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UnfoldPetrusson, Karin January 2020 (has links)
My degree work has been an exploration in what specific skills, knowledge and understandings that are needed in service design as a practice, in order to successfully engage in complex contexts with multiple stakeholders, different relations, structures and regulations. In this investigation, I have been especially interested in the role of physical forms in a process where social structures are discussed and reshaped. With the ambition to create a learning process within this area I have, in collaboration with Förnyelselabbet, been part of a study in Malmö that focus on children and youth with migration experiences living in vulnerable housing situations. The study is done in collaboration with multiple actors such as City of Malmö, The Red Cross, Rädda Barnen, Unicef, Skåne Stadsmission, Sensus etc. These are actors that share the same goal to highlight needs and experiences amongst children and youths. In my work I have designed tools with the ambition to unfold and deepen the understanding of situations, meetings and objects that could enable a feeling of safety, comfort and joy when living in a vulnerable housing situation. In this context, I have recognized the importance of exploring the role of meeting points. For this purpose, I have used three objects; the slide; the sofa and the set table. As a result of this degree project I created something I call a material probe, a object with the function to visualise needs and trigger responses. This material probe captures three fundamental needs; a slide – the possibility for play and activity, a sofa – the possibility for gaining the feeling of safety and belonging, a table – the possibility for sharing experiences and information. By visualising and materialising these needs, I hope to create a discussion that unfolds challenges and promotes the children’s perspective. My work to narrow down the needs is based on multiple interviews and stories from children, youths and parents. The main question is what happens to the continued development process when research findings, needs and experiences are visualised. The main goal of this degree project has been to articulate and reflect on how service designers can combine knowledge within process design, institutional design and design of physical form. How service design as a practice can develop and if including physical forms and visualisations at a higher level in our work can help the development process forward.
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Integrated sustainability assessment and design of processes, supply chains, ecosystems and economy using life cycle modeling methodsGhosh, Tapajyoti 25 October 2019 (has links)
No description available.
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Prospective Life Cycle Assessment of an Electrochemical Hydrogenation Process Over a Nickel Foam Cathode / Prospektiv livscykelanalys av en elektrokemisk hydrogeneringsprocess över en nickelskumkatodAppiah-Twum, Hanson January 2022 (has links)
The need for a safe and sustainable chemical industry has called for the development of emerging technologies with improved environmental performance. In this study, an emerging electrochemical hydrogenation process over Ni foam is being developed at the laboratory scale with an expectation of less environmental impacts than a conventional palladium on carbon hydrogenation process. To understand better the potential environmental performance of the process at the matured scale, a prospective life cycle assessment was conducted to identify environmental hotspots for early process improvement. There is no standardised method for prospective life cycle assessment, hence a methodological recommendation in conducting a prospective LCA was proposed through a literature review. The proposed methodology consists of three steps which are a pre-inventory stage, an inventory stage, and a post-inventory stage. These steps have been connected to the ISO 14044 standard methodology for conducting an LCA where the pre-inventory stage relates to the goal and scope definition, the inventory stage to inventory analysis, and the post-inventory connected to both the inventory analysis, impact assessment, and interpretation stages of the ISO methodology. The proposed methodology was applied to the electrochemical hydrogenation process over nickel foam cathode where a three-case scenario (lab, worst- and best-case scenarios) was investigated to identify hotspots for early process improvement. The theoretical upscaled process had a better environmental performance compared to the lab process. The identified hotspots in the upscaled process (worst-case) include electricity process, evaporation process, and solvent recycling process for ecotoxicity (freshwater), human toxicity (cancer), human toxicity (non-cancer), climate change and resource use (minerals and metals) impact categories. The best-case scenario had its identified hotspots in the electricity process, solvent recycling process, and distillation process. This shows the importance of circularity, recycling, and lean manufacturing to the pillars of sustainability. Reducing resource consumption per unit product while increasing the recycling efficiency of process waste will be imperative towards ensuring a green chemical industry. Based on the results, a reduction of electricity demand for the process, utilisation of an alternative less energy-consuming processes, or cleaner energy sourcing could further improve the potential environmental performance of the process. Based on the quality of the data used, it is recommended that the outcome of the study be cautiously interpreted.
