Sorption reactor

The major equipment items used in the fluorination-sorption tests included a fluorination reactor, an auxiliary reactor, a MgF sorption reactor and a UF cold trap. The fluorinator and the sorption reactor consisted of a 2.54 cm diameter nickel tube mounted vertically with a sieve plate at the bottom to support the bed. The fluorination, auxiliary and sorption reactors were heated with a tube furnace. 

A total of 13 batch fluorination-sorption runs were made in this study with fluorine concentrations of 33 and 100%. The fluorination reactor bed temperature was maintained at 500°C and the MgF sorption reactor temperature was maintained at 100°C in each run. When the auxiliary reactor was used, fluorine was added between the fluorinator and the auxiliary reactor to provide a minimum of 15% excess fluorine. The auxiliary reactor temperature was controlled at 500°C. Magnesium fluoride which was preconditioned with fluorine at 400-550°C and at 100 to 125°C was tested during these runs. The MgF treated at the lower temperature was more effective for technetium removal. 

AT is intended to include any and all of the effects of the sorption rate of monomer on the surface, steric arrangement of active species, the addition of the monomer to the live polymer chain, and any desorption needed to permit the chain to continue growing. We assume a steady state in which every mole of propylene that polymerizes is replaced by another mole entering the shell from the gas, so that all of the fluxes are equal to Ny gmol propylene reacted per second per liter of total reactor volume. The following set of equations relates the molar flux to each of the concentration driving forces. 

Bioreactors containing an nndefined anaerobic consortinm rednced TNT to 2,4,6-triaminotoluene (TAT) in the presence of glncose (Dann et al. 1998). The sorption of TAT to montmorillonite clay was irreversible, and the snbstrate conld not be released by solvent extraction or by acid or alkaline treatment. Similar resnlts were obtained with humic acids in which covalent reactions with carbonyl or activated C=C bonding presumably occurred. Results from laboratory experiments nsing i C-labeled TNT in reactors to which... 

Figure 228 shows the examples of liquid and solid open sorption storage systems. In both cases the Desorption is activated by an hot air stream carrying the heat of desorption. For the solid a packed bed of adsorbent pellets and for the liquid solution a reactor are blown through, leaving the packed bed dry and the solution concentrated. 

In an open sorption storage system air is transporting water vapor and heat in and out of the packed bed of solid adsorbents (see Figure 235) or a reactor where the air is in contact with a liquid desiccant. In desorption mode a hot air stream enters the packed bed or the reactor, desorbs the water from the adsorbent or the salt solution and exits the bed cooler and saturated. In adsorption mode the previously humidified, cool air enters the desorbed packed bed or the... 

Harrison, D.P. and Z. Peng, Low-carbon monoxide hydrogen by sorption-enhanced reaction, Int.. Chem. Reactor Eng., 1, 1-9, 2003. 

Below, we first briefly describe conventional hydrogen production. Then the combination of hydrogen production and CCS is described. Finally, we elaborate on two of the technologies for more efficient hydrogen production with C02 capture that are currently in the R D phase hydrogen membrane reactors and C02 sorption enhanced reactors. 

For combined hydrogen production and C02 capture several novel technologies are in development, most of them for the application in a pre-combustion C02 capture combined cycle. The main focus is to reduce the efficiency penalties and other associated costs of CO2 capture. The most important technologies in the R D phase, membrane reactors and sorption-enhanced reactors, are described below, with special attention paid to the catalytic aspects. 

Fig. 14.8 Schematic representation of sorption-enhanced reforming. The topmost reactor is in reforming mode, the bottom one is being regenerated using steam.

There is a need for low-cost methane steam reforming catalysts that are active at low temperature and resistant to coke formation under membrane reactor conditions. Low-cost (Ni-based) catalysts are also needed that can withstand regeneration conditions in a sorption-enhanced reformer. 

