Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Catalyst data for

Kinetic data for Fischer-Tropsch synthesis on unsupported iron catalysts have been obtained as part of an overall study of the deactivation of iron catalysts. Data for unpromoted and potassium-promoted catalysts reacted at 1 aim total pressure are reported. At the reaction conditions used in this study, kinetic parameters for the potassium-promoted catalyst cannot be obtained without effects of deactivation. Reaction o ers in the power-law expression for the unpromoted catalyst are 1.4 and 0.60 for Ph2 and Pco> respectively. The unpromoted catalyst exhibits a deactivation order of 1 when the generalized power-law expression is used. [Pg.213]

Catalysis has been remarkably successful in reducing emissions. Table 2.3 shows typical emissions for Otto (gasoline) engines with and without a three-way catalyst. Data for diesel engines are also included. [Pg.46]

A number of FCC catalysts was used in the present study. For comparison of the effects of quinoline and phenanthrene additions to the n-hexadecane feedstock a model catalyst of composition, zeolite US-Y (30%), silica binder (25%), Kaolin (25%) and ps do Boehmite matrix (20%) was used. Quinoline and phenanthrene additions to the n-hexadecane amounted to 1% and 10%. The catalysts used to assess the effect of composition on product yields varied from a basic matrix material through a variety of zeolitic catalysts containing 20% zeolite and 15% silica binder, the remainder being clay, to a pure zeolite catalyst. Data for all the catalysts used are presented in Table 1. In addition for the C NMR analysis a sample of coked refinery catalyst obtained from a unit processing heavy feedstock was obtained. The coke level on this catalyst was 0.9% and 30g. of this catalyst was demineralised by standard HF treatment to produce a 250 mg sample of coke concentrate containing 65% carbon. [Pg.314]

It is of interest to compare in absolute values, the HDS activity and SV of two catalysts. (Data for calculation are taken from Ref. 65) For the 2 wt% Mo EV was 3—4 x 10 functioning site mg , the converted thiophene 3,5 X 10 mol/pulse. These values were 4 x 10 f site mg and 4,37 x 10 mol/pulse respectively for the Co(4 wt%) Mo (8wt%) catalyst, i.e., the ratio of V values was 11.76, and that of the thiophene conversions -12, 5. This seems to indicate the reliability of the applied method. It is seen from the data that the maximal density of sites with the higher H2 S release rate within the 0.3-0.4 Co/(Co- - Mo) ratio is typical for the CoMoS phase. At higher Co content, the CogSs phase formation hinders the formation of vacancies with the high sulfur release rate required for this. [Pg.82]

Mixtures of supported platinum and aluminophosphate-based molecular sieves have been tested for w-hexane rearrangement reactions under reforming conditions (900°F, 200 psig). Data were collected for the large, medium, and small pore SAPO molecular sieves mixed with a Pt-alumina catalyst. Data for Pt mixed with chlorided alumina or mixed with silicalite were also taken for reference. The data show that the catalyst consisting of Pt and large pore SAPO-5 is less active than reference Pt-chlorided alumina however, the catalyst appears... [Pg.542]

Synthesis. The total aimual production of PO in the United States in 1993 was 1.77 biUion kg (57) and is expected to climb to 1.95 biUion kg with the addition of the Texaco plant (Table 1). There are two principal processes for producing PO, the chlorohydrin process favored by The Dow Chemical Company and indirect oxidation used by Arco and soon Texaco. Molybdenum catalysts are used commercially in indirect oxidation (58—61). Capacity data for PO production are shown in Table 1 (see Propylene oxide). [Pg.348]

HTS catalyst consists mainly of magnetite crystals stabilized using chromium oxide. Phosphoms, arsenic, and sulfur are poisons to the catalyst. Low reformer steam to carbon ratios give rise to conditions favoring the formation of iron carbides which catalyze the synthesis of hydrocarbons by the Fisher-Tropsch reaction. Modified iron and iron-free HTS catalysts have been developed to avoid these problems (49,50) and allow operation at steam to carbon ratios as low as 2.7. Kinetic and equiUbrium data for the water gas shift reaction are available in reference 51. [Pg.348]

