Catalyst fixed-bed

The thermal catalytic route proposed involves heating the fresh reactant feed plus recycle up to 790°C and feeding this material into a M0S2 catalyst fixed-bed reactor operating at 0.1 MPa (1 atm). The route yields a production of H2 almost 50% higher than the decomposition of H2S route. 

Fig. 1 Schematic drawing of zeolite/quartz-layered-catalyst fixed bed.

Figure 17.13. Multibed catalytic reactors (a) adiabatic (b) interbed coldshot injection (c) shell and tube (d) built-in interbed heat exchanger (e) external interbed exchanger (f) autothermal shell, outside influent-effluent heat exchanger (g) multishell adiabatic reactor with interstage fired heaters (h) platinum-catalyst, fixed bed reformer for 5000 bpsd charge rate reactors 1 and 2 are 5.5 ft dia by 9.5 ft high and reactor 3 is 6.5 x 12.0 ft.

FIG. 19-3 Fixed-bed reactors with heat exchange, (a) Adiabatic downflow, (b) Adiabatic radial flow, low AP. (c) Built-in interbed exchanger, (d) Shell and tube, (e) Interbed cold-shot injection, (f) External interbed exchanger, (g) Autothermal shell, outside influent/effluent heat exchanger. (h) Multibed adiabatic reactors with interstage heaters, (t) Platinum catalyst, fixed-bed reformer for 5000 BPSD charge rates reactors 1 and 2 are 5.5 by 9.5 ft and reactor 3 is 6.5 by 12.0 ft temperatures 502 433, 502 => 471,502 => 496°C. To convert feet to meters, multiply by 0.3048 BPSD to m3/h, multiply by 0.00662. 

Regenerative catalytic reforming serves to increase the fuel octane number. It is performed in catalyst fixed beds in the gas phase (ca. 500 °C, p = 10-50 bar). Thermal effects are fairly pronounced during the first phase of the conversion, which essentially corresponds to the dehydrogenation of the cycloparaffms. 

P H Calderbjnk A D Caldwell, G Ross, The Diluted Catalyst Fixed Bed Reactor for Exothermic Catalytic Reactions, Chemw et Industne-Geme Chumque 1969, 101, 215 230... 

The coupling of a permselective membrane with a packed bed of catalyst pellets (Fig. 5b) has been one of the most widely studied membrane reactor setups. Generally, the catalyst fixed bed is enclosed on the tube side of a porous membrane, although several cases can be found in the literature in which permselective tubular membranes have been inserted at regularly spaced intervals into the packed bed of catalyst pellets (e.g.. Ref. 25). The most interesting property of this membrane reactor type is that the amount of catalyst and the membrane surface area can be varied almost independently within wide ranges, so as to optimize the coupling of reaction and separation. 

Cu-, Ni-, and noble metal-supported catalysts Fixed-bed reactor, 100-600°C H20/EtOH = 6-10 LHSV = 1.6-2.0 h"1 Catalysts were prepared by impregnation and coprecipitation techniques. Among the catalysts tested in the SRE reaction, the Cu0/Zn0/Al203 exhibited better performance. Sheng et al.266... 

In epoxidation, the propene-to-CHP molar ratio is 10 1, the reaction temperature is 60 °C and the pressure is sufficient to maintain propene in the liquid phase. The feed to the epoxidation reactor must contain less than 1% water in order to limit the hydrolysis of PO to glycol. The reaction is catalyzed by a proprietary, silylated, titanium-containing silicon oxide catalyst. The conversion of CHP is greater than 95%. Selectivity for PO based on hydroperoxide is 95%, whereas selectivity based on propene is around 99%. By-products of the reaction are aldehydes, such as acetaldehyde and propionaldehyde, alcohols (methanol and propene glycol), ketones and esters (e.g., acetone and methyl formate). The catalyst fixed-bed is structured into multiple catalyst layers, with heat exchangers in between the layers. This prevents excessive increases in temperature due to the exothermal reaction that would cause both thermal decomposition of the hydroperoxide and consecutive reactions of PO. 

