木质原料性质对KOH活化法制备活性炭的影响

Effect of Raw Material Properties on Activated Carbon Prepared with KOH Activation

以北方落叶松、杨木、桦木、浸提落叶松锯屑和麦秸为原料,采用KOH化学活化,在相同条件下制备高比表面积活性炭,研究原料性质对活性炭的得率、灰分质量分数、比表面积及碘值的影响。以麦秸为原料制得活性炭比表面积最高,为3753.39m2/g;以浸提落叶松为原料制得活性炭得率最高,为22.82%;以落叶松为原料制得活性炭灰分质量分数最高,为10.7%。结果表明:m(KOH)∶m(原料)=4∶1,750℃活化1h,木质素质量分数是活性炭比表面积的主要影响因素。木质素质量分数越高,所制得的活性炭比表面积越小,且碘值相应减小。对针、阔叶材来说,木质素质量分数越大,活性炭的得率越大,且原料灰分对得率的影响没有木质素大。

the same preparation condition, sawdust of larch, poplar, birch, extracted larch and wheat straw was used as starting material for activated carbon production with KOH as activating reagent. Effect of the compositions of raw materials on the yield ratio, specific surface area, iodine adsorption value and ash of activated carbon were systematically investigated. The highest specific surface area, yield ratio and ash of the activated carbon were obtained from the wheat straw, the extracted larch and the larch, with the value of 3753.39 m^2/g, 22.8% and 10.7%, respectively. Result showed that, under the same conditions at a ratio of KOH to sawdust 4： 1, temperature 750 degrees C and retention time 1 hour, the lignin content was the most important factor for the specific surface area. Higher lignin content resulted in the smaller specific surface area and iodine adsorption value. However, yields changed in the opposite tendency. The effect of ash content in the material on the yield of activated carbon was less significant than that of lignin content.