Caracterização físico-quimica da glicerina proveniente de usinas de biodiesel e determinação de metanol residual por CG com amostragem por headspace estático
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Data
2013-04-10
Autores
Sequinel, Rodrigo [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A glicerina bruta emergente da cadeia de produção de biodiesel contém alguns produtos intermediários da reação, resíduos de catalisador, água, metanol e vem se tornando o novo desafio do Programa Nacional de Produção e Uso do Biodiesel – PNPB. Neste trabalho foi realizada a caracterização completa de amostras de glicerina bruta, glicerina loira e glicerina bidestilada. Os parâmetros analisados foram aspecto, pH, teor de água, teor de metanol, teor de matéria orgânica não glicerol (MONG), teor de glicerol, além da realização de ensaio qualitativo para presença de elementos metálicos e não metálicos. De acordo com os resultados obtidos, as características físico químicas variaram muito de uma amostra para outra. Esta diferença foi principalmente observada em decorrência de processos de transesterificação problemáticos ou mesmo devido aos tratamentos de purificação a que são submetidas as amostras de glicerina. Enquanto uma amostra de glicerina loira contém em torno de 80% de glicerol, em uma amostra de glicerina bruta este valor pode ficar abaixo de 50%. Os resultados mostraram também ser possível a obtenção de glicerol com alto grau de pureza, acima de 97%, a partir de amostras de glicerina bruta. O grau de purificação vai depender da aplicação a que estas se destinam, entretanto, a utilização de processos de tratamento incompletos ou inadequados compromete a qualidade do produto. Deste modo, a determinação de todos os parâmetros citados neste trabalho é de suma importância para fornecer dados que possam ser úteis no estabelecimento de padrões de qualidade para a glicerina. No que diz respeito ao teor de metanol, como não foi encontrado um método oficial na literatura, foi validado um novo procedimento analítico para determinação deste parâmetro, utilizando a técnica de CG-HS. As condições cromatográficas utilizadas foram injetor...
The crude glycerin emerging from the biodiesel production process contains some intermediate products from reaction, residue of catalyst, moisture, methanol and for this reason is becoming the new challenge of the National Program of Production and Use of Biodiesel – PNPB. In this thesis it was performed a complete characterization of crude glycerin samples, blond glycerin samples and bi-distilled glycerin samples. All parameters analyzed were aspect, pH, water content, methanol content, material organic non-glycerol, glycerol content, as well as the qualitative determination of some metallic and non-metallic elements that may be present. According to the results obtained there was a great variation among the physic-chemical characteristics from the samples. This difference was mostly due to problematic transesterification process or due to some purification treatment which glycerin samples were submitted. While the glycerol content is around to 80% for a blond glycerin sample, this value may be bellow to 50% for crude glycerin samples. The results also showed it is possible to obtain glycerol of high purity grade, above to 97%, from crude glycerin samples. The desired purity grade depends on the future destination of the glycerin, however, the application of incomplete or inadequate treatment may compromise the quality of the product. Therefore, the determination of all physic-chemical parameters listed in this document becomes an important step to provide enough information to establish a quality standard for glycerin. Regarding the methanol content, since it was not found in literature an official method, it was developed and validated a new test procedure for this determination using GC-HS. The chromatographic conditions were PTV and FID temperatures at 300 °C. The oven temperature program was an initial hold at 50 °C for 3 min, followed... (Complete abstract click electronic access below)
The crude glycerin emerging from the biodiesel production process contains some intermediate products from reaction, residue of catalyst, moisture, methanol and for this reason is becoming the new challenge of the National Program of Production and Use of Biodiesel – PNPB. In this thesis it was performed a complete characterization of crude glycerin samples, blond glycerin samples and bi-distilled glycerin samples. All parameters analyzed were aspect, pH, water content, methanol content, material organic non-glycerol, glycerol content, as well as the qualitative determination of some metallic and non-metallic elements that may be present. According to the results obtained there was a great variation among the physic-chemical characteristics from the samples. This difference was mostly due to problematic transesterification process or due to some purification treatment which glycerin samples were submitted. While the glycerol content is around to 80% for a blond glycerin sample, this value may be bellow to 50% for crude glycerin samples. The results also showed it is possible to obtain glycerol of high purity grade, above to 97%, from crude glycerin samples. The desired purity grade depends on the future destination of the glycerin, however, the application of incomplete or inadequate treatment may compromise the quality of the product. Therefore, the determination of all physic-chemical parameters listed in this document becomes an important step to provide enough information to establish a quality standard for glycerin. Regarding the methanol content, since it was not found in literature an official method, it was developed and validated a new test procedure for this determination using GC-HS. The chromatographic conditions were PTV and FID temperatures at 300 °C. The oven temperature program was an initial hold at 50 °C for 3 min, followed... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Quimica organica, Glicerina, Metanol, Glycerin
Como citar
SEQUINEL, Rodrigo. Caracterização físico-quimica da glicerina proveniente de usinas de biodiesel e determinação de metanol residual por CG com amostragem por headspace estático. 2013. 102 f. Tese (doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Química de Araraquara, 2013.