In order to effectively reduce negative influence of non-condensable gas on falling film evaporation and optimize the geometrical parameters of evaporators

a model for chemical desorption of CO2 in the multi-effect distillation(MED)system is presented.The desorption rate of CO2 and its influencing factors are obtained by simulating an actual MED setup.Compared with previous study and practical operation data of an MED desalination plant

the present model is proved to be reliable and has a higher accuracy.The results indicate that the evaporation temperature is the key factor influencing the chemical reaction rate

which increases as the evaporation temperature increases.The salinity and pH value play an important role in determining chemical reaction rate before the seawater temperature is saturated.The increase in the concentrations of the carbonate systems due to seawater evaporation contributes to the chemical desorption of CO2.The desorption rate of CO2 decreases stage by stage mainly due to the reduction of mass transfer coefficients as the evaporation temperatures in evaporators decrease.