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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.
11

Obten??o de ?lcool al?lico (PROP-2-EN-1-OL) a partir da glicerina derivada do biodiesel de ?leo de mamona

Lima, Luis Ferreira de 20 April 2012 (has links)
Made available in DSpace on 2014-12-17T14:09:14Z (GMT). No. of bitstreams: 1 LuisFL_TESE.pdf: 1981587 bytes, checksum: 1da0819bc859b1e23958de0190156279 (MD5) Previous issue date: 2012-04-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, biodiesel was produced from castor oil that was a byproduct glycerin. The molar ratio between oil and alcohol, as well as the use of (KOH) catalyst to provide the chemical reaction is based on literature. The best results were obtained using 1 mol of castor oil (260g) to 3 moles of methyl alcohol (138g), using 1.0% KOH as catalyst at a temperature of 260 ? C and shaken at 120 rpm. The oil used was commercially available, the process involves the reaction of transesterification of a vegetable oil with methyl alcohol. The product of this reaction is an ester, biodiesel being the main product and the glycerin by-product which has undergone treatment for use as raw material for the production of allyl alcohol. The great advantage of the use of glycerin to obtain allyl alcohol is that its use eliminates the large amount of waste of the biodiesel and various forms of insult to the environment. The reactions for the formation of allyl alcohol was conducted from formic acid and glycerin in a ratio 1/1, at a temperature of 260oC in a heater blanket, being sprayed by a spiral condenser for a period of 2 hours and the product obtained contains mostly the allylic alcohol .. The monitoring of reactions was performed by UV-Visible Spectrophotometer: FTIR Fourier transform, the analysis showed that these changes occur spectrometer indicating the formation of the product allylic alcohol (prop-2-en-1-ol) in the presence of water, This alcohol was appointed Alcohol GL. The absorption bands confirms that the reaction was observed in (? C = C) 1470 -1600 cm -1 and (? CO), 3610-3670 attributed to C = C groups and OH respectively. The thermal analysis was carried out in a thermogravimetric analyzer SDT Q600, where the mass and temperature are displayed against time, that allows checking the approximate rate of heating. The innovative methodology developed in the laboratory (LABTAM, UFRN), was able to treat the glycerine produced by transesterification of castor oil and used as raw material for production of allyl alcohol, with a yield of 80%, of alcohol, the same is of great importance in the manufacture of polymers, pharmaceuticals, organic compounds, herbicides, pesticides and other chemicals / Neste trabalho o biodiesel foi produzido a partir de ?leo de mamona que teve como subproduto a glicerina. A raz?o molar entre ?leo e ?lcool, bem como o uso do (KOH) como catalisador qu?mico para proporcionar a rea??o, foi baseada em dados da literatura. Os melhores resultados foram obtidos, utilizando 1 mol de ?leo de mamona (260g) para 3 mols de ?lcool met?lico (138g). O ?leo utilizado foi adquirido comercialmente, o processo de transesterifica??o envolve a rea??o do ?leo vegetal com um ?lcool met?lico. O produto dessa rea??o ? um ?ster, sendo o biodiesel o seu principal produto e a glicerina o sub-produto a qual foi submetida a tratamento para uso como mat?ria-prima para a obten??o do ?lcool al?lico. A grande vantagem do uso da glicerina para obten??o de ?lcool al?lico ? que sua utiliza??o elimina a grande quantidade de res?duos do biodiesel e v?rias formas de agress?o ao meio ambiente. As rea??es para forma??o do ?lcool alilico foram conduzidas a partir de ?cido f?rmico e glicerina, em uma raz?o 1/1, sob temperatura de 260oC, em uma manta aquecedora, sendo vaporizado por um condensador em espiral por um per?odo de 2 horas, e o produto obtido contem em sua grande maioria o ?lcool al?lico. O acompanhamento das rea??es foi realizado por Espectrofot?metro UV-Vis?vel: FTIR com transformada de Fourier, a an?lise revelou que estas altera??es espectrom?tricas ocorrem indicando a forma??o do produto ?lcool al?lico (prop-2-en-1-ol), em presen?a de ?gua, este ?lcool foi nomeado de ?lcool GL. As bandas de absor??o que confirmam a rea??o foram observadas em (? C=C) em 1470 -1600 cm-1 e em (? C-O), 3610 3670 atribu?das aos grupos C=C e O-H respectivamente. A analise t?rmica foi realizada em um analisador Termogravim?trico SDT Q600, onde a massa e a temperatura ser?o exibidos em fun??o do tempo, isto permite a verifica??o aproximada da taxa de aquecimento. A metodologia inovadora desenvolvida no laborat?rio (LABTAM, UFRN), foi capaz de tratar a glicerina produzida, atrav?s da transesterifica??o de ?leo de mamona e utilizar como mat?ria prima para produ??o do ?lcool al?lico, apresentando um rendimento de 80%, deste ?lcool, o mesmo ? de grande import?ncia na fabrica??o de pol?meros, medicamentos, compostos org?nicos, herbicidas, pesticidas e outros produtos qu?micos
12

Shattering Kraft Recovery Boiler Smelt by a Steam Jet

Taranenko, Anton 19 March 2013 (has links)
Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases the likelihood of dissolving tank explosions. While industry has not dedicated much effort to smelt shattering, the safety implications require smelt shattering to be studied in detail. An experimental set-up was constructed to simulate the shattering operation using a water-glycerine solution and air instead of smelt and steam respectively. The objective was to examine how physical properties and flow characteristics affect shattering. It was found that increasing shatter jet velocity greatly reduced droplet mean diameter. Increasing the liquid flow rate greatly increased droplet size, as expected. Shattering was not significantly affected by viscosity, unless a weak shatter jet was used on a highly viscous fluid. Increasing the proximity of the shatter jet nozzle decreased droplet size.
13

Shattering Kraft Recovery Boiler Smelt by a Steam Jet

Taranenko, Anton 19 March 2013 (has links)
Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases the likelihood of dissolving tank explosions. While industry has not dedicated much effort to smelt shattering, the safety implications require smelt shattering to be studied in detail. An experimental set-up was constructed to simulate the shattering operation using a water-glycerine solution and air instead of smelt and steam respectively. The objective was to examine how physical properties and flow characteristics affect shattering. It was found that increasing shatter jet velocity greatly reduced droplet mean diameter. Increasing the liquid flow rate greatly increased droplet size, as expected. Shattering was not significantly affected by viscosity, unless a weak shatter jet was used on a highly viscous fluid. Increasing the proximity of the shatter jet nozzle decreased droplet size.

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