathematical model of the non-isothermal annular tube-wall reactors for simultaneous catalytic reactions with mixed type non-linear reaction kinetics and volume change is developed. Numerical solutions of two-dimensional component transfer equations, heat transfer equation and fluid flow equation may be obtained with appropriate boundary conditions using a recently developed orthogonal collocation method for annular geometries. The model has been successfully applied to the tube-wall reactors for the Fischer-Tropsch Synthesis. Comparison between model predictions and previous experimental results is good.     

300kt/a氨合成塔外壳的设计

对某 30 0kt/a氨合成塔外壳的设计、材料选择及部分密封件结构与焊接情况等作了说明。筒体采用多层包扎 ;多层筒体与底部球形封头之间用一锻环过渡 ;筒体端部与圆形平盖之间采用大型螺栓紧固的双锥密封结构。内筒材料为SA387Gr .1 2CL2 ,多层层板材料为SA72 4Gr.B ,底部封头材料为SA387Gr.2 2CL2。筒体及筒体与端部的堆焊材料为INCONEL 82。双锥环以柔性石墨作垫片。测试结果表明 ,该设计经济可靠。     

吡啶及其衍生物催化合成进展及应用前景

吡啶及其衍生物广泛应用于医药。农药。橡胶和染料的生产。本文综述了目前世界工业上用Tl,Pd,Pb,Cd等金属改进的沸石分子筛(如ZSM-5。β。Y等)作为催化剂,以醛。酮。醇。不饱和烃或芳胺与氨反应来催化合成吡啶及其衍生物的概况,以及采用甲醇和空气进行催化剂再生的新方法。     

撞击流反应器用于甲醇合成反应

撞击流反应器用于气液固三相甲醇合成反应可以充分发挥其优良的传热、传质性能。在撞击流反应器内,催化剂浆料经喷嘴雾化后成微米尺度的液滴,气液相间接触面积远大于其他三相合成反应器。考察了温度、压力、气体流量、浆料循环量以及喷嘴个数对甲醇合成反应的影响,结果表明,当压力从3.8 MPa上升到5 MPa时,反应器的时空产率增长了近1倍,气体流量达22.4 L·min^-1后时空产率几乎不再变化,增加浆料循环量以及在同一循环量下采用多喷嘴对置都可以增加催化剂时空产率。同时,与固定床、搅拌釜和浆态鼓泡床甲醇合成进行了对比,结果表明,在低空速下撞击流反应器与其他反应器时空产率相当,而在高空速下要优于其他反应器。     

反应器网络综合优化方法的研究进展

反应器网络综合优化方法在选择反应器类型和反应工艺条件时,比传统的方法表现出了很大的优势。综述了各类反应器网络综合优化方法的基本原理和研究进展,并分析了它们的优缺点。这些方法有基于过程特征的方法,包括可得区法和导数分析法;超结构优化法;目标类方法,包括目标法、构造目标法和构造MINLP法;以及经验推断法和分布参数法等。最后分析了这方面研究的发展趋势。     

Application of methanol synthesis reactor to large-scale plants

The developing status of world large-scale methanol production technology is analyzed and Linda's JW low-pressure methanol synthesis reactor with uniform temperature is described. JW serial reactors have been successfully introduced in and applied in Harbin Gasification Plant and the productivity has been increased by 50% and now nine sets of equipments are successfully running in Harbin Gasification Plant,Jiangsu Xinya, Shandong Kenli,Henan Zhongyuan, Handan Xinyangguang,' Shanxi Weihua and Inner Mongolia Tianye. Now it has manufacturing the reactors of 300,000 t/a for Liaoning Dahua. Some solutions for the structure problems of 1000 ～5000 t/d methanol synthesis rectors are put forward.     

Fischer–Tropsch synthesis: Overview of reactor development and future potentialities

An overview of the reactors utilized for the Fischer–Tropsch synthesis is considered during three time periods: discovery to 1945, 1945–1970, and 1970 to date. A brief outline of the scientific and engineering developments related to chemical reactor design for the same three periods is also presented. In general, the reactor developments outpaced the ability to utilize the scientific and engineering advances on the academic level. However, today it appears that the academic and industrial developments closely match each other in content and interests. Even so, the availability of reliable data from large-scale pilot plants and/or commercial operations remain available only to the organization developing the data.     

