			Home About us Contact

Process Industries (process + industry)

Distribution by Scientific Domains

Chemistry	59%
Engineering	31%
2 Other Domains	10%

Kinds of Process Industries

chemical process industry

Selected Abstracts

Development of an Expert System Shell Based on Genetic Algorithms for the Selection of the Energy Best Available Technologies and their Optimal Operating Conditions for the Process Industry

EXPERT SYSTEMS, Issue 3 2001
D.A. Manolas
The development of genetic algorithms started almost three decades ago in an attempt to imitate the mechanics of natural systems. Since their inception, they have been applied successfully as optimization methods, and as expert systems, in many diverse applications. In this paper, a genetic-algorithm-based expert system shell is presented that, when combined with a proper database comprising the available energy-saving technologies for the process industry, is able to perform the following tasks: (a) identify the best available technologies (BATs) among the available ones for a given process industry, and (b) calculate their optimal design parameters in such a way that they comply with the energy requirements of the process. By the term BAT is meant the available energy-saving technology, among the existing ones in the market, that is the best for the case. [source]

Reduction of the Water Demand in the Process Industry by Production-Integrated Application of the Catalytic Electrolysis,

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2004
M. Forstmeier
In many process industry applications fresh water demand can be reduced significantly by production-integrated electrolytic disinfection of the process water. This contribution deals with the basic principles of electrolytic water disinfection and presents two case studies: application of the proposed method during the production of liquid detergents and during a metallurgical production process. [source]

One-zone simulation model of an oil-injected screw chiller

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2004
C. V. Le
Abstract This paper presents a one-zone steady-state system model of an oil-injected screw chiller. The model can be used as a design and optimization tool for system performance of multiple-chiller plant in process industries. All major components of the system are modelled in a modular format including the oil-injected screw compressor, shell and tube condenser, flooded evaporator and a high side-float value. The model results are validated with the experimental data from a multiple-chiller plant at a process industry. The validated results show that the part-load ratio and the glycol,water temperature at the evaporator inlet significantly affect the system performance as compared to the temperature of cooling water entering the condenser. Copyright © 2004 John Wiley & Sons, Ltd. [source]

TNO's work on intensification: practical examples,

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2-3 2003
Jan I Walpot
Abstract TNO, a Dutch organisation for contract research, is and has been involved in numerous process intensification projects in close collaboration with national and international process industries. TNO has different facilities available to fulfil the demands of intensification projects. Depending on the focus of a project, a multidisciplinary team conducts experimental research, feasibility studies, process modelling, process design, pilot research and/or E-evaluations (economics, environment, energy). In this conference paper practical cases are described concerning novel processing techniques as well as novel reactors. © 2003 Society of Chemical Industry [source]

Solid-solid reactions in series: A modeling and experimental study

AICHE JOURNAL, Issue 9 2009
A. K. Suresh
Abstract Reactions among particulate solid phases are important and abundant in many materials, chemical, and metallurgical process industries. Many of these are reaction networks, and not single-step reactions as normally assumed. There is no theoretical framework available for the analysis of such systems, and single-reaction models derived from the gas,solid literature continue to be used. Formation of cement clinker in the rotary cement kiln is a prime example of the genre, in which mechanistic aspects play an important role in determining energy efficiency and the composition and nature of the phases that form. In the present study, we formulate a model within the ambit of the "shrinking core" class of models, for reactions in series among solid phases. The model shows the presence of one or two moving fronts in the reacting particle, depending on the relative rates of the processes involved. A single Thiele-type parameter controls the model behavior, at once describing the relative rates of the intermediate formation and consumption processes, and the diffusion-reaction competition for the product formation step. The model has been shown to reduce to the well known single reaction models at the limits of low and high values of the Thiele parameter. Experimental data have been obtained on the calcia-alumina system, an important one in cement manufacture, in the temperature range 1150,1250°C. The model has been fitted to these data and the kinetic parameters determined. The comparison bears out the salient features of the theory, and shows that a degree of diffusion limitation exists for the intermediate conversion step under these conditions. The diffusivity values estimated are in the range of 10,19 to 10,18 m2/s and agree with values found in the literature for similar systems. The rate constant for the intermediate conversion step is of the order of 10,6 s,1. This being among the first such determinations, this value awaits confirmation from other studies. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Corrosion characteristics of the wrought Ni-Cr-Mo alloys

