对苯二甲酸（PTA）间歇酯化反应计算机模拟

为了研究不同的工艺操作参数对ＰＴＡ转化率和副产物形成的影响，针对ＰＴＡ间歇酯化建立了一较完善的反应模型．模拟过程中考虑了重要工艺参数如乙二醇（ＥＧ）与ＰＴＡ配比、温度等的影响，对既能达到最高生产效率又能最小限度减少副产物的工艺参数范围提出了建议．     

Modeling of poly(ethylene terephthalate) reactors. II. A continuous transesterification process

A comprehensive mathematical model for a continuous transesterification process has been built so as to enable prediction of the influence of different process and operational variables on productivity and by-product formation. The influence of temperatures and temperature profiles, of residence time and residence time distribution, and also of the number of reactors in series has been investigated. The modeling has been done as close to the industrial practice as possible. Important pragmatic implications from the point of view of operation of continuous transesterification are highlighted.     

Modeling of poly(ethylene terephthalate) reactors: 5. A continuous prepolymerization process

A mathematical model for the continuous prepolymerization of BHET to PET, carried out in a series of stirred tank reactors, has been developed. The influence of process and operational variables on productivity, as well as the side-product formation (which controls the product quality), have been studied in a range as close to industrial practice as possible. The overall conclusions concerning the productivity profile, as well as some side products, appear to be substantiated from the available data in the open literature. The results of the mathematical model have been used to highlight the key process and operational variables that are likely to give the best productivity and product quality in industrial practice.     

Modelling of poly(ethylene terephthalate) reactors. III. A semibatch prepolymerization process

A mathematical modelling of a semibatch prepolymerization process has been undertaken. Prepolymerization conducted at constant temperature and pressure and with a predetermined variation in temperature and pressure has been studied. Influence of DMT and TPA addition during prepolymerization has also been examined. The focus has been on investigation of the influence of processing and operational variables on productivity and side product formation, which controls product quality. The results of this investigation (which are applicable only up to DP ? to 30) are borne out by the limited experimental data available in the literature. Important pragmatic implications of the results of the work in terms of design and operation of prepolymerization reactors have been emphasized.     

Modeling of poly(ethylene terephthalate) reactors: 4. A continuous esterification process

A mathematical model has been developed for the direct, continuous esterification process. Influence of process and operational variables, including temperature distribution, residence time distribution, bis(hydroxyethyl)terephthalate recycle, pressure, and ethylene glycol (EG) to terephthalic acid ratio on the reactor performance have been investigated in a range as close to industrial practice as possible. The variables influencing the amount of EG reflux (which governs the energy economy) and side products (which govern the product quality) have been discussed. This investigation provides an analysis of a continuous, direct esterification process, and the results indicate strategies for optimizing productivity and product quality.     

PET预缩聚反应计算机模拟

为了研究不同的工艺操作参数对ＰＥＴ预缩聚反应过程的影响,建立了一间歇预缩聚反应模型。编制了计算机软件对过程进行了模拟,讨论了重要工艺参数压力、温度等对ＰＥＴ预缩聚反应的影响。     

Influence of heat transfer and curing on the quality of pultruded composites. I: Experimental

Blister formation, a major concern in pultrusion, has not been studied in detail. The objective of this study is to investigate the mechanism of blister formation and the effect of process variables such as die temperature, pulling speed, die length, and composite thickness on blister formation. Dies with different length and a stop-start method were used to investigate blister formation. The results show that for a given die and resin system, low temperature and a higher pulling speed lead to blister formation. Longer dies can prevent blister formation. Based on the experimental results, process windows for 4-mm-thick and 6-mm-thick composites are established for a vinyl ester resin. This study suggests that heater power input should be optimized in high-speed pultrusion.     

