Effect Of Catalyst Activity Research Articles

Effect of Catalyst Deactivation on the Energy Consumption of Gasoline–Diesel Hydrotreating Process

The effect of catalyst activity on a 900 000 ton y–1 gasoline–diesel hydrotreating unit is analyzed on the basis of the integration of hydrotreating reactor and the heat exchanger network (HEN). Th...

Fischer–Tropsch synthesis over Co/TiO2 catalyst: Effect of catalyst activation by CO compared to H2

Co/TiO2 catalyst activation for Fischer–Tropsch (FT) reaction by CO in comparison to H2 has been performed. The catalyst, prepared by incipient wetness impregnation, has been characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses after separate reduction using CO and H2 respectively. Temperature programmed reduction (TPR) analyses were also conducted to study the reduction behaviour of the catalyst in presence of H2 and CO respectively. CO improved catalyst reduction and produced a more stable and active catalyst with higher selectivity and yield for C5+ hydrocarbons at extended time-on-stream.

Microwave Assist Synthesis Methyl Ferulate through a Cationic Exchange Resin Catalysis Routine

Methyl ferulate was synthesized by methanol and ferulic acid with strongly acidic cation exchange resin as catalyst under microwave irradiation. The effect of catalyst activity was investigate by single factor experiment. Amount of catalyst, microwave treatment time, microwave output power and methanlo/ ferulic acid ratio were investigate by single factor experiment and orthogonal experiments. The optimal reaction conditions were ferulic acid being 0.1mol, molar radio of ethanol to ferulic acid being 5:1, mass percent of resin being 30％ of the reagent, microwave power being 300W, reaction time being 25 min. The yield of product was 81.2％ under the potimal conditions. The catalytic characteristics of regenerated catalyst were stable and the yield of product may keep greater than 76% after the 732# resin used five times.

Effect of catalyst activity in SMR-SERP for hydrogen production: Commercial vs. large-pore catalyst

In this work, we have evaluated the performance of an SMR-SERP unit (steam methane reforming sorption enhanced reaction process), using two different Ni/Al2O3 catalysts: commercial “Octolyst 2001” from Degussa and a large-pore catalyst (Catalyst A). The selective CO2 sorbent was a potassium modified hydrotalcites. Several experiments were performed under different operating conditions to validate a mathematical model.Experimental results show that the Degussa catalyst is more active and more selective to CO2 producing hydrogen with higher purity and less CO than the large-pore catalyst. Cyclic SMR-SERP experiments were also performed. The cycles comprise four different steps: reaction, depressurization, reactive regeneration and pressurization. In the cyclic experiments, conversion was 43% higher than in an SMR reactor, while H2 purity was 75%, which is 25% higher than in normal SMR operation. Results indicate that more active catalysts also promote a better reactive regeneration optimizing the use of part of the product (H2). The proposed mathematical model was validated in a wide range of operating conditions and in a cyclic experiment. The model was able to describe the SMR-SERP experiments without any fitting parameters.

Effect of phase composition between nano γ- and χ-Al2O3 on Pt/Al2O3 catalyst in CO oxidation

Abstract Alumina supports were prepared by solvothermal method of a mixed solution of toluene and butan-1-ol for various chi/gamma phase compositions and the Pt/Al2O3 catalyst was prepared by the incipient wetness impregnation technique. The catalysts were evaluated in the carbon monoxide oxidation. Increasing amount of %chi phase in the alumina supports has roughly the same BET surface area. The different alumina supports were affected on the Pt dispersion on alumina. The pure chi alumina and pure gamma alumina supports had the same effect of catalyst activity. In the various chi/gamma phase compositions, it was found that Pt dispersion and catalyst activity are lower than pure gamma and chi phases for alumina support with 10% chi. The alumina supports with 30–70% chi gave higher dispersion and activity than pure phase and 10% chi support.

Study of catalysts for catalytic burners for fuel cell power plant reformers

Catalytic burners for fuel cell power plant reformers are alternatives to conventional flame burners. Their application is expected to provide uniform temperatures in the reformer, efficient use of low-calorific gaseous by products and reduction of pollutant emissions. For testing in the burners, a series of spherical Pd/CeO2/Al2O3 catalysts were prepared. An optimum concentration of ceria providing the highest thermal stability of catalysts was determined. An effect of catalyst activation in the reaction mixture-1% methane in air was observed. A series of Mn containing oxide catalysts on spherical γ-Al2O3 or (γ+Χ)-Al2O3, both pure and doped with La, Ce and Mg oxides were prepared. The catalysts were characterized by chemical analysis, X-ray phase analysis, BET surface area and activity measurements in methane oxidation. A batch of Mn-Mg-La-Al-O catalyst was prepared for further long-term testing in a model reformer with a catalytic burner. A model reformer with a catalytic burner was designed and fabricated for testing in the composition of the bench-scale Fuel Cell Power Plant. Preliminary testing of this catalyst showed that it provided complete methane combustion at the specified operational temperatures over 900 °C.

Characteristics of Long Chain Branching in Ethene Polymerization with Single Site Catalysts

Linear and long chain branched ethene homopolymers and copolymers with 1-hexene were produced with metallocene catalysts. The presence and absence of long chain branching in the polymers was studied by dynamic rheological and gel permeation chromatography−on-line viscometry analysis. Long chain branched polymers were produced with 1- and 2-siloxy-substituted derivatives of rac-Et(Ind)2ZrCl2/MAO and MeSi(C5Me4)(N-t-Bu)TiCl2/MAO. As judged by the rheological behavior, n-ButCp2ZrCl2/MAO produced linear chains, as did the meso form of one of the substituted Et(Ind)2ZrCl2 catalyst structures. The rheological behavior of the polymers was affected by the polymerization conditions, especially by the addition of comonomer and the partial pressures of ethene and hydrogen. In addition, the slurry solvent was relevant to some of the catalysts. The effects of catalyst activity and different mass transfer limitations on the long chain branching were studied. As was evident from the rheological behavior, the long chain branching could be controlled by both the choice of the catalyst and the polymerization conditions. The rheological behavior is discussed with reference to the content of the long chain branches and the structure of the branching.

OSCILLATIONS IN THE OXIDATION OF CARBON MONOXIDE ON A PLATINUM FOIL

Abstract Reported here are experimental observations of self-sustained oscillations in the rate of oxidation of carbon monoxide on a platinum foil in a gradientless reactor. The results particularly show the effects of catalyst activity and illustrate some unusual and complex dynamic behavior under nearly isothermal conditions.

A kinetic evaluation of the effect of catalyst activity on the conversion level of crude during fluidized bed cracking

1. The complex constant KC in the kinetic equation for a monomolecular irreversible reaction occurring in a fluidized bed of catalyst particles can be used for making a quantitative evaluation of the effect of catalyst activity on the conversion of the raw material being cracked. 2. The values of the complex constant KC can be determined grapho-analytically, by the paired correlation method, or by the method of averages.