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 9 2005
P. Crook
Abstract This paper concerns the wrought, nickel-chromium-molybdenum (Ni-Cr-Mo) alloys, a family of materials with a long history of use in the chemical process industries. Their attributes include resistance to the halogen acids and resistance to pitting, crevice attack, and stress corrosion cracking in hot, halide salt solutions. The purpose of this paper is to characterize the performance of the Ni-Cr-Mo alloys in several key chemicals, using iso-corrosion diagrams. These indicate the expected corrosion rates over wide ranges of concentration and temperature. Furthermore, the differences between individual Ni-Cr-Mo alloys, and their behavior relative to the stainless steels are defined. The data indicate benefits of both a high chromium content and a copper addition, as used in Hastelloy® C-2000® alloy. [source]

Predicting deflagration to detonation transition in hydrogen explosions

PROCESS SAFETY PROGRESS, Issue 3 2008
Prankul Middha
Abstract Because of the development in computational resources, Computational Fluid Dynamics (CFD) has assumed increasing importance in recent years as a tool for predicting the consequences of accidents in petrochemical and process industries. CFD has also been used more and more for explosion predictions for input to risk assessments and design load specifications. The CFD software FLACS has been developed and experimentally validated continuously for more than 25 years. As a result, it is established as a tool for simulating hydrocarbon gas deflagrations with reasonable precision and is widely used in petrochemical industry and elsewhere. In recent years the focus on predicting hydrogen explosions has increased, and with the latest release the validation status for hydrogen deflagrations is considered good. However, in many of these scenarios, especially involving reactive gases such as hydrogen, deflagration to detonation transition (DDT) may be a significant threat. In previous work, FLACS was extended to identify whether DDT is likely in a given scenario and indicate the regions where it might occur. The likelihood of DDT has been expressed in terms of spatial pressure gradients across the flame front. This parameter is able to visualize when the flame front captures the pressure front, which is the case in situations when fast deflagrations transition to detonation. Reasonable agreement was obtained with experimental observations in terms of explosion pressures, transition times, and flame speeds. The DDT model has now been extended to develop a more meaningful criterion for estimating the likelihood of DDT by comparison of the geometric dimensions with the detonation cell size. This article discusses the new models to predict DDT, and compare predictions with relevant experiments. © 2007 American Institute of Chemical Engineers Process Saf Prog 2008 [source]

An overview of inherently safer design,

PROCESS SAFETY PROGRESS, Issue 2 2006
Dennis C. Hendershot
Inherently safer product and process design represents a fundamentally different approach to safety in the manufacture and use of chemicals. The designer is challenged to identify ways to eliminate or significantly reduce hazards, rather than to develop add-on protective systems and procedures. In the chemical process industries, risk management layers of protection are classified as inherent, passive, active, and procedural. Inherently safer design focuses on eliminating hazards, or minimizing them significantly, to reduce the potential consequence to people, the environment, property, and business. Inherently safer design is considered to be the most robust way of dealing with process risk and can be considered to be a subset of green chemistry and green engineering. It focuses on safety hazards,the immediate impacts of single events such as fires, explosions, and short-term toxic impacts. Many of the strategies of inherently safer design are not specific to the chemical industry, but apply to a broad range of technologies. Strategies for identifying inherently safer options are discussed, with examples. However, for most facilities, a complete risk management program will include features from all categories of layers of protection. Also, the designer must be aware that all processes and materials have multiple hazards and that there can be conflicts among the risks associated with different alternatives. Design alternatives that reduce or eliminate one hazard may create or increase the magnitude of others. Recognition and understanding of these conflicts will enable the designer to make intelligent decisions to optimize the design. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006 [source]

SPC with Applications to Churn Management

QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 5 2004
Magnus Pettersson
Abstract The process of a customer replacing one provider of a service or merchandise for another is called a churn. In competitive business environments, such as telecommunications, insurance, banking, hotels and mail order, customers can easily leave one company,and they really do. Since the cost of recruiting new customers is higher than the cost of retaining them, it is crucial for companies in these trades to monitor their customer population in order to keep churn rates low. Statistical process control (SPC) methods are developed to cover the needs of monitoring industrial processes and intensive care patients. They are based on procedures where data are analysed automatically and on-line. When results indicate that the process is out of control, an alarm alerts an engineer or physician, who can take corrective action in order to get the process back under control. This paper discusses the use of SPC methods as a means to enhance precision in detecting increasing churn rates. We show that SPC methods can give market analysts a powerful tool for tracking customer movements and churn. An early warning system (EWS), based on the same ideas as used in process industries, will give foresight and a longer time to react against churn, hence providing an advantage over competitors. In the examples discussed in this paper we monitor usage in order to detect decreasing volumes that indicate churn. Data were extracted from internal databases, and analysed and reported on-line. We conclude that the potential improvement by using SPC methods in churn management is high. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Fluid-Borne entities in the impeller stream of a rushton turbine

