Design Of Chemical Plants Research Articles

Design of Batch Chemical Plants Under Market Uncertainty

Design of Batch Chemical Plants Under Market Uncertainty

Process synthesis using parallel graph traversal

A new method, using parallel computers, for the synthesis of optimal structures in chemical plant design is presented. Based on a parallel post-order traversal of the superstructure, this method is an extension of a previous method based on simple dynajnic programming techniques. The extension makes the method both more efficient and more general, effective at solving large and small problems involving both separation and reaction units. Timings on two different distributed memory multi-computers are presented.

Qualitätssicherung im Anlagenbau

AbstractQuality Assurance in Plant Design and Construction. In the field of chemical plant design and construction, quality is understood to mean the strict application of the state‐of‐the‐art rules and the fulfilment of all specific requirements specified by the client, including plant take‐over by the client in accordance with the time schedule. Chemical plants can rarely be handled in the same manner as series products. Therefore, quality assurance requires a large organizational scheme. The definition of quality and the system applied to ensure an adequate quality standard are a rather complicated task. The technical divisions involved in a project are responsible for the quality, i.e. there is no sharing of responsibility. It is also impossible to shift this responsibility to a special QA department.

Design of an on-line scheduling strategy for a combined batch/continuous plant using simulation

Scheduling of combined batch/continuous plants is both a process-design and a process-operation problem. This paper illustrates the use of a dynamic simulation model for designing the sequence control and the scheduling of complex plants, checking the production capacity and determining the minimum necessary volume of the buffer vessels. The designed on-line scheduling should be able to determine the throughput of the continuous units and the starting time of the sequences of the batch units. Once the sequence of the batch unit is started, the sequence control of the unit takes over the control of that unit until the sequence is completed. The on-line scheduling will then decide when the new sequence should start. The on-line scheduling proposed in this paper is integrated within the sequence control. The examples and illustrations in this paper are based on experience gained in the design of a complex fine chemical plant.

Incorporating Operability Measures Into the Process Synthesis Stage of Design

Publisher Summary This chapter discusses the issue exchanger networks or separation sequences. It is the issue of incorporating operability measures into the synthesis stage of complete chemical process plant design. Process synthesis is today largely based on steady-state analysis. Synthesis procedures that take into account dynamics, for example, in the form of controllability considerations have been developed but only for the more well-defined tasks such as the synthesis of heat exchanger networks or separation sequences. The steady-state versions of the dynamic equipment models are used to calculate the most economically profitable operating point for the process. During this optimisation, the flow-sheet structure and equipment parameters are held constant. The flexibility analysis classifies the slow disturbances as either economically significant or insignificant by considering the unregulated effect of such disturbances on the nominal economic optimum operating profit of the process.

Optimal process design for specialty products

The present paper is concerned with computer aided design of a specialty chemical product plant. Decisions about batch/continuous operation, time fraction of operation, plant capacity, amount and energy balances including energy integration are the first decisions to be met. Special criteria that could help to decide when a batch process may be favoured over a continuous one, are described. 12 months per year production is rescheduled to 3 months per year production. Design procedure with technological and economic results of different operating variants is described. Analysis of the results shows that the continuous process after energy integration is preferrable over a batch one for all capacities, unless special requirements exist for process related reasons.

Design of an on-line scheduling strategy for a combined batch/continuous plant using simulation

Scheduling of combined batch/continuous plants is both a process-design and a process-operation problem. This paper illustrates the use of a dynamic simulation model for designing the sequence control and the scheduling of complex plants, checking the production capacity and determining the minimum necessary volume of the buffer vessels. The designed on-line scheduling should be able to determine the throughput of the continuous units and the starting time of the sequences of the batch units. Once the sequence of the batch unit is started, the sequence control of the unit takes over the control of that unit until the sequence is completed. The on-line scheduling will then decide when the new sequence should start. The on-line scheduling proposed in this paper, is integrated within the sequence control. The examples and illustrations in this paper are based on experience gained in the design of a complex fine chemical plant.