对撞流反应器甲醇合成实验研究

液相法甲醇合成由于有惰性液体介质的存在,气液相间传质对反应起到了一定的阻碍作用,对撞流反应器使用喷嘴将催化剂浆料雾化从而强化了气液相间传质。文中在对撞流反应器内对甲醇合成温度、合成气比例、气流量、浆料循环量以及喷嘴个数进行了考察,结果表明,温度控制在230℃左右操作比较适宜,二氧化碳参与反应对甲醇合成较为有利,合成气流量在22.4 L/min以后时空产率几乎不再增加,增加浆料循环量和采用对置式二喷嘴或四喷嘴比单喷嘴时空产率和出口甲醇体积分数都有所增加。由结果可知,利用喷嘴雾化和液体对撞可以显著地增强气液传质从而达到增加液相甲醇合成时空产率的目的。     

Optimal synthesis of Fenton reactor networks for phenol degradation

There is an increasing need to treat effluents contaminated with phenol with advanced oxidation processes (AOPs) to minimize their impact on the environment as well as on bacteriological populations of other wastewater treatment systems. One of the most promising AOPs is the Fenton process that relies on the Fenton reaction. Nevertheless, there are no systematic studies on Fenton reactor networks. The objective of this paper is to develop a strategy for the optimal synthesis of Fenton reactor networks. The strategy is based on a superstructure optimization approach that is represented as a mixed integer non-linear programming (MINLP) model. Network superstructures with multiple Fenton reactors are optimized with the objective of minimizing the sum of capital, operation and depreciation costs of the effluent treatment system. The optimal solutions obtained provide the reactor volumes and network configuration, as well as the quantities of the reactants used in the Fenton process. Examples based on a case study show that multi-reactor networks yield decrease of up to 45% in overall costs for the treatment plant.     

Experience with a new type of reactor for Fischer-Tropsch synthesis

Circulating fluidised bed (CFB) reactors have traditionally been used for the high temperature Fischer-Tropsch synthesis-Synthol process. A development program undertaken by Sasol with the assistance of The Badger Company recently led to the successful commissioning of a commercial scale conventional, fixed fluidised bed (FFB) reactor as an alternative to the CFB reactor.Work was done in a small pilot plant which was followed by work in a 1 m diameter semi-works pilot plant operated in parallel with one of the commercial CFB reactors. Based on the positive results obtained, it was decided to build a commercial scale FFB reactor with a capacity similar to existing commercial reactors at Sasol One. This reactor was successfully commissioned and has been in operation since May 1989.The reactor is easy to operate and can withstand major plant instabilities. A techno-economic analysis and comparison between the Synthol-CFB and Synthol-FFB reactors indicates significant advantages for the Synthol-FFB reactor, both with respect to capital and operating costs. The results of this analysis and comparison are presented and the significance of the findings discussed in terms of future plants for the conversion of synthesis gas to liquid fuels.     

Methanol synthesis in a forced unsteady-state reactor network

The feasibility of carrying out the low-pressure methanol-synthesis process in forced unsteady-state conditions, using a network of three catalytic fixed bed reactors with periodical change of the inlet position, has been investigated; advantages and limitations in comparison with the previously proposed reverse-flow reactor have been highlighted. The effect of the main operating parameters—inlet temperature, switching time, inlet flow rate—has been studied. A cyclic-steady-state condition and auto-thermal behaviour are possible; nevertheless, they are attainable only for switching times varying in two narrow ranges. Out of these regions, complex steady-states of high periodicity, where conversion is low, or extinction of the reactors occur. For low values of the switching time, the establishing of optimal temperature profiles along the network allows higher conversions than in the reverse flow reactor. Furthermore, the performances of the network are weakly affected by wash-out, the removal of unconverted gas in correspondence of switching, which is in intrinsic disadvantage of reverse flow operation.     

