The Recovery Of Purify Of HCl Gas In The Air

There often produte exhaust gaseous hydrochloric acid in some industry such as chemical industry, paper making, electroplate and grease produting etc. If purificatory measure does not be taken, the content of HCl gas in the air will arrive at several tens or hundreds mg/m~3 more. The amount is higher than 0.3 mg/m~3 which is the standard amount of letting out of environment and sanitation. The purificatory measure is absolutely necessary. Water is used as sorbent in the experiment. Having studied various absorbable condition, under a appropriate condition, the air is be purified in order to reduce the content of HCl gas in the air till less 0.3 mg/m3 , the standard amount of letting out of environment and sanitation and gain the hydrochloric acid of 4~5%. In order to effectual utilize the formed hydrochloric acid, evaporation method is used to concentrate. Having studied for optimized concentrated condition, hydrochloric acid containing 20% HCl with vacuum evaporation method through Concentrating the formed hydrochloric acid is obtained. The method simplify absorbing equipment more and industrial process flow as well. It possess some value of economy and practicality.Exhaust HCl gas in the air is composed of HCl gas which is from reaction of Vitriol and sodium chloride, and atmosphere with different proportion. The effect of velocity of flow and temperature on driving the gas through water is researched. Velocity of flow of gas is airspeed 100/min and temperature of water reach 30℃, absorptivity of HCl gas is 99% and more. When the content of HCl gas in the intake air is about 0.3 mg/m3, the hydrochloric acid of 4~5% is formed by absorbing exhaust HCl gas in the air through water. The higher the content of HCl gas in the air or the lower the temperature of the water absorbing the gas, the larger the concentration of hydrochloric acid can be got. Therefore, higher the concentration of hydrochloric acid can be got by debasing the temperature of the water absorbing the gas. It can reduce cost of concentration and improve economic benefits.