EFFECTS OF SURFACE-FLUORINATION ON GAS ADSORPTION OF CARBON MOLECULAR SIEVES FOR CO_2 CAPTURE

摘要

Introduction The concentration of carbon dioxide (CO_2) and the main source of CO_2 emissions is from the combustion of fossil fuels in the atmosphere continue to increase, and serious concerns about the effects of CO_2 on the environment have been raised [1]. In order to reduce these environmental concerns, the removal of carbon dioxide is becoming necessary. Carbon dioxide can be removed by several, methods, including membrane separation, adsorption, and absorption [2]. Among these methods, adsorption processes present many advantages. Many adsorbents are easy to regenerate and exhibit high adsorption capacities and separation rates [3]. In particular, carbon molecular sieves (CMSs) possess specific pore size distributions (PSDs). The most important feature of CMSs is their narrow pore size distribution, which can be attained by controlled activation [4] or by conducting pore-narrowing techniques on the inherent pore structure. Many researchers have conducted surface treatments to increase the CO_2 adsorption capacity of a material. Among the surface treatments, fluorination is one of the most effective methods because of the high reactivity' of fluorine gas with carbon at room temperature [5]. In the this study, the surface of CMSs was modified by fluorination. Fluorination changed the surface properties and pore structure of the CMSs and showed significant effects on the CO_2 gas adsorption.