过程系统工程的发展和面临的挑战

过程系统工程是一门蓬勃发展中的重要学科。对这门学科的发展沿革做了简略回顾,然后对这门学科所做出的贡献和差距、存在的问题进行了探讨,最后指出过程系统工程在21世纪所面临的挑战及发展机遇。     

An alternate computational architecture for advanced process engineering

An algorithm for equation-oriented (EO) flowsheeting to which the interfacing of external modular procedures is readily allowed is presented. In the algorithm, all the process units in a flowsheet are solved simultaneously in an EO environment while taking advantage of the external software as it is. The algorithm is the basis for the process simulator MIKAN. The simulator consists of two parts, namely EO main, which is the simulator's executive, and add-on blocks to incorporate external procedures. EO main also serves to solve separation processes. The PBM (Pseudo-Binary-Mixture)-based algorithm for separation processes (Ishii & Otto, 2008) is fully exploited in EO main. The equations of the entire system are composed of a set of equations for separation processes and sets of equations representing the input-output relation of each add-on block. The input-output relation is obtained by numerical perturbation where all the component flow rates are perturbed collectively. Although the proposed perturbation is simple and significantly less expensive, it is very reliable since the interactions among the input variables affecting the output are fully accounted for.Robustness, flexibility and efficiency of the new algorithm have been confirmed by its implementation. A serious drawback with the EO approach is the difficult accessibility to the user when incorporating new or external process models. Easy accessibility is an important attribute of the new algorithm, even though the simulator's executive is highly integrated and complex. It is significant that the derivative information at various levels of a flowsheet is easily obtained in the algorithm. The novel algorithmic capabilities of the algorithm provide a robust platform for the next stage of advanced process engineering.     

Process systems engineering: From Solvay to modern bio- and nanotechnology.: A history of development, successes and prospects for the future

The term Process Systems Engineering (PSE) is relatively recent. It was coined about 50 years ago at the outset of the modern era of computer-aided engineering. However, the engineering of processing systems is almost as old as the beginning of the chemical industry, around the first half of the 19th century. Initially, the practice of PSE was qualitative and informal, but as time went on it was formalized in progressively increasing degrees. Today, it is solidly founded on engineering sciences and an array of systems-theoretical methodologies and computer-aided tools. This paper is not a review of the theoretical and methodological contributions by various researchers in the area of PSE. Its primary objective is to provide an overview of the history of PSE, i.e. its origin and evolution; a brief illustration of its tremendous impact in the development of modern chemical industry; its state at the turn of the 21st century; and an outline of the role it can play in addressing the societal problems that we face today such as; securing sustainable production of energy, chemicals and materials for the human wellbeing, alternative energy sources, and improving the quality of life and of our living environment. PSE has expanded significantly beyond its original scope, the continuous and batch chemical processes and their associated process engineering problems. Today, PSE activities encompass the creative design, operation, and control of: biological systems (prokaryotic and eukaryotic cells); complex networks of chemical reactions; free or guided self-assembly processes; micro- and nano-scale processes; and systems that integrate engineered processes with processes driven by humans, legal and regulatory institutions. Through its emphasis on synthesis problems, PSE provides the dialectic complement to the analytical bent of chemical engineering science, thus establishing the healthy tension between synthesis and analysis, the foundation of any thriving discipline. As a consequence, throughout this paper PSE emerges as the foundational underpinning of modern chemical engineering; the one that ensures the discipline's cohesiveness in the years to come.     

Among the trends for a modern chemical engineering,the third paradigm: The time and length multiscale approach as an efficient tool for process intensification and product design and engineering

