棉杆活性炭的制备及其结构表征

Preparation and structure characterization of activated carbon from cotton stalk

以棉花秸秆为原料,ZnCl_2与AlCl_3组成的熔盐为活化剂,采用化学活化法制备活性炭。利用正交实验探讨了熔盐与原料比例、ZnCl_2与AlCl_3的比例、浸渍时间、活化温度、保温时间对制备的活性炭收率和碘吸附性能的影响,得到了熔盐活化法制备棉杆活性炭的最佳工艺条件:熔盐与棉杆比例为1.5:1、熔盐中ZnCl_2与AlCl_3比例为9:1、浸渍时间16 h、活化温度650℃、保温时间90 min,在此工艺条件下制备的活性炭的收率为23.06%,碘吸附值为708.32 mg/g;采用SEM和XED对制备的活性炭进行表征,结果表明:活性炭的表面分布了发达的、大小形状不一样的孔洞,且活性炭内部是由类石墨结构组成的,但石墨微晶层片排列比较紊乱,石墨化程度不高。

Activated carbon was prepared by molten salt of ZnCl2 and AlCl3 using cotton stalk as raw material.The effects of the ratio of molten salt to cotton stalk,the ratio of ZnCl2 to A1C13,impregnation time,activation temperature and holding time on the yield and iodine adsorption property of activated carbon were evaluated via orthogonal array design.It indicated that the optimum process was as follows：the ratio of molten salt to cotton stalk of 1.5：1,the ratio of ZnCl2 to AlCl3 is 9：1,impregnation time of 16 h,activation temperature of 650℃,and holding time of 90 min.Under the process condition,the yield of activated carbon is 23.06%,and the iodine adsorption value is 708.32 mg/g.Activated carbon was characterized by SEM and XRD.The results show that there are developed holes with different size and shape on the surface of the activated carbon.And the activated carbon is made up of graphite-like structure,but the microcrystalline layer of graphite is disordered,and graphitization degree is not high.