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<p> This thesis considers the problem of control of nonlinear process systems subject to input constraints and faults in the control actuators and process equipments. Faults are considered that preclude the possibility of continued operating at the nominal equilibrium point and a framework (which we call the safe-parking framework) is developed to enable efficient resumption of nominal operation upon fault-recovery. First, Lyapunov-based model predictive controllers, that allow for an explicit characterization of the stability region subject to constraints on the manipulated input, are designed. The stability region characterization is utilized in selecting 'safe-park' points from the safe-park candidates (equilibrium points subject to failed actuators). This safe-park point is chosen as a temporary operating point where process is to be operated during fault rectification. This ensures that process can be safely operated during fault rectification and the nominal operation can be resumed upon fault recovery. When multiple candidate safe-park points are available, performance considerations, such as ease of transition from and to the safe-park point and cost of running the process at the safe-park point, are quantified and utilized in choosing the optimal safe-park point. </p> <p> Next, we extend the safe-parking framework to handle practical issues such as plant-model mismatch, disturbances and unavailability of all process state measurements. \i\Te first consider the presence of constraints and uncertainty and develop a robust Lyapunov-based model predictive controller. This controller is utilized to characterize robust stability region which, subsequently, is utilized to select 'safepark' points. Then we consider the problem of availability of limited measurements. An output feedback Lyapunov-based model predictive controller, with high-gain observer to estimate unmeasured states, is formulated and its stability region explicitly characterized. An algorithm is then presented that accounts for the estimation errors in the implementation of the safe-parking framework. </p> <p> We then further extend the framework to handle faults in large scale chemical plants where multiple process units are connected via material, energy and information streams. In plant-wide setting, the safe-park point for the faulty unit is chosen such that the safe-parking has no or minimum effect on downstream units, and hence, the nominal operation in the downstream units can be continued. Next we consider the scenario where no viable safe-park point for the faulty unit exists such that its effect can be completely absorbed in the subsequent unit. A methodology is developed that allows simultaneous safe-parking of the consecutive units. The efficacy of the proposed framework is illustrated using a chemical reactor example, a styrene polymerization process and two CSTRs in series example. </p> <p> Finally, we demonstrate the efficacy of proposed Lyapunov based Model Predictive Controller and Safe-Parking framework on a polymerization reactor model to control the polymerization reactor and to handle faults that dont allow continuation of the nominal operation in the reactor. </p> / Thesis / Doctor of Philosophy (PhD)

Vibrofluidized microreactor systems have been developed for studies of unsteady-state Fischer-Tropsch synthesis. This development is aimed at preventing carbon deposition on a fused-iron catalyst in a novel reactor called the “heat-tray.” This reactor involves a supernatant gas flowing over a shallow fluidized bed of catalyst particles. Three systems were built: (1) a vibrofluidized-bed microreactor system for obtaining baseline carbon deposition infonnation under industrially important reaction conditions; (2) a sliding-plug vibrofluidized-bed microreactor system for rapid switching of feed gases in the F-T synthesis; and (3) a cold-flow microreactor model for studying the gas mixing characteristics of the sliding-plug vibrofluidized-bed microreactor. The results show that catalyst defluidization occurred under steady-state synthesis conditions below 395°C using a feed gas of H₂/CO ratio of 2:1 or less. Above 395°C, the probability of hydrocarbon chain growth (α) on the fused-iron catalyst was low enough (α < 0.50) to prevent accumulation of high-molecular-weight species that cause defluidization. Carbon deposition was rapid above 395°C when a feed gas of H₂/CO ratio of 2:1 or less was used. Spent catalyst fractions in the form of free-flowing catalyst and "bugdust" were quantitatively analyzed for carbon and iron. Mössbauer spectroscopic analysis of free-flowing catalyst showed mainly Hägg carbide (x-Fe₅C₂) and magnetite (Fe₃O₄) with a smaller fraction present as α-Fe. Scanning electron microscopic analysis of the bugdust revealed a mass of highly porous, fine particles with a high carbon content (18-30 wt%). Cold-flow microreactor model studies show that rapid (on the order of seconds), quantitative switching of feed gases over a vibrofluidized-bed of catalyst could be achieved. Vibrofluidization of the catalyst bed induced little backmixing of feed gas over the investigated flow-rate range of 417 to 1650 actual mm³/s. Further, cold-flow microreactor model studies showed intense solid mixing when a -150+300 µ bed of fused-iron catalyst was vibrofluidized at 24 cycles per second with a peak-to-peak amplitude of 4 mm. The development of this microreactor system has provided an easy way of accurately determining integral fluid-bed kinetics in a laboratory reactor. Further, the unique ability of the microreactor system to rapidly switch feed gases over an intensely-mixed solid has important applications in chemical kinetics and reaction engineering. / Ph. D.

