GRINDING EFFECT ON SUPERHEATED STEAM PYROLYSIS OF CELLULOSE
Authors: Tomohiro Iwasaki
Abstract: In order to develop a high-efficiency treatment process of woody biomass for use as a resource and energy source, we have studied a direct liquefaction process using superheated steam in which cellulose was used as a model material of woody biomass. The co-grinding of cellulose with and without iron compounds as additive was carried out, and the grinding effects on the superheated steam pyrolysis were examined. It was found that the amorphization of cellulose promoted the formation of cross-linking between cellulose molecules during dehydration and thermal decomposition by breakage of the glycosidic linkage in the amorphous region of cellulose. As a result, the yield of lower free fatty acids produced in the superheated steam pyrolysis increased. Furthermore, in the pyrolysis of co-ground cellulose with iron(II) salts, iron(II) ions embeded into the structure of cellulose could enhance the generation of radicals, resulting in the promotion of pyrolysis. Consequently, the yield of lower free fatty acids in the superheated steam pyrolysis of cellulose can be controlled by the crystallinity of cellulose and the kind of iron compounds added in the co-grinding treatment.