热分析在椰壳活性炭制备过程中的应用

Application of Thermal Analysis in Preparation of Cocoanut Activated Charcoal

以椰壳炭为原料，水为活化剂，利用同步热重-差热分析（TG—DTA）仪对椰壳炭活化的机理、浸渍时间、反应热效应以及微波辐照对椰壳活性炭制备的影响进行了探讨。实验表明，不同的椰壳炭都有一个吸热脱水失重阶段。随着浸渍时间的增加，活化点、失重率以及相应放热温度区间的上限温度均增加，当浸渍时间由24h延长到48h时，390～998℃失重率由11．001％增加到32．048％，放热温度区间的上限温度由660℃增加为855℃，放热效应有利于水蒸气与椰壳炭在800～900℃高温下的吸热活化反应，同时有利于使水一椰壳炭通过微波辐照迅速达到活化反应温度，为椰壳活性炭的制备提供理论依据。

Cocoanut activated charcoal was prepared by microwave radiation using cocoanut charcoal as material and water as activator. The activating mechanism and the effects of dipping time, reaction heat effect and microwave radiation on the preparation were researched using a simultaneous thermogravimetric-differential thermal analyzer （TG-DTA）. The results indicate that all kinds of cocoanut charcoal have a period of endotherm and dehydration. With the increase of dipping time, the number of activated points, the rate of weight loss and the ceiling temperature of relevant heat liberation interval are increased. When the dipping time extends from 24 h to 48 h, the rate of weight loss at 390 - 998℃ increases from 11. 001% to 32. 048%, the ceiling temperature of relevant heat liberation interval increases from 660℃ to 855℃. Heat liberation effect is helpful to the heat absorption and activating reaction of water vapor with cocoanut charcoal in high temperature of 800- 900℃, and also helpful to rapid increasing of water-cocoanut charcoal temperature to activating reaction temperature by microwave radiation. The study results provide significant theoretical parameters for the preparation of cocoanut activated charcoal by microwave radiation.