<p>Car exhaust catalysts were introduced in the early 1980’s, to limit the release of pollutants such as hydrocarbons, carbon monoxides and nitrogen oxides. These catalysts contain noble metals such as palladium (Pd), platinum (Pt) and rhodium (Rh) and are able to simultaneously abate all three of the above-mentioned pollutants, hence the name three-way catalyst (TWC). The exposure to high temperatures (800-1000 °C) during operation and the presence of additives in petrol such as lead, calcium, silicon, magnesium, manganese, chromium, sulphur and phosphorus will after a certain time start to lower the overall effectiveness of the catalyst. These effects are either of a mechanical or a chemical nature. High temperatures reduce the active area by causing the noble metals to agglomerate and sinter whereas the additives alter the activity by either fouling the pores of the support material (phosphorus) or by interacting with the metals (sulphur and lead).</p><p>The main objective of this work was to develop a method to redisperse the catalytically active sites, comprising Pd, Pt and Rh on the washcoat surface, in an effort to regain lost catalyst activity. For this purpose, a wide spectrum of different commercial car exhaust catalysts containing varying noble metal loadings, aged under various driving conditions and with mileages ranging from 30 to 100 000 km were evaluated.</p><p>The influence of a thermal treatment in a controlled gas atmosphere, such as oxygen or hydrogen and a redispersing agent, e.g. chlorine, on the activity of TWC was investigated by means of laboratory-scale activity measurements. Several complementary characterisation methods such as SEM/TEM, XRD, BET and TPR were used to verify the effects of the regeneration treatments on the catalyst morphology (Paper I). Partial regeneration of catalyst activity and noble metal dispersion was achieved after thermal treatment in an oxygen-chlorine rich atmosphere at temperatures below 500 °C.</p><p>Finally, an investigation of the effects of an oxy-chlorine thermal treatment for regeneration of a ‘full-scale’ commercial automotive three-way catalyst was performed. Catalyst activity and performance prior to and after the oxy-chlorine thermal treatment was measured on a test vehicle in accordance with the European driving cycle (EC2000). The catalyst surface was further characterised using XRD and EDX (Paper II). Improved catalyst activity for a high mileage catalyst could be observed, with emissions lowered by approximately 30 to 40 vol% over the EC2000 driving cycle</p>

Der Betrieb von prozesstechnischen Produktionsanlagen wird stetig von verschiedenen Aufgaben begleitet, zum Beispiel der Steuerung und Optimierung der Produktion und der Aufrechterhaltung der Verfügbarkeit. Alle Gewerke, die sich mit dem Zustand der Anlage und des darin ablaufenden Prozesses beschäftigen, sind auf Daten angewiesen, die in der Anlage erfasst werden. Ein Großteil dieser Daten werden für die automatische Steuerungs-, Regelungs- und Sicherheitstechnik erfasst und darin in Echtzeit verarbeitet. Apparate und anderes Equipment sind zumeist nicht mit für deren Zustandsüberwachung dedizierter Messtechnik ausgestattet. Um Qualitätsmerkmale, Anlagenzustände oder Wartungsbedarfe erkennen zu können, müssen andere in der Anlage vorhandene Daten kombiniert und in Berechnungsmodellen kondensiert werden. Diese Methodik teilt sich in unterschiedliche Schritte auf: Datenakquise, Entwurf von Auswertemodellen, Modellintegration und Auswertung von Ergebnissen mit Ableitung von Aufgaben. Die vorliegende Arbeit ordnet sich in die Softwareaspekte dieser Methodik ein. Dabei versucht sie, die zentrale Frage „Wie könnte eine Infrastruktur auf Basis von verbreiteten Standardtechnologien aussehen, welche alle Schritte des Engineeringprozesses für freie Apparatemodelle automatisieren kann?“ anhand eines Vorschlags für eine Infrastruktur zu beantworten. Es wird eine Möglichkeit dargelegt, im Betrieb ohne Änderungen am bestehenden System kontinuierlich Daten für die Weiterverwendung in Apparatemodellen auszulesen. Der Entwurf und die Implementierung von Auswertemodellen wurde mit Hilfe eines entwickelten Werkzeugs unterstützt und dadurch die Struktur der Apparatemodelle vorgegeben, um eine einheitliche Modellintegration zu ermöglichen. Die Durchführung der Modellintegration erfolgte über die automatische Auswertung von Planungsdaten. Eine auf offenen Technologien basierende Ausführungsplattform für die Bewertungsmodelle wurde implementiert. Die Auswertung von Berechnungsergebnissen wurde über die Integration der Modelle in verbreitete, für Feldgeräte vorgesehene Standardwerkzeuge ermöglicht. Diese Infrastruktur ermöglicht es den verschiedenen Gewerken des Anlagenbetreibers, generische Bewertungsmodelle auf die Apparateinstanzen in der Anlage anzuwenden, und mit deren Berechnungsergebnissen ihre Aufgaben einfacher oder besser bearbeiten zu können. Nach einer Analyse der technischen Rahmenbedingungen wurde ein Konzept zur Modellintegration entwickelt und dessen Automatisierbarkeit diskutiert. Dieses Konzept wurde prototypisch umgesetzt. Es wurden Softwarekomponenten für den Betrieb sowie Softwarewerkzeuge für die Unterstützung sowohl der Erstellung als auch der Integration von Apparatemodellen entwickelt. Anhand dieser wurde Umsetzbarkeit des Konzepts überprüft / Operating