Catalyst screening tests

Catalyst Screening Tests. The catalysts used in these tests were obtained from commercial sources. Table II shows the manufacturer, manufacturer s number, active metals, and catalyst designation for each of the catalysts tested. Three of the catalysts were received in the form of 1/16-in. extrusions and were used as such. The other catalysts, obtained in larger sizes, were crushed and sized to 10-20 mesh. 

Table 14.1. Catalyst Screening Test Results for the Hydrogenation of Fatty Acid Esters in Supercritical C02...

The liquids require a hydrorefining step to stabilize their reactive properties, to reduce the asphaltenes and preasphaltenes, to reduce sulfur, nitrogen, and oxygen, and to make the liquids more distillable. The extent of hydrorefining depends on the end use of liquids—fuel oil or chemical feedstocks. The objective of this work is to evaluate the hydrorefining processibility of ORC flash pyrolysis coal tar as a part of the tar characterization task. Results of the initial phase of catalyst screening tests are reported in this chapter. 

When the catalyst is available in a small amount, a microreactor assembly is often used (Miller, 1987). This is a simple T-type reactor heated by a fluidized sand bath. The mixing is provided by mechanical agitation that shakes the reactor up and down within the fluidized bed. Because of the small amount of slurry, and an effective heat transfer in the fluidized sand bath, the heat-up period in such a reactor is small. The nature of mechanical agitation is, however, energy-efficient. The reactor provides only a small sample for the product analysis, which makes the usefulness of the reactor for detailed kinetic measurements somewhat limited. The reactor has been extensively used for laboratory catalyst screening tests in coal liquefaction. 

Catalyst screening tests were conducted in 40-mL microautoclave reactors. The liquefaction conditions were the following temperature, 425°C reaction pressure, 1000 psig H2 (pressure at room temperature) residence time, 1 hour and solvenVcoal, 2/1. The coal used was Illinois No. 6 hvBb from the Burning Star Mine, properties of the coal used are summarized in Table I. 

The most widely used conventional chemical methods are pyrolysis [21-25] and catalytic cracking [13, 26-30], The latter yields products with a smaller range of carbon numbers and of a higher quality than products generated by the former method. Several types of solid acid catalysts, which are known to be effective for catalytic cracking (e.g. HZSM-5, HY and rare earth metal-exchanged Y-type (REY) zeolite and silica-alumina (SA)) were evaluated by catalyst screening tests and are listed in Table 6.1. The acidic... 

Similar gelation tests were also used with m-xylylene diisocyanate and with hexamethylene diisocyanate [146]. In these tests the order of strength of the catalysts was found to be different from when tolylene diisocyanate was used. Table 12 lists the results of some catalyst screening tests with the three different diisocyanates. 

With the introduction of Pt/Re catalysts, it is possible to achieve the ensemble control with much smaller sulfur addition. The su1fur-free Pt/Re catalyst by itself has a higher relative activity for hydrogenolysis than a platinum catalyst. However, this is changed when sulfur Is present In the feed. Kughes has described the first observations in a pilot plant. The catalyst produced more methane than any other that had been tested, and the run would probably have been aborted if it had not been an ordinary catalyst screening test. However, after the first and second weeks on stream, the selectivity improved and finally became similar to that of a fresh platinum/ alumina catalyst and as the run continued, the catalyst proved to be more stable than any previous catalyst tested. These results were ascribed to the presence of sulfur in the feed and could be obtained even with very low sulfur contents, l.S ppm. ... 

Since no information is available for the reaction using heterogeneous catalysts, catalyst screening test was first employed by using E2 and propene. Catalysts tested were metal oxides including solid acids such as SOs rOz, SA. HY and solid base, MgO. 

Table 3.1 Typical results of the catalyst screening test for the direct polyc( densation of OLLA [7]...

Suppose that you are looking for the composition of a catalyst in terms of support, active material, and promoter. A catalyst screening test for a combination of all parameters may require a large number of expensive experimentation and a large number of samples. Instead, factoring out these three independent parameters in 2 full factorial design (Table E7.1.1) will enable you to determine the focal point of the optimum composition. The measured variable is the reaction rate. Careful measures should be taken to determine the reaction rate free from artifacts which will be explained in the later sections of this chapter. 

Fig. 3 Examples of catalyst screening tests. Typical results from (a) thermal aging, (b) constant-potential aging, and (c) potential cycling...

