Carbon dioxide–air mixtures: mass transfer in recycling packed-bed absorption columns operating under high liquid flow rates

Abstract

Abstract The absorption of carbon dioxide–air mixtures in water in a packed-bed recirculating absorption column with an inner diameter of 0.08 m and a length of 1.20 m was investigated. A model is derived and numerically solved for recycling packed-bed absorption systems in order to determine the overall mass transfer coefficients. The relationship between the K L a values calculated in this work and the operating hold-up is presented. The model is based on physical gas absorption from multi-component mixtures, and the model predicted concentration–time profiles are compared with those of the experimental measurements. This procedure is repeated by changing the value of mass transfer coefficients in the model until a good agreement is reached with the experimental measurements. Experimental data were collected during absorption of carbon dioxide in water using different carbon dioxide–air gas compositions in recirculating packed columns operating under high flow rates (8.33×10 −5 –1.50×10 −4 m 3 s −1 ). The experiments were carried out at 20, 25 and 30°C. It was found that the K L a values of this study are in agreement with the literature values.