A tubular stainless steel reactor (I.D. 104 mm) heated by an electrical oven at atmospheric pressure is used for the oxidation of toluene [Fig. 1]. The toluene is dosed with an HPLC pump (LKB2150) to an evaporator at 320 °C and then mixed to the O2 and N2 flows which are controlled with mass flow controllers (Bronkhorst High-Tech B. V ). Nitrogen is used as diluent. The catalyst fixed-bed preceded by quartz beads is maintained between quartz wool. The temperature of the fixed-bed is measured with a K-type thermocouple (Philips AG). The outlet gases are cooled in three consecutive condensers. The liquid products are collected and analysed by gas chromatography with a flame ionisation detector for quantification (Perkin-Elmer Autosystem gas chromatograph, capillary column Supelco SPB-1, 30 m x 0.53 mm I.D. X 0.50 jum film thickness) and with an electron ionisation detector for identification (Hewlett-Packard, G1800A, GCD System, capillary column HP-5, 30 m x 0.25 mm I.D. x 0.25 fm film thickness). The experiments are carried out at a conversion less than 5 per cent. 

Main reaction section where the major part of the reaction takes place on an acidic catalyst. Fixed-bed reactors or expanded bed reactors may be used depending upon operating severity. 

Figure 8. Selectivity (C5+) for promoted catalysts. Fixed-bed tests at 210 °C and 20 bar with H2/CO inlet ratio of 2.1.

DuPont sump reactor (liquid and gas are passed cocurrent from below into catalyst fixed bed) several catalyst beds with intermediate cooling... 

Carbonylation (oxo, hydroformylation) react synthesis gas with olefin, GL, catalyst, fixed bed, CSTR or bubble reactor [-140 MJ/kmol] wide range temperatures 100-200 °C, 3-40 000 s. (5 species, 15 data) no apparent trends. 

Pressure drop measurements across the catalytic filter candle have been performed under varying temperature conditions, both in the unloaded state and as a function of time during gasification with consequential build-up of dust cake on the filtration surface. These results are reported in Figure 11.26 [103]. The impregnation of the porous filter stmcture with catalyst - thereby decreasing its porosity - and, where relevant, the inclusion of a catalyst fixed bed both result in increase in pressure drop with respect to that of a non-catalytic filter of the same structural characteristics (Figure 11.13). 

It was shown that placing the fixed bed of a phosphorus-loaded solid upstream of the catalyst fixed bed resulted in catalyst deactivation due to devolatilization of phosphorus that deposited on catalyst. Under the same conditions, Group VIII TMS were resistant to this form of deactivation. " The HDS activity increase observed under the same conditions may support the similar observation involving the commercial NiMo/Al203 catalysts. 

More common for kinetic studies of heterogeneously catalyzed gas reactions are tubular reactors loaded with catalyst (fixed bed reactor). The tubular reactor displays a simple design and is easy to operate. A simultaneous integral and differential mode of operation can be achieved in a reactor with taps for measuring concentration and temperatures at defined axial positions (Figure 4.11.9). By using a tab reactor, the density of information obtainable during experiments with fixed bed reactors is improved. 

Figure 5.5 shows a typical autothermal reformer with burner and adiabatic catalyst fixed bed in the lower part As in the case of steam reforming with catalyst tubes fired from outside the endothermal methane reaction occurs on a nickel catalyst Due to the lack of heat supply, the gas mixture cools down and reaches almost the value of the methane and water-gas shift equilibrium according to reactions (5.1) and (5.2) at the outlet Typical values for the outlet temperature vary from 900 °C to 1100 °C [5.26] depending on the application. Since the autothermal reformer has to be brick lined similar to the PO-reactor, there is no limitation to pressures of max. 40 bar compared to steam reformers with catalyst tubes. 

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