微波椰壳活性炭制作过程中的热分析研究

Preparation of Activated Carbon of Coconut Shell with Microwave Radiation by Thermal Analysis

以椰壳炭为原料，水为活化剂，利用同步热重／差热分析仪（TG／DTA）对椰壳炭活化的机理、反应热效应以及微波辐照对微波椰壳活性炭制备的影响进行了探讨。结果表明：在40℃／min升温条件下，不同的椰壳炭都有一个吸热脱水失重阶段。浸渍后失重速率、活化点以及相应放热温度区间也随着增加。椰壳炭浸渍时间为48h，在390～998℃失重达到32．048％，放热温度区间为153．62～855℃，放热效应有利于水蒸气与炭在800～900℃高温下的吸热活化反应，同时微波辐照能使水一椰壳炭迅速达到活化反应温度。当活化时间为3～5min，水蒸气流量为3．5～5．5mL／min时，微波椰壳活性炭的碘吸附值达到1031mg／g，亚甲基蓝吸附值达到10mL·0.l／g。研究结果为微波椰壳活性炭的制备提供了理论依据。

Preparation activated carbon from the charring coconut shell with the water as active agent by simultaneous measurements of thermogravimetry and differential thermal analysis was studied. Effects of activating mechanisms of the charring coconut shell, enthalpy and microwave radiation on the preparation of activated carbon by microwave radiation were obtained. According to the experimental data, thermal analysis curves of different the charring coconut shell all had a heat absorption and water loss stage in 40℃ heating rate. Soaked in the water increase the weight loss rate, activating point and heat releasing temperature interval. The soak time was 48 h, weight loss reach at 32. 048% in temperature range 390-998 ℃, heat releasing temperature interval was from 153.62 ℃ to 855 ℃, enthalpy of heat releasing was helpful for activating and heat absorption reaction of the charring coconut shell in high temperature from 800 ℃ to 900 ℃. Water-charring coconut shell reached at activating reaction temperature rapidly by microwave radiation. Activated time was 3- 5 min, flow rate of water vapor was 3.5 5.5 mL/min, experiment showed that iodine value of activated carbon was 1 031 mg/g, methylene blue adsorption was 10 mL 0.1/g. The study results provided significant theoretical parameters in preparation of activated carbon of the charring coconut shell by microwave radiation.