Studies On The Activation Process And Separation Ability Of Pitch-based Molecular Sieve ACF

In this work, pitch-based activated carbon fibers (PACF) were prepared from pitch-based carbon fiber (PCF) through oxidation, carbonization and activation. The activation process and reaction mechanism of PACF with narrow pore size distributions and highly selective adsorption were studied. The preparation conditions, microstructure, adsorption ability and the effect of microstructure on separation ability of PACF were discussed.In this paper the work mainly contains the studies on carbonization and three kind multiplex activation processes, the tests on adsorption ability of PACF and investigation on separation ability of PACF with CH₄/CO₂ separation system as study object. The mainly results as follows:The results from the study of carbonization influences on the properties of PACF indicate that carbonization can improve the yield, surface area and adsorption ability of PACF evidently. Carbonization can reduce the crystal order degree of PCF and PACF evidently. So carbonization is propitious to disorder of graphite-like crystal layer and formation of a great deal micropores.The experiment studies on the three multiplex activation methods indicate that air oxidation makes PCF to form a great deal micropores and active points of reaction. This is propitious to that active agents react with amorphism carbon or fringe carbon atoms under the more mild reaction condition and pore size distribution becomes narrow. Meanwhile, the yield and surface area of PACF are increased at a certain extent. Because air and vapor all have high reactivity and they are so easy to react with more steady crystallite that make the pore wall falls in and bring some big pore, so this makes against producing PACF with narrow pore distribution. The reactivity of vapor with PCF is higher than carbon dioxide. The multiplex activation method about vapor and carbon dioxide can prepare PACF with high surface area.