To respond to the changing needs of the chemical and related industries in order both to meet today's economy demands and to remain competitive in global trade, a modern chemical engineering is vital to satisfy both the market requirements for specific nano and microscale end-use properties of products, and the social and environmental constraints of industrial meso and macroscale processes. Thus an integrated system approach of complex multidisciplinary, non-linear, non-equilibrium processes and phenomena occurring on different length and time scales of the supply chain is required. That is, a good understanding of how phenomena at a smaller length-scale relates to properties and behaviour at a longer length-scale is necessary (from the molecular-scale to the production-scales). This has been defined as the triplet “molecular Processes-Product-Process (3PE)” integrated multiscale approach of chemical engineering. Indeed a modern chemical engineering can be summarized by four main objectives: (1) Increase productivity and selectivity through intensification of intelligent operations and a multiscale approach to processes control: nano and micro-tailoring of materials with controlled structure. (2) Design novel equipment based on scientific principles and new production methods: process intensification using multifunctional reactors and micro-engineering for micro structured equipment. (3) Manufacturing end-use properties to synthesize structured products, combining several functions required by the customer with a special emphasis on complex fluids and solid technology, necessating molecular modeling, polymorph prediction and sensor development. (4) Implement multiscale application of computational chemical engineering modeling and simulation to real-life situations from the molecular-scale to the production-scale, e.g., in order to understand how phenomena at a smaller length-scale relate to properties and behaviour at a longer length-scale. The presentation will emphasize the 3PE multiscale approach of chemical engineering for investigations in the previous objectives and on its success due to the today's considerable progress in the use of scientific instrumentation, in modeling, simulation and computer-aided tools, and in the systematic design methods.     

Making programme learning outcomes explicit for students of process and chemical engineering

There is a global shift in education from solely content-driven teaching to teaching that takes learning outcomes into account. This movement underpins much of the educational reform in the area of engineering education. Programme learning outcomes for degrees in engineering education are more commonplace as more and more professional accrediting bodies require fulfillment or compliance with prescribed learning outcomes. However, the students may not be presented with these learning outcomes as they are often “hidden” in documentation submitted by institutions for accreditation purposes and hence may not be divulged to students. Undergraduate students (2006–2008) taking the BE degree programme in Process & Chemical Engineering at UCC were first surveyed to assess their level of knowledge of the learning outcomes concept and of the degree programme learning outcomes. The contents of two documents used in applications for accreditation by professional accreditation bodies as well as professional Institution guidelines were reviewed to formulate the degree programme learning outcomes which were presented to the students. These students were then surveyed after the presentation. The results of the questionnaire completed by students demonstrated a major improvement in their knowledge of both the concept of learning outcomes and also of the degree programme learning outcomes. It also showed that the students found the session to be of overall beneficial value.     

Unified targeting algorithm for diverse process integration problems of resource conservation networks

A single algorithm is developed to establish minimum resource targets for diverse process integration problems including those of heat/mass exchange, water, hydrogen, carbon emission and material reuse networks. Previous algorithms such as the problem table algorithm for heat exchange networks and the composite table algorithm for resource allocation networks are special cases of the newly proposed unified targeting algorithm (UTA). The conversion of streams to equivalent inlet-outlet (demand-source) pairs is shown to be a key basis for the unified approach. The tabular data from the UTA may be plotted to obtain the grand composite curve (GCC) or the limiting composite curve (LCC). These provide graphical representations of the net load deficit/surplus at various levels for resource targeting and pinch identification. For allocation networks with system loss/gain, the UTA with increasing level sort order yields the Deficit LCC to target the minimum resource, whereas the UTA with decreasing level sort order provides the Surplus LCC to target the minimum waste/excess. A single UTA calculation along with the use of fundamental overall system balance equations is sufficient to establish complete targets for a problem. Six practical case studies from diverse domains are presented to illustrate the detailed steps of the UTA.     

化工建设项目环境影响评价中提高清洁生产水平的方法探讨

充分利用环境影响评价工程分析的结果和清洁生产原理,研究开发化工建设项目清洁生产的中高费方案,作为污染防治的主要措施,可提高建设项目环境影响评价的清洁生产水平和环评质量,改变末端治理为全过程控制,以实现节能、降耗、减污、增效的目标,谋求经济效益和环境效益的同步协调发展。     

A tribute to professor Roger Sargent: Intellectual leader of process systems engineering

