Method for recovering hydrogen from tail gas of chlorate electrolysis

Abstract

The invention discloses a method for recovering hydrogen from tail gas of chlorate electrolysis. The method comprises the following steps of: removing chlorine and carbon dioxide; removing vapour; removing oxygen, namely, conveying the defoamed gas into a first oxygen remover, enabling hydrogen with oxygen to react to remove most of oxygen, conveying a high-temperature gas at 360-420 DEG C after oxygen removal into a heat exchanger to cool, conveying a cooled gas into a third water-cooling tower, conveying 70% (V / V) hydrogen into a heat exchanger tube to exchange heat with an inter-tube gas, increasing the temperature of the gas to a temperature of greater than 200 DEG C, conveying the gas into a second oxygen remover, reducing the content of oxygen in hydrogen to be less than 0.1%, and finally cooling to a temperature of lower than 30 DEG C via a fourth water-cooling tower and conveying hydrogen in a gas cabinet; and compressing and bottling the qualified hydrogen after being treated. The method disclosed by the invention is simple to operate during startup and shutdown, strong in adaptability, reasonable in process design, high in purity of the recovered hydrogen, higher in quality of hydrogen via secondary oxygen removal, and wider in the application of hydrogen and has an oxygen removal effect.

Description

technical field [0001] The invention relates to a process for recovering hydrogen from electrolytic tail gas in chlorate production, and is especially suitable for a technique for recovering high-purity hydrogen for fine chemical hydrogenation. Background technique [0002] The production of chlorate is based on saturated brine as raw material, which is prepared electrochemically in an electrolytic cell without a diaphragm, and the anode reaction is mainly Cl - The electrons are lost to generate chlorine gas, which is circulated and absorbed in the electrolytic cell with the electrolyte, and sodium chlorate is generated under the condition of 80°C. The cathodic reaction is mainly H + Electrons are obtained to generate hydrogen, which is evacuated with the tail gas. If the hydrogen in the tail gas is not recovered, the electric energy consumed by the half-reaction of the cathode of the electrolyzer will be wasted in the form of hydrogen venting, which is really a pity. [...

AI Technical Summary

Problems solved by technology

It can be seen that there are no enterprises in my country that recover hydrogen from chlorate and use hydrogen for fine chemical hydrogenation.

In addition, due to problems in the production process, hydrogen recycling manufacturers in the same industry have poor quality of recycled hydrogen, and the use of deoxidation catalysts has not been good, so they cannot be recycled continuously, which brings hidden dangers to production safety.

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