Pyrolysis of Cellulose Residue from Disogenin with Zinc Chloride

The understanding of the mechanism of activated carbon prepared from cellulose residues from the acid hydrolysis of Discorea zingiberensis C.H.Wright may help us to investigate systematically, with the help of TG-FTIR, the pyrolysis of the carbonization with ZnCl₂ on different conditions. The pyrolysis was related to such different conditions as impregnation ratio, atmosphere, and heating rate. At a low temperature, oxygen prompts the formation of activated carbon, but results in the loss of carbon at a high temperature. The lower activated temperature could be adopted on the condition that the higher impregnation ratio is employed since more ZnCl₂ may erode raw material into a harder one. The organic matters of raw material can store more heat for the decomposition at a lower heating rate corresponding to a lower activated temperature. The trends for gas emission analyzed by FTIR were similar to that by TG, which proved that there was no time delay between them. Accordingly, the primary process for the preparation of activated carbon is determined as follows: the raw material was carbonized at about 300℃, then was activated at about 500℃ with deoxidizing atmosphere (eg.N₂) at the heating rate of 10 k/min. It is recommended that the highest temperature for activation should not go beyond 650℃ even on the condition of the industrial production.