Study On The Absorption Performance Of CO₂ In PZ Promoted K₂CO₃ Aqueous Solutions

The viscosities of piperazine?PZ?promoted potassium carbonate?K₂CO₃?aqueous solutions and the absorption capacity and loading of CO₂ in K₂CO₃-PZ aqueous solutions were measured at normal pressure.The temperatures ranged from 323.2K to 343.2K.The mass fractions of PZ and K₂CO₃ respectively range from 0 to 0.03 and 0.2 to 0.3.The viscosities were modeled by using the Weiland equation and the effects of temperature and mass fraction on viscosities were demonstrated.The absorption rates were determined by using the experimental data of the time-dependent absorption capacities.The effects of temperature,solution concentration and solution viscosity on the absorption capacity,CO₂ loading and absorption rate were illustrated.Our results show that:?1?The absorption capacity of CO₂ respectively increases and decreases with increasing mass fraction of absorbent and increasing temperature,while the CO₂ loading decreases with the increase of both mass fraction of absorbent and increasing temperature;?2?The absorption rate of CO₂ can be accelerated remarkably when K₂CO₃ aqueous solution was promoted by small amount of PZ.However,with the increase of the addition of PZ,the enhancement gets less significant;?3?The viscosity of K₂CO₃-PZ aqueous solutions respectively increases and decreases with increasing mass fraction and temperature;?4?The Weiland equation can correctly capture the effects of mass fraction and temperature on viscosities,and satisfactorily fit the experimental data;?5?The absorption rate increases with increasing solution concentration and temperature.However,the increase of solution concentration leads to higher solution viscosity,thus may decrease the absorption rate.