Synthesis and Characterization of a Novel Multifunctional Carbon Molecular Sieve

Carbon molecular sieves were prepared from petroleum coke by chemical activation. The effects of activation temperature, holding time, preliminary treatments and activated agent ratio on surface area, pore structure of the carbon molecular sieves produced in our lab were investigated. The specific surface area and average pore size of the carbon are obviously increased with increasing use of activator and rise of activating temperature. The rate of elevating temperature is not specifically limited. But the heat-retaining time has much influence on the performance of the activated carbon. Suitable holding time may lead to high degree of activation, with result of increase in pore diameter of micropore and mesopore. But too long holding time can destroy pore structure and result in decrease of specific area. In addition, the effects of coke pre-oxidation on activating results were also investigated. Coke pre-oxidation leads to a remarkable decrease of mesopore volume. The carbon molecular sieves prepared in our lab are about 3000 m2/g in BET specific area. Diffraction peaks in XRD patterns indicate the generation of a new crystalline phase of carbon. The prepared carbon molecular sieves with extremely high specific area and uniform micropore distribution are ideal materials for natural gas adsorption storage as vehicular fuel. Carbon molecular sieves differing in BET surface area were used to evaluate the natural gas storage capacity on them at different pressures by two-vessel volumetric method at 293 K and up to 5.0 m a . In addition, this kind of carbon molecular sieve can also be used as microwave absorbent and PSA adsorbent for gas separation.