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Optimization of chemical process simulation: Application to the optimal rigorous design of natural gas liquefaction processesSantos, Lucas F. 30 June 2023 (has links)
Designing products and processes is a fundamental aspect of engineering that significantly impacts society and the world. Chemical process design aims to create more efficient and sustainable production processes that consume fewer resources and emit less pollution. Mathematical models that accurately describe process behavior are necessary to make informed and responsible decisions. However, as processes become more complex, purely symbolic formulations may be inadequate, and simulations using tailored computer code become necessary. The decision‐making process in optimal design requires a procedure for choosing the best option while complying with the system’s constraints, for which task optimization approaches are well suited. This doctoral thesis focuses on black‐box optimization problems that arise when using process simulators in optimal process design tasks and assesses the potential of derivative‐free, metaheuristics, and surrogate‐based optimization approaches. The optimal design of natural gas liquefaction processes is the case study of this research. To overcome numerical issues from black‐box problems, the first work of this doctoral thesis consisted of using the globally convergent Nelder‐Mead simplex method to the optimal process design problem. The second work introduced surrogate models to assist the search towards the global optimum of the black‐box problem and an adaptive sampling scheme comprising the optimization of an acquisition function with metaheuristics. Kriging as surrogate models to the simulation‐optimization problems are computationally cheaper and effective predictors suitable for global search. The third work aims to overcome the limitations of acquisition function optimization and the use of metaheuristics. The proposed comprehensive mathematical notation of the surrogate optimization problem was readily implementable in algebraic modeling language software. The presented framework includes kriging models of the objective and constraint functions, an adaptive sampling procedure, a heuristic for stopping criteria, and a readily solvable surrogate optimization problem with mathematical programming. The success of the surrogate‐based optimization framework relies on the kriging models’ prediction accuracy regarding the underlying, simulation‐based functions. The fourth publication extends the previous work to multi‐objective black‐box optimization problems. It applies the ε constraint method to transform the multi‐objective surrogate optimization problem into a sequence of single‐objective ones. The ε‐constrained surrogate optimization problems are implemented automatically in algebraic modeling language software and solved using a gradient‐based, state‐of‐the‐art solver. The fifth publication is application-driven and focuses on identifying the most suitable mixed‐refrigerant refrigeration technology for natural gas liquefaction in terms of energy consumption and costs. The study investigates five natural gas liquefaction processes using particle swarm optimization and concludes that there are flaws in the expected relationships between process complexity, energy consumption, and total annualized costs. In conclusion, the research conducted in this doctoral thesis demonstrates the importance and capabilities of using optimization to process simulators. The work presented here highlights the potential of surrogate‐based optimization approaches to significantly reduce the computational cost and guide the search in black‐box optimization problems with chemical process simulators embedded. Overall, this doctoral thesis contributes to developing optimization strategies for complex chemical processes that are essential for addressing some of the current most pressing environmental and social challenges. The methods and insights presented in this work can help engineers and scientists design more sustainable and efficient processes, contributing to a better future for all.
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A Methodology for the Development of a Production Experience Database for Earthmoving Operations Using Automated Data CollectionKannan, Govindan 26 June 1999 (has links)
Automated data acquisition has revolutionized the reliability of product design in recent years. A noteworthy example is the improvement in the design of aircrafts through field data. This research proposes a similar improvement in the reliability of process design of earthmoving operations through automated field data acquisition. The segment of earthmoving operations addressed in this research constitutes the truck-loader operation. Therefore, the applicability of this research extends to other industries involving truck-operation such as mining, agriculture and forest logging and is closely related to wheel-based earthmoving operations such as scrapers.
The context of this research is defined by data collection needed to increase the validity of the results obtained by analysis tools such as simulation, performance measures and graphical representation of variance in an activity's performance, and the relation between operating conditions and the variance in an activity's performance. The automated cycle time data collection is facilitated by instrumented trucks and the collection of information on operating conditions is facilitated by image database and paper forms. The cycle time data and the information on operating conditions are linked together to form the experience database.
This research developed methods to extract, quantify and understand the variation in each component of the earthmoving cycle namely, load, haul and return, and dump activities. For the load activity, the simultaneous variation in payload and load time is illustrated through the development of a PLT (PayLoad Time) Map. Among the operating conditions, material type, load area floor, space constraints and shift are investigated. A dynamic normalization process of determining the ratio of actual travel time to expected travel time is developed for the haul and return activities. The length of the haul road, sequence of gear downshifts and shift are investigated for their effect on the travel time. The discussion on the dump activity is presented in a qualitative form due to the lack of data.
Each component is integrated within the framework of the experience database. The implementation aspects with respect to developing and using the experience database are also described in detail. The practical relevance of this study is highlighted using an example. / Ph. D.
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Sustainable process synthesis, design, and analysis: Challenges and opportunitiesMartin, M., Gani, R., Mujtaba, Iqbal M. 28 March 2022 (has links)
Yes / In this perspective paper, we present challenges and opportunities that the chemical, biochemical and related industries pose to the process system engineering community to help deliver reliable and novel sustainable alternatives. More specifically, we highlight the need for a systems approach where model-based sustainable process synthesis, design, and analysis serve as opportunities to tackle the challenges. Three technology areas (interlinked to each other) that impact the sustainability of earth, namely, chemical processes linked with CO2 capture and utilization, biorefineries and water desalination are selected to highlight our views as well as the need for further development of computer-aided tools to efficiently solve the large and complex mathematical systems the problems represent. Analysis of these problems and their reported solutions indicate that opportunity exists for development of a new class of model-based methods and tools and their integration with the currently available ones to obtain the desired sustainability development goals.