On the effect of cluster resolution in riser flows on momentum and reaction kinetic interaction

Fine grid simulations of reactive gas-solid flows in a riser were carried out using an Eulerian multi-fluid kinetic theory of granular flow (KTGF) approach. A translationally periodic section of the riser was used to replicate experimental data collected in the fully developed region of a tall riser. The spatial and temporal resolution was varied in designed experiments to find an appropriate compromise between overall numerical accuracy and computational time. Results revealed that, when first order implicit timestepping is used, no timestep independence could be reached with timestep sizes that are practically feasible. Timestep independence could only be achieved by using second order implicit timestepping. Grid independence was studied in terms of cell width and cell aspect ratio. Solution independence could be reached at a cell width in the range of 10 particle diameters, but no complete grid aspect ratio independence could be achieved. Results suggested that grids with an aspect ratio smaller than one might be necessary to attain grid independent solutions. When sufficiently fine grids are used, however, the effect of a change in aspect ratio is sufficiently small to attain accurate solutions with an aspect ratio of two or lower. Certain important conversion measures were identified for scaling between simulation results collected in a 3D cylindrical domain and those predicted by a 2D planar simulation. System behavior predicted using these scaling rules agreed well with experimental results.     

Controlled synthesis of alumina in a spray flame aerosol reactor

In this study, a spray flame aerosol reactor (S-FLAR) is used to synthesize alumina nanoparticles. The as-produced powders are then characterized by X-ray diffraction, N₂ physisorption, and transmission electron microscopy to determine the crystal phase, surface area, particle size distribution, and morphology. The effects of the precursor, dispersion oxygen, and sheath oxygen rates on the characteristics of synthesized alumina were investigated. On increasing the precursor rate, decreasing the dispersion oxygen rate or sheath oxygen rate; the alumina powder surface area decreased. With increasing precursor rates and decreasing dispersion oxygen rates, the proportion of theta alumina increased and that of eta alumina decreased. When using an S-FLAR to synthesize alumina, the dispersion oxygen rate offers the best control of the surface area, while the precursor rate controls the crystal phase proportions. This result is useful for the design and operation of spray flame aerosol reactors to produce alumina-based catalysts.     

Self-Tuning control of fischer-tropsch synthesis in a tube-wall reactor

This paper describes the implementation of a self-tuning controller (STC) on a bench-scale tube-wall reactor for the Fischer-Tropsch synthesis using a plasma-sprayed iron catalyst. The concentration of the hydrocarbons in the C₁₀ range in the reactor effluent was controlled by manipulating the H₂/CO ratio of the inlet synthesis gas. The output of the self-tuner was cascaded to two PI-controllers which maintained a constant total inlet gas flow rate as well as ensuring the desired H₂/CO ratio. The concentration measurement was performed by an on-line gas chromatograph with an analysis time of approximately 30 s. The performance of the STC in set-point tracking, rejection of randomly occurring deterministic disturbances, and estimation and adaptation to the unknown process dead time was investigated. The STC was able to reduce the variance of the process output and of the manipulated variable when compared to the variances obtained with a PI-controller.     

环氧乙烷合成反应器温度-时间优化策略

根据工业实际生产数据反算得到能够反映催化剂失活特性的银催化剂失活动力学方程.在失活模型基础上,对环氧乙烷合成反应器的管外沸腾水温度-时间策略进行优化,得到最优沸腾水升温曲线,从而提高环氧乙烷反应的经济效益.对同系列新型催化剂的反应器操作优化提出了可行的研究方法.     

Non-ideal reactor network synthesis through IDEAS: Attainable region construction

The attainable region (AR) for non-ideal reactor networks is constructed for the first time using the Infinite DimEnsionAl State-space (IDEAS) framework. The axial dispersion model is used to represent a non-ideal reactor, and it is shown that the IDEAS framework and associated Shrink-wrap algorithm are applicable to this model. A case study demonstrates that the AR for a reactor network featuring non-ideal dispersion models is larger than the AR for a reactor network featuring only ideal CSTR/PFR models.