A bio-refinery is a processing facility that produces liquid transportation fuels and/or value-added chemicals and other products. Because of the dwindling resources and escalating prices of fossil fuels, there are emerging situations in which the economic performance of fossil-based facilities can be enhanced by retrofitting and incorporation of bio-mass feedstocks. These systems can be regarded as bio-refineries or integrated fossilbio- refineries. This work presents a retrofitting analysis to integrated bio-refineries. Focus is given to the problem of process modification to an existing plant by considering capacity expansion and material substitution with biomass feedstocks. Process integration studies were conducted to determine cost-effective strategies for enhancing production and for incorporating biomass into the process. Energy and mass integration approaches were used to induce synergism and to reduce cost by exchanging heat, material utilities, and by sharing equipment. Cost-benefit analysis was used to guide the decision-making process and to compare various production routes. Ethanol production from two routes was used as a case study to illustrate the applicability of the proposed approach and the results were bio-refinery has become more attractive then fossil-refinery.

Recent publications on ethanol production and purification shows optimized energy and water consumptions as low as 22,000 Btu/gal ethanol and 1.54 gal water/gal ethanol respectively using multieffect distillation. Karuppiah, et al use column rating and mathematical optimization methods and shortcut design models to design evaluate and optimize the energy and water consumption. In this work, we compare shortcut design and rigorous simulation models for an ethanol purification distillation system, and we show that distillation systems based on shortcut design underestimate the true energy and water consumption of the distillation system. We then use ASPEN Plus, to design a multieffect distillation system and an extractive distillation system using rigorous simulation and compare the two for energy and water consumptions. We show that the extractive distillation system has lower steam and cooling water consumptions and consequently lower energy and water consumptions than multieffect distillation in corn-to-ethanol production and purification. We also show that the extractive distillation system is cheaper than the multieffect distillation system on a cost per gal ethanol basis. This work gives an energy consumption of 29987 Btu/gal ethanol and water consumptions 2.82 gal/gal ethanol for the multieffect distillation system at a manufacturing cost of $3.03/gal ethanol. For the extractive distillation system, we calculate an energy consumption of 28199 Btu/gal ethanol and a water consumption of 2.79 gal/gal ethanol at a manufacturing cost of $2.88/gal ethanol. / Master of Science

Continuous process improvement is a critical element in maintaining competitiveness of the process industries. An important category of process improvement is process debottlenecking which is associated with plants that have sold-out products while making a profit. In such cases, market conditions and the prospects for enhancing revenues and profits drive the process to increase production. To overcome the limitation of conventional sequential unit-by-unit debottlenecking approach, this work introduces a new approach. This new approach is simultaneous in nature and is based on posing the debottlenecking task as a process integration task which links all the design and operating degrees of freedom and exploits synergies among the units and streams to attain maximum debottlenecking. Additionally, this new approach considers heat integration of the process while simultaneously performing the debottlenecking. Because of the general nonconvexity of the process model, a rigorous interval-based bounding technique is used to determine the target for maximum extent of debottlenecking aside from the problem nonconvexity. Inclusion isotonicity using interval arithmetic is used to determine a global bound for the maximum extent of process debottlenecking. Focus is given to no/low cost debottlenecking such as modest changes in design and operating degrees of freedom. Two case studies are solved to illustrate the applicability of the new approach and its superior results compared to the conventional sequential approach. Intensification, to debottleneck a process and to improve process safety is also addressed in this work. A new definition and classification of intensification is introduced. This classification distinguishes between two types of intensification: single unit and whole process. Process integration and optimization techniques are used to develop a systematic procedure for process intensification. Focus is given to the interaction among the process units while enhancing the intensification of the process. A case study is solved to illustrate the usefulness of the developed approach.