Near-fluidizing microwave drying to stabilize encapsulated material: Analysis of kinetic,energy and quality elements

Dehydration of the encapsulated material containing nutritional ingredients was determined to be necessary for functional foods and probiotics production. The application of a suitable drying process was required. This study proposes the development of a new dehydration process, called near fluidizing microwave drying (NFMD), to minimize the problems observed in other drying processes, such as spray drying or lyophilization. Several heating strategies, which are employed in microwave applications under fluidizing conditions, were adequately modeled to analyze the effect of the operational variables. The fitting of experimental data has enabled the determination of the mass and heat transfer coefficients: diffusivity and heat convection. The drying phases were analyzed based on the obtained values of these parameters as basis for the selection of the most favorable operational conditions. Under these conditions, the NFMD process has been employed for the dehydration of the encapsulated probiotic Bifidobacterium animalis subsp. Lactis (BB12). The best results of the cell viability were around 90%, demonstrating the suitability of this novel technology for these thermo-sensitive materials.     

Glycerylbisether sulfates. I: Improved synthesis

Sparse literature outlines previous syntheses for glycerylbisether sulfates, which, while giving rise to the desired molecules, are somewhat cumbersome and suffer from undersired by-product formation. We now report an improved synthesis of the title compounds that results in greater simplicity and reduced by-product formation. An hypothesis is advanced to explain the by-product formation.     

聚酯（PET）反应过程研究：Ⅶ后缩聚反应过程研究和数学模拟

对聚酯的后缩聚反应过程进行了分析，把该过程分解为反应动力学和反应器内各种传质；对后缩聚反应进行了实验研究。建立了适用于工业装置的后缩聚反应过程的数学模型     

Simulation of three-stage nylon 6 reactors with intermediate mass transfer at finite rates

A three-stage isothermal nylon 6 reactor with a kinetic scheme incorporating ring opening, polycondensation, polyaddition, cyclic dimer formation, and reaction with monofunctional acids has been modeled. In the first and third stages, removal of the condensation by-product, water, is prevented. The second stage of this sequence, however, involves finite rates of diffusion of water to cocurrently flowing inert gas bubbles. the number-average chain length of the polymer obtained in this reactor differs substantially from that obtained assuming instantaneous water removal and is a function of the various design variables. It is observed that several choices of these design variables can be made to obtain the same product, thus emphasizing the need for more comprehensive optimization studies than hitherto carried out.     

Comparison of by-product and heat-recovery cokemaking technologies

This paper describes comparison of the heat-recovery and by-product cokemaking technologies. Different conditions of the plant, such as availability and cost of energy sources, site area, plant configuration can play a key role in cokemaking technology selection process. Two studies for cokemaking technology selection using methodology developed by Hatch has been shown with different technology chosen in each case due to influence of the different key factors.     

Preparation of activated carbons from olive-tree wood revisited. II. Physical activation with air

Olive-tree has been grown in the Mediterranean countries for centuries. For an adequate development of the tree it must be subjected to different treatments such as trimming, large amounts of a woody residue being produced. Such a residue has been traditionally used as a domestic fuel or simply burnt in the landfield. In both cases greenhouse gases are generated to a large extent. Thus, the preparation of activated carbons from olive-tree wood appears as an attractive alternative to valorize this by-product. Commonly, two activation strategies are used with such an aim, namely chemical and physical activation. In this study, the optimization of the physical activation method with air for the production of activated carbon has been analyzed. The results obtained clearly show that if the preparation conditions are adequately controlled, it is possible to prepare activated carbons showing tailored properties in terms of micro- or mesoporous texture and surface area.     

氰化钠工业发展趋势分析

回顾了氰化钠工业的发展过程;结合对轻油裂解法、安氏法、丙烯腈副产法以及其它生产工业的发展、技术水平和制约因素的论述,分析了行业当前的现状和问题;对今后的发展予以展望。     

竖炉焙烧过程METSIM动态模拟

竖炉焙烧是我国赤铁矿选矿工业中常见的工艺环节。其关键工艺指标是磁选管回收率, 反映了矿石焙烧的质量。但磁选管回收率无法在线实时测量。在实际生产中, 对竖炉焙烧磁选管回收率的控制一般通过运行优化控制实现。而运行优化控制策略的设计需要进行大量工业现场实验, 建立磁选管回收率相对于主要控制变量的动态响应关系, 这样做的成本高, 风险大。为了解决这一问题, 基于冶金模拟软件METSIM设计了竖炉焙烧工艺动态模型, 并采用与实际一致的过程控制软硬件系统建立了竖炉过程半实物仿真系统。通过仿真实验获得磁选管回收率与燃烧时温度设定值之间的动态关系, 并与实际数据进行了比较验证。表明该平台能够作为运行优化控制方法设计的实验和测试工具。     