A structured approach to occupational hygiene in the design and operation of fine chemical plant.

In order to ensure appropriate occupational hygiene controls can be incorporated in the design and operation of fine chemical plant, a structured scheme has been developed based upon the intrinsic hazard of the materials in use. The scheme provides guidelines for managing the inherent risks to health presented by the operation of such plant, including basic recommendations on the selection and operation of selected plant equipment. Although the scheme has focused on a carcinogenic ranking system for aromatic amines and nitro compounds, with suitable modifications its underlying philosophy and principles should be capable of application to any toxicological scheme for ranking the relative hazard of chemical substances.

The design of flexible chemical plants by the application of interval mathematics

Reliable methods for the design of multiproduct batch chemical plants under uncertainty are expensive in computing time. Useful practical results can be obtained more speedily by the application of interval optimization. In a two-stage procedure for optimal design under uncertainty the inner optimization, comprising a stochastic linear program, is replaced by a linear interval optimization procedure. The influence of both more and less optimistic design stategies and of various problem parameters in the resulting designs is presented.

Preliminary chemical engineering plant design

Preliminary chemical engineering plant design , Preliminary chemical engineering plant design , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Flow‐Sheeting‐Programme für die Prozeßsimulation

AbstractFlowsheeting systems for process simulation. Simulation of process plants with flowsheeting systems has been state of the art in chemical plant design and in the chemical industry for many years. Modern computers now permit steady state simulation of complex chemical plants with sufficient accuracy. This paper outlines the different approaches to steady state process simulation, names the advantages and disadvantages, and gives an outlook on further developments. Process optimization, process integration, and process synthesis will be discussed. The integration of different programs, e.g. the connection between flowsheeting systems and computer‐aided design (CAD) will be described. An advance in user friendliness will be reached by latest developments in the field of personal computers and workstations and by database management systems.

Möglichkeiten computergestützter Konstruktion im Chemieanlagenbau

AbstractComputer aided design of chemical plant. The effort necessary for computing and design of a chemical plant as well as the preparation of documentation has increased. This is a result of the growing complexity of process design in order to satisfy economic criteria and more stringent safety and environmental requirements. The available time is limited. CAD is one of the tools that assists the plant designer by solving all these requirements. Even at the very beginning of the development of digital computers, their possibilities in graphics electronic data processing were recognized. Since the 1970s, CAD has been utilized in plant design. The use of two‐dimensional or three‐dimensional CAD software is possible. In most cases this is done by using self‐contained dedicated solutions. The integration of the applications promises an increase of productivity. To reach this aim a database management system (DBMS) may be useful. DBMS is also useful as an interface to other computing tools like FEM‐ or process flowsheeting programs. The development of the soft‐ and hardware domain has reached a level of sophistication which makes the economic utilization of CAD possible. Nevertheless, much work still remains to be done.

A Human Factors and Human Reliability Programme for the Design of a Large UK Nuclear Chemical Plant

This paper outlines a three year long, fifteen person-year effort to achieve a safer and more productive plant through the integration of human factors into the design and assessment process for a new plant. The implementation of the human factors and human reliability programme is at half-way point. This programme addresses issues such as adequacy of the VDU monitoring and control system, adequacy of panels in the Central Control Room and on local plant, and staffing arrangements, using techniques ranging from task analysis and audit techniques, to the running of experiments to determine acceptable VDU information density, and the application of techniques of human error analysis and workload assessment. The human reliability side of the programme has involved the development of a new human reliability management system, based partly on two experiments which comparatively evaluated error identification and error quantification techniques. The programme, as carried out so far, on the design and proposed operational structure, and future work proposals, are briefly outlined.

Optimal design of multi-purpose batch chemical plants

A new solution method has been developed for the optimal design of multi-purpose batch chemical plants. The minimum capital investment cost serves for the optimality criterion. The algorithm is built upon two decomposition stages: a combinatorial step allowing the use of some heuristics and a nonlinear programming stage. A quasi-optimal solution is guarantied.