For example, biotransformation of naphthalene in an operating actiyated sludge treatment system (after correction for abiotic processes) was modelled a priori by an elementary first-order (in naphthalene concentration) rate equation (24). The complex actiyated sludge system was perturbed by induction of sinusoidal naphthalene feed concentrations for eight sinusoidal frequencies while the naphthalene in the reactor offgas was measured eyery ten minutes. Abiotic fates (stripping, and sorption) were accounted for and... 

These reactors may be modelled with precision based on past engineering experience. Therefore, more obscure biotic and abiotic fate processes (e.g., biotransformation and sorption) may be studied in context of the structure of these obscure processes in context of the engineering model. For instance, a CSTR containing 400 g/L of contaminated MGP soil was fed a sinusoidal concentration of naphthalene in the liquid reactor feed (0-14... 

This paper is devoted to the sorption of uranyl, which exhibits a complex aqueous and surface chemistry. We review briefly the sorption behaviour of An in the environment, and illustrate the variety of environmental processes using published data of uranyl sorption in the Ban-gombe natural reactor zone. After summarizing the general findings of the mechanisms of An sorption, we then focus particularly on the current knowledge of the mechanisms of uranyl sorption. A major area of research is the influence of the aqueous uranyl speciation on the uranyl surface species. Spectroscopic data of U(VI) sorbed onto silica and alumina minerals are examined and used to discuss the role of aqueous uranyl polynuclear species, U02(0H)2 colloids and uranyl-carbonate complexes. The influence of the mineral surface properties on the mechanisms of sorption is also discussed. 

Uranyl sorption processes in the Bangombe natural reactor zone... 

Del Nero, M., Salah, S., Miura, T., Clement, A. Gauthier-Lafayf., F. 1999a. Sorption/deso-rption processes of uranium in clayey samples of the Bangombe natural reactor zone, Gabon. Radiochimica Acta, 87, 135-149. 

Tremaine et al. (1994) conducted pilot-scale studies to compare the effect of a suspended-growth reactor and a fixed-film bioreactor with a constructed wetland environment in removing creosote-PAHs from contaminated water recovered from a wood-preserving facility. Mass balanced chemical analysis of 5 PAHs used as model constituents of creosote showed that the wetland yielded between 20 and 84% removal, whereas the fixed-film reactor yielded 90 to 99% PAH removal. Biodegradation accounted for >99% of the losses observed in the fixed-film reactor, but only 1-55% of the compounds removed in the artificial wetland was attributable to biodegradation. Again, physical sorption of PAHs, especially HMW PAHs, was found to be significant. 

Many investigators use pulse techniques in which a catalyst reacts with hydrocarbons, oxygen etc. separately in time. This can provide an insight into the nature and significance of the individual reaction and sorption steps, but it should be emphasized that selectivities and other data may be unrepresentative for conditions in a flow reactor. In particular, selectivities may be considerably lower under steady state conditions. If the selectivity differences between pulse and flow experiments are very large, a cyclic mode of operation may be attractive for the practical application of the catalyst concerned. Oxidation and reduction are then separated. 

Concern about fission-product release from coated reactor fuel particles and fission-product sorption by fallout particles has provided stimulus to understand diffusion. In a fallout program mathematics of diffusion with simple boundary conditions have been used as a basis for (1) an experimental method of determining diffusion coefficients of volatile solutes and (2) a calculational method for estimating diffusion profiles with time dependent sources and. time dependent diffusion coefficients. The latter method has been used to estimate the distribution of fission products in fallout. In a fission-product release program, a numerical model which calculates diffusion profiles in multi-coated spherical particles has been programmed, and a parametric study based on coating and kernel properties has provided an understanding of fission product release. 

The discussion above explains why basic information on sorption and diffusion under the reaction conditions, especially at elevated pressures, is required for kinetic and mass- and heat- transfer modelling of catalytic polymerization reactors. If such information is sufficiently available, one should be able, for example, to compare the kinetics of gas-phase and slurry-processes directly by taking into account both gas solubilities in swollen polymers and the hydrocarbons used in slurry processes. 

Copper, Manganese, Nickel Plants — Flow injection on-line sorption preconcentration in a reactor, electrothermal [84]... 

---