A sequence of tests has been devised to evaluate antioxidants for use in automotive crankcase lubricants. The Indiana Stirring Oxidation Test (ISOT) JISK2514 is an example of a laboratory screening test. The oil is stirred at 165.5°C in the presence of air. Copper and iron strips are used as metal catalysts. The development of sludge, viscosity, and acidity are deterrnined periodically. Failure time is determined when the development of acidity requires... 

In the present study, catalysts containing 0.5 wt% transition metals were prepared and reaction was carried out. The results of these studies are presented in Fig. 3. In screen test of various transition metals loaded AC catalysts acetone was used as the solvent. It was also found that Fe containing catalyst gave the highest yield of phenol. Hence, for further study catalysts containing Fe loaded on activated carbon were chosen. 

A small-scale PROX system was manufactured in a type of heat exchanger using non-pellet catalyst. Pt-Ru catalyst screened was impregnated on the support sheet. The support sheet was made by coating y-AlaOs on porous SUS-mesh plate (thickness 1.0 mm). The surface area of the catalyst sheet was 96 mVg. The catalyst sheet was applied to a heat exchanger type reactor of PROX as shown in Fig. 2. The PROX reactor was manufactured as a unit module and tested. Fig. 3 is the test-set of the PROX. Air was applied as the coolant. 

Muller, A., Drese, K., Gnaser, H., Hampe, M., Hessel, V, Lowe, H., Schmitt, S., Zapf, R., Fast preparation and testing methods using a micro-structured modular reactor for parallel gas phase catalyst screening, Catal. Today 81 (2002) 377-391. 

The C-5 sugar alcohols produced from the hydrolysis of hemicellulose are both xylitol and arabitol [6], Equivalence testing was performed with Ni/Re catalyst in the batch reactor to verily similar performance between xylitol and arabitol feedstocks. The operating conditions were 200°C and 8300kPa H2 using the procedure outlined in section Catalyst Screening section. 

The catalysts which have been tested for the direct epoxidation include (i) supported metal catalysts, (ii) supported metal oxide catalysts (iii) lithium nitrate salt, and (iv) metal complexes (1-5). Rh/Al203 has been identified to be one of the most active supported metal catalysts for epoxidation (2). Although epoxidation over supported metal catalysts provides a desirable and simple approach for PO synthesis, PO selectivity generally decreases with propylene conversion and yield is generally below 50%. Further improvement of supported metal catalysts for propylene epoxidation relies not only on catalyst screening but also fundamental understanding of the epoxidation mechanism. 

Nanotechnology is an evolving research area especially in materials and biotechnological sciences. First studies have shown that the special properties of nanoparticles can give rise to highly active and selective catalysts to enable chemists to perform entirely novel transformations. Discussion and evaluation of the potential of nanoparticles for chemical research in a pharmaceutical company with experts in the field was needed. Other areas in catalysis like biotransformations and metal catalyst screening and development continue to expand the possibilities for the manufacturing of test compounds and development candidates. 

The bench-scale unit for the study of catalytic reactions has been designed with features such as accessibility, isothermal operation, and catalyst pretreatment. The use for catalytic screening tests makes easy accessibility a necessity, while the study of kinetics prescribes isothermal operation. 

Catalysts were tested for oxidations of carbon monoxide and toluene. The tests were carried out in a differential reactor shown in Fig. 12.7-1 and analyzed by an online gas chromatograph (HP 6890) equipped with thermal conductivity and flame ionization detectors. Gases including dry air and carbon monoxide were feed to the reactor by mass flow controllers, while the liquid reactant, toluene was delivered by a syringe pump. Thermocouple was used to monitor the catalyst temperature. Catalyst screening and optimization identified the best catalyst formulation with a conversion rate for carbon monoxide and toluene at room temperature of 1 and 0.25 mmolc g min1. Carbon monoxide and water were the only products of the reactions. 

The screening tests in optimised conditions confirmed the excellent performances of raw attapulgite/montmorillonite mixtures (Granosil 750 JF and Mega Dry) (Fig. 5). It is worth noting that these latter catalysts showed better... 

Initial screening tests were performed without oxygen in the reactant feed. Table 1 lists the results obtained with different catalysts. Depending on the catalyst used, the GLC-analysis of the condensed reactor effluents showed the presence of at least 4 compounds, which could be separated by preparative GLC. Structure elucidation of the isolated compounds was done by GLC-MS analysis and NMR-spectroscopy. 

Results of screening tests with different catalysts in the absence of oxygen in the gas phase. Conditions T = 230°C, 6.0 g of catalyst, 2.9 g of 1 was passed through the catalyst bed within 20-25 min. The catalyst was preheated 30 min prior to its use. 

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