盐酸作吸收剂用于气态膜法从废水中脱除/回收氨氮

考察了盐酸作吸收剂时用气态膜技术从水溶液中脱氨的可行性,鉴于盐酸的挥发性,着重考察了不同料液氨水浓度下气态膜过程可以稳定操作时所对应的吸收液中盐酸的临界浓度。在此基础上,研究了料液氨氮浓度、料液流速、吸收液流速、吸收液盐酸浓度和操作温度等操作参数对膜传质性能的影响,并考察了该工艺的长期操作稳定性。实验结果证明,气态膜脱氨过程可采用一定浓度的稀盐酸溶液作为吸收剂,并可通过向吸收液中不断添加浓盐酸的方式得到浓度为>15%的氯化铵溶液。在料液浓度为2000 mg/L、吸收液盐酸浓度为2%、操作温度为25 ℃的操作条件下,中空纤维膜组件持续稳定运行了650 h以上,总传质系数保持在4.25×10?6 m/s左右。用盐酸作吸收剂时废水中氨氮可脱至15 mg/L以下,符合国家环保标准。这表明采用盐酸作吸收液用气态膜法从废水中脱除回收富集氨氮是可行的。     

苯加氢生产环乙烷工艺的研究和改进

介绍一种新型苯加氢生产环己烷工艺路线。现场生产数据表明,该工艺具有设备投资低,催化剂使用寿命长,环己烷选择性好,副产蒸汽品质高等特点,具有很好的经济前景。     

Stability Study on Ethylene Oxide Industrial Reaction from the Management of Critical Process Variables

The performance of an ethylene oxide process is measured by the selectivity reaction. A production unit was studied in order to maximize selectivity by developing a strategy to manage key process variables. A statistical analysis of data indicated that four variables account for the influence over selectivity. Regression models were developed in order to represent the process selectivity as a function of these variables. The model proposed was statistically and phenomenologically validated, demonstrating consistency with the current data process. The model was deployed in subsets, representing possible operational conditions. Surface responses were evaluated for each model deployed and provided to identify the optimum operational conditions.     

Alternative calcium-sulfate-bearing materials as cement retarders: Part II. FGD gypsum

The aim of this paper is to investigate the possible displacement of natural gypsum (CaSO₄·2H₂O) in cement with an alternative setting retarder, such as the industrial by-product derived from flue gas desulfurization process called FGD gypsum. These calcium-sulfate-bearing materials (CSBM), alone or in mixtures, were ground with clinker both in laboratory and industrial scale to examine their influence on the physical and mechanical properties of cement, as well as on the industrial production line of cement. From the present work, it is extracted that the use of mixtures of sulfate-bearing materials with gypsum seems to be advantageous for the actual control of setting time. The addition of FGD gypsum increases setting time without affecting compressive strength profile. During the industrial trial, the formation of hemihydrate form of calcium sulfate dihydrate has a profound regulatory effect on the setting and strength performance of the cement partially replaced with FGD gypsum.     

一种新型的基于Levenshtein距离层次聚类的时序操作优化方法

现代流程工业过程中，DCS采集并存储了大量的操作时序数据，若能将其中有价值的操作经验和操作信息提取出来，则可大大提高操作系统的性能。然而，操作经验概念较为模糊，无法具体量化。因此，将具有时序特征的操作数据符号化，使操作经验以区块化形式表示，并提出一种基于Levenshtein距离的时序层次凝聚聚类算法，通过对操纵变量的历史时序操作数据进行相似性搜索，进而获得多种相似的操作模式，并将每种类型的操作模式对应的过程变量进行性能分析，从而得到并保存实际工作过程中所需的操作经验，以达到生产过程操作优化的目的。为了验证所提出方法，将其用于连续组分精馏操作过程，实验结果表明所提出的基于Levenshtein距离层次聚类的操作优化方法的有效性。