Reactor dissolution

The first approach to separation of the two stages was the nonintegrated two-stage liquefaction (NTSL) process,55 in which a second-stage upgrading reactor was placed downstream of an SRC-I type dissolution reactor. Nonintegrated means that the second-stage catalytic hydrotreater did not contribute... 

The dissolution reactor is shown in figure 1. It was agitated by a three-bladed, marine propellor at 720 rpm. 

Reaction conditions depend on the composition of the bauxite ore, and particularly on whether it contains primarily gibbsite, Al(OH)2, or boehmite [1318-23-6] AlOOH. The dissolution process is conducted in large, stirred vessels or alternatively in a tubular reactor. The process originated as a batch process, but has been converted to a continuous one, using a series of stirred tank reactors or a tubular reactor. 

W. S. Groenier, Equipmentfor the Dissolution of Core Materialfrom S beared Power Reactor Fuels, ORNL/TM-3194, Oak Ridge National Laboratory, Oak... 

Plants handling aqua regia Aqua regia is used extensively in the extraction and refining of the precious metals, and tantalum, as one of the few metals resistant to this medium, is used for dissolution/evaporation pans, reactor lids and all immersed ancillary equipment. 

Thermal oxide reprocessing plant, 6, 885 Thermal reactor fuels, 6,926 dissolution, 6,927 irradiated... 

FIG. 9 Saponification of alkane sulfochlorides (Leuna technology). 1, Saponification reactor 2, pH control 3, separation tube 4, cooler 5, dilution stirring unit 6, preheater 7, vaporizer 8, cyclone separator 9, condensor 10, cooling roller 11, stirred dissolution tank. 

GP 10] [R 18] Cold spots in the reactor lead to water condensation [2], This results in dissolution of water-soluble gases such as ammonia and hydrogen cyanide. As a consequence, the measurements of the gas levels of these compounds may differ considerably from the real values. After dissolution they are much too low after reevaporation of the aqueous solutions, unrealistically high values appear. 

Salt, of density 2350 kg/m3, is charged to the top of a reactor containing a 3 m depth of aqueous liquid of density 1100 kg/m3 and of viscosity 2 mN s/m2 and the crystals must dissolve completely before reaching the bottom. If the rate of dissolution of the crystals is given by ... 

The steady-state dissolution rate of chrysotile in 0.1m NaCI solutions was measured at 22°C and pH ranging from 2 to 8. Dissolution experiments were performed in a continuously stirred flowthrough reactor with the input solutions pre-equilibrated with atmospheric concentrations of C02. Both magnesium and silicon steady-state fluxes from the chrysotile surface were regressed and the following empirical relationships were obtained ... 

Markov chains theory provides a powerful tool for modeling several important processes in electrochemistry and electrochemical engineering, including electrode kinetics, anodic deposit formation and deposit dissolution processes, electrolyzer and electrochemical reactors performance and even reliability of warning devices and repair of failed cells. The way this can be done using the elegant Markov chains theory is described in lucid manner by Professor Thomas Fahidy in a concise chapter which gives to the reader only the absolutely necessary mathematics and is rich in practical examples. 

Rates of dissolution of U02(s) obtained in a thin layer continuous flow-through reactor as a function of pH. 

Various devices can be used to determine the kinetics and rates of chemical weathering. In addition to the batch pH-stats, flow through columns, fluidized bed reactors and recirculating columns have been used (Schnoor, 1990). Fig. 5.15a illustrates the fluidized bed reactor pioneered by Chou and Wollast (1984) and further developed by Mast and Drever (1987). The principle is to achieve a steady state solute concentration in the reactor (unlike the batch pH-stat, where solute concentrations gradually build up). Recycle is necessary to achieve the flow rate to suspend the bed and to allow solute concentrations to build to a steady state. With the fluidized bed apparatus, Chou and Wollast (1984) could control the AI(III) concentration (which can inhibit the dissolution rate) to a low level at steady state by withdrawing sample at a high rate. 

Fig. 5.15b shows a thin-film continuous flow reactor used by Bruno et al. (1991) for determining the dissolution rate of U02 under reducing conditions. A known weight of U02(s) was enclosed into the reactor between two membrane filters (0.22 jum). The reducing conditions of the feed solution were obtained by bubbling H2(g) in the presence of a palladium catalyst. The dissolution rates determined using continu-... 

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