Avaliação de um sistema para controle de temperatura em um reator de polimerização de resinas acrílicas
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Citações na Scopus
Tipo de produção
Trabalho de Conclusão de Curso
Data
2023-06-15
Autores
Batista, Denise Faria Devides
Soares, Emilly Santos
Lima, Gabriela Pereira
Reis, Natalia Martins dos
Soares, Emilly Santos
Lima, Gabriela Pereira
Reis, Natalia Martins dos
Orientador
Poço, João Guilherme Rocha
Periódico
Título da Revista
ISSN da Revista
Título de Volume
Citação
Texto completo (DOI)
Palavras-chave
PMMA,polimerização,síntese direta,controle em processo,polymerization,direct synthesis,process control
Resumo
O mercado de tintas e vernizes atualmente está em expansão e vem utilizando tecnologias de ponta em seus processos industriais, a fim de atender as exigências do fornecimento de produtos com melhor qualidade. Uma das matérias-primas deste mercado é o polimetacrilato de metila (PMMA), que vem sendo utilizado devido suas propriedades químicas e mecânicas. O processo de polimerização do PMMA da planta industrial deste estudo é realizado em um reator semi-batelada, cuja reação acontece de maneira exotérmica e é conduzida em solução aplicando o xilol como solvente e o peróxido de benzoíla como iniciador da polimerização. Logo, é importante que essas indústrias implementem um sistema de controle de temperatura para manter as condições de processos, visando assegurar as propriedades do polímero. No entanto, o controle existente possui a possibilidade de ser aprimorado e à vista disso, com os dados reais de uma planta que produz o PMMA, este trabalho propõe avaliar e aperfeiçoar o controle das condições de operação, melhorando a velocidade e a eficiência de resposta do controlador. Para isto, elaborou-se o modelo matemático dinâmico que contempla a cinética, os balanços de massa e de energia desse sistema, onde a simulação foi realizada com o auxílio do software Matlab. Por intermédio dos resultados obtidos do modelo matemático, considerando o processo isotérmico, destacou-se a influência da temperatura do meio reacional e as vantagens de se operar próximo de 116 °C, como por exemplo, o grau de conversão esperado e a velocidade de adição próxima à velocidade de consumo. No balanço de energia foi determinado os parâmetros do coeficiente de película de transferência de calor interno e externo para estimar o coeficiente global de troca térmica, obtendo-se o valor de aproximadamente 1,2 kW/(m².K). Então, foi possível avaliar a importância do óleo térmico para o processo, visto que ele desempenha um papel fundamental no controle da temperatura. Em condições elevadas de temperatura do óleo térmico, observou-se um maior consumo e uma alta conversão no processo. Ademais, o modelo matemático foi validado com os dados reais da planta, assegurando a avaliação do sistema de controle de temperatura a partir das ações proporcional e integral (PI), e sendo utilizada a sintonia pelo método de síntese direta. O controlador proposto demonstrou uma estabilidade superior ao controle atual da planta, alcançando o setpoint de 116 °C com menor tempo de resposta, sem oscilações e overshoot.
The paint and varnish market is currently expanding and has been using state of the art technologies in its industrial processes in order to meet the requirements of providing products with better quality. One of the raw materials in this market is polymethyl methacrylate (PMMA), which has been used due to its chemical and mechanical properties. The PMMA polymerization process at the industrial plant in this study is carried out in a semi-batch reactor, whose reaction takes place exothermically and is carried out in solution by applying xylene as solvent and benzoyl peroxide as polymerization initiator. Therefore, it is important that these industries implement a temperature control system to maintain the process conditions, to ensure the polymer properties. However, the existing control has the possibility of being improved and in view of that, with real data from a plant that produces PMMA, this work proposes to evaluate and improve the control of operating conditions, improving the speed and efficiency of response from the controller. For this, a dynamic mathematical model was elaborated, which contemplates the kinetics, mass and energy balances of this system, where the simulation was carried out with the help of Matlab software. Through the results obtained from the mathematical model, considering the isothermal process, the influence of the temperature of the reaction medium and the advantages of operating close to 116 °C were highlighted, such as the expected degree of conversion and the speed of addition close to consumption rate. In the energy balance, the parameters of the internal and external heat transfer film coefficient were determined to estimate the global thermal exchange coefficient, obtaining a value of approximately 1.2 kW/(m².K). Thus, the importance of thermal oil in the process and its role in temperature control were evaluated. At elevated temperatures of the thermal oil, higher consumption and increased conversion in the process were observed. Furthermore, the mathematical model was validated using real plant data, ensuring the evaluation of the temperature control system based on proportional and integral (PI) actions, and tuning was performed using the direct synthesis method. The proposed controller demonstrated superior stability compared to the current control system in the plant, achieving the setpoint of 116 °C with a faster response time, without oscillations or overshoot.
The paint and varnish market is currently expanding and has been using state of the art technologies in its industrial processes in order to meet the requirements of providing products with better quality. One of the raw materials in this market is polymethyl methacrylate (PMMA), which has been used due to its chemical and mechanical properties. The PMMA polymerization process at the industrial plant in this study is carried out in a semi-batch reactor, whose reaction takes place exothermically and is carried out in solution by applying xylene as solvent and benzoyl peroxide as polymerization initiator. Therefore, it is important that these industries implement a temperature control system to maintain the process conditions, to ensure the polymer properties. However, the existing control has the possibility of being improved and in view of that, with real data from a plant that produces PMMA, this work proposes to evaluate and improve the control of operating conditions, improving the speed and efficiency of response from the controller. For this, a dynamic mathematical model was elaborated, which contemplates the kinetics, mass and energy balances of this system, where the simulation was carried out with the help of Matlab software. Through the results obtained from the mathematical model, considering the isothermal process, the influence of the temperature of the reaction medium and the advantages of operating close to 116 °C were highlighted, such as the expected degree of conversion and the speed of addition close to consumption rate. In the energy balance, the parameters of the internal and external heat transfer film coefficient were determined to estimate the global thermal exchange coefficient, obtaining a value of approximately 1.2 kW/(m².K). Thus, the importance of thermal oil in the process and its role in temperature control were evaluated. At elevated temperatures of the thermal oil, higher consumption and increased conversion in the process were observed. Furthermore, the mathematical model was validated using real plant data, ensuring the evaluation of the temperature control system based on proportional and integral (PI) actions, and tuning was performed using the direct synthesis method. The proposed controller demonstrated superior stability compared to the current control system in the plant, achieving the setpoint of 116 °C with a faster response time, without oscillations or overshoot.