不同胺基CO2固体吸收剂的热稳定性能

Thermal stability of various amine CO_2 absorbents

引言为应对温室效应对全球气候的影响,CO2的捕集和封存（carbon capture and storage,CCS）技术成为近年来的研究热点。我国能源消费结构以煤为主,煤燃烧排放的CO2约占我国CO2排放总量的82%,主要用于发电。

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.