CO2 absorption by alkanolamine aqueous solution is an important method for biogas purification. A series of experimental tests were conducted in a packed tower using aqueous solution of MEA and DEA

in which the percent conversion η

absorption rate N and volumetric overall mass transfer coefficient in gas phase KGae were analyzed at various absorbent concentrations

gas flow rates

CO2 concentrations and absorption temperatures.The results show that the increment of absorbent concentration can improve η

N and KGae effectively.With the increment of gas flow rate

the percent conversion η decreases obviously

while the absorption rate N increases within a certain range and then decreases

the change of KGae is similar to that of absorption rate N

but the value of KGae will maintain a relatively stable value when the gas flow rate is high enough.The percent conversion η and decrease as CO2 concentration increases

while the absorption rate N increases.The effect of absorption temperature on η and KGae are approximately parabolic.The optimum absorption temperature of MEA and DEA is about 40-60℃

and it decreases with the increment of CO2 loading.The experimental results of this study can provide some guidance for the further study and practical application of biogas purification technology by alkanolamine aqueous solution.