Preparation Of Phenol Formaldehyde Based Microfiltration Carbon Membrane And Carbon Molecular Sieve Memerane

Carbon membrane, a new kind of inorganic membrane, has been rapidly developed in recent years for its high thermal and chemical stability. Carbon membrane for microfiltration has been reported in commercial use, while carbon membrane for gas separation is still in the laboratory scale. In this paper, PF (phenol formaldehyde resin)-based carbon membranes have been prepared for microfiltration and gas separation.The commercially available PF novolac resin was cured partly and ground followed by mixing into dough with additives and water. The dough was then extruded to form a tube. The tube was dried and then carbonized in an argon atmosphere. The gas bubble pressure method was selected to determine the pore size distribution of the carbon membrane and SEM for the microstructure of carbon membrane. The results indicated that the structure of the carbon membrane is micrometer scale. The N2 permeation rate is 10-3 -10-1 cm3/cm2.s.cmHg. Low particle size of raw material, high molding pressure, high methyl cellulose content and high carbonization temperature resulted in carbon membrane with a narrow pore size distribution, smaller mean pore size and low N2 permeation rate. By activated with C02 it can open the closed pore and increase the pore size of carbon membrane.In this paper, a new method, pre-crosslinking control method, has been developed for controlling the pore structure of carbon membrane. By this method, the pore structure of carbon membrane was controlled by adjusting the fusibility of resin through varying the hexamine content used in the pre-crosslinking treatment. Compare with conventional method, this method is simple and the pore size can be controlled in a wider range.Besides the PF novolac resin, the homemade thermosetting PF resin was also used for preparing carbon membrane. In the experiment, thermosetting PF resin was mixed with adhesive and water and the dough was molded and carbonized. Compared with PF novolac resin, the thermosetting PF need more adhesive for molding. In addition, the particle of novolac resin is lumpish while the particle of thermosetting...