Evaluation, catalytic

Under related reaction conditions bis (aryUmino) pyridine ferric halides can also serve as active precatalysts for ethylene polymerization [6]. While MAO or MMAO continues to be the preferred co-catalyst/activator, a range of alternative activators have also been screened (Table 5.1). 

A fixed-bed reactor is usually utilized. Temperature is ranged during the tests but total pressure and space velocity remain constant. The experiments are performed continuously for 30 days. 

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Gold Nanoparticles From Preparation to Catalytic Evaluation... 

The selectivity toward sulfur compound structure was differently induced for the CB1 culture, than that of the CB2 culture. In the first case DBT was used as the sole sulfur substrate, while in the second case, biphenyl sulfide was employed. One might deduce then, the application of the CB1 strain for oil and CB2 strain for coal and heavy oils. Plasmid characterization and strain catalytic evaluation results indicated that oxidation of DBT by CB 1 is not plasmid mediated and that inorganic sulfur forms cannot be oxidized by CB 1. 

This section presents the result of the catalytic performances in the case of phenylacetylene hydrogenation reaction. The catalytic evaluation was performed in a classical well-stirred stainless steel reactor operating in batch mode under constant H2 pressure (10 bar) at 17°C using n-heptane as the solvent. As mentioned in Section 13.2.2, no modification of the particle size distribution has been observed by transmission electron microscopy before or after reduction of colloidal oxide particles. 

Catalytic evaluations were conducted using microactivity tests (MAT) ( ) at 910 F initial temperature, 15 WHSV, 6.0 g catalyst, and a 5.0 cat-to-oil ratio. The feedstock was a metals-free mid-continent gas oil. Each data point shown is the average of two MAT runs. Only MAT runs with acceptable mass balance were used (96 to 101%). Additionally, MAT data was normalized to 100% mass balance. Extensive error analysis of conversion, coke, and hydrogen yields indicates the following respective standard deviations 1.62, 0.29, 0.025. The effects of nickel and vanadium on the hydrogen and coke make were calculated by obtaining the difference between the yields obtained with uncontaminated catalysts and that of the contaminated catalyst at the same conversion. 

Catalytic evaluation of the different pillared clays was performed using a microactivity test (MAT) and conditions described in detail elsewhere (5). The weight hourly space velocity (WHSV) was 14-15 the reactor temperature was 510 C. A catalyst-to-oil ratio of 3.5-3.8 was used. The chargestock s slurry oil (S.O., b.p. >354 C), light cycle oil (LCGO, 232 C < b.p. <354 C) and gasoline content were 62.7 vol%, 33.1 vol% and 4.2 vol% respectively. Conversions were on a vol% fresh feed (FF) basis and were defined as [VfVp/V ] x 100, where is the volume of feed... 

Studies in these laboratories have resulted in the synthesis and catalytic evaluations on a wide range of perovskites and ion modified homogeneous solid solutions for Fischer-Tropsch catalysis, copper modified spinels for higher alcohol synthesis, ion substituted perovskites for methane activation, alkali modified metal... 

In this work, the performance of two green acid catalysts, a Ti02 synthesized by the sol-gel method and sulfated in situ was compared with a traditional NiY zeolite in the trimerization of isobutene. The reaction was carried out at mild conditions atmospheric pressure and 40°C of temperature. The results obtained in the catalytic evaluation showed higher conversion and stability as well as a better selectivity to tri-isobutylene for the sulfated titania catalyst with respect to the NiY zeolite. 

Catalytic test. The catalytic behavior was evaluated for the gas phase isobutene trimerization reaction using a fixed bed reactor, with dimensions of 2 cm of diameter and 55 cm of length respectively. The operation conditions and evaluation procedure were as follows the catalyst was activated at 400°C in flowing air (1 ml/s) during 8 hours. After the activation treatment, temperature was lowered to 40°C and a mixture of isobutane/isobutene 72 28 w/w was feed. The GHSV value was varied to 8, 16, 32 and 64 h respectively. The average time of reaction was 11 h. The time of reactor stabilization after the beginning of the catalytic evaluation was 2 h. 

Catalytic Evaluation In order to investigate support effects in these iron/zeolite catalysts prepared from Fe3(C0)12 by the extraction technique, three catalysts of similar weight percent iron loading were evaluated for their ability to catalyze synthesis gas conversion these catalysts were 15.0% Fe/ZSM-5, 16.4% Fe/Mordenite andl5.0% Fe/13X. All catalysts were evaluated under similar conditions as described in the experimental section. Catalytic data is presented in the accompanying figures in each figure the first three points for each catalyst are data obtained at 280°C, the second three points are data at 300°C. 

B. Structures and Catalytic Evaluation of Surface-Grafted Mixed Metal Clusters... 

Table 4. Catalytic evaluation of experimental silico-aluminates.

The combined characterisation and catalytic evaluation of the Y zeolites obtained by progressive dealumination via the (NH4)2SiF6 method revealed that the strength of the acid sites had a dominant effect on the catalytic behaviour [26,27], The zeolite activity increased for Si/Al ratios from 2.6 to 6.2 since the decline in the acid site density was more than compensated for by the concomitant... 

The oxidation of cyclohexene using hydrogen peroxide was chosen as a test reaction for the catalytic evaluation of the titanium modified hexagonal NaY sanq)les. Scheme I illustrates some of the typical products of cyclohexene oxidation. The epoxide and the diol which is a hydrolysis product of the epoxide, generally reflect a concerted process. In contrast the allylic alcohol and ketone are often ascribed to an autoxidation or radical process. We anticipated that some homolytic decomposition of the peroxide may be observed with these acidic zeolites. In fact, there was -74% conversion of H2O2 over calcined hexagonal NaY after heating at 55 C for 24 hours. This resulted in only a 1% conversion of... 

The first catalytic evaluation was performed using thermal analysis which gave the onset decomposition temperature and the exothermicity of the reaction. The DTA results of both supports and catalysts are given in Fig. 3. The features are in agreement with previous work ° they present a weak endothermic peak corresponding to water evaporation followed by a strong exothermic peak attributed to the catalytic decomposition (Fig. 1 profile a). In the absence of catalyst the thermal decomposition occurs at 160 Both supports exhibit similar profile with broadened endothermic peaks due to water vaporization and... 

P-19 - Preparation and catalytic evaluation of [Ga]MCM-58 and of MCM-58-type catalysts with different aluminum contents... 

New selective uniform catalysts for direct oxidation with air Development of new, high-productivity, tools for catalyst synthesis and catalytic evaluation... 

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