GB1286570A - Process for recovery of iodine - Google Patents

Abstract

1286570 Recovery of iodine NAUCHNO ISSLEDOVATELSKY INSTITUT MONOMEROV DLYA SINTETICHESKOGO KAUCHUKA 31 Oct 1970 51888/70 Heading C7B A process for recovering iodine from the products of iodizing dehydrogenation reactions of hydrocarbons comprises contacting with an aqueous solution of an alkali or an alkali metal carbonate or a mixture thereof, the product of an iodizing dehydrogenation reaction to obtain an alkaline solution containing an iodide and an iodate; electrolyzing the alkaline solution to obtain separate solutions of iodine and alkali and removing elemental iodine by blowing oxygen or oxygen-containing gas, or a mixture thereof with water steam into the solution. The products of iodizating dehydrogenation reaction are fed through pipeline 1 into a scrubber 2 where they are treated with the alkali. Iodine and its compounds are recovered as sodium iodate and iodide. The products are continuously fed from the scrubber 2 via a pipeline 5 through a heat exchanger 6 and a level regulator 7. Electrolysis is carried out in a diaphragm threechamber electrolyzer 8 whose anodes may be made of platinum, graphite or magnetite. The cathodes are made of low carbon steel and the diaphragms of asbestos, glass fabric or cardboard. The alkaline solution is introduced into the intradiaphragm space from whence it passes through the diaphragms into the anode and cathode spaces. Electrolysis gives the solution of iodine and iodide at the anode, and hydrogen and alkali at the cathode. The anode solution of iodine with iodide is fed through a pipeline 12 into a desorption column 12 where elementry iodine is blow off from the solution by oxygen or oxygen-containing gas supplied through pipe 14. Iodine desorbed is recycled as a steam and gas mixture into the dehydrogenation zone through a pipeline 16.