CAE in der Prozeßleittechnik

AbstractCAE in process control engineering. The design and operation of chemical engineering plant involves collaboration of various specialist departments over a long period in an iterative sequence of steps. Any change in data in any of the necessary iterative steps can generate expensive errors. The aim of computer application and computerized development is thus basically to improve the integration of the various applications. Technical data processing, especially the use of CAD/CAE systems, therefore provides a framework for a whole group of measures intended to provide tools for mediumterm automatic handling of data and re‐use of partial solutions in memory.

Process Design and Evaluation of a Continuous Chemical Plant for the Singlet Oxygen-Iodine Laser

Process designs were evaluated for the continuous, large-scale generation of singlet delta oxygen for use in a chemical oxygen-iodine laser. The excited singlet oxygen is generated from the chemical reaction of chlorine gas with basic hydrogen peroxide. The chemical reaction also produces a large waste brine stream that can be controlled by recycling through a chlor-alkali cell, which regenerates the reactants Cl2 and NaOH. To prevent deactivation of this excited oxygen, a large excess of hydrogen peroxide is typically used to change the reaction mechanism. This use of excess hydrogen peroxide or nonstoichiometric generation leads to substantial increases in capital and operating costs when compared with theoretical stoichiometric (no excess) generation. For the generation of singlet oxygen at a 500-kW level of equivalent lasing power, a theoretical stoichiometric plant producing all reactants has an estimated capital cost of $38 million. The capital cost for a nonstoichiometric plant is $98 million. Operating costs are $0.68 and $2.12/lb of singlet oxygen, respectively. The energy efficiency of generation is ∼6.3% for the theoretical stoichiometric flow sheet and 3.3% for the nonstoichiometric flow sheet. At this nonstoichiometric efficiency, the use of a chemical oxygen iodine laser for photoneutralization of negative ion beams is probably not competitive with other technologies below a 750-keV neutral beam level.

On the design of multi-purpose batch chemical plants

An algorithm is proposed for the automatical design of large multi-purpose batch chemical plants. This first design is improved in an iterative process by alternatively evaluating the plant through the solution of the scheduling problem, and changing the plant.

Expert systems to aid design against corrosion

Abstract The prediction of corrosion-limited service life and the evaluation and specification of materials in terms of corrosion resistance are important aspects in the design and maintenance of chemical and process plant. By combining current developments in computing, information management and knowledge engineering with corrosion expertise, a sound foundation for design against corrosion can be achieved. A demonstration expert system is now available to provide advice on certain aspects of the performance of carbon and stainless steels. The paper discusses the development of the system and usefulness to design engineers and others when required to ensure trouble-free service from chemical and other plant. other plant.

Design of chemical plants with multiregime capabilities and robust dynamic operability characteristics

Most chemical plants go through various steady-state regimes during their operation mainly due to economic reasons dictated by changing plant conditions. If the dynamics of such plants are not considered at the design stage, such a flexible operation may not be possible because of operational bottlenecks at certain optimal steady-state regimes. This study dwells on the possibility of improving such process designs to guarantee dynamically operable regimes based on the stability and performance robustness concepts. A two-state optimization procedure is proposed that constitutes the backbone of a computer-aided design strategy.

A simple technique for the optimization of lay‐out and location for chemical plant safety

AbstractA computer program to optimize the use of land and ensure safe operation of plant. A logical process flow is maintained, while the position of plant items is optimized using a hill‐climbing technique.A number of quantitative techniques exist for the measurement of hazard values for comparison of process routes in chemical plant design and operation. Such numerical values can also be used as a basis in lay‐out considerations. There is a need for a simple technique, which allows for the optimization of separation distances between plant by determining the minimum requirement for safe operation. This requirement determines the cost of land and that of piping and control lines. It is then possible to carry out economic comparisons between using separation distances and the installation of mobile and fixed prevention and protection systems. An optimization technique based on a modified hill‐climbing method is described.