The escalating energy prices and the increasing environmental impact posed by the industrial usage of energy have spurred industry to adopt various approaches to conserving energy and mitigating negative environmental impact. This work aims at developing a systematic approach to integrate solar energy into industrial processes to drive thermal energy transfer systems producing power, cool, and heat. Solar energy is needed to be integrated with other different energy sources (biofuels, fossil fuels, process waste heat) to guarantee providing a stable energy supply, as industrial process energy sources must be a stable and reliable system. The thermal energy transform systems (turbines, refrigerators, heat exchangers) must be selected and designed carefully to provide the energy demand at the different forms (heat, cool, power). This dissertation introduces optimization-based approaches to address the following problems: • Design of cogeneration systems with solar and fossil systems • Design and integration of solar-biofuel-fossil cogeneration systems • Design of solar-assisted absorption refrigeration systems and integration with the processing facility • Development of thermally-coupled dual absorption refrigeration systems, and • Design of solar-assisted trigeneration systems Several optimization formulations are introduced to provide methodical and systematic techniques to solve the aforementioned problems. The approach is also sequenced into interacting steps. First, heat integration is carried out to minimize industrial heating and cooling utilities. Different forms of external-energy sources (e.g., solar, biofuel, fossil fuel) are screened and selected. To optimize the cost and to overcome the dynamic fluctuation of the solar energy and biofuel production systems, fossil fuel is used to supplement the renewable forms of energy. An optimization approach is adopted to determine the optimal mix of energy forms (fossil, bio fuels, and solar) to be supplied to the process, the system specifications, and the scheduling of the system operation. Several case studies are solved to demonstrate the effectiveness and applicability of the devised procedure. The results show that solar trigeneration systems have higher overall performance than the solar thermal power plants. Integrating the absorption refrigerators improves the energy usage and it provides the process by its cooling demand. Thermal coupling of the dual absorption refrigerators increases the coefficient of performance up to 33 percent. Moreover, the process is provided by two cooling levels.

This work addresses the problem of using seawater for cooling and the associated environmental problems caused by the usage and discharge of biocides. The discharged biocide and its byproducts are toxic to aquatic lives and must be decreased below certain discharge limits on load prior to discharge. The conventional approach has been to add biocide removal units as an end-of-pipe treatment. This work introduces an integrated approach to reducing biocide discharge throughout a set of coordinated strategies for inplant modifications and biocide removal. In particular, process integration tools are used to reduce heating and cooling requirements through the synthesis of a heat-exchange network. Heat integration among process of hot and cold streams is pursued to an economic extent by reconciling cost reduction in utilities versus any additional capital investment of the heat exchangers. Other strategies include maximization of the temperature range for seawater through the process and optimization of biocide dosage. This new approach has the advantage of providing cost savings while reducing the usage and discharge of biocides. A case study is used to illustrate the usefulness of this new approach and the accompanying design techniques.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17164号 / 工博第3654号 / 新制||工||1555(附属図書館) / 29903 / 京都大学大学院工学研究科化学工学専攻 / (主査）教授 長谷部 伸治, 教授 田門 肇, 教授 宮原 稔 / 学位規則第4条第1項該当

