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

The absorption of carbon dioxide-air mixtures in water in a packed-bed reci rculating absorption column with an inner diameter of 0.08 m and a length o f 1.20 m was investigated. A model is derived and numerically solved for re cycling packed-bed absorption systems in order to determine the overall mas s transfer coefficients. The relationship between the K(L)a values calculat ed 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 pre dicted concentration-time profiles are compared with those of the experimen tal measurements. This procedure is repeated by changing the value of mass transfer coefficients in the model until a good agreement is reached with t he experimental measurements. Experimental data were collected during absor ption of carbon dioxide in water using different carbon dioxide-air gas com positions in recirculating packed columns operating under high flow rates ( 8.33 x 10(-5)-1.50 x 10(-4) m(3) s(-1)). The experiments were carried out a t 20, 25 and 30 degrees C, It was found that the K(L)a values of this study are in agreement with the literature values. (C) 1999 Elsevier Science B.V . All rights reserved.