Mathematical Modeling of CO2 Removal in a Venturi Scrubber and Parametric Study on the Effect of Evaporation/Condensation of Droplets and Cooling Effect of Evaporation

In this study the effects of the evaporation/condensation phenomena and the evaporative gas cooling due to heat exchange with liquid phase is investigated on CO2 absorption in a venturi scrubber. The results show that despite the short residence time of gas in this type of scrubbers, the effects of heat and mass transfer between gas and liquid on the separation efficiency of CO2 is remarkable. The main reasons include (1) the high heat and mass transfer coefficients, due to high relative velocity between gas and droplets, and (2) the large heat and mass surface area, resulted from the fine atomization of injected liquid. The effect of operational parameters on absorption efficiency in non-isothermal operation is investigated. The results show that the decreasing the temperature of inlet gas and increasing its humidity are two effective tools to increase absorption efficiency. In fact, installation of a gas cooling-humidifying system prior to venturi scrubbers is strongly recommended.