Experiment And Model For The Viscosity And Solubility Of Carbonated MDEA-PZ Aqueous Solutions

The solubility of CO2in N-methyl-diethanolamine (MDEA)-piperazine (PZ)aqueous solution and the viscosity of the carbonated aqueous solution were measuredat1atm in this work.The solubility of CO2in MDEA-PZ aqueous solution was measured by using asoap film flowmeter, with the temperatures ranging from303.15to323.15K. Theinfluence of the mass fractions of MDEA and PZ on the solubility, CO2loading andthe absorption rate was illustrated. The experimental results show that:(1) When the mass fraction is of very small value, PZ promotes the absorptionrate of CO2very significantly. The absorption rate of CO2increases with the increaseof temperature;(2) The temperature and the mass fraction dependences of the solubility of CO2can be approximately expressed by linear relationships in the investigated temperaturerange. The solubility of CO2respectively increases and decreases with increasingmass fraction of PZ and temperature.The viscosities of carbonated aqueous solutions of MDEA-PZ were measured atthe temperatures ranged from293.15to323.15K by using a NDJ-1rotationalviscometer. The Weiland equation was proposed to correlate and predict theviscosities. The effects of temperature, amine concentration and CO2loading on theviscosities of carbonated solutions were demonstrated on the basis of experiments andcalculations. Our results show that:(1) The increase of CO2loading tends to increase the viscosity of carbonatedsolutions due to the increase of ion concentration.(2) The increases of amine concentration and temperature respectively increaseand decrease the viscosity of carbonated solutions.(3) By taking into account the contribution of CO2loading, the Weilandequation can correctly correlate and predict the viscosities of carbonated solutions.The agreement with experiments is satisfactory.