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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Convers?o t?rmica e termocatal?tica ? baixa temperatura do ?leo de girassol para obten??o de bio-?leo

Ara?jo, Aruzza Mabel de Morais 01 July 2011 (has links)
Made available in DSpace on 2014-12-17T14:08:49Z (GMT). No. of bitstreams: 1 AruzzaMMA_DISSERT.pdf: 1774693 bytes, checksum: a3fe2aad8bc5ee5d62f0d84e6a4733c6 (MD5) Previous issue date: 2011-07-01 / The use of biofuels remotes to the eighteenth century, when Rudolf Diesel made the first trials using peanut oil as fuel in a compression ignition engine. Based on these trials, there was the need for some chemical change to vegetable oil. Among these chemical transformations, we can mention the cracking and transesterification. This work aims at conducting a study using the thermocatalytic and thermal cracking of sunflower oil, using the Al-MCM-41 catalyst. The material type mesoporous Al-MCM-41 was synthesized and characterized by Hydrothermical methods of X-ray diffraction, scanning electron microscopy, nitrogen adsorption, absorption spectroscopy in the infrared and thermal gravimetric analysis (TG / DTG).The study was conducted on the thermogravimetric behavior of sunflower oil on the mesoporous catalyst cited. Activation energy, conversion, and oil degradation as a function of temperature were estimated based on the integral curves of thermogravimetric analysis and the kinetic method of Vyazovkin. The mesoporous material Al-MCM-41 showed one-dimensional hexagonal formation. The study of the kinetic behavior of sunflower oil with the catalyst showed a lower activation energy against the activation energy of pure sunflower oil. Two liquid fractions of sunflower oil were obtained, both in thermal and thermocatalytic pyrolisis. The first fraction obtained was called bio-oil and the second fraction obtained was called acid fraction. The acid fraction collected, in thermal and thermocatalytic pyrolisis, showed very high level of acidity, which is why it was called acid fraction. The first fraction was collected bio-called because it presented results in the range similar to petroleum diesel / O uso dos biocombust?veis remota ao s?culo XVIII, quando Rudolf Diesel realizou os primeiros ensaios utilizando o ?leo de amendoim como combust?vel em um motor de igni??o por compress?o. Com base nesses ensaios, constatou-se a necessidade de realizar algumas transforma??es qu?micas ao ?leo vegetal. Dentre essas transforma??es qu?micas, pode-se citar a transesterifica??o e o craqueamento. Este trabalho tem como objetivo, realizar um estudo utilizando-se o craqueamento t?rmico e termocatal?tico do ?leo de girassol, utilizando o Al-MCM-41 como catalisador. O material mesoporoso tipo Al-MCM-41 foi sintetizado hidrotermicamente e caracterizado pelos m?todos de difra??o de raios-X, microscopia eletr?nica de varredura, adsor??o de nitrog?nio, espectroscopia de absor??o na regi?o do infravermelho e an?lise termogravim?trica (TG/DTG). Ainda foi realizado o estudo do comportamento termogravim?trico do ?leo de girassol sobre o catalisador mesoporoso citado. Com base nas curvas integrais das an?lises termogravim?tricas e o m?todo cin?tico de Vyazovkin, foram estimados a energia de ativa??o, a convers?o e a degrada??o do ?leo em fun??o da temperatura. O material mesoporoso Al-MCM-41 apresentou forma??o hexagonal unidimensional. O estudo do comportamento cin?tico do ?leo de girassol com o catalisador mostrou uma menor energia de ativa??o frente ? energia de ativa??o do ?leo de girassol puro. Na pir?lise t?rmica e termocatal?tica do ?leo de girassol foram obtidas duas fra??es l?quidas. A primeira fra??o obtida foi denominada de bio?leo e a segunda fra??o obtida foi denominada de fra??o ?cida. A fra??o ?cida coletada tanto na pir?lise t?rmica como na termocatal?tica apresentou ?ndice de acidez muito elevado, raz?o pela qual foi denominada fra??o ?cida. A primeira fra??o coletada foi denominada de bio?leo porque apresentou resultados na faixa semelhante ao diesel de petr?leo

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