Made available in DSpace on 2014-12-17T15:41:46Z (GMT). No. of bitstreams: 1 StevieHLpdf.pdf: 1475886 bytes, checksum: e83c49569bddebb612701e2de7e607bc (MD5) Previous issue date: 2009-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In last years it has talked a lot about the environment and the plastic waste produced and discarded. In last decades, the increasing development of research to obtain fuel from plastic material, by catalytic degradation, it has become a very attractive looking, as these tailings are discarded to millions worldwide. These materials take a long time to degrade themselves by ways said natural and burning it has not demonstrated a viable alternative due to the toxic products produced during combustion. Such products could bring serious consequences to public health and environment. Therefore, the technique of chemical recycling is presented as a suitable alternative, especially since could be obtain fractions of liquid fuels that can be intended to the petrochemical industry. This work aims to propose alternatives to the use of plastic waste in the production of light petrochemical. Zeolites has been widely used in the study of this process due to its peculiar structural properties and its high acidity. In this work was studied the reaction of catalytic degradation of high-density polyethylene (HDPE) in the presence HZSM-12 zeolites with different acid sites concentrations by thermogravimetry and pyrolysis coupled with GC-MS. The samples of the catalysts were mixed with HDPE in the proportion of 50% in mass and submitted to thermogravimetric analyses in several heating rates. The addition of solids with different acid sites concentrations to HDPE, produced a decrease in the temperature of degradation of the polymer proportional the acidity of the catalyst. These qualitative results were complemented by the data of activation energy obtained through the non-isothermal kinetics model proposed by Vyazovkin. The values of Ea when correlated to the data of surface acidity of the catalysts indicated that there is a exponential decrease of the energy of activation in the reaction of catalytic degradation of HDPE, in function of the concentration of acid sites of the materials. These results indicate that the acidity of the catalyst added to the system is one of the most important properties in the reaction of catalytic degradation of polyethylene / Nos ?ltimos anos tem-se falado muito sobre o meio ambiente e sobre o lixo pl?stico produzido e descartado. Nas ?ltimas d?cadas, o crescente desenvolvimento de pesquisas com o intuito de obter combust?veis a partir de material pl?stico, via degrada??o catal?tica, tem-se tornado uma busca muito atrativa, j? que esses rejeitos s?o descartados aos milh?es em todo mundo. Esses materiais levam muito tempo para se degradar por meios ditos naturais e sua incinera??o n?o tem se demonstrado uma alternativa vi?vel devido aos produtos t?xicos produzidos durante sua combust?o. Tais produtos conseq?entes poderiam trazer s?rios problemas de sa?de p?blica e ambiental. Logo, a t?cnica da reciclagem qu?mica apresenta-se como uma alternativa adequada, inclusive porque podemos obter fra??es leves do petr?leo que podem ser destinadas ao setor petroqu?mico. Este trabalho tem como objetivo propor alternativas para o aproveitamento de lixo pl?stico na produ??o de combust?veis l?quidos. Ze?litas tem sido amplamente utilizada no estudo desse processo devido ?s suas propriedades estruturais peculiares e sua alta acidez. Neste trabalho, investigou-se a rea??o de degrada??o de Polietileno de Alta Densidade (PEAD) na presen?a de HZSM-12, com diferentes concentra??es de s?tios ?cidos, atrav?s da termogravimetria e pir?lise acoplada ? cromatografia ? g?s e ao espectr?metro de massa (Py-GC-MS). As amostras de catalisadores foram misturadas com PEAD na propor??o de 50% em massa e submetidas a an?lises em diferentes taxas de aquecimento. A adi??o de catalisadores com diferentes concentra??es de s?tios ?cidos produziu uma diminui??o na temperatura de degrada??o do pol?mero proporcional ? acidez do catalisador. Estes resultados qualitativos foram complementados por dados da energia de ativa??o (Ea) obtidos atrav?s do modelo cin?tico n?o-isot?rmico proposto por Vyazovkin. Os valores das Ea quando correlacionados com os dados da acidez superficial dos catalisadores, indicaram que h? uma redu??o exponencial da Ea da rea??o catal?tica de degrada??o em fun??o da concentra??o dos s?tios ?cidos dos materiais, indicando que esta propriedade ? significativa neste tipo de rea??o