ＲＩＴＥ−ＣＨＩＢＡ LＡＢＯＲＡＴＯＲＹ in Kawasaki Steel Corporation

Coal pitch-derived activated carbon fiber, made from coal tar pitch as a major source materials, is characterized by higher yield than that from other materials, because of higher contents of carbon in pitch, and by higher adsorption capacity than that of conventional activated carbon because of finer fiber configuration.

The development of an innovative continuous fabrication process and high functional adsorber has been achieved by introducing a spheroidizing step of pitch-based fiber into the production to improve the functional performance by optimizing the porous structure to meet the specific application requirements, such as (1) reduction of the contents of volatile hydrocarbon, and (2) separation or recovery of CO2 or other gases, and the basic manufacturing technology has been studied with a bench-scale system.

(1) Volatile hydrocarbon adsorber has been prepared by processing spher oidized carbon fiber so as to achieve high efficiency adsorption of gasoline and other volatile hydrocarbon and excellent desorption properties in air, through the study on technology of controlling mesoscopic pore size distribution above 20Å, and the product of trial manufacturing has been evaluated by measuring the effective adsorption capacity for butane.

Consequently, very effective adsorber for volatile hydrocarbon of butane working content (BWC) as high as 12.1g/100cc (up to 14.3g/100cc at a purge flow rate of 645cm3/min) has been obtained by carbonizing and activating spheroidezed high density fiber in a ratory kiln.

(2) Separation/recovery agent for CO2 and other gases has been manufactured through the development of control technology for microscopic pore size (smaller than 10Å, normally 3-5Å) and its distribution, and the practical performance of CO2/methane separation has been evaluated by use of a pass-through curve measuring system.

Consequently, the molecular s ieve properties has been given to spheroidized active carbon fiber through the continuous carbonization process in a rotary kiln, and a molecular sieve gas separation/recovery agent suited for separation of CO2 and methane has been obtained.

The technology for fabricating volatile hydrocarbon adsorber and gas separation/recovery agent from coal tar pitch, as described in the above, has been implemented in the bench-scale level.