This thesis is concerned with the design of press tool run-ofts. Run-off is the area on the punch surrounding the panel and its shape is of great importance to the control of metal flow during the draw. The design, although influenced by engineering considerations, is principally a geometric problem, which traditionally has been time-consuming. The overall objective is to reduce the run-oft definition time and hence improve the lead time. Current Austin Rover design procedures are described in Chapter 2 and form the basis of the C.A.D. program outlined in Chapter 3. This specification distils the need for a number of geometric algorithms. In general, obtaining the required continuity between the panel and run-off surface will require some degree of boundary curve approximation. Chapter 4 details four alternative approximation techniques which are compared in Chapter 5; and constitute the main results of the thesis. The salient issues of run-off surface interpolation are considered in Chapter 6.

No description available.

Chemical process industries are constantly challenged to operate profitably and efficiently, despite the presence of significant uncertainties and disturbances on the operational conditions, and various operational limitations. The capability to meet the challenge relies on the quality of process control design, which should integrate the dynamic controllability characteristics in addition to the traditional economic considerations. The focus of this thesis is the development of a systematic controllability assessment framework for process control design. The framework addresses the controllability aspects in process and controller structures, as well as in time-domain dynamic performances. The aim is to provide clearer relationships between process profitability, controllability, and operational switching strategies in response to variations in the operating conditions. The skeleton of the framework is a mathematical optimisation algorithm. This algorithm considers the structural, operational and economic problems arising in process control design as a progressive, dynamic, and uncertain semi-infinite mixed integer nonlinear programming problem. The algorithm is an iterative, two-level optimisation, which determines the optimum process design and the associated controllability index within an optimisation window. The window progresses along a time horizon, ensuring optimal process design within the window while accommodating the design switching during the course of load variations in a larger time horizon. The controllability index quantifies the design capability to satisfy a given economic objective. Unique to other existing approaches, the process controllability index is computed based on the multi-dimensional geometric representation of the disturbances and uncertainties, measured process dynamics, and feasible operating spaces. These representations account for variable interactions existing in a multivariable process operation, in contrast to separate quantification in traditional single variable assessments. The geometric computation of the index requires the analysis and elimination of redundant measurement variables, which occur in different combinations at different process and controller structures. The redundancy is detected and eliminated based on statistical collinearity among the process data, allowing the assessment to focus on the retained functional variables and the associated critical disturbances and uncertainties. The redundancy analysis is tailored with a dynamic mixed integer nonlinear programming (MINLP) solver, which is dedicated to select the optimum process and controller structure within the design. The solver is developed based on the branch and bound strategy over the design tree, which consists of alternative nonlinear programming (NLP) sub-problems. In addition to the redundancy analysis, the solver is equipped with a compact MINLP formulation, an alternating depth-first and breadth-first search strategy, sub-problems. The tailored strategy ensures fast and efficient convergence of convex problems, as well as superior optimum of non-convex counterparts. Finally, the framework is performed within a time window, which progresses along the time horizon. This strategy provides realistic responses to major variations along greater length of time, by switching between optimum operational modes, while maintaining the optimum process controllability. The performance of the framework is illustrated through several case studies. Each case demonstrates the novelty of addressing various computational features in a concise algorithm. These include the industrial case, which involves the systematic controllability assessment of an industrial five-effect liquor-burning evaporator within an Alumina refinery, which highlights the contribution of this framework in bridging the process design methodologies with the industrial implementation. The thesis consists of eight chapters, presenting the systematic development of the framework. The numerical implementations have been organised in a MATLAB Toolbox, accompanied with the relevant case studies.

Energy consumption is one of the main areas in the study of chemical process design. It is usually referred to as the critical element that is continuously needed for running a chemical process, and is daily effected by the prices of energy. Therefore, poor designs which are not energy integrated normally lead to less profit due to high consumption of energy. These simple economics are the reason for tackling the area of energy integration in process design. A styrene production process is taken to be the model process for carrying out the design work incorporating the various energy integration techniques. A thorough review of the published work in this subject area was the first step in this research work. This has been followed by calculating mass and energy balances around the overall plant and the individual process steps, so that information about flowrates and energy consumed and released was obtained for the base case. After this all the possible distillation sequence configurations were tested in order to find the sequence that required least energy compared with all the other possible sequences. This step is the first part of integrating the distillation train. The second part considered the heat exchanger network associated with the distillation train and this has been taken in the context of overall process integration. "Pinch technology" was used as an aid for targeting the minimum hot and cold utilities required, designing the heat exchanger network that was compatible with the minimum use of utility and to seek further improvements on the process heat exchanger network which made it capable of recovering even more energy. Utility supplies are designed with respect to the process design, hence the next step considered the interaction between the utility and process design. Thus, the utilities were introduced in a more efficient way, resulting in a better heat exchanger network and increasing the interprocess heat exchange. Finally the steam and power system in the styrene plant was tested in order to determine how much this system had benefited due to the overall efficiency of energy supply and demand.