This article and this issue of the AIChE Journal, is a tribute to Professor Roger Sargent who, as pioneer and intellectual leader of process systems engineering, has had a profound impact on the discipline of chemical engineering. Spanning more than five decades, his work has provided a strong mathematical foundation to process systems engineering through the development of sophisticated mathematical and computational tools for the simulation, design, control, operation and optimization of chemical processes. In this article we first give a brief overview of his career that included several leadership positions and the establishment of the Centre for Process Systems Engineering (CPSE) at Imperial College London. We next review his research contributions in the areas of process modeling, differential algebraic systems, process dynamics and control, nonlinear optimization and optimal control, design under uncertainty, and process scheduling. We highlight the tremendous impact that he has had through his students, students' students, and his entire academic family tree, which at present contains over 2000 names, probably one of the largest among the academic leaders of chemical engineering. Finally, we provide a brief overview of him as a modest and charming individual with a wonderful sense of humor. He is without doubt a true intellectual giant who has helped to expand the scope of chemical engineering by providing a strong systems component to it, and by establishing strong multidisciplinary links with other fields. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2951–2958, 2016     

Development of a batch manager for dynamic scheduling and process management in multiproduct batch processes

A batch manager is developed for the dynamic scheduling and on-line management of process operations. The developed system consists of a process monitoring module and a dynamic scheduling module. When a deviation from the initial schedule is detected in a process monitoring module, dynamic scheduling is performed in the dynamic scheduling module and the initial schedule is adjusted to the proper schedule by using rescheduling algorithms presented in this paper. The adjusted schedule is shown in the process monitoring module. The dynamic scheduler in the batch manager copes with several unexpected process events of batch process operations by adjusting the EST (Earliest Start Time) of equipment, redetermining the batch path and reassigning tasks to equipment. This study focuses on the implementation of a batch manager with on-line dynamic scheduling for batch process management. Examples of fodder production batch processes illustrate the efficiency of the algorithms. This paper was supported by nondirected research fund, Korea Research Foundation, 1997.     

化学工业环境保护的进展及规划设想

十多年来,化工污染防治工作取得很大的进展,但还未从根本上解决全行业的污染问题。本文介绍了2020年之前的环保规划设想。     

Multiobjective optimization of an industrial styrene monomer manufacturing process

Multi-objective optimization of the operation and design of a styrene manufacturing process has been studied with the elitist non-dominated sorting genetic algorithm (NSGA-II). In the first part, the study focused on bi-objective optimization and comparative analysis of three different styrene reactor designs—the single-bed, the steam-injected and the double-bed reactors. The objectives were to simultaneously maximize styrene flow rate and styrene selectivity. In the second part, on the other hand, a tri-objective optimization study was performed involving the entire manufacturing process consisting of the reactor, heat-exchangers and separation units. Only the double-bed reactor was considered in this study for maximizing the styrene flow rate and selectivity and minimizing the total heat duty required by the manufacturing process. Results are presented and discussed in detail.     

Development of hidden semi-Markov models for diagnosis of multiphase batch operation

This paper deals with automatic on-line detection and diagnosis of fault patterns in multiphase batch processes. A novel and flexible approach based on the combination of hidden segmental semi-Markov models (HSMM) and multiway principal component analysis (MPCA) is proposed. In all batch operations, process variables may have correlations with each other, and MPCA is used to handle cross-correlation among process variables. In multiphase batch processes, the effect of external factors on process variables is phase-specific and the duration of each phase varies from batch to batch. HSMM is used to model the multiphase batch operation by representing each phase with a macro-state whose duration is determined by a phase-specific probability distribution of a number of micro-states. The output of each micro-state corresponds to the values of the monitored variables at a specific point in time. Given this structure, MPCA-HSMM parameters are trained by the batch operation data and recursive Viterbi algorithm is used to find out the optimum state sequence from each batch. Probability values of the optimum state sequence are collected to construct the probabilistic model which is used to compute the corresponding control limit for the specified operating condition. One MPCA-HSMM model is to be built for each type of previously known operating condition—normal and fault events. The power and advantages of the proposed method are successfully demonstrated in a simulated fed-batch penicillin cultivation process. MPCA-HSMM correctly identifies the type of fault from the batch operation data.     

合成盐酸生产工艺的安全环保改进

介绍了合成盐酸三合一炉生产工艺改进情况,改造后,实现了安全生产,消除了环境污染。     

Process simulation and debottlenecking for an industrial cocoa manufacturing process

Cocoa is a common ingredient for various food and confectionery products. Industrial production of this ingredient however is normally not optimised, due to the lack of appropriate analytical tools. Furthermore, cocoa processing is normally operated in semi-continuous mode, and this adds to the difficulty in optimising the various unit operations involved. In this work, a computer-aided process simulation tool was used to model and debottleckneck an industrial cocoa manufacturing process, with the aim to identify an economically viable production scheme that would double the current production rate.     