Tubular Reactors. The tubular reactor is exceUent for obtaining data for fast thermal or catalytic reactions, especiaHy for gaseous feeds. With sufficient volume or catalyst, high conversions, as would take place in a large-scale unit, are obtained conversion represents the integral value of reaction over the length of the tube. Short tubes or pancake-shaped beds are used as differential reactors to obtain instantaneous reaction rates, which can be computed directly because composition changes can be treated as differential amounts. Initial reaction rates are obtained with a fresh feed. Reaction rates at... [Pg.515]

The switch from the conventional cobalt complex catalyst to a new rhodium-based catalyst represents a technical advance for producing aldehydes by olefin hydroformylation with CO, ie, by the oxo process (qv) (82). A 200 t/yr CSTR pilot plant provided scale-up data for the first industrial,... [Pg.522]

The choice of parameter used in the determination of size distribution should include consideration of the information needed in the interpretation of the data. For example, in the case of a manufacturer of paint pigment, the size parameter that best describes the hiding power (performance of the pigment) is the projected area of particles. A powdered catalyst manufacturer is primarily concerned with surface-area equivalence. [Pg.126]

The NRC Committee s estimates of catalyst use for 1972, 1974, and 1975 were 40—80% higher than the BOM s, and the former s estimates for overall use, including ceramics, electronics, and unspecified uses, were 3—39% higher. Data pubHshed by the BOM through 1980 show a precipitous decline in total annual use from ca 311 t in 1974 to ca 82 t in 1980. The decline appears to have been caused mainly by unfavorable business conditions and conservation efforts, but part of the apparent decline may stem from incomplete collection of data. [Pg.394]

SolubiHty of carbon dioxide in ethanolamines is affected by temperature, amine solution strength, and carbon dioxide partial pressure. Information on the performance of amines is available in the Hterature and from amine manufacturers. Values for the solubiHty of carbon dioxide and hydrogen sulfide mixtures in monoethanolamine and for the solubiHty of carbon dioxide in diethanolamine are given (36,37). SolubiHty of carbon dioxide in monoethanolamine is provided (38). The effects of catalysts have been studied to improve the activity of amines and provide absorption data for carbon dioxide in both mono- and diethanolamine solutions with and without sodium arsenite as a catalyst (39). Absorption kinetics over a range of contact times for carbon dioxide in monoethanolamine have also been investigated (40). [Pg.22]

One goal of catalyst designers is to constmct bench-scale reactors that allow determination of performance data truly indicative of performance in a full-scale commercial reactor. This has been accompHshed in a number of areas, but in general, larger pilot-scale reactors are preferred because they can be more fully instmmented and can provide better engineering data for ultimate scale-up. In reactor selection thought must be given to parameters such as space velocity, linear velocity, and the number of catalyst bodies per reactor diameter in order to properly model heat- and mass-transfer effects. [Pg.197]

Vehicle data represents the complex interaction of many variables, including vehicle performance, reactor design and location, as well as catalyst properties. For a catalyst that has failed, one must ponder whether the converter design used in the vehicle is suitable for the catalyst, the quantity of the catalyst used is correct, the distance of the converter from the exhaust manifold is suitable, the catalyst has been inadvertantly overheated to above 2000°F or poisoned by lead and sulfur, or whether the catalyst can be modified to produce a far superior product. [Pg.79]

Very recently, Luckner et al. (116) obtained initial rate data for the metathesis of propene using the W0r-Si02 catalyst at flow rates where mass transfer effects were found to be negligible. Their experimental data referring to measurements at 0.1 to 0.9 MNm-2 and 672 to 727 K could be correlated by Eq. (53). [Pg.163]

Horton (H9, H10) has obtained additional acoustic-admittance data for a series of composite propellants. At a given frequency, decreasing the mean oxidizer particle size increases the acoustic admittance and thereby the tendency for instability. Horton also investigated the effects on the acoustic admittance of the incorporation of traces of copper chromite, a known catalyst, for the decomposition of ammonium perchlorate, lithium fluoride (a burning-rate depressant), and changes in binder these data are difficult to analyze because of experimental errors. [Pg.55]