No description available.

Many recent studies on the relative costs and benefits of biofuels have raised the need for a detailed and rigorous analysis of the operations of a biorefinery that is focused on optimization. The current thesis concentrates on the design and optimization of plants for producing biodiesel and ethanol from cellulosic biomass. We have performed numerical simulations combined with systematic parametric analyses to investigate the effect of various parameters on the overall material and energy balances of each biorefinery. The efficiency of the simulated processes was investigated by introducing and/or estimating various metrics in order to select the more beneficial directions for process improvements. Particular emphasis has been paid on heat integration and the design of highly efficient combined heat and power (CHP) units that generate the steam and electricity needed for the purification of biofuels and their co-products. The first part of the thesis is focused on biodiesel production via transesterification of soybean oil with methanol, under alkali-catalyzed conditions. We have analyzed the performance of several reactor configurations in order to improve the conversion of the reversible transesterification reactions. The effect of the oil to alcohol ratio has also been extensively explored. Furthermore, the energy requirements of the simulated process have been rigorously calculated. Since biodiesel facilities can be used either for small-scale, distributed applications or for large-scale production, we have explored whether it is more energy efficient to burn the glycerol-rich stream in a combined heat and power (CHP) plant, or purify the glycerol and use it a feedstock for producing higher-value chemicals with further biotechnological processes. The second part of the thesis focuses on the production of cellulosic ethanol. Having developed the process model, a detailed parametric analysis was carried out to determine how the energy balances and overall efficiency of the biorefinery were influenced by changes in (a) the composition of the biomass feedstock, and (b) the conversion levels of the hydrolysis and fermentation stages. Furthermore, the requirements of the utility section of the ethanol plant were calculated. The utility section included a combined heat and power unit where by-product streams of the production process were utilized for energy generation. The parametric analysis indicated that these streams were in most cases an insufficient fuel source for meeting the energy requirements of the plant and thus, additional fuel was required (biomass, coal, or natural gas). The calculations of this section indicated a significant trade-off between ethanol production and external energy inputs, thus casting some doubt on the ultimate effectiveness of efforts to develop genetically modified energy crops (with high carbohydrate content) in order to maximize fuel production.

The process industries are characterized by the significant consumption of fresh resources. This is a critical issue, which calls for an effective strategy towards more sustainable operations. One approach that favors sustainability and resource conservation is material recycle and/or reuse. In this regard, an integrated framework is an essential element in sustainable development. An effective reuse strategy must consider the process as a whole and develop plant-wide strategies. While the role of mass and energy integration has been acknowledged as a holistic basis for sustainable design, it is worth noting that there are many design problems that are driven by properties or functionalities of the streams and not by their chemical constituency. In this dissertation, the notion of componentless design, which was introduced by Shelley and El-Halwagi in 2000, was employed to identify optimal strategies for resource conservation, material substitution, and overall process integration. First, the focus was given on the problem of identifying rigorous targets for material reuse in property-based applications by introducing a new property-based pinch analysis and visualization technique. Next, a non-iterative, property-based algebraic technique, which aims at determining rigorous targets of the process performance in materialrecycle networks, was developed. Further, a new property-based procedure for determining optimal process modifications on a property cluster diagram to optimize the allocation of process resources and minimize waste discharge was also discussed. In addition, material substitution strategies were considered for optimizing both the process and the fresh properties. In this direction, a new process design and molecular synthesis methodology was evolved by using the componentless property-cluster domain and Group Contribution Methods (GCM) as key tools in developing a generic framework and systematic approach to the problem of simultaneous process and molecular design.

No description available.

This thesis describes research into a methodology for the systematic development of engineering line diagrams (ELOs) from process tlowsheets with a particular emphasis on safety, health and environmental (SHE) and operability issues. The current approach to the consideration of safety in design is largely reactive, relying on design reviews such as the HAZOP. If design safety is to be improved, then a comprehensive system, incorporating both proactive and reactive methods, must be adopted. The facility to develop proactive safety systems relies upon the presence of a systematic design procedure. Since design at this stage seems generally to be rather haphazard, there is a need to introduce structure to the design task before any progress can be made in the improvement of safety. Introducing structure to the design task not only provides a framework for the incorporation of SHE and operability issues, but should also improve the effectiveness of the overall design and the efficiency with which it is completed. More specifically, fewer good design opportunities should be lost due to poor information handling and thc amount of rework arising from misunderstandings between different disciplines should be minimised. In addition, learning how to perform the design task should become easier for new recruits. Relevant work in the fields of process design, process safety, engineering drawings and ELO development is discussed. An analysis of perceptions of the design task within industry is presented. The generation of a systematic method by iterative case study work with designers is described. The structural features of this method are explained. Some examples of the application of the method are given and the results of a trial within industry are discussed. This research has shown that there is no existing work which captures the logic for the order in which decisions for developing a first ELO are made. Neither is there a complete analysis of the activities and issues contributing to ELO development. A novel method for the systematic generation of ELOs has been produced and used as a framework for the incorporation of SHE and operability issues into design. Trials of the method within industry have shown it to be successful.

