Supercritical reactor configurations

This chapter first explains enzyme nomenclature, describes enzymatic, supercritical reactor configurations, and gives a compilation of published experimental results. The- most important topics concerning enzymatic reactions in SCFs are then covered. These are factors affecting enzyme stability, the role of water in enzymatic catalysis, and the effect of pressure on reaction rates. Studies on mass transfer effects are also reviewed as are factors that have an effect on reaction selectivities. Finally, a rough cost calculation for a hypothetical industrial process is given. 

Borealis introduced a dual reactor configuration in 1995 in Finland combining a sliury-loop reactor with a gas-phase reactor under the trade-name of Borstar Polyethylene that is available for license. The 280 million poimd per year reactor is imique in that the first reactor is a slurry-loop process utilizing propane as diluent imder supercritical conditions rather than the usual slurry diluent isobutane. Supercritical propane offers lower polymer solubility than isobutane so that the risk of reactor fouling is lower with supercritical propane. 

The configuration of the reactor for the supercritical-phase reaction was similar to that of a conventional pressurized fixed-bed flow reactor system. The only difference was that a vaporizer and an ice-cooled high pressure trap were set upstream and downstream of the reactor, respectively, as shown in Figure 4.8-1. To compare characteristic features of the gas-phase, liquid-phase and supercritical-phase reactions, all three kinds of reactions were conducted in the fixed bed reactor. The liquid-phase reaction was operated in a downflow-type trickle bed. The balance materials were nitrogen for the gas-phase reaction, and n-hexadecane and nitrogen for the liquid-phase reaction [15-17]. 

This section covers the Reactor that uses 49% enriched 49 kg fuel. The Alternative 1 reactor uses smaller radius fuel pins enriched to 49% and was the simpler of the two cores to achieve a supercritical configuration with. The active length of the older source core was retained, the cross sectional flow are increased, and the overall core radius decreased. Cross sectional screenshots of the design are shown in Figure 5-7 through Figure 5-9. 

UV-Vis spectra are generally highly sensitive but less informative, because they typically consist of a few broad absorption peaks. Chemical reaction monitoring using UV-Vis spectroscopy is less common than using other spectroscopic techniques. Two major devices have been developed for supercritical fluids the fiber-optic and the cell device. Hunt et al. [9] reported the development of a fiber-optic-based reactor connected directly to a CCD array UV-Vis spectrometer for in situ determination of reaction rates in SCCO2. The cell can be configured either to study the kinetics of chemical reactions or to determine the rate of dis-... 

Since OO s Gydropress has developed supercritical water-cooled water-moderated power reactors (WER-SKD) in two circuit (with steam generators) and direct cycle configurations. The more advanced direct cycle concept has the following characteristics, as shown in Table 12.9 (Sidorenko, 2010 Glebov et al., 2014 Gabriel et al., 2013). 

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