Integrated catalyst testing

For catalyst testing, conventional small tubular reactors are commonly employed today [2]. However, although the reactors are small, this is not the case for their environment. Large panels of complex fluidic handling manifolds, containment vessels, and extended analytical equipment encompass the tube reactors. Detection is often the bottleneck, since it is still performed in a serial fashion. To overcome this situation, there is the vision, ultimately, to develop PC-card-sized chip systems with integrated microfluidic, sensor, control, and reaction components [2]. The advantages are less space, reduced waste, and fewer utilities. 

Jensen gives several examples for his present highly integrated chip systems [101], including a gas-phase reactor, a liquid-phase reactor, a catalyst-testing reactor, and a packed-bed multi-phase reactor. In addition, he provides the vision of a multiple micro-reactor test station (see Section 1.5.5.2). 

Catalyst Testing Integrated Reactor Formats as Critical Key Components... 

Prepared the catalyst and feed samples for the pyrolyzer-reformer integration shakedown and longterm catalyst testing at Scientific Carbons Inc. 

Complete integration and testing of the pyrolyzer, reformer, analytical instruments, and accessories, and begin long-term catalyst testing at Blakely, GA. 

Steady-State Reactors for Testing Fixed-Bed Catalysts Lab-scale fixed-bed reactors for catalyst testing usually reveal diameters between 5 and 15 mm. Steady-state reactors are operated in either an integral or a differential mode. 

Thus, benzaldehyde hydrogenation was tested imder practice-relevant conditions in a catalyst test reactor of simple design, and parameter smdies were carried out. The construction of the laboratory plant is shown schematically in Figure 13-17. Since we are dealing with an integral reactor, in spite of the relatively small amount of catalyst in the trickle-bed reactor, only comparitive measurements were carried out. Continuous hydrogenation of benzaldehyde in the solvents hexane and isopropanol ... 

Today parallel reactor systems for rapid catalyst testing under real process conditions are state-of-the-art. An example of an integrated system is the 48-parallel high-throughput reactor, which can be apphed to discover and to optimize new heterogeneous catalysts. It provides continuous flow of the reactants through separate... 

The intrinsic rate is measured in the laboratory with small catalyst particles, which do not exhibit any diffusion limitations. For a given catalyst, integral reactor tests provide enough information to determine the temperature-dependent coefficients in the intrinsic rate equation. However, since diffusion-free small catalyst particles cannot be used in large reformers because of excessive pressure drop considerations, the impact of diffusion limitations on industrial catalysts must be taken into accovmt as well ... 

The effect of oxidation pretreatment and oxidative reaction on the graphitic structure of all CNF or CNF based catalysts has been studied by XRD and HRTEM. From the diffraction patterns as shown in Fig. 2(a), it can be observed the subsequent treatment do not affect the integrity of graphite-like structure. TEM examination on the tested K(0.5)-Fe(5)/CNF catalysts as presented in Fig.2(b), also indicates that the graphitic structure of CNF is still intact. The XRD and TEM results are in agreement with TGA profiles of fi-esh and tested catalyst there is no obviously different stability in the carbon dioxide atmosphere (profiles are not shown). Moreover, TEM image as shown in Fig. 2(b) indicates that the iron oxide particle deposited on the surface of carbon nanofibcr are mostly less than less than 10 nm. 

In order to explore composition modulation of the final stage of a converter further, Briggs et al. (1978) added a second integral reactor, also holding about 30 g of the vanadia catalyst. With the preconverter in place, this system was operated on a typical feed from sulfur burning, with a S02 02 N2 composition in vol% of 10.8 15.2 74, and from a smelter effluent with a composition of 8.0 6.2 85.8. The cycled beds of vanadia catalyst were held in a fluidized sand bath at 401°C for the former feed and at 405°C for the latter one. The space velocity for both the air and the S03/S02 mixture was about 24 min 1 (STP). Table II summarizes the experimental results for the cycle periods tested. 

In general, it is not strictly correct to conclude that a particular reaction order fits the data based simply on the conformity of data to an integrated equation. As illustrated above, multiple initial concentrations which vary considerably should be employed to assess whether the rate is independent of concentration. Multiple integrated equations should also be tested. It may be useful to show that the reaction rate is not affected by species whose concentrations do not change considerably during an experiment these may be substances not consumed in the reaction (i.e., catalysts) or present in large excess [23,108]. 

In subsequent stages validation experiments were performed over monolith catalyst samples at two different scales (i) monolith core samples (up to 10 cm3) in a laboratory rig for integral reactor experiments and (ii) full-scale honeycomb monoliths (up to 43 L in size) in engine test bench runs. 

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