尾巨桉稀碱抽出物热解特性的研究

Pyrolysis mechanism of dilute alkali extractives from eucalyptus grandis

采用1%稀碱溶液在回转式密封炉下对按木片进行抽提预处理,获得稀碱抽提固形物(AES)和稀碱抽提木质素(AEL).利用热重分析和热裂解-气相色谱/质谱联用分析等对AES和AEL进行了热解特性分析.结果表明,AES中含有的酯类和糖类等物质是其最大失重峰峰值温度低的原因之一;此外,AES中的Na盐对有机物大分子的热分解起到了催化促进作用,亦降低了其受热分解的峰值温度.AES和AEL主要的热解产物均是酚类物质,但AES的热解产物较AEL复杂.

Eucalyptus grandis chips were pretreated under 1% NaOH solution with a sealed helicoid furnace to get solid alkali extractives（AES） and lignin from alkali extraction（AEL） . TG and PyGC/MS experiments were designed to explore the pyrolysis properties of AES and AEL .The results showed that the peak temperature of maximum weight loss of AES was lower than that of AEL .On one aspect carbohydrates and esters in AES caused this phenomenon .The catalysis of Na salt was the other main reason ,which lowered the peak temperature of maximum weight loss .Phenols were the main pyrolysis products of both AES and AEL ,but pyrolysis products of AES were more complex than those of AEL .