摘要
磷酸活化法是目前工业上生产生物质基活性炭的主要方法,但较高的灰分含量限制其在医药、食品等高端领域应用。基于此,以湿法磷酸为活化剂、废木屑为碳源,研究活化条件(温度、时间等)和洗涤条件(介质、酸浓度、温度等)对活性炭灰分及性能的影响,运用TG、FT-IR、XRD、SEM和TEM等表征方法分析活性炭的表面性质和微观结构。结果表明,难溶性磷酸盐是活性炭灰分产生的主要因素,通过控制活性炭制备和洗涤工艺可调控难溶性磷酸盐含量,从而调控活性炭灰分、碘值和亚甲蓝值。获得最佳工艺条件:活化温度为500℃、活化剂H_(3)PO_(4)质量分数为70%、酸屑质量比为2∶1、活化时间为60min及N_(2)气氛保护;洗涤液用量为100mL、洗涤介质为H_(3)PO_(4)、H_(3)PO_(4)质量分数为20%、洗涤温度为80℃及洗涤时间为60 min。最佳工艺条件下制备的活性炭灰分为1.07%、碘值为1241.4 mg/g、亚甲蓝值为285 mg/g、比表面积为2290 m^(2)/g,表明该技术制备的活性炭具有应用于食品、医药等高端行业领域的潜质。
Phosphoric acid activation is currently the main method for industrial production of biomass-based activated carbon,but the higher ash content limits its application in high-end fields such as medicine and food.Based on this,the effect of activation conditions(temperature,time,etc.)and washing conditions(medium,acid concentration,temperature,etc.)on the ash content and properties of activated carbon was investigated by using wet phosphoric acid as the activator and waste wood chips as the carbon source,and the surface properties and microstructure of activated carbon were analyzed by using TG,FT-IR,XRD,SEM and TEM characterization.The results showed that insoluble phosphate was the main factor in the generation of activated carbon ash,and that the activated carbon ash,iodine and methylene blue values could be regulated by controlling the activated carbon preparation process and washing process.The optimal process conditions were activation temperature of 500℃,phosphoric acid concentration of 70%,acid to chip ratio of 2∶1,activation time of 60 min,N_(2) protection,washing solution dosage of 100 mL,washing solution concentration of 20%,washing medium of H_(3)PO_(4),washing temperature of 80℃and washing time of 60 min.The activated carbon prepared under these conditions had an ash content of 1.07%,iodine value of 1241.4 mg/g,methylene blue value of 285 mg/g,specific surface area of 2290 m^(2)/g,indicating that the activated carbon prepared by this technology had the potential to be applied in high-end industries such as food and medicine.
作者
张丽
张丹
潘红艳
董永刚
李文飞
秦红
ZHANG Li;ZHANG Dan;PAN Hongyan;DONG Yonggang;LI Wenfei;QIN Hong(School of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China;Guizhou Wengfu Chemical Co.,Ltd.,Guiyang 550002,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2024年第2期95-103,120,共10页
Inorganic Chemicals Industry
基金
国家自然科学基金项目(22262068009、22262006)
黔科合基础-ZK[2003]050
黔科合支撑项目([2003]043)
贵州省教育厅创新集群项目(2021010)。
关键词
活性炭
湿法磷酸
灰分
吸附性能
activated carbon
wet-process phosphoric acid
ash
adsorption performance
