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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

Development of Iron-based Catalyst for Isobutane Dehydrogenation to Isobutylene

Alahmadi, Faisal 07 1900 (has links)
Abstract: Isobutylene is a high demand chemical that contributes to the production of fuel, plastic, and rubbers. It is produced industrially by different processes, as a byproduct of steam cracking of naphtha or a fluidized catalytic cracking or by isobutane dehydrogenation. Catalytic dehydrogenation of isobutane is in increasing importance because of the growing demand for isobutylene and the better economic advantage compared to other isobutylene production processes. Isobutane dehydrogenation is an endothermic reaction and to achieve good yields; it is preferred to work at higher temperatures. At these temperatures, carbon deposition leads to catalyst deactivation, which requires the catalyst to be regenerated on a frequent basis. Most of the current processes to produce isobutylene use either expensive platinum-based metal or toxic chromium-based catalysis. Hence, there is a demand to search for alternative catalysts that are a relatively cheap and non-toxic. To achieve this goal, Zirconia-supported Iron catalysts were prepared. To study the effect of active phase distribution, different iron loadings were tested for impregnation (3% to 10%) and co-precipitation (10%-20%). The catalysts show promising results that can achieve an isobutylene selectivity and yield of 91% and 31%, respectively, with isobutane conversion of 35%.
2

Katalytisk omvandling av pyrolysgas i WoodRoll-processen för ökad processtillförlitlighet / Catalytic Conversion of Pyrolysis Gas in the WoodRoll Process for Enhancing Process Reliability

Halvarsson, Alfred January 2015 (has links)
This project was a cooperation between the division of Chemical Technology at KTH, Cortus Energy and Haldor Topsoe A/S. The goal was to build up a totally new setup for converting and deoxygenate pyrolysis bio-oil, in order to increase the performance of Cortus Energy’s WoodRoll process. Therefore an iron based catalyst from Haldor Topsoe was used. The building up of the new setup with all reactors and the control panel was a complicated and time-consuming work. This led to an only short time slot for performing experiments, which means that more work needs to be done to get more valuable results. The most important success of this project was to get all the knowledge about the system and to make everything (the whole experimental setup) running properly. However, the sampling system needs to be improved before making further experiments. The experiments which have been done show promising results and that the iron based catalyst was working well for converting the bio-oil. During the two hour long experiment there were not shown any indications of deactivation, when looking at the gas compositions, but the results from temperature programmed oxidation (TPO) show carbon deposition on the catalyst and the BET surface also shows a slight decrease in surface area.

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