Study On The Coabsorption Of Hydrogen Chloride And Carbon Dioxide Binary System

Chlorinated volatile organic compounds have a wide range of applications in industrial production processes,and they are toxic and pose great harm to the environment and human health.With the increasing awareness of environmental protection and attention to health,people’s control of industrial exhaust emissions is becoming increasingly strict.The adsorption concentration catalytic combustion method is widely used in the treatment of chlorine containing volatile organic compounds due to its excellent performance.But its exhaust still contains a large amount of carbon dioxide and hydrogen chloride gas.Separate absorption is not only troublesome to operate,but also increases construction costs and floor space.Therefore,this article aims to find a composite absorbent that can simultaneously absorb a mixture of carbon dioxide and hydrogen chloride.Because water has a strong absorption capacity for hydrogen chloride gas,the focus of mixed gas absorption is on the absorption of carbon dioxide.Among numerous absorbents,due to the excellent absorption and regeneration performance of piperazine,it is chosen to be compounded on the basis of piperazine aqueous solution.Firstly,the optimal operating parameters of piperazine aqueous solution were explored in the bubbling device,and it was found that the absorption effect was best under the conditions of 60 m L of 0.7 mol/L piperazine solution,inlet gas velocity of 1 L/min,and inlet carbon dioxide concentration not exceeding 8050 ppm.And under this parameter,different concentrations of sodium hydroxide,sodium carbonate,and sodium bicarbonate were used to compound the piperazine aqueous solution,and the mixed gas containing 8050 ppm carbon dioxide and 2000 ppm hydrogen chloride was absorbed.The composite solution of 0.7 mol/L piperazine and 0.4 mol/L sodium carbonate was found to have the best absorption effect on the mixture of carbon dioxide and hydrogen chloride when used as an absorbent.Subsequently,experiments were conducted using this composite absorbent in a packed tower to explore its optimal absorption conditions.It was found that when the dosage of the composite absorbent was 300 m L,under the conditions of an inlet gas velocity of 3 L/min,a peristaltic pump speed of 35 r/min,and a composite absorbent of 0.7 mol/L piperazine and 0.4 mol/L sodium carbonate,the composite absorbent had the best absorption effect of carbon dioxide alone,with a carbon dioxide absorption rate of over 90% for 91 minutes.Then,under these conditions,the mixture of carbon dioxide and hydrogen chloride is absorbed,and the time for the carbon dioxide absorption rate to exceed 90% is 80 minutes;And the removal rate of hydrogen chloride remains above 91.8% within 80 minutes.In summary,the composite solution of 0.7 mol/L piperazine and 0.4 mol/L sodium carbonate as an absorbent has good absorption effect on a mixture of carbon dioxide with a volume concentration of 8050 ppm and hydrogen chloride gas with a volume concentration of 2000 ppm.