Ethylene polymerization by Cp2ZrCl2-B(C6F5)3-TEA catalyst system using low Al/Zr ratio has been studied with varying ethylene pressure, catalyst concentration, Al/Zr ratio, and reaction temperature. The study showed that there was an optimum condition for each variable at which maximum productivity was obtained. It was proposed that there were two competing reactions, the catalyst activation an...

Operando spectroscopic techniques (Diffusive Reflective Infrared Fourier-Transform and Mössbauer emission spectroscopy) were combined to investigate the role of oxygenates deposition on deactivation cobalt titania Fischer-Tropsch catalysts at high pressure. Clear formation carboxylates was seen for prepared via both impregnation precipitation, but more heavier impregnated catalyst. This effect ...

The in situ characterization of catalysts provides important information on the catalyst and understanding its catalytic performance selectivity for a specific reaction. Temperature programmed analyses (TPX) techniques reveal role support stabilization dispersion active sites. However, these can be altered at high temperatures since sintering species occur as well possible carbon deposition whi...

The kinetics of catalyst deactivation and coke formation during dehydrogenation of propane over supported Pt–based catalysts and, in particular, the effect of alkali metal promoters on catalyst activity and stability were studied. The analysis of propane conversion data showed that there is an optimum level of alkali metal promoter loading for both catalyst activity and stability.A model ba...

The CO2 reforming of coke oven gases (COG) was carried out over a Ni/γAl2O3 catalyst in order to obtain a suitable syngas for methanol synthesis. The influence of different operating conditions, such as temperature and volumetric hourly space velocity (VHSV), was studied. It was found that the H2 present in the feed gas promotes the Reverse Water Gas Shift reaction (RWGS), which produces water....

Inefficient use of raw materials in most catalytic processes can be attributed mainly to the deactivation of the catalyst in chemical reactors. In order to achieve efficient use of raw materials, this paper addresses mitigation of deactivation through optimization of inlet temperature-time trajectories. The optimization of temperature profiles in reactors is one of the key problems in the synth...

A systematic study of two-staged upgrading process of vacuum residue for light fuel production has been carried out in a semi-batch binary reactor apparatus over Y, ZSM-5 and alkaline treated ZSM-5 zeolites. Prepared catalyst samples were characterized with XRD and BET. Density and Viscosity physical properties parameters estimation, as well as GC/SIMDIS analyses were conducted on liquid produc...

Results of electron spectroscopy (XPS and UPS) of platinum black catalyst measured in various states of the catalyst have been summarized. XPS showed up to almost 50% carbon and up to 20% oxygen on a sample stored in air. These, however, had almost no influence on the chemical state of Pt, except for the appearance of minor surface oxide. A Pt purity of ~90% could be reached by regeneration wit...

A range of catalysts comprising of platinum supported on silica, prepared by an impregnation method, have been studied for the total oxidation of naphthalene, which is a representative Polycyclic Aromatic Hydrocarbon. The influence of platinum loading and calcination temperature on oxidation activity was evaluated. Increasing the platinum loading up to 2.5 wt.% increased the catalyst activity, ...