Selection of the sequence of separation of ternary mixtures

Two optimization problems are considered. One of them is the problem of the sequence of separation of a ternary mixture in a two-step system for which the energy consumption in processes at given capacities is minimal, and the other is the problem of the optimal distribution of contact surfaces between the first and second steps. For thermal separation systems, the dependence of the maximum possible capacity of the system on the sequence of separation of components is analyzed.     

Studies in process synthesis—I: Branch and bound strategy with list techniques for the synthesis of separation schemes

The synthesis of a good flowsheet for a multicomponent separation problem constitutes a formidable task even for a small scale problem. The number of alternate, feasible separator sequences increases rapidly as the number of components in the mixture and the number of allowed separation methods increase. Some methods to select a sequence are almost purely heuristic to permit rapid screening among the alternatives without a guarantee of optimality. Another is based on dynamic programming and for special problems can in principle locate the best sequence, but it is notably time consuming.This paper uses primal and dual bounds in a branch and bound strategy to develop a procedure for locating a small number of nearly optimal separation sequences; furthermore, the optimal sequence must be among those found. Restrictions necessary for the dynamic programming approach can be relaxed (serial structure, high product purity), and in principle the method should generally be significantly faster.Two examples illustrate the approach.     

Separation of ideal mixtures in multistage systems: An algorithm for selecting a separation sequence

An algorithm is suggested for selecting a separation sequence for multicomponent mixture separation in multistage systems such that the mixture entering each step is separated into two streams. The optimality criterion is minimum energy consumption at a given throughput capacity for systems utilizing mechanical energy and maximum throughput capacity for heat-driven systems. Expressions for optimal distribution of heat transfer and mass transfer areas among the separation stages are presented.     

应用遗传算法实现精馏分离序列优化综合

阐述了采用遗传算法求解具有组合爆炸特征的精馏分离序列综合问题。首先在数据结构上将精馏分离序列抽象为二叉树结构编码,然后应用图论方法建立起有效的交叉和变异算子,最后对10组分精馏分离序列综合问题实例进行求解。结果表明,遗传算法对最优解命中率达80％,平均空间搜索率仅为0．0318。因此遗传算法能够成功解算大规模精馏分离序列优化综合问题。     

蒸馏顺序和塔间热集成的研究

本文通过对多组元蒸馏分离成本的定量分析肯定了两步法合成热集成蒸馏流程的合理性,并且提出了一种新的两步合成方法.首先用分枝定界搜索法找出最优和接近最优的非热集成分离顺序,再在已找出的每一顺序中用0—1规划建立热集成网络,最后通过比较热集成后几个分离流程的总分离成本决定出最优热集成蒸馏流程.这种合成方法具有计算量最少,且可在微型机上连续地完成合成过程等特点.     

Evolutionary synthesis method of energy integrated distillation separation process

A two-stage evolutionary method is developed to synthesize an optimal energy integrated distillation separation process: the search of the separation sequence, and the introduction of energy integration to the given separation sequence. For the former an evolutionary procedure first generating initial separation sequences and then evolving them is developed. For the latter an evolutionary procedure, first indicating the direction of the evolution by the thermodynamic analysis and then estimating it based on the objective function, is developed. An example problem of a five-component separation demonstrates the effectiveness of this proposed method.     

天然气脱水工艺乙二醇损耗大原因分析及处理

某处理厂脱水脱烃装置天然气处理量在远低于设计能力的情况下发生乙二醇异常损耗,经分析判断确定是低温分离器分离效果差所致,在对低温分离器进行开罐检查发现后确认是设备制造的问题,在对低温分离器进行封堵处理后,一切恢复正常,但此种非正常情况的多次出现还是令人深思。     

精馏分离序列综合超级结构研究

运用组合数学理论深入研究了精馏分离序列综合问题,简明分析了有序剖分问题的计算复杂性;在可行域中采用二叉树数据结构,实现了对精馏分离序列的随机搜索;通过中间结点和叶子结点相互变换机制,构造了一种高效演化邻域(超级)结构。     

Evaluating the Efficiency Frontier of Separation Processes

The problem of finding the minimum work to be done to separate a mixture at a fixed process duration or at a given process capacity is considered. The estimates of the work done in an irreversible process substantially exceed those of the work done in reversible separation, and the work done in irreversible separation of depleted mixtures is finite even when the concentration of the minor component is arbitrarily close to zero. A method is proposed for extending these estimates to separation processes consuming heat rather than mechanical energy.     

间二甲苯装置增产技术方案的应用

介绍了间二甲苯装置增产技术方案的选择及工业应用情况。通过实施增产技术,装置日产量增加5t,物耗由1.090降低至1．088,解决了装置产能受吸附分离能力限制的瓶颈问题。     

基于自适应并行禁忌搜索的精馏分离序列优化综合

由于精馏分离序列与二叉树之间具有同构性,在数据结构上精馏分离序列可以抽象为二叉树.采用图论方法建立了二叉树相邻切分点变换机制,进而形成有效的邻域结构.将自适应机制和并行技术引入禁忌搜索算法中,根据记忆频率信息自适应调整禁忌长度与候选集规模,通过搜索任务分配安排形成多任务并行处理.数值实验表明自适应并行禁忌搜索算法能够成功解算大规模精馏分离序列优化综合问题.     

