Performance of cobalt-based eggshell catalyst in low-temperature Fischer-Tropsch synthesis process to produce long-chain hydrocarbons from synthesis gas utilizing fixed-bed reactor technology

Mahmoudi, Hamid (2015). Performance of cobalt-based eggshell catalyst in low-temperature Fischer-Tropsch synthesis process to produce long-chain hydrocarbons from synthesis gas utilizing fixed-bed reactor technology. University of Birmingham. Ph.D.

[img]
Preview
Mahmoudi15PhD.pdf
PDF - Accepted Version

Download (10MB)

Abstract

Preliminary studies of the Fischer-Tropsch synthesis (FTS) process were begun in 2010 at the University of Birmingham. A mini-scale F-T plant was designed and built at the School of Mechanical Engineering to study the production of long-chain hydrocarbons over a cobalt-based FTS process. For this purpose, a series of eggshell cobalt catalysts supported with silica powder with a dissimilar porous structure were investigated to examine the effect of support variables on the catalysts’ performance. The prepared catalysts were characterized with nitrogen adsorption/desorption, X-Ray Diffraction (XRD), Temperature-Programmed Reduction (TPR), Scanning-Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) experiments to ensure the qualification of the catalysts for the F-T plant. A highly metal-dispersed catalyst was achieved by controlling three key parameters: (i) cobalt content, (ii) impregnation solution and (iii) meso-porous silica of average pore diameter during catalyst preparation. The catalysts were relatively activated at high temperature because of the formation of small particles. The concentration of the active site was maximized in order to enlarge the hydrogenation activity of the cobalt-based eggshell catalyst to produce middle distillates products.

The optimisation study of the F-T process at low-temperature and low/medium pressure was performed to acquire the maximum production of liquid diesel fuel in a single-pass F-T process. The orthogonal arrays’ approach was employed to design a set of experiments. The investigations were successful to maximise the conversion in reactants (up to 98%) and lower the activity of the co-reactions at the same time. The change in reactant consumption and hydrocarbons’ selectivity was monitored over the time on stream and the responsible mechanisms for short-term deactivation within the first reaction cycle were studied, to achieve the optimum reaction conditions in terms of later deactivation of the catalyst.

Type of Work: Thesis (Doctorates > Ph.D.)
Award Type: Doctorates > Ph.D.
Supervisor(s):
Supervisor(s)EmailORCID
Wyszynski, Miroslaw L.UNSPECIFIEDUNSPECIFIED
Licence:
College/Faculty: Colleges (2008 onwards) > College of Engineering & Physical Sciences
School or Department: School of Mechanical Engineering
Funders: None/not applicable
Subjects: Q Science > QD Chemistry
T Technology > TJ Mechanical engineering and machinery
URI: http://etheses.bham.ac.uk/id/eprint/5656

Actions

Request a Correction Request a Correction
View Item View Item

Downloads

Downloads per month over past year