Modelagem molecular da Nafta visando a otimização de produtos
Data
2021-12-21
Autores
Silva, Aline Pioli da [UNIFESP]
Orientadores
Concha, Viktor Oswaldo Cárdenas [UNIFESP]
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A nafta bruta é a matéria-prima mais empregada pela indústria petroquímica no Brasil para produção de insumos básicos como olefinas e aromáticos. A nafta pode ser obtida por diversos processos, sendo os principais a destilação direta e a reforma catalítica. Sua principal utilização é na obtenção de insumos básicos como gasolina, etileno, propileno, BTX (benzeno-tolueno-xilenos), butadieno, entre outros. Por ser um produto oriundo do petróleo, apresenta diferentes composições, dependendo do processo de refino e da origem do óleo. Pode ser avaliada em termos dos hidrocarbonetos, classificação PIONA, sendo (P) as parafinas, (I) Isoparafinas, (O) olefinas, (N) naftênicos e (A) os aromáticos, e consequentemente qualificada como nafta parafínica ou naftênica. Naftas parafínicas são indicadas para a produção de olefinas (teor máximo de parafinas de 78 %) e as naftênicas geralmente destinadas a produção de aromáticos (teor máximo de 65 % de parafinas). Foi desenvolvido via modelagem molecular dois modelos de previsão de propriedades da nafta, um usando o conceito de Matriz de Série Homóloga do tipo molecular (MTHS) associado ao conceito de Maximização Entrópica (Modelo A) e um segundo modelo usando somente o conceito de MTHS (Modelo B), ambos modelos foram validados com dados experimentais e comparados entre si. Os modelos calculam e reportam a partir da entrada de alguns dados experimentais a curva TBP (True Boiling Point), a massa molar, a densidade e as frações moleculares em %massa. Após a validação o modelo selecionado foi o que usa somente o conceito MTHS, apresentando um erro de 1,2 % para densidade, 6,1 % para massa molar, a curva TBP foi plotada a partir da conversão da Curva de Destilação ASTM D86 através da equação de Riazi-Daubert (1987) e em relação as frações molares, foram reportadas as que apresentaram abaixo de 15 % (n-hexano, 2-metilpentano, ciclohexano, metilciclohexano e o tolueno). O benzeno apresentou um erro de 17,3 %, mas foi reportado por conta da sua toxicidade ao meio ambiente e ao ser humano. O modelo escolhido permitirá uma resposta mais rápida à produção, facilitando os ajustes dos parâmetros de processos e otimizando a conversão da nafta para que se tenha um bom rendimento na obtenção de produtos.
Crude naphtha is the raw material most used by the petrochemical industry in Brazil for the production of basic inputs such as olefins and aromatics. Naphtha can be obtained by various processes, the main ones being direct distillation and catalytic reforming. Its main use is in obtaining basic inputs such as gasoline, ethylene, propylene, BTX (benzene-toluene-xylenes), butadiene, among others. As it is a product derived from petroleum, it has different compositions, depending on the refining process and the origin of the oil. It can be evaluated in terms of hydrocarbons, PIONA classification, being (P) paraffins, (I) isoparaffins, (O) olefins, (N) naphthenics and (A) aromatics, and consequently classified as paraffinic or naphthenic naphtha. Paraffin naphtha are suitable for the production of olefins (maximum paraffin content 78 %) and naphthenics generally intended for the production of aromatics (maximum paraffin content 65 %). Two models of prediction of naphtha properties were developed via molecular modeling, one using the concept of Homologous Series Matrix of the Molecular Type (MTHS) associated with the concept of Entropic Maximization (Model A) and a second model using only the concept of MTHS (Model B), both models were validated with experimental data and compared to each other. The models calculate and report from the input of some experimental data the TBP curve (True Boiling Point), molar mass, density and molecular fractions in % mass. After validation, the selected model was the one that uses only the MTHS concept, presenting an error of 1.2% for density, 6.1% for molar mass, the TBP curve was plotted from the conversion of the ASTM D86 Distillation Curve through of the Riazi-Daubert equation (1987) and in relation to the molar fractions, those that presented below 15 % (n-hexane, 2-methylpentane, cyclohexane, methylcyclohexane and toluene) were reported. Benzene had an error of 17.3 %, but it was reported because of its toxicity to the environment and humans. The chosen model will allow a faster response to production, facilitating the adjustment of process parameters and optimizing the conversion of naphtha so that you have a good yield in obtaining products.
Crude naphtha is the raw material most used by the petrochemical industry in Brazil for the production of basic inputs such as olefins and aromatics. Naphtha can be obtained by various processes, the main ones being direct distillation and catalytic reforming. Its main use is in obtaining basic inputs such as gasoline, ethylene, propylene, BTX (benzene-toluene-xylenes), butadiene, among others. As it is a product derived from petroleum, it has different compositions, depending on the refining process and the origin of the oil. It can be evaluated in terms of hydrocarbons, PIONA classification, being (P) paraffins, (I) isoparaffins, (O) olefins, (N) naphthenics and (A) aromatics, and consequently classified as paraffinic or naphthenic naphtha. Paraffin naphtha are suitable for the production of olefins (maximum paraffin content 78 %) and naphthenics generally intended for the production of aromatics (maximum paraffin content 65 %). Two models of prediction of naphtha properties were developed via molecular modeling, one using the concept of Homologous Series Matrix of the Molecular Type (MTHS) associated with the concept of Entropic Maximization (Model A) and a second model using only the concept of MTHS (Model B), both models were validated with experimental data and compared to each other. The models calculate and report from the input of some experimental data the TBP curve (True Boiling Point), molar mass, density and molecular fractions in % mass. After validation, the selected model was the one that uses only the MTHS concept, presenting an error of 1.2% for density, 6.1% for molar mass, the TBP curve was plotted from the conversion of the ASTM D86 Distillation Curve through of the Riazi-Daubert equation (1987) and in relation to the molar fractions, those that presented below 15 % (n-hexane, 2-methylpentane, cyclohexane, methylcyclohexane and toluene) were reported. Benzene had an error of 17.3 %, but it was reported because of its toxicity to the environment and humans. The chosen model will allow a faster response to production, facilitating the adjustment of process parameters and optimizing the conversion of naphtha so that you have a good yield in obtaining products.