6 research outputs found

    Technical-economic analysis in early stages of process design - Case study : nitric acid plant

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    Orientadores: Roger Josef Zemp, Valdir Apolinário de FreitasDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuímicaResumo: Um projeto de engenharia e realizado em cinco etapas consecutivas: planejamento do negocio, desenvolvimento do escopo, definição do projeto, execução (engenharia de detalhamento e construção) e, finalmente, partida e operacao. Muitas vezes percebe-se, na conclusão das etapas de desenvolvimento do escopo e de definição do projeto, apos intenso uso de tempo e de recursos, que o projeto não e mais viável economicamente, sendo abandonado ou reestudado. Decisões de projeto tomadas no inicio da concepção determinam configurações que afetarão permanentemente investimentos e custos operacionais. A engenharia de processos pode aliar conhecimentos técnicos a conceitos econômicos nas etapas iniciais, a fim de avaliar o impacto das decisões de configuração na viabilidade do projeto. Apesar de parecer natural, essa não e uma pratica comum na industria. Nesse contexto, o presente trabalho tem por objetivo realizar uma analise técnico-econômica de alternativas de configuração em estágios preliminares de um projeto. Para tal, será utilizado como estudo de caso o processo produtivo de acido nítrico a partir da combustão de amônia, em duas situações distintas: projeto de uma planta nova (síntese) e projeto de modificação de uma planta existente (revamp). A partir de analises simples, utilizando ferramentas que facilitam a avaliação da influencia de parâmetros no projeto, serão analisados os impactos das variações desses parâmetros em diferentes propostas de configuraçõesAbstract: An Engineering Project happens in 5 consecutive steps: business assessment, scope development, project definition, execution (detailed engineering and construction) and, finally, startup and operations. Many times, in the conclusion of the scope development and project definition steps, after intense use of time and resources, one realizes that the project is not economic feasible anymore, being abandoned or restudied. Project decisions taken in the early stages of design determine configurations that will affect permanently the investments and operational costs. The process engineering can combine technical knowledge to economic concepts at the early stages, to evaluate the impact of configurations decisions in the feasibility of the project. Although this may seem natural, it's not a common practice in the industry. In this context, this work aims to make a techno-economic analysis of configuration alternatives at the preliminary stages of a project. For this purpose, it will be used as a case study the production process of the nitric acid through the ammonia combustion, in two different situations: project of a new plant (synthesis) and project of modification in an existing plant (revamp). Through simple analysis, using tools that facilitate the evaluation of the parameters influence in the project, the impacts of the variations of these parameters in different alternatives of configuration will be evaluatedMestradoSistemas de Processos Quimicos e InformaticaMestra em Engenharia Químic

    Using micro-and nanofibrillated cellulose as a means to reduce weight of paper products : A review

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    Based on publications related to the use of micro-and nanofibrillated cellulose (MNFC) in papermaking applications, three sets of parameters (intrinsic and extrinsic variables, furnish composition, and degree of dispersion) were proposed. This holistic approach intends to facilitate understanding and manipulation of the main factors describing the colloidal behavior in systems comprising of MNFC, pulp fibers, and additives, which directly impact paper product performance. A preliminary techno-economic assessment showed that cost reductions driven by the addition of MNFC in paper furnishes could be as high as USD 149 per ton of fiber (up to 20% fiber reduction without adverse effects on paper's strength) depending on the cost of papermaking fibers. It was also determined that better performance in terms of strength development associated with a higher degree of MNFC fibrillation offset its high manufacturing cost. However, there is a limit from which additional fibrillation does not seem to contribute to further strength gains that can justify the increasing production cost. Further research is needed regarding raw materials, degree of fibrillation, and combination with polyelectrolytes to further explore the potential of MNFC for the reduction of weight of paper products.Peer reviewe
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