Catalyst activity and performance are the most important factors for selecting a catalyst in different processes. The Fischer-Tropsch synthesis is a very important synthesis that extensive action has been taken place to increase the activity of its catalysts in the recent century. Deactivation of the catalysts of the process is influenced by many factors, among which coking and sintering have c...

in the present study, tin-promoted pd/mwnts nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. tem images showed a restricted distribution of nanoparticles in the range of 3-5 nm. the results indicated that nanoparticles sizes were resistant to further catalyst deactivation. xrd patterns signified alloying between pd and ...

The fundamentals of catalyst deactivation are presented in this review. The chemico-physical aspects concerning the various deactivation causes (i.e. poisoning, sintering, coking, solid-state transformation, masking, etc.) have been analyzed and discussed, along with the mathematical description of the deactivation phenomena. # 1999 Elsevier Science B.V. All rights

fischer-tropsch synthesis is a promising route for production of light olefins via co hydrogenation over transition metals. co is one of the most active metals for fischer-tropsch synthesis. some different variables such as preparation parameters and operational factors can strongly affect the selectivity of fischer-tropsch synthesis toward the special products. in the case of preparation varia...

the effects of electronic properties of inner and outer surfaces of carbon nano tubes (cnts) on the deactivation of cobalt fischer-tropsch (ft) catalysts were studied. the comparative characterization of the fresh and used catalysts by tem, xrd, tpr, bet and h2 chemisorption showed that cobalt re-oxidation, cobalt-support interactions and sintering are the main sources of catalyst deactivation....

In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and ...

A kinetic model of a fixed bed tubular reactor incorporating catalyst deactivation was developed for the ISOMAX unit of Arak refinery. The kinetic parameters for the hydrocracking reactions over the commercial catalyst were determined using initial activity plant data i.e. when the catalyst is fresh. Catalyst deactivation was then taken into account by means of deactivation function based on pl...

A study was made of the coking of a commercial fresh sulfide Ni-Mo/Al2O3 catalyst in a fixed-bed reactor. The catalyst was coked using different coke precursors in the gas oil under accelerated conditions at temperatures of 400 to 450°C to yield different deactivated catalysts containing 2-20 wt% C. Two cases were studied; crushed catalyst without diffusional ...

Although catalyst deactivation rate greatly varies depending on many factors, including the catalyst structure, reactor feed composition, and operating conditions; it is usually inevitable. Since catalyst deactivation modeling has so far been poorly addressed in the literature, in the present study, nine experimental sets of cobalt based Fischer-Tropsch catalysts activity-time data were conside...

a study was made of the coking of a commercial fresh sulfide ni-mo/al2o3 catalyst in a fixed-bed reactor. the catalyst was coked using different coke precursors in the gas oil under accelerated conditions at temperatures of 400 to 450°c to yield different deactivated catalysts containing 2-20 wt% c. two cases were studied; crushed catalyst without diffusional resistance and extruded pellets wit...