• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Experimental Study of In Situ Combustion with Decalin and Metallic Catalyst

Mateshov, Dauren 2010 December 1900 (has links)
Using a hydrogen donor and a catalyst for upgrading and increasing oil recovery during in situ combustion is a known and proven technique. Based on research conducted on this process, it is clear that widespread practice in industry is the usage of tetralin as a hydrogen donor. The objective of the study is to find a cheaper hydrogen donor with better or the same upgrading performance. Decalin (C10H18) is used in this research as a hydrogen donor. The experiments have been carried out using field oil and water saturations, field porosity and crushed core for porous medium. Four in situ combustion runs were performed with Gulf of Mexico heavy oil, and three of them were successful. The first run was a control run without any additives to create a base for comparison. The next two runs were made with premixed decalin (5 percent by oil weight) and organometallic catalyst (750 ppm). The following conditions were kept constant during all experimental runs: air injection rate at 3.1 L/min and combustion tube outlet pressure at 300 psig. Analysis of the performance of decalin as a hydrogen donor in in-situ combustion included comparison of results with an experiment where tetralin was used. Data from experiments of Palmer (Palmer-Ikuku, 2009) was used for this purpose, where the same oil, catalyst and conditions were used. Results of experiments using decalin showed better quality of produced oil, higher recovery factor, faster combustion front movement and higher temperatures of oxidation. API gravity of oil in a run with decalin is higher by 4 points compared to a base run and increased 5 points compared to original oil. Oil production increased by 7 percent of OOIP in comparison with base run and was 2 percent higher than the experiment with tetralin. The time required for the combustion front to reach bottom flange decreased 1.6 times compared to the base run. The experiments showed that decalin and organometallic catalysts perform successfully in in situ combustion, and decalin is a worthy replacement for tetralin.
2

Nouveaux catalyseurs et systèmes catalytiques appliqués à la synthèse du polyuréthane via la réaction isocyanate – alcool / New catalysts and catalytic systems applied to the synthesis of polyurethane via the isocyanate - alcohol reaction

Lhomme, Julien 17 December 2013 (has links)
L’objectif de ce travail est de remplacer les catalyseurs organométalliques à base d’étain et de mercure utilisés lors de la synthèse de polyuréthane via la réaction isocyanate – alcool. Une étude bibliographique a montré que la basicité et la nucléophilie d’un catalyseur organique gouvernent son activité et le mécanisme réactionnel qu’il induit. Pour les catalyseurs organométalliques, ces propriétés catalytiques s’expliquent par des considérations électroniques ainsi que par le principe HSAB. D’autre part, une étude approfondie du catalyseur organomercuriel a été menée. Elle a révélé l’intérêt d’ajouter à l’espèce catalytique organométallique un acide carboxylique, de préférence à longue chaîne carbonée. Celui-ci ralentit l’hydrolyse du catalyseur tout en augmentant sa sélectivité envers la réaction isocyanate – alcool. De nouveaux catalyseurs ou systèmes catalytiques originaux ont ensuite été évalués grâce à un test simplifié. Trois catalyseurs organométalliques ont ainsi été sélectionnés pour de nouveaux essais dans des conditions plus proches de celles rencontrées dans l’industrie. Ils se sont tous révélés actifs, mais seul le -dicétonate de zinc II permet d’obtenir un prépolymère incolore et transparent, deux critères essentiels pour les applications visées. Il pourrait donc remplacer le catalyseur organostannique. Enfin, l’étude de la sélectivité de systèmes catalytiques impliquant un catalyseur commercial en présence d’acide néodécanoïque a confirmé le rôle protecteur de ce dernier. La sélectivité du complexe de zinc retenu précédemment a par ailleurs été évaluée et apparaît 2,5 fois supérieure à celle du complexe organomercuriel à remplacer. / The aim of this work is to replace organotin and organomercury catalysts used for the synthesis of polyurethane via the isocyanate – alcohol reaction. A bibliographic review revealed that basicity and nucleophilicity of an organic catalyst affect its activity and the reaction mechanism it induces. For organometallic catalysts, these catalytic properties can be explained by electronic considerations and by the HSAB principle. On the other hand, a comprehensive study of the organomercury catalyst highlighted the benefit to combine it with a carboxylic acid, preferably with a long carbon backbone. This slows down hydrolysis of the catalyst while increasing its selectivity toward the isocyanate – alcohol reaction. New original catalysts or catalytic systems were then evaluated using a simplified experiment. Three organometallic catalysts were selected for further testing in conditions closer to industrial ones. They all showed appropriate catalytic activity, but the zinc II -diketonate is the only one to provide a colorless and transparent prepolymer, two essential criteria for the intended applications. This complex could therefore replace the organotin catalyst. Finally, the study of the selectivity of catalytic systems involving a commercial catalyst in the presence of neodecanoic acid confirmed its protective role toward hydrolysis. The previously retained zinc complex was also evaluated and revealed a selectivity 2.5 times greater than that of the organomercurial complex to replace.

Page generated in 0.0698 seconds