Model-based approach for the plant-wide economic control of fluid catalytic cracking unit

Fluid catalytic cracking (FCC) is one of the most important processes in the petroleum refining industry for the conversion of heavy gasoil to gasoline and diesel. Furthermore, valuable gases such as ethylene, propylene and isobutylene are produced. The performance of the FCC units plays a major role on the overall economics of refinery plants. Any improvement in operation or control of FCC units will result in dramatic economic benefits. Present studies are concerned with the general behaviour of the industrial FCC plant, and have dealt with the modelling of the FCC units, which are very useful in elucidating the main characteristics of these systems for better design, operation, and control. Traditional control theory is no longer suitable for the increasingly sophisticated operating conditions and product specifications of the FCC unit. Due to the large economic benefits, these trends make the process control more challenging. There is now strong demand for advanced control strategies with higher quality to meet the challenges imposed by the growing technological and market competition. According to these highlights, the thesis objectives were to develop a new mathematical model for the FCC process, which was used to study the dynamic behaviour of the process and to demonstrate the benefits of the advanced control (particularly Model Predictive Control based on the nonlinear process model) for the FCC unit. The model describes the seven main sections of the entire FCC unit: (1) the feed and preheating system, (2) reactor, (3) regenerator, (4) air blower, (5) wet gas compressor, (6) catalyst circulation lines and (7) main fractionators. The novelty of the developed model consists in that besides the complex dynamics of the reactorregenerator system, it includes the dynamic model of the fractionator, as well as a new five lump kinetic model for the riser, which incorporates the temperature effect on the reaction kinetics; hence, it is able to predict the final production rate of the main products (gasoline and diesel), and can be used to analyze the effect of changing process conditions on the product distribution. The FCC unit model has been developed incorporating the temperature effect on reactor kinetics reference construction and operation data from an industrial unit. The resulting global model of the FCC unit is described by a complex system of partial-differential-equations, which was solved by discretising the kinetic models in the riser and regenerator on a fixed grid along the height of the units, using finite differences. The resulting model is a high order DAE, with 942 ODEs (142 from material and energy balances and 800 resulting from the discretisation of the kinetic models). The model offers the possibility of investigating the way that advanced control strategies can be implemented, while also ensuring that the operation of the unit is environmentally safe. All the investigated disturbances showed considerable influence on the products composition. Taking into account the very high volume production of an industrial FCC unit, these disturbances can have a significant economic impact. The fresh feed coke formation factor is one of the most important disturbances analysed. It shows significant effect on the process variables. The objective regarding the control of the unit has to consider not only to improve productivity by increasing the reaction temperature, but also to assure that the operation of the unit is environmentally safe, by keeping the concentration of CO in the stack gas below a certain limit. The model was used to investigate different control input-output pairing using classical controllability analysis based on relative gain array (RGA). Several multi-loop control schemes were first investigated by implementing advanced PID control using anti-windup. A tuning approach for the simultaneous tuning of multiple interacting PID controllers was proposed using a genetic algorithm based nonlinear optimisation approach. Linear model predictive control (LMPC) was investigated as a potential multi-variate control scheme applicable for the FCCU, using classical square as well as novel non-square control structures. The analysis of the LMPC control performance highlighted that although the multivariate nature of the MPC approach using manipulated and controlled outputs which satisfy controllability criteria based on RGA analysis can enhance the control performance, by decreasing the coupling between the individual low level control loops operated by the higher level MPC. However the limitations of using the linear model in the MPC scheme were also highlighted and hence a nonlinear model based predictive control scheme was developed and evaluated.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Gasification for Practical Applications

Although there were many books and papers that deal with gasification, there has been only a few practical book explaining the technology in actual application and the market situation in reality. Gasification is a key technology in converting coal, biomass, and wastes to useful high-value products. Until renewable energy can provide affordable energy hopefully by the year 2030, gasification can bridge the transition period by providing the clean liquid fuels, gas, and chemicals from the low grade feedstock. Gasification still needs many upgrades and technology breakthroughs. It remains in the niche market, not fully competitive in the major market of electricity generation, chemicals, and liquid fuels that are supplied from relatively cheap fossil fuels. The book provides the practical information for researchers and graduate students who want to review the current situation, to upgrade, and to bring in a new idea to the conventional gasification technologies

An Investigation On Model Predictive Controllers’ Applications Of A Chemical Engineering Process

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2006Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2006Bu çalışmada, Model Öngörülü Kontrol edicilerin kimya mühendisliğinin en öenmli uygulamalarından biri olan kimyasal reaktörlerde kullanımı ve performansı incelenmiştir. Propilen oksit ve su reaksiyonundan ortaya çıkan propilen glikolun konsantrasyonu ve reaktörün sıcaklığı, propilen oksit ve soğutma suyunun akış debisinin ayarlanması ile control edilmiş, soğutma suyu sıcaklığı ve propilen oksitin giriş konsantrasyonu bozucu etki olarak değerlendirilmiştir. Tasarlanan kontrol edici, ayar noktası değişimleri ve bozucu etkilere karşı cevabı yönünden incelenmiştir. Bu etkilere kontrol edicinin kısa sürede cevap verdiği gözlemlenmiştir. Ayrıca kontrol edicinin gürbüzlüğünü test etmek amacı ile sistem parametreleri değiştirilmiş ve kontrol edicinin yeni sistemde de o modele ait olmayan basamak cevabı ile reaktörü kontrol edebildiği gözlemlenmiştir.In this study, applications and performance of MPC on chemical reactors, one of the most important chemical engineering applications, are examined. Propylene glycol concentration, resulting from reaction of propylene oxide and water, is controlled with reactor temperature by manipulating propylene oxide and coolant flow rates. Temperature of cooling water and initial concentration of propylene oxide are evaluated as measured disturbances. The designed controller is examined in terms of set point tracking and disturbance rejection. It is seen that the controller tracks the set point and rejects the effect of disturbances in a reasonably short time. Also in order to test the robustness of the controller, the system parameters have been changed and it is observed that the controller performs finely with old step response data model.Yüksek LisansM.Sc

