Twin reactor system

The ratio of evolved H2 and O2 was in agreement with the stoichiometric ratio (2 1) of H2 and O2 in H2O. An average H2 generafion rate of 1.59 pmol/g-h was achieved in the twin-reactor system, which was twice as much as that in the conventional Z-scheme system. The improved H2 yield was due to the prevention of the H2O decomposition backward reaction in the twin reactor. 

The KLT-40 is a twin-reactor system intended to produce fresh water and electric power in different proportions. It may also be used for heat production in a co-generation cycle. The KLT-40 design is based entirely on the serially produced marine NSSS being used in the Russian nuclear-powered ice-breakers. 

If a linear mbber is used as a feedstock for the mass process (85), the mbber becomes insoluble in the mixture of monomers and SAN polymer which is formed in the reactors, and discrete mbber particles are formed. This is referred to as phase inversion since the continuous phase shifts from mbber to SAN. Grafting of some of the SAN onto the mbber particles occurs as in the emulsion process. Typically, the mass-produced mbber particles are larger (0.5 to 5 llm) than those of emulsion-based ABS (0.1 to 1 llm) and contain much larger internal occlusions of SAN polymer. The reaction recipe can include polymerization initiators, chain-transfer agents, and other additives. Diluents are sometimes used to reduce the viscosity of the monomer and polymer mixture to faciUtate processing at high conversion. The product from the reactor system is devolatilized to remove the unreacted monomers and is then pelletized. Equipment used for devolatilization includes single- and twin-screw extmders, and flash and thin film evaporators. Unreacted monomers are recovered for recycle to the reactors to improve the process yield. 

There was no comprehensive comparison smdy to illustrate the advantages and disadvantages of MR systems with respect to TR. Therefore, as a case study, the generation of H2 and O2 via H2O decomposition reaction was investigated in both conventional Z-scheme reactor and Z-scheme MR systems (Lo et al., 2010). In conventional Z-scheme reactor, H2 and O2 gases were evolved simultaneously in the form of a mixture in a single reactor and in the Z-scheme MR, modified Nafion membrane with Fe -form was used to separate the two compartments of a linked twin reactor and the results are presented in Figure 7.11 and Table 7.4. 

Eickelpasch, N, Lasch, M. Investigations on transport and activation of corrosion products in the 2X 1300MWe twin boiling water reactors of Gundremmingen. Proc. 4. BNES Conf Water Chemistry of Nuclear Reactor Systems, Bournemouth, UK, 1986, Vol. 2,... 

Figure 6.5 shows the process configuration of different FB gasification concepts, from single-reactor concepts to twin fluid-bed systems. The FB gasifiers are operated in a typical temperature window of 800-950°C. Producers of such FB gasifiers (also including air... 

Figure 4.42. Demonstration of the efficiency of the incorporation of an ion-exchange preconcentration column into a FIA system for the determination of lead by atomic absorption spectrometry. In (A) is shown the recordings obtained for a series of aqueous lead standards in the range 25-100 xg/L, using the manifold depicted in Fig. 4.41 comprising a dual-column system, that is, the twin peaks for each concentration refer to the outputs for reactors A and B respectively. (B) is the output for a 100 tig/L lead solution prepared in a matrix simulating seawater. For comparison the response of the same instrument, operated under conventional experimental conditions of direct continuous aspiration, but without the inclusion of the on-line preconcentration column, is shown in (C).

PP granules plus the final product additive package are finished in a twin screw extrusion system (4) including any post-reactor modification of the polymer molecular weight and molecular weight distribution required by the specific product application, typically referred to as controlled rheology (CR) technology. 

Typical ceramic materials produced on a co-rotating twin screw extruder are for example catalyst carriers. They are commonly shaped into granules for use as bulk material in reactors in the chemical industry or into honeycombs for catalytic converters in automobiles exhaust systems (Fig. 12). After extrusion, the catalyst carriers are cut oversized in the lineal direction, dried and then cut to the proper length. Afterwards the binder is removed and the carriers are calcinated or sintered. Finally, to provide them with catalytic properties, they are impregnated with an active film in a bath [Fri76]. 

Clariant has installed a series of pilot units at the Department of Oxidation Catalysis, each equipped with reactor tubes of the different, industrially-realized diameters. The pilot reactors have been designed and built by DWE, Germany, one of the most experienced reactor construction companies in operation. The units are fully controlled by a Siemens S7 DCS system and equipped with mobile or multipoint thermocouples and on-Une gas analysis allowing a 24/7 operation, comparable to an industrial plant. Each reactor unit is connected to twin-switch condensers for product separation, mimicking an industrial environment. The oxidation of o-xylene is industrially processed in fixed-bed tubular reactors with up to 30,000 tubes. Reaction temperatures range from 300 to 450 C with o-xylene feed concentrations between 0.5 vol% and 1.8 vol% in air. The reaction is conducted at nearly... 

The continuous trials were performed on a twin shaft, co-rotating 31-liter kneader reactor that was equipped with a twin-screw discharge system. The rotation speed of the reactor shafts was higher than in the batch trials. Samples of the discharge from the twin-screw discharge system were tested for polymer conversion and the same process data was collected as in the batch trials. 

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