El desarrollo de procesos químicos eficientes, tanto desde un punto de vista económico como desde un punto de vista ambiental, es uno de los objetivos principales de la Ingeniería Química. Para conseguir este propósito, durante los últimos años, se están empleando herramientas avanzadas para el diseño, simulación, optimización y síntesis de procesos químicos, las cuales permiten obtener procesos más eficientes y con el menor impacto ambiental posible. Uno de los aspectos más importantes a tener en cuenta para diseñar procesos más eficientes es la disminución del consumo energético. El consumo energético del sector industrial a nivel global representa aproximadamente el 22.2 % del consumo energético total, y dentro de este sector, la industria química representa alrededor del 27 %. Por lo tanto, el consumo energético de la industria química a nivel global constituye aproximadamente el 6 % de toda la energía consumida en el mundo. Además, teniendo en cuenta que la mayor parte de la energía consumida es generada principalmente a partir de combustibles fósiles, cualquier mejora de los procesos químicos que reduzca el consumo energético supondrá una reducción del impacto ambiental. El trabajo recopilado en esta Tesis Doctoral se ha llevado a cabo dentro del grupo de investigación COnCEPT, perteneciente al Instituto Universitario de Ingeniería de los Procesos Químicos de la Universidad de Alicante, durante los años 2014 y 2017. El objetivo principal de la presente Tesis Doctoral se centra en el desarrollo de herramientas y modelos de simulación y optimización de procesos químicos con el fin de mejorar la eficiencia energética de éstos, lo que conlleva a la disminución del impacto ambiental de los procesos. Más concretamente, esta Tesis Doctoral se compone de dos estudios principales, que son los objetivos concretos que se pretenden conseguir: - Estudio y evaluación de los modelos surrogados para la mejora en la optimización basada en simuladores de procesos químicos. - Desarrollo de nuevos modelos para la optimización de procesos químicos y la integración de energía simultánea, para redes de intercambiadores de calor.

Using seawater in cooling systems is a common practice in many parts of the world where there is a shortage of freshwater. However, biofouling is one of the major operational problems associated with the usage of seawater in cooling systems. Microfouling is caused by the activities of microorganisms, such as bacteria and algae, producing a very thin layer that sticks to the inside surface of the tubes in heat exchangers. This thin layer has a tremendously negative impact on heat transferred across the heat exchanger tubes in the system. In some instances, even a 250 micrometer thickness of fouling film can reduce the heat exchanger's heat transfer coefficient by 50 percent. On the other hand, macrofouling is the blockage caused by relatively large marine organisms, such as oysters, mussels, clams, and barnacles. A biocide is typically added to eliminate, or at least reduce, biofouling. Typically, microfouling can be controlled by intermittent dosages, and macrofouling can be controlled by continuous dosages of biocide. The aim of this research work is to develop a systematic approach to the optimal operating and design alternatives for integrated seawater cooling systems in industrial facilities. A process integration framework is used to provide a holistic approach to optimizing the design and operation of the seawater cooling system, along with the dosage and discharge systems. Optimization formulations are employed to systematize the decision-making and to reconcile the various economic, technical, and environmental aspects of the problem. Building blocks of the approach include the biocide water chemistry and kinetics, process cooling requirements, dosage scenarios and dynamic profiles, biofilm growth, seawater discharge, and environmental regulations. Seawater chemistry is studied with emphasis on the usage of biocide for seawater cooling. A multi-period optimization formulation is developed and solved to determine: * The optimal levels of dosing and dechlorination chemicals * The timing of maintenance to clean the heat-exchange * The dynamic dependence of the biofilm growth on the applied doses, the seawater-biocide chemistry, the process conditions, and seawater characteristics for each time period. The technical, economic, and environmental considerations of the system are accounted for and discussed through case studies.

