摘要
为制备高性能刺竹活性炭,需将活化前刺竹炭进行脱灰处理。以刺竹为原料,采用单因素实验法研究酸浸水浸刺竹粉、炭化后与碱混合二次炭化刺竹炭、再次酸浸水浸刺竹炭三流程脱灰工艺。通过灰分含量测定,确定最佳脱灰工艺;通过傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、比表面积(BET)、电感耦合等离子体(ICP)测试,研究刺竹炭官能团、微观结构、元素含量变化等情况。实验结果表明,最佳脱灰工艺为:2 mol/L HCl酸浸刺竹粉,温度和时间分别为40℃和60 min;去离子水水浸刺竹粉温度和时间分别为40℃和40 min;炭化后刺竹炭与NaOH质量比1∶5进行二次炭化,温度和时间分别为600℃和1 h;最后2 mol/L HCl酸浸刺竹炭,温度和时间分别为20℃和40 min、去离子水浸刺竹炭温度和时间分别为40℃和40 min。刺竹炭灰分含量从7.91%降至0.50%,下降了93.68%。FT-IR分析得出脱灰处理对刺竹炭峰值影响较小,降低灰分的同时并不会破坏刺竹炭的主要结构;刺竹炭峰值强度明显增强,利于处理中反应的进行。元素含量分析得出酸浸、水浸对钾、钠、钙、镁元素脱除作用较明显,与碱混合二次炭化刺竹炭对铝和硅元素脱除作用较明显。BET与SEM分析得出随着三流程脱灰工艺进行,处理后的刺竹炭比表面积、总孔容、微孔容都呈上升趋势,结合各项测试表明部分脱灰工艺参数选择不当会造成灰分含量明显升高。
In order to prepare high-performance activated carbon from Bambusa sinospinosa, it is necessary to deash the charcoal before the activation process. In this experiment, Bambusa sinospinosa was used as a raw material, and three processes of deashing were studied by the single factor experiment: acid water soaking Bambusa sinospinosa powder, carbonization mixed with alkali for secondary carbonization of Bambusa sinospinosa charcoal, and acid water soaking Bambusa sinospinosa charcoal again. Through the determination of ash contents, the best deashing process was determined. The Fourier transform infrared spectrometer(FT-IR), scanning electron microscope(SEM), BET surface area(BET) and inductive coupled plasma emission spectrometer(ICP) were used to study the functional groups, microstructure, and element contents of Bambusa sinospinosa charcoal. The results showed that the optimum deashing process was as follows: 2 mol/L HCl acid soaking Bambusa sinospinosa powder at 40 ℃ for 60 min, deionized water soaking Bambusa sinospinosa powder at 40 ℃ for 40 min;the carbonized Bambusa sinospinosa charcoal and NaOH mass ratio of 1∶5 for secondary carbonization, secondary carbonization temperature and time at 600 ℃ for 1 h;at last, 2 mol/L HCl acid soaked Bambusa sinospinosa charcoal at 20 ℃ for 40 min, and deionized water soaked Bambusa sinospinosa charcoal at 40 ℃ for 40 min. The ash content decreased from 7.91% to 0.50%, with a decrease of 93.68%. The element content analysis showed that, there were more silicon, sodium, magnesium, potassium, iron, calcium, and aluminum, while relatively less boron, sulfur, phosphorus, manganese, and chromium, and extremely low other elements. The infrared spectrum analysis showed that the deashing treatment had slight effect on the peak value of Bambusa sinospinosa charcoal, and did not destroy the main structure of Bambusa sinospinosa charcoal while reducing ash content. However, the peak strength of Bambusa sinospinosa charcoal was obviously enhanced, which was beneficial to the reaction in the treatment. The element content analysis showed that the acid water soaking had obvious removal effect on potassium, sodium, calcium and magnesium, and the secondary carbonization of Bambusa sinospinosa charcoal mixed with alkali had obvious removal effect on aluminum and silicon. BET and SEM analysis showed that the specific surface area, total pore volume and micropore volume of treated Bambusa sinospinosa charcoal increased with the three-process deashing treatments. The specific surface area increased from 1.520 2 m~2/g to 408.555 9 m~2/g, the total pore volume increased from 0.003 2 cm~3/g to 0.176 5 cm~3/g, and the micropore volume increased from 0.000 7 cm~3/g to 0.172 5 cm~3/g. Combined with various tests, the excessive NaOH would produce insoluble silicic acid colloid, which would increase the ash content and block the pores. It was difficult to separate from the Bambusa sinospinosa charcoal, showing that the improper selection of some deashing process parameters would cause obvious increase in ash content.
作者
邵远超
田华宇
王国睿
郝海彦
张敏
张文标
SHAO Yuanchao;TIAN Huayu;WANG Guorui;HAO Haiyan;ZHANG Min;ZHANG Wenbiao(College of Chemistry and Materials Engineering,Zhejiang A&F University,Hangzhou 311300,China;Jinglei Science and Technology Co.Ltd.,Yibin 644000,China)
出处
《林业工程学报》
CSCD
北大核心
2023年第1期80-87,共8页
Journal of Forestry Engineering
基金
浙江省重点研发计划项目(2021C03146)。
关键词
刺竹炭
碱酸处理
脱灰
孔隙结构
元素含量
性能表征
Bambusa sinospinosa charcoal
alkali and acid treatment
deashing
pore structure
element content
performance characterization