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2000
Larry A. Glasgow
Abstract The breakage or disintegration of suspended entities by energetic fluid motions in stirred tanks is an essential aspect of many operations in the chemical process industries. However, the hydrodynamic inhomogeneity of such tanks makes it extremely difficult to characterize the stresses experienced in any simple manner. This work provides a determination of both the location and the frequency of interaction of spherical fluid-borne entities with the discharge of a Rushton turbine. These data show how both particle size and impeller speed affect the severity of the exposure, setting the groundwork for improved descriptions of the dynamic behaviour of the particle size distribution in a wide variety of dispersed-phase processes. La rupture ou la désintégration de particules suspendues par des déplacements de fluides énergé-tiques dans des réservoirs agités est un aspect essentiel de nombreuses opérations des industries de procédés chimiques. Toutefois, la non-homogénéité hydrody-namique de ces réservoirs rend extrçmement difficile la caractérisation des forces en jeu par une méthode simple. On détermine dans ce travail la position et la fréquence d'interaction de particules sphériques transpottées par le fluide dans la zone de refoulement d'une turbine Rushton. Ces données montrent comment la taille des particules et la vitesse de la turbine influent toutes deux sur la sévérité de l'exposi-tion, jetant ainsi les bases pour améliorer la description du comportement dynamique de la distribution de taille des particules dans un large éventail de procédés en phase dispersée. [source]

Megapixels, Millimetres and Microsieverts: Packaging Digital Photogrammetry for Emerging Industrial Markets

THE PHOTOGRAMMETRIC RECORD, Issue 95 2000
D. P. Chapman
As the performance of megapixel digital imaging systems continues to improve, the rapid growth of high-end consumer markets drives prices ever lower. When such cameras are married with emerging, desktop "photogrammetric" software packages, the close range photogrammetric community is faced with many new challenges and opportunities. The dramatic changes in the technological arena are matched by a rapidly changing business environment in which concepts such as "Partnering" and "Supply chain management" have become key themes. As organizations of all sizes seek to thrive within this new business landscape, there appears to be a willingness to think more flexibly about the client-supplier relationship and the sharing of risks and rewards. This, in turn, has encouraged the development of highly customized measurement solutions across a wide range of market sectors. In each of these solutions the emphasis is not on a generic photogrammetric product, but on a highly tailored system tightly coupled to existing workflows, and focused on the specific needs of the client. Such systems pose particular challenges to their designers, since they are frequently operated by users with relatively little photogrammetric background and yet must always meet the challenging requirement of producing an output which is "fit for purpose". Thus this paper hopes to show how novel megapixel imaging systems can be configured to deliver flexible measurement systems capable of millimetric level accuracy within the challenging engineering environments typical of the nuclear and process industries (hence the microsievert component of the title). [source]

P/Pd Types Of Override Control Systems

ASIAN JOURNAL OF CONTROL, Issue 4 2002
Yaw-Ying Tsai
ABSTRACT The override control provides protective action against abnormal operation and/or incipient process failure. In terms of control theory, it is a logic-based switching system and, in terms of operation, it is usually activated between the soft constraint and the hard constraint. It is used in all process industries, and most PID control loops are patched with some type of override system. Despite widespread application, little research has been done to analyze override control systems. In this work, the properties of the override control are explored. The stability of the override control is also studied. Counter to intuition, many well-known override systems may exhibit instability and lead to oscillatory responses as the process approaches constraints. Approaches are proposed for the design of override control systems to ensure inherent safe operation. [source]

Decentralized Control for Multivariable Processes with Actuator Nonlinearities

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1-2 2006
S. W. Su
Decentralized control is the most widely used control strategy in the process industries because of the simplicity to design and implement the controller, and the potential to achieve failure tolerant control. Actuator nonlinearities are often encountered in many chemical processes. This paper presents a decentralized control method for processes which have static actuator nonlinearities, such as saturation and dead zone. The proposed decentralized integral controller is designed based on feedforward passivation, which can be applied to nonminimum phase processes and/or processes of high relative degree. The concept of marginally stable positive real systems is used to analyse the stability of a closedloop system. The feedforward system is constructed to attain dynamic performance on the basis of frequency based passivity analysis. The effectiveness of the proposed approach is demonstrated using an example of a quadruple tank control problem. [source]