Orientador: Roger Josef Zemp / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T10:03:36Z (GMT). No. of bitstreams: 1 Salviano_FlaviaRichterFernandez_M.pdf: 1544610 bytes, checksum: faf01181a27b65fd972f0e2414e7112b (MD5) Previous issue date: 2010 / Resumo: Originalmente a Análise Pinch foi aplicada em projetos de novas redes de trocadores de calor em plantas industriais. No entanto, com a ampliação de plantas ou modificação das condições de processos, surgiu a necessidade de se adaptar o conceito de integração de processos para modificar redes existentes. Diante da limitação de ferramentas para auxílio em círculos e a dificuldade de se desenvolver projetos de retrofit, foi desenvolvida uma planilha eletrônica de cálculo baseada nos programas Microsoft Excel e Visual Basic for Applications (VBA). Os dados da rede existente e/ou proposta são inseridos pelo usuário e a planilha utiliza os conceitos de balanço energético e Network Pinch para calcular temperaturas de saída dos fluidos nos trocadores e temperaturas finais das correntes de processo. A ferramenta também permite ao usuário a identificação dos limites de recuperação de calor da rede existente e a minimização do consumo de utilidades sem mudanças topológicas / Abstract: Pinch analysis techniques were originally developed for projects of new heat exchangers networks in industrial plants. However the increasing capacity of plants or modifications in process parameters generated the necessity of adaptation of the original concept of process integration to retrofit of existing networks. Due to the limitation of tools to support calculations and the difficulty in developing retrofit projects, an electronic worksheet based on softwares Microsoft Excel and Visual Basic for Application (VBA) was created. The information of the existing and/or proposed network is inserted in the worksheet by the user and the program uses the concepts of energy balance and Network Pinch to calculate the outlet temperature of fluids in each heat exchanger and the outlet temperature of each process stream in the network. This tool also allows the identification of limits of heat recovery and the minimization of utilities consumption with no topological changes / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Orientador: Roger Josef Zemp / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-20T09:52:33Z (GMT). No. of bitstreams: 1 Santana_MarianaFraga_M.pdf: 1967335 bytes, checksum: 90f67a6bf06f7540d4dea0d84fc080bc (MD5) Previous issue date: 2012 / Resumo: Desde a crise energética dos anos 70, a otimização do consumo de energia se tornou uma importante tarefa para os engenheiros de processo. Duas diferentes metodologias têm sido aplicadas para minimizar o uso de energia em processos químicos. A primeira é a metodologia Pinch, que envolve a aplicação de análise termodinâmica do processo e baseia-se em metas de energia e custo para obter uma rede de trocadores de calor que opera com o mínimo consumo de energia. A segunda é a programação matemática, que consiste na elaboração de modelos matemáticos complexos resolvidos através de métodos numéricos. Neste trabalho, uma nova metodologia para a síntese de redes de trocadores de calor é apresentada. O procedimento proposto combina a abordagem sistemática da tecnologia Pinch com métodos de programação matemática (linear inteira mista) e procedimentos evolutivos. A nova metodologia é baseada na otimização de uma superestrutura cuja complexidade varia ao longo do procedimento de síntese da rede de trocadores, e que permite ao engenheiro de projeto a consideração das restrições do processo sem necessidade de formulação matemática das mesmas. Uma vantagem da metodologia é a possibilidade de considerar aspectos práticos como operabilidade e controlabilidade. O método proposto é ilustrado com a integração energética de três problemas típicos: um caso-teste com quatro correntes, o caso padrão em estudos de integração energética da planta simplificada de aromáticos e o caso recente do sistema de célula combustível a membrana trocadora de prótons. Foram obtidas redes alternativas para os casos estudados, que são energeticamente eficientes, mais baratas e simples / Abstract: Since the energy crisis of the 70s, the optimization of energy consumption has become an important task for process engineers. Two different methodologies have been applied to minimize energy use in chemical processes. The first methodology is the pinch method, which involves applying process thermodynamic analysis and it is based on energy and cost targets for a network of heat exchangers operating at the minimum power consumption. The second one is the mathematical programming, which is the development of complex mathematical models solved through numerical methods. In this work, a new methodology for the synthesis of heat exchanger networks is presented. The proposed procedure combines the systematic approach of Pinch technology with mathematical programming methods (mixed integer linear) and evolutionary procedures. The new methodology is based on the optimization of a superstructure whose complexity varies throughout the synthesis procedure of the network of exchangers, which allows the design engineer to consider the constraints of the process without having to include them into the mathematical formulation. One advantage of this methodology is the possibility of considering practical aspects such as controllability and operability. The proposed method is illustrated by the energy integration of three typical problems: a test case with four streams, the standard case in studies of energy integration simplified aromatics plant and the recent case of fuel processor system coupled to proton exchange membrane fuel cell. Alternative networks were obtained for the cases studied, which are energy efficient, cost-effective and simpler / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química