31. A preliminary study of preparation of carbon fiber from supercritical extracts of Loy Yang

Abstract

We have shown that Loy Yang could be liquified by treatments in supercritical alcohols to give phenols such as phenol, cresols and xylenols as well as unidentified heavy components. In the present study, we conducted a preliminary study on preparation of carbon fibers from the heavy components obtained by decomposition of Loy Yang with supercritical iso-propanol at conditions of 400℃ and 280kg/cm^2. The obtained liquid products were fractionated with THE and hexane, then the obtained TS-HI and HS fractions were subjected to inspections of thermal behavior, spinnability, stabilization treatment and carbonization behavior. Particularly HS showed an excellent spinnability, so this component was spun into fiber after heat treated at 200℃ for 15min. Stabilization with an acidic formaldehyde aq. soln gave an increase in the carbon yield for carbonization up to 500℃, however finally gave only 24% of yield at 1000℃ without leaving fiber forms. It was concluded that preparing carbon fibers from brown coals should be possible by some improvements of HS component such as increasing the melting points and finding a proper stabilization techniques.