摘要
半焦具有固定碳含量高、反应性好、孔隙发达等特点,是一种良好的吸附剂,其表面含有大量含氧官能团,易被修饰,通常用作吸附剂或催化剂,经过改性的半焦可以产生更多的孔隙,具有更好的吸附能力。为了研究化学改性对半焦吸附性能的影响,以神木气体热载体立式热解炉生产的半焦为原料,采用酸、碱等不同改性处理方式对其进行改性。通过FTIR、SEM、氮气吸附等方法研究了酸、碱对半焦的孔结构、形貌、比表面积以及脱灰率和吸附性能的影响。结果表明:半焦经过处理后灰分降低,酸碱联合处理脱灰率高达89.5%。酸改性后的半焦其羧酸、酚类等表面酸性含氧基团的数目增加,比表面积、孔容、孔径以及对亚甲基蓝和碘值的吸附量均有所降低。而碱改性后的半焦比表面积、孔容、孔径以及对亚甲基蓝和碘值的吸附量均增加,表面微孔数量增多,微孔比表面积和微孔孔容分别为0.0097 m^(2)/g、35.5194 cm^(3)/g,对亚甲基蓝和碘值的吸附量为1.05、714.11 mg/g,表现出良好的吸附性能。不同改性处理条件下,半焦吸附性能的高低分别为:碱处理半焦>原半焦>酸碱联合处理半焦>酸处理半焦。
Semi-coke is a good adsorbent because of its high fixed carbon content, good reactivity and developed pores. Its surface contains a large number of oxygen functional groups, which is easily modified, often used as an adsorbent or catalyst.More pores and better adsorption capacity can be produced by the modified char. In order to study the influence of chemical modification on the adsorption property of semi-coke, the semi-coke produced by Shenmu gas heat carrier vertical pyrolysis furnace was used as raw material and modified by different modification methods such as acid and alkali. The effects of acid and alkali on the pore structure, morphology, specific surface area, deashing rate and adsorption property of semi-coke were studied by FTIR,SEM and nitrogen adsorption methods. The results show that the ash content of semi-coke is reduced after treatment, and the deashing rate of acid-base combined treatment is up to 89.5%. After acid modification, the number of surface acid oxygen-containing groups such as carboxylic acid and phenolic increase, and the specific surface area, pore volume, pore size and adsorption capacity of methylene blue and iodine value decrease. After alkali modification, the specific surface area, pore volume, pore size and adsorption capacity of methylene blue and iodine value increase, and the number of micropores on the surface increase. The specific surface area and pore volume of micropores are 0.009 7 m^(2)/g and 35.519 4 cm^(3)/g,respectively. The adsorption capacities of methylene blue and iodine are 1.05 mg/g and 714.11 mg/g, showing good adsorption performance. Under different treatment conditions, the adsorption performance of semi-coke is as follows: alkali treatment semi-coke>primary treatment semi-coke > acid-base combined treatment semi-coke>acid treatment semi-coke.
作者
李军
LI Jun(Yulin Shenhua Energy Co.,Ltd.,Yulin719000,China)
出处
《洁净煤技术》
CAS
北大核心
2021年第5期152-156,共5页
Clean Coal Technology
关键词
半焦
酸改性
碱改性
孔结构
吸附性能
semi-coke
acid modification
alkali modification
pore structure
adsorption performance
