Modelagem, simulação e otimização operacional de unidades de síntese de metanol

• Ano de defesa: 2007
• Autor(a) principal: Ornelas, Danielle Lanchares
• Orientador(a): Costa, André Luiz Hemerly
• Banca de defesa: Caldas, Jorge Navaes , Mizutani, Fábio Takeshi , Tôrres, Alexandre Rodrigues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Engenharia Química
• Departamento: Centro de Tecnologia e Ciências::Instituto de Química
• País: BR
• Palavras-chave em Português: Metanol; método de simulação; otimização matemática
• Palavras-chave em Inglês: Methanol; methods of simulation; mathematical optimization
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/11948

The chemical process industries have been suffering considerable transformations due to the increase of competition. Important technological progresses have been reached through techniques of modeling, simulation and optimization that make possible the development of new tools, aiming an increase in profitability and continuous improvement in industrial processes. In this context, methanol plants, one of the most important petrochemical products, can be highlighted. Currently, the main raw material for methanol manufacture is the natural gas. The methanol production is characterized by three steps: syngas generation, conversion of the syngas into methanol (synthesis unit or synthesis loop) and distillation/purification of the product to the required specification. Fixed and variable costs of methanol synthesis units are strongly dependent on operational variables such as temperature, pressure, recycle ratio and make up gas composition. In this way, it was developed a computational set of models and algorithms to represent units of methanol synthesis. The model presents unit operations associated to the following equipment: splitters, mixers, compressors, heat exchangers, flash vessels and reactors. Initially, a stationary simulator was considered, that served as base for a pseudo-stationary one, which contemplates the catalyst deactivation for thermal sintering. The simulators were created using a sequential modular architecture and a direct substitution method is employed for the convergence of recycle streams. The study involved two typical flowsheets, one consisting of adiabatic reactors in series and other based on a quench reactor. An analysis of the effect of the main operational variables was carried out for the reactor and the synthesis loop. It was studied the effect of catalyst deactivation with time. An optimization tool was used to seek the maximum production varying the fraction of cold feed to beds. An optimization problem was also formulated so as to maximize a profit function using as decision variables operating times of reactor beds before catalyst change. The results had shown that the tool developed is promising for the understanding and optimization of the object unit of this study