L -Lysine Monohydrochloride Syrup Concentration using a Membrane Hybrid Process of Ultrafiltration and Vacuum Membrane Distillation

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 11 2008
O. Bakhtiari
Abstract The development of energy saving membrane separation processes is finding a unique position in process industries. One of the important areas where they are employed is the biotechnology industry. This industry has its own specifications and requirements, e.g., levels of diluteness, thermal, chemical and shear fragility. Membrane separation processes have the characteristics necessary to match these specifications and needs. In this research, the determination of the experimental concentration of L -Lysine monohydrochloride (L -lysine-HCl) syrup was investigated using ultrafiltration (UF) and vacuum membrane distillation (VMD) hybrid membrane processes. Four parameters that are known to have significant influence on the UF process were examined, i.e., pressure difference across the membrane, feed concentration of L -lysine-HCl, feed velocity on the membrane surface, and pH. For the VMD unit, pressure difference and pH were replaced with feed temperature and vacuum pressure on the permeate side of membrane. Each process was carried out separately and the results were used to design a bench-scale process. In order to save time and money, the Taguchi method of experimental design was employed. The effects of feed concentration, pressure difference across the membrane, feed velocity on the membrane surface, and pH on the target variable, i.e., the membrane flux, in the UF process were 39.93, 38.65, 9.36, and 9.59,%, respectively. For the VMD process, these values were 64.79, 22.16, 6.21, and 2.14,% for feed temperature, feed concentration, vacuum pressure on the permeate side, and feed velocity on the membrane surface, respectively. [source]

Development of an Expert System Shell Based on Genetic Algorithms for the Selection of the Energy Best Available Technologies and their Optimal Operating Conditions for the Process Industry

One-zone simulation model of an oil-injected screw chiller

A novel dual-mode predictive control strategy for constrained Wiener systems

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 9 2010
Hai-Tao Zhang
Abstract In process industry, there exist many Wiener systems with input magnitude constraints for which, however, most of the existing control algorithms cannot guarantee to have sufficiently large regions of asymptotic stability. In this paper, the subspace method is applied to separate the nonlinear and linear blocks in a constrained multi-input/multi-output (MIMO) Wiener system and a novel dual-mode nonlinear model predictive control algorithm is developed to maximize the region of the asymptotic stability. Simulation results are presented to demonstrate the virtues of this new control algorithm. The limitation is the requirement that the state and input matrices of the Wiener system's linear block should be accurately identified. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Process integration technology review: background and applications in the chemical process industry

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2003
Russell F Dunn
Abstract Process integration is a holistic approach to process design and operation which emphasizes the unity of the process. Process integration design tools have been developed over the past two decades to achieve process improvement, productivity enhancement, conservation in mass and energy resources, and reductions in the operating and capital costs of chemical processes. The primary applications of these integrated tools have focused on resource conservation, pollution prevention and energy management. Specifically, the past two decades have seen the development and/or application of process integration design tools for heat exchange networks (HENs), wastewater reduction and water conservation networks, mass exchange networks (MENs), heat- and energy-induced separation networks (HISENs and EISENs), waste interception networks (WINs) and heat- and energy-induced waste minimization networks (HIWAMINs and EIWAMINs), to name a few. This paper provides an overview of some of these developments and outlines major driving forces and hurdles. The fundamental aspects of this approach along with their incorporation in an overall design methodology will be discussed. The paper also highlights several recent applications of process integration to industrial processes. Copyright © 2003 Society of Chemical Industry [source]

ACTIVITY DISTRIBUTION OF DIGESTIVE PROTEASES FROM NEMIPTERUS VIRGATUS AND THEIR RESPONSES TO pH VALUE AND TEMPERATURE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2008
HONG TAO
ABSTRACT In the present study, three groups (I,III) of Nemipterus virgatus, with average body weights of 154.36, 250.72 and 329.09 g, respectively, were used to investigate the changes in the activity and distribution of digestive proteases in different organs and sections of the digestive tract. Another group of N. virgatus (average body weight of 188.41 g) was used to analyze the changes in the activity of digestive proteases in response to various pH values and temperatures. The activity of digestive proteases in all analyzed organs increased with the increase of body weight at the range of 154.36,329.09 g. The activities of digestive proteases in the different sections of the digestive tract were compared, and a similar change was found among groups I,III. The activities of digestive proteases from various organs were in a descending order: pylorus ceca > stomach > foregut > midgut > hindgut > hepatopancreas. Through observing the zymograms of substrate,sodium dodecil sulphate-polyacrylamide gel electrophoresis, many kinds of digestive proteases could be found in different organs and the varieties were changed with the change of body weight. Two peaks in the diagram between protease activity and pH value were found at pH 3.0 and 10.0, respectively. The activity under alkaline condition was 60% higher than that under acidic condition. The optimal temperature for protease activity was 50C, while the protease activity at 10C was only 30% of that at 50C. PRACTICAL APPLICATIONS Nemipterus virgatus is one of the most important commercial fishes in the East China Sea and South China Sea. The digestive tract of N. virgatus is rich in digestive proteases and they can be employed as important biotechnological tools. The activities of digestive proteases from various organs and the effects of pH value and temperature on them were investigated in this study. The effect of body weight of N. virgatus was also evaluated. All these information would be helpful to extensively utilize this resource for the fish process industry. [source]

