Influence of heat-treatment on the selective adsorption of CO2 in a model natural gas over molecular sieve carbons
✍ Scribed by Isao Mochida; Shunsuke Yatsunami; Yuji Kawabuchi; Yusuke Nakayama
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 766 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0008-6223
No coin nor oath required. For personal study only.
✦ Synopsis
The kinetically selective adsorption of CO2 in CH, was studied using three commercially available molecular sieve carbons. All as-received carbons examined in this study exhibited poor kinetic selectivity. However, heat-treatment at around 1273 K significantly improved the kinetic selectivity of one carbon (K-MSC) with the least decrease of adsorptive capacity of COz. No improvement was obtained with other two carbons. The heat-treatment at 1273 K removed oxygen functional groups on the surface of K-MSC and significantly increased the degree of graphitization. The extent of graphitization of the other carbons remained unchanged by heat-treatment. The increasing degree of graphitization caused shrinkage of K-MSC and controlled the slit width of the pores. Higher temperature of the heattreatment further increased the kinetic selectivity but markedly reduced the adsorptive capacity because of too much shrinkage, owing to excess graphitization. Heat-treatment at 1273 K enhanced the hydrophobicity of the carbon surface and reduced the inhibition of CO, adsorption by water in the relative humidity range of O-50%. At higher humidity, the effect was minimal as condensation on the pore wall occurred. Removal of oxygen functional groups by heat-treatment appears favorable for improving this kind of selectivity.