Método alternativo para detecção de não conformidade em gasolina comercial brasileira do tipo C
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Data
2013-04-09
Autores
Munhoz, João Fernando Villarrubia Lopes [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O Governo brasileiro intervia diretamente na comercialização de combustíveis até a década de 90. Com a abertura do mercado, pequenos revendedores sem contrato exclusivo com qualquer distribuidora, chamados de ‘bandeiras brancas’, surgiram no ambiente concorrencial. Com o propósito de assegurar a qualidade, a Agência Nacional do Petróleo, Gás Natural e Biocombustíveis, ANP, criou portarias especificando as características físico-químicas da gasolina comercial brasileira, tal como a Portaria nº 309. Com a crescente quantidade de informações, a diminuição do tempo de análise é uma necessidade. Uma técnica promissora é a cromatografia gasosa ultrarrápida, capaz de realizar uma corrida em poucos minutos, ou até mesmo em alguns segundos. Para isso, o comprimento da coluna capilar e seu diâmetro interno são reduzidos e seu aquecimento é feito através de uma resistência encapsulada. Assim, é possível obter os mesmos resultados em tempo diminuído e com a mesma qualidade. O aumento do volume de informações obtido experimentalmente exige ferramentas matemáticas mais avançadas para seu tratamento. Desde a década de 70, a quimiometria tem sido aplicada na obtenção, representação e transformação destes dados. O objetivo deste trabalho é criar um método de cromatografia gasosa ultrarrápida para análise de gasolinas comerciais brasileiras e, com ferramentas quimiométricas, classificar quanto à qualidade segundo a ANP. No desenvolvimento, cerca de 580 amostras de gasolinas comerciais foram coletadas mensalmente na região centro-oeste do estado de São Paulo. Os ensaios físico-químicos obtidos revelaram que grande parte não estava em conformidade com as portarias estabelecidas, possuindo apenas um parâmetro em discordância: a quantidade de etanol em sua composição...
The Brazilian government intervened directly in the commercialization of fuel until de 90s. By opening of the marketing, small dealers without exclusive contract with any distributor, called ‘white flags’, appeared in the competitive environment. In order to ensure quality, the National Agency of Petroleum, Natural Gas and Biofuels, ANP, has created ordinances which specify physico-chemicals characteristics of Brazilian commercial gasoline, such as the Ordinance No 309. By increasing the amount of information, reducing the analysis time is a necessity. A promising technique is the ultra-fast gas chromatography, able to perform a chromatographic run in just few minutes, or even in seconds. Thereunto, the capillary column length and its internal diameter are reduced and its heating is done via an encapsulated resistor. It is possible to obtain the same results in reduced time and with the same quality. The increasing volume of information obtained experimentally requires more advanced mathematical tools for their treatment. Since the 70s, Chemometrics has been applied in acquisition, representation and processing these data. The objective of this work is to create an ultrafast gas chromatography method for analisys of the Brazilian commercial gasoline and, with chemometric tools, sort by their quality according to ANP. In development, about 580 commercial gasoline samples were collected monthly in the central-western state of São Paulo. The physico-chemical assays reveled that a great fraction of which was not in accordance with the ordinances established, having only one parameter in disagreement: the amount of ethanol in its composition. The addition of adulterants to some samples was necessary to increase the variability of the data. Monthly, 50 of 580 samples were selected by the hierarchical cluster analysis... (Complete abstract click electronic access below)
The Brazilian government intervened directly in the commercialization of fuel until de 90s. By opening of the marketing, small dealers without exclusive contract with any distributor, called ‘white flags’, appeared in the competitive environment. In order to ensure quality, the National Agency of Petroleum, Natural Gas and Biofuels, ANP, has created ordinances which specify physico-chemicals characteristics of Brazilian commercial gasoline, such as the Ordinance No 309. By increasing the amount of information, reducing the analysis time is a necessity. A promising technique is the ultra-fast gas chromatography, able to perform a chromatographic run in just few minutes, or even in seconds. Thereunto, the capillary column length and its internal diameter are reduced and its heating is done via an encapsulated resistor. It is possible to obtain the same results in reduced time and with the same quality. The increasing volume of information obtained experimentally requires more advanced mathematical tools for their treatment. Since the 70s, Chemometrics has been applied in acquisition, representation and processing these data. The objective of this work is to create an ultrafast gas chromatography method for analisys of the Brazilian commercial gasoline and, with chemometric tools, sort by their quality according to ANP. In development, about 580 commercial gasoline samples were collected monthly in the central-western state of São Paulo. The physico-chemical assays reveled that a great fraction of which was not in accordance with the ordinances established, having only one parameter in disagreement: the amount of ethanol in its composition. The addition of adulterants to some samples was necessary to increase the variability of the data. Monthly, 50 of 580 samples were selected by the hierarchical cluster analysis... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Quimica organica, Gasolina, Quimiometria, Gasoline
Como citar
MUNHOZ, João Fernando Villarrubia Lopes. Método alternativo para detecção de não conformidade em gasolina comercial brasileira do tipo C. 2013. 181 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Química de Araraquara, 2013.