Acoplamento oxidativo do metano como alternativa do uso do gás natural para a produção de eteno: uma revisão
Data
2022-02-02
Autores
Almeida, Gabriela Pereira de [UNIFESP]
Santos, Henrique Pereira dos [UNIFESP]
Orientadores
Lima, Sania Maria de [UNIFESP]
Tipo
Trabalho de conclusão de curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O eteno é um produto com grande importância e relevância econômica para a indústria química, devido a alta demanda de seus derivados (PE, PET, PVC, entre outros) com aplicação em diversos setores. Além disso, há projeções que mostram um constante crescimento de consumo mundial desse insumo, ou seja, faz-se necessário o desenvolvimento de tecnologias e de rotas alternativas para sua produção, para o atendimento da sua demanda, pois o eteno ainda é obtido majoritariamente da nafta. Sendo assim, uma das rotas alternativas para obtenção do eteno por meio da conversão direta do metano é a reação de acoplamento oxidativo do metano (AOM). Contudo, a reação de AOM enfrenta grandes desafios, devido à reação ser altamente exotérmica e necessitar de altas temperaturas, o que leva à desativação catalítica, além de concorrer com a barreira termodinâmica das reações não seletivas deste processo, resultando em baixa seletividade em produtos C2. Em vista dessas dificuldades, muitos estudos têm sido produzidos a fim de contorná-las e tornar esse processo industrialmente viável. Com isso, o presente trabalho teve como objetivo realizar uma revisão bibliográfica sistemática, levantando trabalhos recentes acerca dos principais catalisadores utilizados na reação de AOM, a fim de determinar qual deles exibe o melhor desempenho catalítico. A partir da base de dados e palavras-chave especificadas neste trabalho, foram levantados 299 trabalhos publicados, os quais passaram por uma análise por meio da metodologia empregada, que resultaram em 84 trabalhos selecionados para o embasamento deste estudo. Após a análise de todas as referências e comparação entre elas, concluiu-se que os catalisadores suportados em sílica, especialmente o Mn-Na2WO4/SiO2 dopados com diferentes metais, são os catalisadores mais promissores, de acordo com o conhecimento atual, e que proporcionam o melhor rendimento a eteno na reação de AOM.
Ethene is a product with great importance and economic relevance to the chemical industry, due to the high demand of its derivatives (PE, PET, PVC, among others) with application in several sectors. In addition, there are projections that show a constant growth of global consumption of this chemical compound, that is, it is necessary to develop technologies and alternative routes for its production, to meet its demand, because the ethene is still obtained mostly from naphtha. Thus, one of the alternative routes to obtain ethene through the direct conversion of methane is the reaction of oxidative coupling of methane (OCM). However, the OCM reaction faces great challenges, due to the reaction being highly exothermic and requiring high temperatures, which leads to catalytic deactivation, besides competing with the thermodynamic barrier of non-selective reactions of this process, resulting in low selectivity in C2 products. In view of these difficulties, many studies have been produced in order to circumvent them and make this process industrially viable. Then, the present work aimed to perform a systematic bibliographic review, raising recent studies about the main catalysts used in the reaction of OCM, toward to determine which of them exhibits the best catalytic performance. From the database and keywords specified in this work, 299 published papers were collected, which underwent an analysis through the methodology employed, which resulted in 84 papers selected for the basis of this study. After analyzing all references and comparing them, it was concluded that the catalysts supported in silica, especially Mn-Na2WO4/SiO2, are the most promising catalysts, according to current knowledge, and that provide the best yield to ethene in the OCM reaction.
Ethene is a product with great importance and economic relevance to the chemical industry, due to the high demand of its derivatives (PE, PET, PVC, among others) with application in several sectors. In addition, there are projections that show a constant growth of global consumption of this chemical compound, that is, it is necessary to develop technologies and alternative routes for its production, to meet its demand, because the ethene is still obtained mostly from naphtha. Thus, one of the alternative routes to obtain ethene through the direct conversion of methane is the reaction of oxidative coupling of methane (OCM). However, the OCM reaction faces great challenges, due to the reaction being highly exothermic and requiring high temperatures, which leads to catalytic deactivation, besides competing with the thermodynamic barrier of non-selective reactions of this process, resulting in low selectivity in C2 products. In view of these difficulties, many studies have been produced in order to circumvent them and make this process industrially viable. Then, the present work aimed to perform a systematic bibliographic review, raising recent studies about the main catalysts used in the reaction of OCM, toward to determine which of them exhibits the best catalytic performance. From the database and keywords specified in this work, 299 published papers were collected, which underwent an analysis through the methodology employed, which resulted in 84 papers selected for the basis of this study. After analyzing all references and comparing them, it was concluded that the catalysts supported in silica, especially Mn-Na2WO4/SiO2, are the most promising catalysts, according to current knowledge, and that provide the best yield to ethene in the OCM reaction.