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The modelling of equilibrium data for the solvent extraction of metals.Forrest , Christopher January 1977 (has links)
In the design of a solvent extraction plant for metals it
is necessary to treat the equilibrium data either graphically or
analytically. This enables stagewise calculations to be performed
to explore solvent usage and feed conditions and so optimise on
the cost of recovery of the metal. The present study reviews the
methods of presenting and correlating equilibrium data for solvent
extraction systems involving metals; the limitations of each approach are
highlighted.
The most important example of metal extraction which has been studied
falls into that class involving a metal species, in acid aqueous media,
which displaces protons from the organic extractant during the mass
transfer process. In the typical case of copper extracted by
hydroxyoximes the equilibrium problem reduces to one of modelling a
surface. The concentration of copper in the organic phase is a function
of the concentrations of copper and sulphuric acid in the aqueous phase.
Empirical models seem to be as satisfactory to the engineer as chemical
ones provided the model is used between restricted regions of data.
Practical work has involved the measurement of equilibrium data
for the extraction of zinc and copper by di- (2-ethylhexyl) phosphoric
acid (D2EHPA) in a kerosene diluent. Both the single and binary metal
systems have been studied. The data reported are for feeds between
2-40 g/l zinc, 2-60 g/l copper and 20% V/v D2EHPA. A limited number
of results are also presented for 10% V/v D2EHPA. Specific chemical and
empirical models have been developed to correlate these data. Because
the extractant has a high affinity for zinc in the presence of copper
the binary data can be modelled making the assumption that the interaction
of copper on zinc is negligible. However the effect of zinc on the
limited extraction of copper is significant, the zinc reducing the copper
loading markedly. In this way zinc can be decontaminated of copper.
The methods for presentation of equilibrium data are discussed
and a computer program is given which displays three dimensional
equilibrium surfaces. Classical design procedures for stagewise.
calculations are used against these three dimensional data plots.
Computer programs which allow the investigation of a variety of
operating conditions have also been written.
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Quaternary and Quintenary Semicontinuous DistillationWijesekera, Kushlani 23 April 2015 (has links)
The separation of four or more components traditionally requires the use of three or more distillation columns. Due to the associated high costs, process intensification techniques have been studied. Semicontinuous separation is one method that allows multiple separations using one column integrated with middle vessels.
This thesis aims to develop a new semicontinuous separation process that can separate a mixture with four or more components into high purity products with one column and two or more middle vessels. It is an extension of the conventional ternary semicontinuous process, which has been repeatedly shown to be profitable at intermediate throughputs when compared to continuous systems. The semicontinuous process operates in a forced cycle, with three operating modes that ensure separation objectives are met.
The performance of the proposed quaternary semicontinuous separation is analyzed through rigorous dynamic simulations over a range of production capacities. To determine the feasibility, operability, and applicability to non-ideal mixtures, three case studies were considered:
1. Equimolar mixture of alkanes (n-hexane; n-heptane; n-octane; n-nonane).
2. Equimolar mixture of aromatics (benzene; toluene; ethyl-benzene; and o-xylene).
3. Non-ideal mixture of mixed-alcohols (methanol, ethanol, and water; propanol; isobutanol; pentanol and hexanol)
The extendibility of the quaternary semicontinuous separation process, referred to as quintenary semicontinuous separation, is then evaluated on a five-component alkane mixture (n-hexane; n-heptane; n-octane; n-nonane; n-decane), via three case studies:
1. Equimolar mixture
2. Non-equimolar mixture, rich in light and heavy components.
3. Non-equimolar mixture, rich in intermediate components.
The results for both the quaternary and quintenary semicontinuous processes indicate that this new technique is successful at achieving separation objectives while staying within safe operating limits. Comparison of both equimolar mixtures of alkanes for quaternary and quintenary semicontinuous processes with continuous systems indicates that the proposed system is profitable for intermediate flow rates. / Thesis / Master of Applied Science (MASc) / Traditionally, several large distillation columns (that can be hundreds of feet tall) are required to split a mixture of liquid chemicals into its individual components. Distillation is the separation of mixtures due to differences in boiling points. When the mixture is heated, the vapour phase will contain the components with lower boiling points, which can be separated once the vapour phase is cooled and condensed. The main goal of this research is to create a new system that can carry out the same separation, but using complex techniques that require only one column and a few extra storage tanks that are much cheaper and smaller than a distillation column. Different liquid mixtures were used to show how well the new process is able to separate the liquid into its individual components, while remaining in safe operating limits.
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Nature in Engineering: Modeling Ecosystems as Unit Operations for Sustainability Assessment and DesignGopalakrishnan, Varsha 11 December 2017 (has links)
No description available.
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COMBINED SAFETY AND ECONOMIC OPTIMALITY IN CHEMICAL PROCESS DESIGNSahin, Kemal Hunkar January 2000 (has links)
No description available.
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