Thin film fixed bed reactor

Bekbolet, M., Lidner, M., Weichgrebe, D., and Bahnemann, D., Photocatalytic detoxification with the thin-film fixed bed reactor clean up of highly polluted landfill effluents using a novel Ti02 photocatalyst, Solar Energy, 56(5), 455, 1996. 

Thin-film fixed-bed reactor Solar T102-UV/V1S Pilot Freudenhammer et al. (1997)... 

Figure 2 Thin film fixed bed reactor (reprinted from Bahnemann, 2004, with permission from Elsevier).

Non-concentrating - Double skin sheet reactor (van Well - Thin film fixed bed reactor... 

Bockelmami, D., Goslich, R., Weichgreb, D.,aiid Bahiiemaiiii, D., 1993, Solar detoxification of polluted water Comparing the efficiencies of a parabolic reactor and a novel thin-film fixed-bed reactor, in Photocatalytic purification and treatment of water, Ollis, D., and Al-Ekabi, H., eds., Elsevier, New York, pp. 639-644. 

Zayani G, Boussehni L, Mhenni F, Ghrabi A (2009) Solar photocatalytic degradation of commercial textile azo dyes performance of pilot plant scale thin film fixed-bed reactor. Desalination 246 344—352... 

Abstract The principle of catalytic SILP materials involves surface modification of a porous solid material by an ionic liquid coating. Ionic liquids are salts with melting points below 100 °C, generally characterized by extremely low volatilities. In the examples described in this paper, the ionic liquid coating contains a homogeneously dissolved Rh-complex and constitutes a uniform, thin film, which itself displays the catalytic reactivity in the system. Continuous fixed-bed reactor technology has been applied successfully to demonstrate the feasibility of catalytic SILP materials for propene hydroformylation and methanol carbonylation. 

This review puts its focus on high-throughput preparation of heterogeneous catalysts, that is, solid-state materials that are apphed in fixed-bed reactors for gas-phase reactions and in trickle-bed or stirred-tank reactors for liquid or gas-hquid reactions, respectively. Other fields of catalysis are not discussed since very different catalytic systems are used. We refer to the following reviews for homogeneous catalysis (2, 3), where combinatorial catalysis deals mainly with variation of ligands and for electrochemical catalysis [4,5], where catalysts are prepared as arrays of thin films in electrochemical cells. 

Magnifying the section of a SILP surface, we should obtained a picture similar to that hypothesized in Figure 38. The IL film is physically adsorbed on the surface of the solid support and contains the dissolved catalyst. Since the film has the size of the diffusion layer, all metal complexes are involved in the catalytic reaction. When SILP particles are used as the fixed bed of a flow reactor, reagents enter the IL film, they react under homogeneous conditions (the thin IL film) and products, eventually, are desorbed into the carrier gas stream. 

If the transport limitation is significant, the catalysis occurs predominantly near the surface of the ionic liquid, and the [Rh(CO)2l2] dissolved in the bulk is not fully utilized. One attempt to address these issues was to use a supported ionic liquid phase (SILP) catalyst, as reported by Riisager et al. [Ill], In this system, the ionic liquid (l-butyl-3-methylimidazolium iodide) was supported as a thin film on solid silica (the thin film offers little mass-transport resistance) and used in a fixed-bed continuous reactor with gas-phase methanol. Rates were achieved that were comparable to those in Eastman s bubble column carbonylation reactor with gas-phase reactants [109], but using a much smaller amount of ionic liquid. 

Jensen and coworkers studied phosgene synthesis using a micropacked-bed reactor [7]. A silicon reactor consisting of a 20 mm long, 625 (im wide and 300 pm deep reaction channel (volume 3.75 mL) was employed (Figure 11.2). In order to avoid corrosion by chlorine, the microchannels were coated with a thin sflicon dioidde film (5000.. A fixed bed of activated carbon catalyst (1.3 mg, 53-73 pm) supported on alumina particles ( 3mg, 53-71 pm) was placed inside the microchannel. Chlorine and CO were mixed and fed into the microchannel network. The exit stream could be analyzed on-line using a mass spectrometer. 

Gas Phase The photocatalytic process with the pellet forms has the advantage because it is free from filtration to recover the catalysts from the gaseous product mixture. With a fixed-bed gas-solid photocatalytic reactor provided with commercial Ti02 pellets, irradiated by UV light, the yield of CH4 is higher than that obtained from processes using thin films or anchored Ti02 catalysts and comparable to that of the powders [3]. 

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