Dissertation
NICKEL- MOLYBDENUM CATALYSTS FOR SYNTHESIS GAS GENERATION
Doctor of Philosophy (PhD), Washington State University
01/2015
Handle:
https://hdl.handle.net/2376/6167
Abstract
The aim of this research is to optimize Mo-based catalysts for synthesis gas generation via partial oxidation of logistic fuels. The most conventional reforming catalysts used in industry for reforming are Ni based catalysts. Ni provides metallic sites necessary for adsorption of hydrocarbons and breaking of C-H, C-C bonds. However Ni catalysts are prone to coking, as the rate of carbon deposition is faster than its reaction with a gaseous oxidizing agent.
Logistic fuels are either long chain hydrocarbons or a mixture of long chain hydrocarbons, which makes them even more complicated and prone to coking. Previous work done in our lab has demonstrated the ability of MoO2 and Mo2C to reform logistic fuels such as dodecane, Jet-A fuel, surrogate biodiesel and gasoline, with good conversion, synthesis gas generation and resistance to coking. However, the performance of these catalysts leave a huge scope of improvement in terms of conversion and syn-gas generation at high weight hour space velocity (WHSV). This can be achieved in two ways, one by increasing the surface area and another by addition of metallic sites. The increase in surface area is achieved by supporting the catalysts on a high surface area silica support and for addition of metallic sites, Ni is added to the catalyst. Hence, first Mo2C supported Ni catalysts are synthesized and tested for partial oxidation of surrogate biodiesel (methyl oleate). Activity tests conducted for the synthesized catalysts showed 100% carbon conversion with 90% H2 yield without deactivation due to coking over 24 h time-on-stream.
Then MoO2 catalysts are modified by supporting it on silica. Nanoparticle MoO2 supported on SiO2 is synthesized and its activity is tested and compared with commercial MoO2 at high WHSV for partial oxidation of dodecane. Silica supported MoO2 catalysts are active upto WHSV 51 h-1, whereas commercial MoO2, deactivated at WHSV 20-1. Finally Ni is added to silica supported MoO2 catalysts, in order to increase the syn-gas generation at high WHSV. As expected, the hydrogen yield after addition of Ni, increases from 60% for silica supported MoO2 catalysts to 94%.
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Details
- Title
- NICKEL- MOLYBDENUM CATALYSTS FOR SYNTHESIS GAS GENERATION
- Creators
- SHREYA SHAH
- Contributors
- SU HA (Advisor)M. GRANT NORTON (Committee Member)BERNARD J. VAN WIE (Committee Member)RICHARD ZOLLARS (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 167
- Identifiers
- 99900581639501842
- Language
- English
- Resource Type
- Dissertation