process plants goes along with different tasks, e. g. control and optimization of the production and maintaining availability of the plant. There are several subsections of operations who deal with the state of the plant and the processes it runs. They are all dependent on information which is gathered throughout the plant. Most of this data is acquired for the automatic control, regulation, and safety gear and is processed in real-time. Apparatuses and other equipment are usually not equipped with measurement devices which are dedicated to monitor their state. For being able to recognize specific quality attributes, states of the plant, or maintenance needs, the existing measurements have to be combined and condensed by calculations. This methodology can be split into the following steps: data acquisition, design of evaluation models, integration of these models, and assessment of findings including inferring actions. This thesis addresses software aspects of this methodology. It tries to answer the key question „How to build an infrastructure, which shall be based on common standard technologies, in which all steps to engineer equipment models may be automated?“ by proposing a concrete infrastructure. A technique has been designed to continuously acquire data for further processing in equipment models without any changes to existing systems. The process of design and implementation of equipment models has been supported by a purpose-built tool. This tool puts out the designed models in a uniform structure to allow uniform model integration. This integration has been automated using the plant’s engineering data. An execution platform has been developed based on open technologies. Infrastructure and model structure have been designed to easily integrate calculation results into standard tools for being able to use them in common work environments. It enables the different subsections of operations in a plant to apply generic equipment assessment models on concrete equipment instances. Using the output of the models, they shall be enabled to perform their task in an easier or better manner. The technical requirements and prerequisites have been analyzed. Using the resulting conclusions, a concept to integrate models has been developed and the options to automate it have been discussed. This concept has been implemented prototypically. This implementation includes a runtime component and two tools to support development of models and their instantiation. It has been used to prove the feasibility of the concept.

Der Betrieb von prozesstechnischen Produktionsanlagen wird stetig von verschiedenen Aufgaben begleitet, zum Beispiel der Steuerung und Optimierung der Produktion und der Aufrechterhaltung der Verfügbarkeit. Alle Gewerke, die sich mit dem Zustand der Anlage und des darin ablaufenden Prozesses beschäftigen, sind auf Daten angewiesen, die in der Anlage erfasst werden. Ein Großteil dieser Daten werden für die automatische Steuerungs-, Regelungs- und Sicherheitstechnik erfasst und darin in Echtzeit verarbeitet. Apparate und anderes Equipment sind zumeist nicht mit für deren Zustandsüberwachung dedizierter Messtechnik ausgestattet. Um Qualitätsmerkmale, Anlagenzustände oder Wartungsbedarfe erkennen zu können, müssen andere in der Anlage vorhandene Daten kombiniert und in Berechnungsmodellen kondensiert werden. Diese Methodik teilt sich in unterschiedliche Schritte auf: Datenakquise, Entwurf von Auswertemodellen, Modellintegration und Auswertung von Ergebnissen mit Ableitung von Aufgaben. Die vorliegende Arbeit ordnet sich in die Softwareaspekte dieser Methodik ein. Dabei versucht sie, die zentrale Frage „Wie könnte eine Infrastruktur auf Basis von verbreiteten Standardtechnologien aussehen, welche alle Schritte des Engineeringprozesses für freie Apparatemodelle automatisieren kann?“ anhand eines Vorschlags für eine Infrastruktur zu beantworten. Es wird eine Möglichkeit dargelegt, im Betrieb ohne Änderungen am bestehenden System kontinuierlich Daten für die Weiterverwendung in Apparatemodellen auszulesen. Der Entwurf und die Implementierung von Auswertemodellen wurde mit Hilfe eines entwickelten Werkzeugs unterstützt und dadurch die Struktur der Apparatemodelle vorgegeben, um eine einheitliche Modellintegration zu ermöglichen. Die Durchführung der Modellintegration erfolgte über die automatische Auswertung von Planungsdaten. Eine auf offenen Technologien basierende Ausführungsplattform für die Bewertungsmodelle wurde implementiert. Die Auswertung von Berechnungsergebnissen wurde über die Integration der Modelle in verbreitete, für Feldgeräte vorgesehene Standardwerkzeuge ermöglicht. Diese Infrastruktur ermöglicht es den verschiedenen Gewerken des Anlagenbetreibers, generische Bewertungsmodelle auf die Apparateinstanzen in der Anlage anzuwenden, und mit deren Berechnungsergebnissen ihre Aufgaben einfacher oder besser bearbeiten zu können. Nach einer Analyse der technischen Rahmenbedingungen wurde ein Konzept zur Modellintegration entwickelt und dessen Automatisierbarkeit diskutiert. Dieses Konzept wurde prototypisch umgesetzt. Es wurden Softwarekomponenten für den Betrieb sowie Softwarewerkzeuge für die Unterstützung sowohl der Erstellung als auch der Integration von Apparatemodellen entwickelt. Anhand dieser wurde Umsetzbarkeit des Konzepts überprüft / Operating process plants