废利乐包资源化回收铝及制备活性炭研究

将废利乐包热解并对获得的热解炭和铝箔进行分拣,再以热解炭为原料,K₂CO₃为活化剂制备活性炭。通过热重/差热-傅里叶变换红外光谱(TG/DTA-FTIR)联用对废利乐包的热解特性进行分析,采用自动气体吸附仪测定活性炭的氮气吸附/脱附曲线,采用FTIR对活性炭的表面官能团进行表征,利用TG-FTIR联用研究了活性炭的活化机理。结果表明,废利乐包中的纸和聚乙烯分别在365和490 ℃发生热解,铝箔则在664 ℃时熔化,填充剂CaCO₃在720 ℃发生分解。活性炭的比表面积和总孔体积分别为1 215 m ²/g和0.768 cm ³/g,其表面官能团主要为C=O、C—O—C和脂肪族C—H。热解炭本身含有的CaCO₃在740 ℃分解生成CO₂,CO₂会氧化刻蚀炭基体进行造孔;820 ℃之后熔融的K₂CO₃也会与炭基体反应生成CO并造成炭的损耗,上述2个过程均参与了活性炭的活化造孔。

Study on aluminum recovery and the preparation of activated carbon from Tetra Pak waste

Char and aluminum were obtained by pyrolysis of Tetra Pak waste and separated from each other. The activated carbon was prepared from the char as raw materials and K2CO3 as activator. The pyrolysis characteristics of Tetra Pak waste was investigated by thermogravimetric/differential thermal analyzer coupled with Fourier transform infrared spectrometer (TG/DTA-FTIR). The N2-adsorption/desorption curves of activated carbon were determined by automatic gas adsorption instrument and the surface functional groups of activated carbon were characterized by FTIR. TG-FTIR was used to gain insight into the activation mechanism of activated carbon. Experimental results showed that the pyrolysis of paper and polyethylene and the melting of aluminum in Tetra Pak waste occurred at 365, 490 and 664 ℃, respectively. The filler CaCO3 decomposed at 720 ℃. The specific surface area and total pore volume of activated carbon were 1 215 m 2/g and 0.768 cm 3/g, respectively, and the surface functional groups of activated carbon were mainly C=O、C—O—C and aliphatic C—H. The decomposition of CaCO3 contained in char at 740 ℃ led to the formation of CO2, and pores can be created via the in-situ reduction of CO2 by char; K2CO3 began to be melted at 820 ℃, and the molten K2CO3 reacted with the carbon matrix to form CO and caused the loss of carbon. Both processes were involved in the formation of pores of activated carbon.