Iodide decomposition reactor

Flo. 8.3. Metal reactor for iodide decomposition 1, high-vacuum pump ... 

Kinetic Studies. Peracetic Ac id Decomposition. Studies with manganese catalyst were conducted by the capacity-flow method described by Caldin (9). The reactor consisted of a glass tube (5 inches long X 2 inches o.d.), a small centrifugal pump (for stirring by circulation), and a coil for temperature control (usually 1°C.) total liquid volume was 550 ml. Standardized peracetic acid solutions in acetic acid (0.1-0.4M) and catalyst solutions also in acetic acid were metered into the reactor with separate positive displacement pumps. Samples were quenched with aqueous potassium iodide. The liberated iodine was titrated with thiosulfate. Peracetic acid decomposition rates were calculated from the feed rate and the difference between peracetic acid concentration in the feed and exit streams. 

Peracetic acid decomposition kinetics in the presence of cobalt or copper acetates were studied in the same apparatus used for the manganese-catalyzed reaction. However, in these studies it was used as a batch reaction system. The reactor was charged with peracetic acid (ca. 0.5M in acetic acid) and allowed to reach the desired temperature. At this time the catalyst (in acetic acid) was added. Samples were withdrawn and quenched with potassium iodide at measured time intervals. 

Hwang, G.J. and Onuki, K., Simulation study ou the catalytic decomposition of hydrogen iodide in a membrane reactor with a silica membrane for the thermochemical water splitting IS process. Journal of Membrane Science, 194, 207, 2001. 

A reactor is first out-gassed at 510°C and a pressure of 10 < mm of mercury, for a number of hours, with the crushed iodine present in a refrigerated side-tube. Thorium iodide is then allowed to form at 260°C and volatilized at about 450°C for the decomposition reaction. The filament temperature is maintained between 900°C and 1700°C, 1000°C being found satisfactory. 

Bums, W. G., Marsh, W. R. The decomposition of aqueous iodide solution induced by y-radiolysis and exposure to temperatures up to 300 °C. Proc. 3. BNES Conf. Water Chemistry in Nuclear Reactor Systems, Bournemouth 1983, Vol. 1, p. 89-101 Bums, W. G., Marsh, W. R. The thermal and radiolytic oxidation of aqueous I and the hydrolysis and disproportionation of aqueous h. Report AERE-R-10767 (1986)... 

For the decomposition of hydrogen peroxide reaction studied by Nyquist and Ramirez (1971), a second control variable is possible. This is the flow rate of potassium iodide catalyst solution to the reactor. Modify the process model to allow for a variable catalyst flow rate and therefore a variable catalyst concentration. The reaction rate is modeled as... 

In this manner, a flow reaction can have a short residence time, allowing the oxiranyllithium species 2, which is an unstable reactive species with a short lifetime, to react with methyl iodide before the species decomposes. In contrast, a batch reaction cannot be completed in a short reaction time due to the time for its conduction needed for the reaction. A batch reaction on an extremely small scale may be completed within a reaction time of 1 min or less, but a batch reaction on a large scale cannot be completed in a short time because the dropping of s-BuLi to a solution of 1 requires an additional time. Fast dropping in a batch reactor may cause rapid increase in the temperature which accelerates the decomposition of 2. Thus, flow microreactor synthesis can offer crucial advantages. 

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