Kolbel et al. (K16) examined the conversion of carbon monoxide and hydrogen to methane catalyzed by a nickel-magnesium oxide catalyst suspended in a paraffinic hydrocarbon, as well as the oxidation of carbon monoxide catalyzed by a manganese-cupric oxide catalyst suspended in a silicone oil. The results are interpreted in terms of the theoretical model referred to in Section IV,B, in which gas-liquid mass transfer and chemical reaction are assumed to be rate-determining process steps. Conversion data for technical and pilot-scale reactors are also presented. [Pg.120]

The catalytic activity of doped nickel oxide on the solid state decomposition of CsN3 decreased [714] in the sequence NiO(l% Li) > NiO > NiO(l% Cr) > uncatalyzed reaction. While these results are in qualitative accordance with the assumption that the additive provided electron traps, further observations, showing that ZnO (an rc-type semi-conductor) inhibited the reaction and that CdO (also an rc-type semi-conductor) catalyzed the reaction, were not consistent with this explanation. It was noted, however, that both NiO and CdO could be reduced by the product caesium metal, whereas ZnO is not, and that the reaction with NiO yielded caesium oxide, which is identified as the active catalyst. Detailed kinetic data for these rate processes are not available but the pattern of behaviour described clearly demonstrates that the interface reactions were more complicated than had been anticipated. [Pg.266]

This appears to be a typographical error in the original paper. Data for FeClj as catalyst. [Pg.150]

A reaction with a rate constant that conforms to Eq. (10-21)—particularly to the feature that the catalysts are H+ and OH-, and not weak acids and bases—is said to show specific acid-base catalysis. This phenomenon is illustrated by the kinetic data for the hydrolysis of methyl o-carboxyphenyl acetate16 (the methyl ester of aspirin— compare with Section 6.6) ... [Pg.232]

In practice, one proceeds as follows. The value of bh >s determined for the reaction with a series of acids of similar structure, that is, for carboxylic acids or ammonium ions, etc. Limiting the data to a single catalyst type improves the fit. since the inclusion of data for a second ype of acid catalyst might define a close but not identical line. This means that Ga may be somewhat different for each catalyst type. A plot of log(kBH/p) versus log(A BH(7//i) is then constructed. This procedure most often results in a straight line, within the usual —10-15 percent precision found for LFERs. One straightforward example is provided by the acid-catalyzed dehydration of acetaldehyde hydrate,... [Pg.234]

The latest catalyst development is the contact DeH-9, which in terms of activity and stability is comparable with DeH-7 but with improved selectivity (fewer iso- and cycloparaffins and aromatics). This contact has been produced since 1990 and probably used commercially since 1992 [59]. In Table 7 the composition of the dehydrogenation products in relation to the catalyst and the application of the DeFine step is summarized. Table 8 shows the performance data for various catalysts [10] in relation to LAB production. [Pg.60]

An example of the promotional action of sodium supply to the catalyst was given in Fig. 4.40 which shows steady-state (potentiostatic) rate data for... [Pg.447]


See other pages where Catalyst data for is mentioned: [Pg.519]    [Pg.519]    [Pg.701]    [Pg.428]    [Pg.39]    [Pg.392]    [Pg.219]    [Pg.280]    [Pg.2075]    [Pg.2123]    [Pg.137]    [Pg.564]    [Pg.742]    [Pg.192]    [Pg.409]    [Pg.166]    [Pg.6]    [Pg.24]    [Pg.419]    [Pg.442]    [Pg.914]    [Pg.120]    [Pg.151]    [Pg.157]    [Pg.167]    [Pg.366]    [Pg.207]   
See also in sourсe #XX -- [ Pg.135 , Pg.187 ]

See also in sourсe #XX -- [ Pg.135 , Pg.187 ]




SEARCH



© 2024 chempedia.info