Um novo processo para craqueamento térmico: produção de hidrocarbonetos com alto valor agregado a partir de resíduos de Polietileno

• Ano de defesa: 2013
• Autor(a) principal: Duque, João Vitor Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Engenharia Mecânica; Centro Tecnológico; UFES; Programa de Pós-Graduação em Engenharia Mecânica
• Palavras-chave em Português: Thermal analysis; Combustion; Cracking; Plastics; Wastes; Análises térmicas; Combustão; Craqueamento; Plásticos; Resíduos; Engenharia Mecânica; 621
• Link de acesso: http://repositorio.ufes.br/handle/10/4203

The huge variety of products consumed are produced from various types of plastics, generating a considerable amount of environmental and socioeconomic problems due to their incorrect disposal and irresponsible. In this context, this study proposes a new thermal cracking conversion process, as an alternative, to turn the polyethylene (PE) residue into a noble hydrocarbon. For that, a detailed thermochemical characterization was preformed. Elemental analysis detected only amounts of carbon and hydrogen. The proximate analysis, due to lack of standards for this especific waste material, was possible to determine, only, the amount of moisture and ash. Volatile material was obtained by difference, up to 98 wt.%. The PE calorific value was between 31 – 49 MJ kg-1. The thermogravimetry analysis (TGA), between 30 – 700 °C, and at three heating rates (2, 20 e 10 0 K min-1), and under two atmospheres, inert (N2) and oxidant (air) was carried out. The results show agreement with proximate analysis for ash and moisture. Also, the TGA revels that the PE sample can be converted into one to three mechanism steps, depending on the number of recycle and on the type. The differential scanning calorimetry (DSC) was carried out for PE samples and for the product recovery from the process. From the data obtained in the DSC, the Arrhenius kinetic parameters were established for an overall reaction mechanism for PE pyrolysis. The trial for the product shows that almost all quantity produced can be used as fuel. To verify the efficacy of the new process, the cracking of waste polyethylene was also performed in a eletric way. The recovered products were analyzed and a high calorific value was found. However, due to the large amount of volatile material, we suggest that the PE co-combustion with a carbonaceous material can reach temperatures enough to convert all PE into a noble hydrocarbon, and ensuring self-sustening process.