黄姜皂素纤维渣的氯化锌热解特性

Pyrolysis of Cellulose Residue from Disogenin with Zinc Chloride

探讨氯化锌活化黄姜皂素纤维渣的机理,应用TG-FTIR联用技术考察了黄姜皂素纤维渣的氯化锌热解特性.不同的配比、氛围及升温速率对热解均有影响.低温氧化有利于活性炭的形成,但高温氧气的存在对炭体烧失较大;氯化锌与原料的配比越高,对原料的侵蚀性越强,采取相应的活化温度较低;升温速率越低越有利于原料中有机质蓄积热量热解,相应的活化温度也越低;红外光谱图也表示挥发分产物的出现与热重分析相符,没有时间滞后现象.因此,确定制备活性炭的初步工艺为先在300℃左右低温炭化,再在保护气氛中(如N2)500℃左右活化,升温速率10K/min左右.工业生产条件下,活化温度最高不宜超过650℃.

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.