设计演化算法实现精馏分离序列优化综合

采用演化算法求解具有组合爆炸特征的精馏分离序列优化综合问题。由于精馏分离序列与二叉树之问具有同构性．在数据结构上精馏分离序列可以抽象为二又树,直接采用二叉树结构编码方案可以同时表达个体的基因型和表现形。借鉴生物界父本可以经过有性繁殖或无性繁殖得到子代的现象。对遗传算子进行设计。应冒图论方法建立有效的二叉树结构演化重组机制,从而形成基于双亲或单亲父本的交叉算子。实例表明：双亲遗传操作其空间搜索率较低,而单亲遗传操作其最优解命中率较高。因此。演化算法能够成功解算大规模精馏分离序列优化综合问题。     

Evolutionary synthesis of a multicomponent multiproduct separation process

The introduction of stream division into the separation process that separates a raw material into multicomponent products is effective in reducing the separation cost. However, it is difficult to synthesize this separation process optimally because of information feedback between the separation sequence and introduction of stream division, and the high complexity of the relation between products when the number of products is more than two. The strategy in which two stages—search of the optimal separation sequence and search of the optimal division ratios—are repeated until the objective function is not improved further is adopted in this paper. Manipulation of a diagram which shows graphically the relation between the raw material and the streams outflowing from the separation process, and the functions of separation, division and blending, is effective in searching the optimal division ratios. A useful method for the generation of a suitable diagram (modified material allocation diagram) is developed by considering the species combination of the subproducts decomposed from the product and the outflowing streams. A four-component five-product separation process synthesis problem demonstrates the effectiveness of this method.     

基于模糊逻辑推理的精馏分离序列优化综合

模糊逻辑推理能够反映自然语言要素信息传递特性. 通过抽象有效重组参数提炼if-then模糊逻辑推理规则、根据精馏分离序列综合问题数字特征创建Sugeno模糊逻辑推理模型,系统化地提出了基于模糊逻辑推理的精馏分离序列优化综合方法.     

考虑中间换热器的能量集成精馏序列合成

针对考虑中间换热器（IHE）的精馏序列合成问题,提出基于随机优化策略的能量集成非清晰精馏序列（IHE-HIDSs）合成方法。通过对精馏序列分离任务合并处引入二元0/1变量表示是否存在IHE,以精馏序列的年总成本（TAC）为优化目标,建立了该合成问题的隐式混合整数非线性规划模型（MINLP）,通过模拟退火和粒子群优化（SA-PSO）混合随机优化算法进行求解。为验证在精馏序列合成中同时考虑IHE的必要性以及所提出合成方法的有效性,对五组分醇类混合物和五组分烷烃类混合物两个算例的精馏序列合成问题进行了研究。结果表明,相比同时考虑热耦合和能量集成的精馏序列,IHE-HIDS具有更低的TAC。此外,所提出的方法可以在合理的计算时间内以高概率获得多个分离序列方案。     

5种芳氧苯氧丙酸类除草剂的超临界色谱手性分离

[目的]获得单一的高效异构体对于提高农药药效和减少环境污染具有重要意义。[方法]采用Sino-ChiralOJ柱在超临界色谱中以CO2为流动相对5种芳氧苯氧丙酸类除草剂进行手性分离。探索了系统温度(25-45℃)、流动相改性剂(甲醇、乙醇或异丙醇)及添加量(5%-15%)对分离效果的影响。[结果]唑禾草灵、吡氟禾草灵、喹禾灵获得了完全分离,其最大分离度分别为11.66、1.48、8.34,而禾草灵酸和吡氟氯禾灵均未获得分离。[结论]随着改性剂添加量的增大,唑禾草灵、吡氟禾草灵、喹禾灵的容量因子和分离度逐渐减小,而分离因子基本保持不变。在同一改性剂添加量下,容量因子按甲醇-乙醇-异丙醇的顺序基本逐渐增大,而分离因子基本保持不变。随着系统温度的升高,容量因子逐渐增大,分离因子和分离度逐渐减小。各物质结构上的差异导致分离效果不同。     

Design and Computational Fluid Dynamics Analysis of a Three-Phase Decanter Centrifuge for Oil-Water-Solid Separation

The separation of oil, water, and sand has always been a significant problem in the treatment of oily sludge in oil field and petroleum refinery. The flow field and separation performance in a new three-phase decanter centrifuge with vertical boards and annular liquid separation plate for oil-water-solids separation were investigated, using the computational fluid dynamics (CFD) software Fluent with Euler-Euler three-phase flow model, which provides a basis for the improvement and optimization of the centrifuge. After calculation, the velocity and pressure field were analyzed. The increase of solids content of the feed affected the separation efficiency regularly, and high or low treatment capacity also had a certain impact on the separation efficiency.     

某核电站凝结水精处理系统高塔分离技术探讨

针对参考电站凝结水精处理系统投运后离子升高的现象,某核电站混床树脂分离采用高塔分离法。本文主要介绍该核电站混床树脂的分离再生步序,并针对高塔分离法调试过程中的技术难点进行了重点说明。     

金属有机骨架材料在CO2/CH4吸附分离中的研究进展

CO₂/CH₄分离能耗高是生物甲烷过程核心难题之一。金属有机骨架材料（metal organic frameworks,MOFs）由于其优异的CO₂吸附分离性能,被视为最具潜力的CO₂分离捕集材料,近年来引起了广泛的关注。本文结合沼气的特点和MOFs研究的最新进展,对MOFs材料在CO₂/CH₄吸附分离过程的相关实验研究工作进行了综述。     

空分装置增产改造总结

介绍了KDON-40000／45850-I型空分装置增产改造情况。改造后，解决了制约合成氨、甲醇生产能力的问题，基本达到了节能降耗的预期效果。