Biodiesel has achieved worldwide recognition for many years due to its renewability, lubricating property, and environmental benefits. The abstract represents a summary of all the chapters of the thesis. The research chapters are defined as research phases in the abstract. The thesis starts with an introduction followed by literature review. In the literature review, all the necessary data were collected reviewing the literature. Then an artificial neural network model (ANN) was built based on the published research data to capture the general trends or to make predictions. Both catalyst properties and reaction conditions were trended and predicted using the network model. The review study revealed that esterification and transesterification required catalysts with slightly different properties. In the first phase of the study, biodiesel production using 12-Tungstophosphric acid (TPA) supported on SBA-15 as a solid acid catalyst was studied. In this phase of the study, a large number of 0-35% TPA on SBA-15 catalysts were synthesized by impregnation method and the effects of various operating conditions such as–catalyst wt.% and methanol to oil molar ratio on the transesterification of model feedstock Triolein were studied. A 25% TPA loading was found to be the optimum. A 4.15 wt.% catalysts (based on Triolein) and 39:1 methanol to Triolein molar ratio was found to be the optimum reaction parameter combination, when the reaction temperature was kept fixed at 200C, stirring speed of 600 rpm and 10 h reaction time. The biodiesel yield obtained using this condition was 97.2%. In the second phase of the study, a 12-Tungstophosphoric acid (TPA) was supported by using organic functional group (i.e. 3-aminopropyltriethoxysilane (APTES)) and was incorporated into the SBA-15 structure. A 45 wt.% TPA incorporated SBA-15 produced an ester with biodiesel yield of 97.3 wt.%, when 3 wt.% catalyst (based on the green seed canola (GSC) oil) and 25.8:1 methanol GSC oil molar ratio were used at 2000C for reaction time of 6.2 h. In the third phase, process sustainability (i.e. process economics, process safety, energy efficiency, environmental impact assessment) studies were conducted based on the results obtained in phase three. Based on the study, it was concluded that heterogeneous acid catalyzed process had higher profitability as compared to the homogeneous acid catalyzed process. Additionally, it was obtained that heterogeneous acid catalyzed process was safe, more energy efficient and more environment friendly than homogenous process. In the fourth phase, the catalytic activity of Tungsten oxide (WO3) and TPA supported (by impregnation) on H-Y, H-β and H-ZSM-5 zeolite catalysts were tested for biodiesel production from Green Seed Canola (GSC) oil. In this phase iii of the study, TPA/H-Y and TPA/H- zeolite were proved to be effective catalysts for esterification and transesterification, respectively. A 55% TPA/H- showed balanced catalytic activity for both esterification and transesterification. It yielded 99.3 wt.% ester, when 3.3 wt.% catalyst (based on GSC oil) and 21.3:1 methanol to GSC oil molar ratio were used at 200C, reaction pressure of 4.14 MPa and reaction time of 6.5 h. Additionally, this catalyst (55% TPA/H-) was experimented for etherification of pure glycerol, and maximum conversion of glycerol (100%) was achieved in 5 h at 120C, 1 MPa, 1:5 molar ratio (glycerol: (tert-butanol) TBA), 2.5% (w/v) catalyst loading. Later, these conditions were used to produce glycerol ether successfully from the glycerol derived after transesterification of green seed canola oil. A mixture of GSC derived biodiesel, and glycerol ether was defined as biofuels. In the fifth phase, catalytic activity of H-Y supported TPA (using different impregnation methods) was studied in details further for esterification of free fatty acid (FFA) of GSC oil. From the optimization study, 97.2% FFA (present in the GSC oil) conversion was achieved using 13.3 wt.% catalyst, 26:1 methanol to FFA molar ratio at 120C reaction temperature and 7.5 h of reaction time. In the sixth- and final phase, techno-economic and ecological impacts were compared between biodiesel and combined biofuel production processes based on the results obtained in phase four. Based on the study, it was concluded that, biodiesel production process had higher profitability as compared to that for combined biofuel production process. Additionally, biodiesel production process was more energy efficient than combined biofuel production process. However, combined biofuel production process was more environment-friendly as compared to that for biodiesel production process.