Purification process for an inorganic rechargeable lithium battery and new safety concepts

We have investigated an inorganic lithium battery system in which LiCoO₂ is used as the positive electrode and lithium, intercalated into graphite, serves as negative electrode. The conducting salt is lithium tetrachloroaluminate (LiAlCl₄). The electrolyte is based on SO₂. It has been shown that a layer of lithium hydroxide is present on the surface of the lithium cobalt oxide. This has a negative impact on the stability of the electrode. To improve stability, we have developed a purification process for removing the lithium hydroxide from the surface of the positive electrode. After purification the cells show no significant change in either capacity or internal resistance when cycled. Up to 70% of the theoretical capacity of electrodes which have been purified in this way can be used without any negative effects being observed. To prevent the deposition of metallic lithium leading to a hazardous situation, a new safety concept was developed whereby local short circuits are allowable. Safe functioning of the new concept has been demonstrated with tests on complete cells.     

Towards a methodology for the systematic analysis and design of efficient chemical processes: Part 1. From unit operations to elementary process functions

A successful intensification of a chemical process requires a holistic view of the process and a systematic debottlenecking, which is obtained by identifying and eliminating the main transport resistances that limit the overall process performance and thus can be considered as rate determining steps on the process level. In this paper, we will suggest a new approach that is not based on the classical unit operation concept, but on the analysis of the basic functional principles that are encountered in chemical processes.A review on the history of chemical engineering in general and more specifically on the development of the unit operation concept underlines the outstanding significance of this concept in chemical and process engineering. The unit operation concept is strongly linked with the idea of thinking in terms of apparatuses, using technology off the shelf. The use of such “ready solutions” is of course convenient in the analysis and design of chemical processes; however, it can also be a problem since it inherently reduces the possibilities of process intensification measures.Therefore, we break with the tradition of thinking in terms of “unit apparatuses” and suggest a new, more rigorous function-based approach that focuses on the underlying fundamental physical and chemical processes and fluxes.For this purpose, we decompose the chemical process into so-called functional modules that fulfill specific tasks in the course of the process. The functional modules itself can be further decomposed and represented by a linear combination of elementary process functions. These are basis vectors in thermodynamic state space. Within this theoretical framework we can individually examine possible process routes and identify resistances in individual process steps. This allows us to analyze and propose possible options for the intensification of the considered chemical process.     

化工过程分析与开发教学案例制作

案例教学作为一种教学方法,早已广泛应用于医学、工商管理、教育等领域。通过对案例研发过程的解析,我们将化工过程开发的知识点以简单易懂的方式传授给学生,以锻炼学生独立思考解决问题的能力。     

Development and characterization of niobium-releasing silicate bioactive glasses for tissue engineering applications

Novel niobium-containing bioactive glass formulations (Nb-BGs) were designed, produced and used to fabricate sintered glass-ceramic granules to examine their in vitro bioactivity and angiogenic potential. Nb-BGs were prepared by melting and quenching. Afterwards, the glasses were crushed and milled into fine powders. These powders were used to make aqueous slurries which were poured into molds, dried and sintered to produce pellets, from which granules of 0.5–0.85 mm in size were obtained. In vitro bioactivity was tested by immersing the granules in simulated body fluid for up to 14 days. Cell biology tests were carried out by indirect culture of bone marrow stromal cells (ST-2) with supernatants resulting from incubation of BG granules in cell culture medium. The effect of dissolution products from Nb-BGs on the secretion of vascular endothelial growth factor (VEGF) was assessed to characterize the angiogenic potential of the new Nb-containing BG compositions.     

精细化工过程及设备CAI软件系统的开发

用多媒体著作工具Authorware开发了“精细化工过程及设备”课程交互式CAI软件。详细介绍了软件制作工具的选择、系统的总体设计、各模块功能的实现等开发过程。说明了利用Authorware工具开发CAI教学软件的主要设计方法和手段。