不同胺基CO2固体吸收剂的热稳定性能

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%^1],主要用于发电.因此研究燃煤电站烟气中脱除CO₂的技术具有重要意义.

Thermal stability of various amine CO2 absorbents

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.