Studies of steam-activated viscose rayon chars

Abstract

Standard techniques, such as nitrogen adsorption, mercury porosimetry, and X-ray photoelectron spectroscopy, have been used to characterise steam-activated viscose rayon-derived chars pretreated with aqueous solutions of boron- or phosphorous-containing compounds. It was found that some significant differences existed between chars prepared with these two impregnants, which were highlighted by using transmission electron microscopy. Staining techniques improved both the contrast and quality of the micrographs and thus pore size distribution within the fibre cross-section, pore size, and shape became much more easily defined. Mechanisms of gasification have been postulated on the basis of these latest findings. © 1992.