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PhD UK/EU Studentship: Selective Oxidation Reactions - A Chemical Looping Approach, Combustion Group


A fully funded PhD studentship (EPSRC iCASE award with Johnson Matthey) is available working with Prof. J. S. Dennis (CEB) and Dr S. A. Scott (CUED) on the use of chemical looping for the selective oxidation of organic feedstocks of industrial interest.

Due to funding regulations, this studentship is only available to students who meet the eligibility criteria of the UK Research Councils: http://www.graduate.study.cam.ac.uk/finance/funding

The principle of utilising regenerable lattice oxygen from a solid carrier akin to a Mars and van Krevelen mechanism is illustrated in Fig. 1 and it is proposed to use this approach to produce valued industrial chemicals through selective oxidation chemistry. The hypothesis of a chemical looping approach to selective oxidations is to render the reaction safer (no direct contact of air or molecular oxygen with a flammable feedstock), more selective (lattice oxygen rather than molecular oxygen) and more intensive (less recycle and more facile product separation with improved selectivity and a nitrogen-free product). The improved safety could also expand the capacity range of the process and the potential of a distributed product. An environmental benefit is a reduction in the (thermodynamically favoured) CO2 emissions and also NOx in some cases. The reactor technologies involved could either be circulating fluidised bed systems comprising of a main reactor and an air regeneration reactor, or an array of parallel fixed-bed units with gas-switching. The questions being asked are whether the envisaged improvements are both observable (and quantifiable) and can these improvements actually be realized in a viable process flowsheet that significantly improves on the existing industrial technology?

A main challenge is the development of a stable redox catalyst, often comprising of supported metal, or mixed-metal oxides e.g. Mn, V, Bi, Ag. This material must be capable of providing a selective catalytic surface as well as exhibiting an appropriate lattice oxygen capacity, whilst undergoing multi-cycle redox at temperature. Literature data will provide some of the formulations to try and some of these will be made and developed further by Cambridge, who have experience in material synthesis for chemical looping projects, with guidance from JM. JM can also provide its own samples to evaluate within this project. The work will focus on two industrially important selective oxidation reactions, namely the ODH of ethane and propane as mentioned and also the epoxidation of ethylene using a supported Ag-based redox catalyst.

The programme will include both an experimental evaluation side, including material development of the redox catalyst, and a process evaluation aspect using simulation tools available at Cambridge e.g. Aspen Plus flowsheet simulator; the latter is deemed important to understand the (implementable) performance benefits and how they affect the process economics, for such novel processes when compared with the current industrial technology. Fixed bed laboratory reactors are available at Cambridge in both Prof. Dennis's group (Dept. Chemical Engineering and Biotechnology) and also Dr. Stuart Scott's (Dept. of Engineering). Characterization equipment e.g. XRD, SEM-EDX, ICP to establish understanding of both the fresh and spent materials is available at both Cambridge and JMTC Sonning.

For information about the Combustion Group please see: http://www.ceb.cam.ac.uk/research/groups/rg-combustion

Applicants should have a First Class (or a high 2:1) degree in a relevant discipline such as chemical engineering, physics, chemistry, or engineering. The successful applicant will be expected to apply formally for admission through the University's Graduate Admissions Office and meet any conditions of admission they set forth.

Fixed-term: The funds for this post are available for 4 years in the first instance.

To apply for this studentship: Please email a detailed curriculum vitae (to include numerical details of grades obtained in relevant examinations) to: recruitment@ceb.cam.ac.uk

Applicants should ensure their application is complete and submitted by 5pm on the closing date.

Please quote reference NQ11561- UK/EU Studentship: Combustion Group on your application and in any correspondence about this vacancy.

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