PhD Position (4) TW12 - Department of Chemical engineering and technical chemistry, Ghent University

• Last application date: 2012-04-30 17:00
• Department: TW12 - Department of Chemical engineering and technical chemistry
• Contract: bepaald
• Degree: MSc in Chemical Engineering or related subject
• Occupancy rate: 100%
• Vacancy Type: wp

Unraveling Complex Kinetics on Metal Catalysts.

Aim

Development and application of the Single-Event MicroKinetic (SEMK) methodology towards Co based catalysts. Fundamental consideration of aspects such as metal atom versus active site, multiple types of sites and subsurface reactants and analysis of their effects on mean field microkinetic models.

Justification

Fischer Tropsch synthesis is an alternative route towards chemicals and fuels starting from gas, coal or biomass via synthesis gas. Typically, large scale facilities are involved and minor improvements to the process can have significant repercussions on its economics. It is, hence, logic not to limit the understanding of the reaction kinetics to correlative models, but to explore the detailed reaction mechanism in a microkinetic way.

In this respect Ghent University (Belgium) and Shell Global Solutions International B.V. (The Netherlands) have teamed up to pursue the above stated aims. Ghent University has a proven track record in the Single-Event MicroKinetic modeling of large scale processes such as hydrocracking, catalytic cracking, methanol-to-olefins, aromatics hydrogenation and Fischer-Tropsch synthesis, while Shell Global Solutions International B.V., is a leading multinational in natural gas valorization via Fischer-Tropsch synthesis. The presently available SEMK model has been constructed mainly based on Fe-based data, whereas the current catalytic system of interest is a Co-based one.

Program

Various parallel and consecutive activities will lead to the targeted microkinetic description of Fischer-Tropsch synthesis:

• Literature survey on the microkinetic modelling of metal-catalysed reactions and analysis of the relevance of accounting for additional details in mean field microkinetic models. This survey will serve the preparation of the following activities:
• Metal atoms versus active sites: the definition of an active site on a metal surface can be ambiguous. Molecules may chemisorb in different configurations and the reactive configuration is not necessarily the most stable one. How can such effects be accounted for in mean field microkinetic modelling and is it relevant to do so?
• Analysis of the effect of accounting for different types of sites. What added value does it contribute to the model and what conditions need to be fulfilled to significantly exploit these features?
• Simulation of intrinsic experimental kinetic data will be used as part of the above described activities. A reaction network will be selected and constructed based on literature information as well as on discussions between the project partners. Kinetic parameter values will be determined from first principles as well as by regression of experimental data. A reaction path analysis based on the microkinetic model: identification of the most important surface reaction routes in the catalytic mechanism, of “dead ends” routes and an assessment of the intermediates surface concentrations.

Advisors: Joris W. Thybaut and Guy B. Marin

PhD Fellowships are available in the following domains:

• Biomass Conversion
• Transient Kinetics
• Metal catalyzed reactions
• Radical Polymerization
• Pyrolyis and Steam cracking
• Computational Fluid Dynamics coupled with kinetics
  

Typical activities during a 4 year PhD project:

• Experimental acquisition of intrinsic reaction rate data.
• Model construction based on reaction mechanisms and estimation of kinetic parameters by data regression and/or quantum chemical calculations.
• Scale-up of lab data and simulation of industrial processes by developing and implementing reactor models accounting for transport next to reaction. Development and application of Computational Fluid Dynamics models in that context.
• Normal duties will apply, including the preparation of scientific reports and publications and assisting in supervising of MSc students.

Requirements

Applicants must possess a MSc in Chemical Engineering or related subject and a TOEFL certificate (minimum score of 580(paper)/92(iBT)/237(computer)) or equivalent. Relevant experience in the area of reactor engineering, kinetics, and/or computational chemistry is strongly recommended. Candidates must have a strong mathematical background and be willing to focus on obtaining quantitative rather than qualitative results. Excellent candidates with a PhD in the above domains and willing to spend between 1 and 3 years at LCT can also apply for a postdoctoral fellowship.

Any additional information can be obtained by contacting Guy B. Marin. Any application should enclose a C.V., a one page justification of your interest and at least two references.

Guy.Marin@UGent.be

09 264 45 17