高导热系数活性炭的制备及其性能

Preparation and properties of activated carbons with high thermal conductivity

基于传统的活性炭导热系数低,在脱附过程中容易产生局部过热现象,导致燃烧降低再生效率等问题,文章采用了在核桃壳原料中掺杂膨胀石墨制备高导热系数复合活性炭,分别考察了活化温度、活化时间、活化剂用量及膨胀石墨用量等不同工艺参数对活性炭结构性能的影响,对活性炭的比表面积、总孔容等进行了表征,结果表明:高导热系数活性炭的导热系数比普通活性炭提高了6倍。其直接热脱附床层温度低于实验室制备的普通活性炭25℃,同时,其甲苯脱附活化能为50.81 kJ/mol,低于在商业活性炭上的脱附活化能(68.01 kJ/mol)25%以上。保持良好的吸附性能的同时又具有很好的再生脱附效果,在活性炭脱附再生方面具有广泛的应用前景。

Due to low thermal conductivity of the traditional activated carbon, the desorption process is prone to local overheating, which leads to burning, thus reducing the regeneration efficiency and other issues. The activated carbon with high thermal conductivity was prepared by doped graphite composite with walnut shells as raw material. The influence of the different process parameters such as activation temperature, activation time, activator dosage and expanded graphite dosage on the properties of activated carbons were investigated, and the specific surface area, total pore volume and pore size distribution of activated carbons were characterized. The results show that the thermal conductivity of the optimal activated carbon is 6 times higher than those of activated carbons without added expanded natural graphite. The temperature difference in the composite activated carbon bed is 25 ~C. The desorption activation energy of toluene on the composite activated carbon is 50.81 kJ/mol, which is 25% lower than that on the industrial activated carbons （68.01 kJ/mol ）. It indicates that the activated carbon with high thermal conductivity not only maintains its good adsorption performance, but also has very good regeneration desorption effect, and has broad application prospects for regeneration of the activated carbon desorption.