乙醇胺和N,N-二甲基乙醇胺改性埃洛石对CO_2的吸附行为

Adsorption Behavior of Carbon Dioxide with Halloysite Modified by Ethanol Amineand N,N-Dimethyl Ethanolamine

研究了煅烧和混和胺改性后的埃洛石对CO_2的吸附研究.分别考察了提纯、煅烧和混合胺改性对埃洛石比表面积的影响.实验结果表明,埃洛石提纯后比表面积为30.11 m2/g;埃洛石经过煅烧后的X射线衍射结果显示,随着温度的增加衍射峰变尖锐,但到300℃以后反而下降,因此选择的煅烧温度为300℃,比表面积达到了37.04 m^2/g;测得常温常压下吸附CO_2的质量分数为3.141%.用混合胺对其改性,红外光谱结果显示制备成功,其比表面积下降至33.09 m^2/g;常温常压下吸附CO_2的质量分数为17.21%,远远高于仅煅烧的埃洛石吸附CO_2的质量分数.说明吸附二氧化碳在改性埃洛石上的行为主要是化学吸附.

The carbon dioxide adsorption capacities of halloysite after calcination and modified by amine were studied. The effects of purification, calcining temperature and mixed amine modification on the specific suIface area were inspected. The results show that the specific surface area of purified halloysite is 30.11 m^2/g. X-ray diffraction results demonstrate that the diffraction peaks become sharper with calcining temperature increasing. However, the diffraction peaks begin to decrease when the temperature is greater than 300℃. As a result, the optimum calcining temperature is set as 300℃ and corresponding specific surface area is 37.04 m^2/g. The mass fraction of carbon dioxide absorptionon halloysite is 3.141% at ambient temperature and atmospheric pressure. After calcination at 300℃ , the halloysite was modified by mixed amine. The infrared spectra show that the modification is successful. The specific surface area decreases to 33.09 m^2/g. On the contrary, the mass fraction of carbon dioxide absorption with modified halloysite is 17.21%, which is much higher than that of calcined halloysite, proving that carbon dioxide adsorption behavior on modified halloysite is mainly a chemical process.