Modeling of partial oxidation in gas,solids downer reactors

AICHE JOURNAL, Issue 8 2010
S. Vaishali
Abstract Selective partial oxidations represent an important class of reactions in the process industry. Of particular interest is the partial oxidation of n-butane to maleic anhydride (MAN), which is arguably the largest commercialized alkane partial oxidation process. Partial oxidation of n-butane, which uses vanadium phosphorous oxide (VPO) as a heterogeneous catalyst, is believed to operate through a unique mechanism in which lattice oxygen oxidizes n-butane selectively to MAN. Past work has shown that performing partial oxidation reactions in gas,solids riser configuration is realizable and commercially viable, which has lead to commercialization of this technology in the last decade. Though the riser configuration allows optimal and independent control of the oxidation and reduction steps, the riser unit suffers from solid backmixing at walls, which in turn result into lower conversion, nonoptimal selectivity and diminished overall yield of desired product. In recent years, there has been growing interest in downers involving cocurrent downflow of both solids and gas phases, hence offering relatively uniform flow characteristics. In this contribution, we explore through modeling the implications of effecting partial oxidation reactions in a downer (gas,solids cocurrent downflow) compared to that in a conventional riser reactor (gas,solids cocurrent up flow) operated under equivalent operating conditions. Further, we explore the operational space of downers for these reactions, suggesting ways for improving the productivity of downer for partial oxidation applications. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]

Best starting point to comprehensive process safety education

PROCESS SAFETY PROGRESS, Issue 3 2007
Milos Ferjencik
Abstract Instruction in process safety began at the Faculty of Chemical Technology, University of Pardubice, in the nineties. In 1994, a course named the Safety Engineering was formed. We aimed to equip our students with a theory that would orientate them in safety problems during their professional lives. Similar to analogous courses at other universities, the Safety Engineering course tends to follow basic steps of the quantitative risk analysis (QRA). An accident analysis and two basic notions,a system and a hazard,were selected as starting points of the course. But after a few years of experience we felt that the Safety Engineering course did not represent exactly what the majority of our students needed. Although the concept of risk analysis represents a fundamental part of any process safety theory, there is another concept that seems to be essential for professionals involved in the process industry,safety management. We started to recognize that an introduction into comprehensive process safety education should be divided into two stages. The safety management and the risk analysis should represent focal points of the first and the second stages, respectively. Two stage arrangement of the process safety course seems to suit needs of our students better than the previous scheme. After the idea of division of the process safety course had arisen, a new starting point for the comprehensive safety education had to be found. An old approach of Kletz's on "learning from accidents" showed itself to be suitable to fulfill this role most naturally. © 2007 American Institute of Chemical Engineers Process Saf Prog 26:195,202, 2007 [source]

What risk should public accept from chemical process facilities?

PROCESS SAFETY PROGRESS, Issue 2 2007
Ernst Meyer
Abstract Major incidents in chemical process plants such as Bhopal have raised the questions of facility, safety, and security by stakeholders and interest groups. How will the facility be perceived as safe given the possible consequences? No one denies that there have been improvements in process safety since Bhopal and many safety regulations have come into effect. The public may still question whether it is safe to live or work near a chemical plant today. This paper discusses the risk that the public should accept under governmental leadership and guidance. Also discussed is how the chemical process industry should ensure risk acceptance criteria compliance and maintenance of compliance throughout the lifetime of a facility. Safety may be enforced by compliance with a pre-defined set of risk acceptance criteria. These criteria may be absolute and tangible, but in some cases are more abstract. Different practices are seen among different countries, states, and regions as well as between different industry segments. This paper discusses the meaning of risk acceptance criteria and how exposed people and regulatory bodies should relate to the criteria. © 2007 American Institute of Chemical Engineers Process Saf Prog, 2007 [source]