goes along with different tasks, e. g. control and optimization of the production and maintaining availability of the plant. There are several subsections of operations who deal with the state of the plant and the processes it runs. They are all dependent on information which is gathered throughout the plant. Most of this data is acquired for the automatic control, regulation, and safety gear and is processed in real-time. Apparatuses and other equipment are usually not equipped with measurement devices which are dedicated to monitor their state. For being able to recognize specific quality attributes, states of the plant, or maintenance needs, the existing measurements have to be combined and condensed by calculations. This methodology can be split into the following steps: data acquisition, design of evaluation models, integration of these models, and assessment of findings including inferring actions. This thesis addresses software aspects of this methodology. It tries to answer the key question „How to build an infrastructure, which shall be based on common standard technologies, in which all steps to engineer equipment models may be automated?“ by proposing a concrete infrastructure. A technique has been designed to continuously acquire data for further processing in equipment models without any changes to existing systems. The process of design and implementation of equipment models has been supported by a purpose-built tool. This tool puts out the designed models in a uniform structure to allow uniform model integration. This integration has been automated using the plant’s engineering data. An execution platform has been developed based on open technologies. Infrastructure and model structure have been designed to easily integrate calculation results into standard tools for being able to use them in common work environments. It enables the different subsections of operations in a plant to apply generic equipment assessment models on concrete equipment instances. Using the output of the models, they shall be enabled to perform their task in an easier or better manner. The technical requirements and prerequisites have been analyzed. Using the resulting conclusions, a concept to integrate models has been developed and the options to automate it have been discussed. This concept has been implemented prototypically. This implementation includes a runtime component and two tools to support development of models and their instantiation. It has been used to prove the feasibility of the concept.

The concept of open innovation has received increased attention among practitioners as well as in academia in recent years. It provides a conceptual platform for understanding how external sources of knowledge drive internal growth. In addition, it also addresses the internal configurations needed for managing a more externally oriented innovation process. However, many firms still experience major managerial challenges in trying to adopt the principles of open innovation. The perhaps most important challenge in realizing the potential benefits of open innovation lies in modifying existing innovation activities and processes to incorporate the principles of open innovation, rather than creating something completely new. Therefore, the purpose of this thesis is to study the problems and opportunities arising when firms attempt to integrate open innovation activities within their development processes. Empirically, the results are based on three exploratory case studies within the process industries. In total, this thesis is based on 73 interviews from 2 process firms and 9 equipment suppliers to the process industries. Data was gathered in several different countries, and collectively these firms represent perspectives from Sweden, Norway, Finland, Switzerland, Germany, The Netherlands and The United Kingdom.Three papers are appended with the thesis. Paper I studies the overall challenges of integrating open innovation activities within an existing product development process. The key contribution is the enactment of a practitioner-oriented work model, named the open Stage-Gate model, which exploits the advantages of "openness" while simultaneously capturing the benefits deriving from the systematic and structured approach implied by the Stage-Gate process. Paper II studies a concrete application of open innovation by focusing on the development and installation of new or upgraded process equipment in process plants where collaborative efforts by a process firm and various suppliers of process equipment often are required. The analysis focuses on problems and opportunities in different stages of the equipments lifecycle and finds that the content and the intensity of the collaboration should be tailored to the different stages of the equipment's lifecycle. As such, the conclusions highlight the fact that being totally open in development activities is not always the most suitable option. Instead, different degrees of "openness" may be suitable at different stages. Paper III studies collaboration in the later operational stages of a process equipments lifecycle, from an equipment supplier perspective. The results presented in this paper underscore the importance of collaboration in the operational stages as these stages are critical to facilitate technology transfer and production performance.