成型生物质快速热解炭制备活性炭活化工艺研究及其性能表征

Activation process and characterization of activated carbon derived from fast pyrolytic char

采用水蒸汽为活性介质,对粉状樟子松快速热解炭(FPC)与生物油酚醛树脂(BPF)粘结剂混合模压成型物——成型热解炭进行活化处理,得到了成型活性炭(ACM)。采取正交试验方法,考察了活化温度、活化时间和活化剂流量对ACM碘值、亚甲基蓝吸附值和抗压强度三项性能指标的影响,优化了ACM活化工艺;采用比表面积及孔隙度分析仪、X射线衍射仪、傅里叶红外光谱仪、元素分析仪及场发射电镜扫描仪对ACM孔隙结构与理化性能进行了表征。结果表明:活化过程中各因素对ACM抗压强度、碘值及亚甲基蓝吸附值作用差异程度依次为活化温度、活化时间和活化介质流量;最佳活化工艺为活化温度800℃,活化时间60min,活化介质流量600mL/min;ACM碘及亚甲基蓝吸附值分别为690.64mg/g和111mg/g,BET比表面积为731.303m^2/g,总孔容为0.5892cm^3/g,平均孔径为3.223nm,抗压强度达到3.74MPa;ACM呈介孔吸附特点,石墨化程度较低,表面活性较强,含有酚、醇、醚、酯和烯烃等多种官能团,同时具有吸附能力和催化作用,可用于生活污水处理。

Activated carbon monoliths（ACM）were prepared by H_2O activation method using powered fast pyrolytic char（FPC）as a raw material and bio-oil phenol-formaldehyde（BPF）resin as a binder.The effect of activation temperature,activation time,and activation medium flow on the physical and mechanical properties（iodine adsorption value,methylene blue adsorption value,compressive strength）of resultant was investigated.The properties of ACM were observed using BET,XRD,FT-IR and SEM,etc.The results showed that the main influential factor was activation temperature,followed by the activation time,with the activation medium flow being relatively less.The optimum conditions were activation temperature of 800℃,activation time of 60 min and activation medium flow of 600 mL/min.The adsorption values of iodine and methylene blue reached 690.64 mg/g and 111 mg/g respectively.BET surface area,total pore volume and average pore diameter were 731.303 m2/g,0.5892 cm3/g and 3.223 nm.The compression strength of activated carbon monolith reached 3.74 MPa.ACM appeared to be mainly mesoporous with low graphitization and contained phenol,alcohol,ether,ester and olefin groups which could be used in sewage treatment.