几种干果核壳活性炭的表征与性能比较

Characterization and Properties of Activated Carbon from Several Nut Shells

以南疆地区盛产的巴旦杏核壳、核桃壳和白杏核壳为原料,采用微波辐照磷酸法分别制备了巴旦杏核壳活性炭（BAC）、核桃壳活性炭（HAC）和白杏核壳活性炭（XAC）,干果核壳基质活性炭的制备工艺：10 g干果核壳以固液比1∶3（g∶mL）浸渍40%磷酸24 h,微波功率640 W,活化时间16 min。采用物理吸附仪、扫描电镜（SEM）、傅里叶红外光谱（FT-IR）、X射线衍射（XRD）等表征方法比较研究了不同种类干果核壳活性炭性能差异。结果表明：巴旦杏核壳、核桃壳和白杏核壳活性炭的热分解过程、残留基团基本一致,活性炭晶型均以非晶态为主。3类干果核壳活性炭表面分布着大量孔洞,且孔洞主要为0.4~1.2 nm的微孔和3~6 nm的中孔。其中,白杏核壳活性炭的性能最优,BET比表面积达981.5 m2/g,总孔容达0.570 cm3/g,亚甲基蓝吸附值达269.6 mg/g,碘吸附值达1 162.8 mg/g。

A series of activated carbon was prepared using almond shell,walnut shell and white apricot shell as raw materials by microwave radiation with H3PO4as activating agent.Activated carbon was carbonized and activated by the nut shell immersed in the mass fraction of H3PO440% solution,liquid ratio 1 ∶ 3.After 24 h of immersion,the microwave with power of 640 W irradiated for 16 min.Pyrolysis mechanism,micromorphology,microstructure,components,nitrogen adsorption-desorption isotherm and pore size distribution of activated carbon were analyzed by TG,XRD,FT-IR,SEM,BET etc.The activated carbon obtained from nut powder by almond shell,walnut shell and white apricot shell have the approximate consistent on the thermal decomposition process and functional groups.They are a typical non-graphitizable.The nut shell of activated carbon has abundant interconnected pores and pore spaces,which size is about 0.4 to 1.2 nm of micropore and 3 to 6 nm of mesopore.It is shown that white apricot shell activated carbon has porous characteristic structure with 981.5 m2/g for specific surface area and 0.570 cm3/g for total pore volume.The adsorption value for methylene blue by white apricot shell activated carbon is 269.6 mg /g,and the iodine value is 1 162.8 mg /g.