Implementation and performance assessment of a real-time optimization system on a virtual fluidized-bed catalytic-cracking plant

This thesis develops and evaluates RTO implementation in a FCCU virtual plant, taking into account each RTO stage (noise elimination, steady-state detection, data validation, parameter estimation, and optimization). The dynamic data to carry out this analysis were obtained from an FCCU virtual plant based on a dynamic deterministic model developed in Matlab®. The model output data were contaminated with Gaussian and gross errors to simulate measurements from a real plant. For denoising, steady-state detection, data reconciliation, parameter estimation, and optimization, different strategies and algorithms were studied and assessed, while a decentralized PID was proposed for the control system. Finally, the most appropriate strategies for the case study were implemented and their performance was fully evaluated.Resumen: Esta tesis desarrolla y evalúa la implementación de la RTO en una planta virtual de FCCU, teniendo en cuenta cada etapa de una RTO (eliminación de ruido, detección de estado estable, validación de datos, estimación de parámetros y optimización). Los datos dinámicos para llevar a cabo este análisis se obtuvieron de una planta virtual de FCCU basada en un modelo determinista dinámico desarrollado en Matlab®. Los datos de salida del modelo se contaminaron con error de Gauss y error grueso para simular mediciones de una planta real. Para la eliminación de ruido, la detección de estado estable, la reconciliación de datos, la estimación de parámetros y la optimización, se estudiaron y evaluaron diferentes estrategias y algoritmos, mientras que para el sistema de control se propuso un PID descentralizado. Finalmente, se implementaron las estrategias más apropiadas para el estudio de caso y se evaluó su desempeño en conjunto.Maestrí

Proceeding Of Mechanical Engineering Research Day 2016 (MERD’16)

This Open Access e-Proceeding contains a compilation of 105 selected papers from the Mechanical Engineering Research Day 2016 (MERD’16) event, which is held in Kampus Teknologi, Universiti Teknikal Malaysia Melaka (UTeM) - Melaka, Malaysia, on 31 March 2016. The theme chosen for this event is ‘IDEA. INSPIRE. INNOVATE’. It was gratifying to all of us when the response for MERD’16 is overwhelming as the technical committees received more than 200 submissions from various areas of mechanical engineering. After a peer-review process, the editors have accepted 105 papers for the e-proceeding that cover 7 main themes. This open access e-Proceeding can be viewed or downloaded at www3.utem.edu.my/care/proceedings. We hope that these proceeding will serve as a valuable reference for researchers. With the large number of submissions from the researchers in other faculties, the event has achieved its main objective which is to bring together educators, researchers and practitioners to share their findings and perhaps sustaining the research culture in the university. The topics of MERD’16 are based on a combination of fundamental researches, advanced research methodologies and application technologies. As the editor-in-chief, we would like to express our gratitude to the editorial board and fellow review members for their tireless effort in compiling and reviewing the selected papers for this proceeding. We would also like to extend our great appreciation to the members of the Publication Committee and Secretariat for their excellent cooperation in preparing the proceeding of MERD’16

ReSCon '12, Research Student Conference: Book of Abstracts

The fifth SED Research Student Conference (ReSCon2012) was hosted over three days, 18-20 June 2012, in the Hamilton Centre at Brunel University. The conference consisted of 130 oral and 70 poster presentations, based on the high quality and diverse research being conducted within the School of Engineering and Design by postgraduate research students. The conference is held annually, and ReSCon plays a key role in contributing to research and innovations within the School

Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes

The book documents 25 papers collected from the Special Issue “Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes”, highlighting recent research trends in complex industrial processes. The book aims to stimulate the research field and be of benefit to readers from both academic institutes and industrial sectors

Recent Advances on The Enhanced Thermal Conductivity of Graphene Nanoplatelets Composites: A Short Review

Graphene nanoplatelets (GNPs) have attracted significant attention in the field of thermal management materials due to their unique morphology and remarkable thermal conductive properties. In addition, their impressive thermal properties make them interesting nanofillers for producing multifunctional composite materials with a multitude range of applications. This work specifically reviews the recent advances of the application of GNPs as nanofillers for the development of enhanced thermal conductivity of various materials or composites. In this review, the insight on the improved thermal conductivity of the composites bestowed by the GNPs with comprehensive comparison are briefly discussed. This review might unlock windows of opportunities and paves the way towards the production of enhanced materials for thermal applications including electronics, aerospace devices, batteries, and structural reinforcement