Four types of solid amines were prepared by impregnating disordered porous silica gel Q-10 in tetraethylenepentamine(TEPA)and polyethylenimine(PEI)with various molecular weight of 600

1200 and 1800.Their absorption capacity and thermal stability were investigated.The experiment results indicate that absorption capacity is higher and thermal stability less for TEPA-SiO2 than for PEI-SiO2.The initial temperature of volatilization for amine on TEPA-SiO2 is 115℃

while the thermal stability of PEI-SiO2 absorbents will be improved with increasing PEI molecular weight.After cycle 10 times and regeneration at N2 gas

the absorption capacity of three PEI-based adsorbents at 105℃ keeps stable and the loss of their mass is only 0.6%

0.2%

0.1% for various molecular weight PEI

indicating that PEI-SiO2 absorbents has excellent thermal stability.Under 80% CO2 the regeneration temperature will be raised above 140℃

the high-molecular weight PEI-based absorbents still have good thermal stability and the volatilization of amine has little influence on its performance in several cycles.