Box-Behnken design approach towards optimization of activated carbon synthesized by co-pyrolysis of waste polyester textiles and MgCl2

• Published in: Applied surface science 2018-01, Vol.427, p.340-348
• Main Authors: Yuan, Zhihang, Xu, Zhihua, Zhang, Daofang, Chen, Weifang, Zhang, Tianqi, Huang, Yuanxing, Gu, Lin, Deng, Haixuan, Tian, Danqi
• Format: Article
• Language: English
• Subjects: Activated carbon; Box-Behnken design; MgCl2; Waste polyester textiles
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.08.241

•Activated carbons were prepared from waste polyester textiles (WPT) and MgCl2 by co-pyrolysis method.•Optimum preparation conditions of activated carbons were determined efficiently by Box-Behnken design.•AC-MgCl2 presented higher surface area, pore volume and more turbostratic structure compared to AC-CO2.•Pore-forming mechanism of AC-MgCl2 could be interpreted as the template action of MgO as well as the dehydration of MgCl2. Pyrolysis activation of waste polyester textiles (WPT) was regarded as a sustainable technique to synthesize multi-pore activated carbons. MgO-template method of using MgCl2 as the template precursor was employed, which possessed the advantages of ideal pore-forming effect and efficient preparation process. The response surface methodology coupled with Box-Behnken design (BBD) was conducted to study the interaction between different variables and optimized preparation conditions of waste polyester textiles based activated carbons. Derived from BBD design results, carbonization temperature was the most significant individual factor. And the maximum specific surface area of 1364m2/g, which presented a good agreement with the predicted response values(1315m2/g), was obtained at mixing ratio in MgCl2/WPT, carbonization temperature and time of 5:1, 900°C and 90min, respectively. Furthermore, the physicochemical properties of the sample prepared under optimal conditions were carried on utilizing nitrogen adsorption/desorption isotherms, EA, XRD, SEM and FTIR. In addition, the pore-forming mechanism was mainly attributed to the tendency of carbon layer coating on MgO to form pore walls after elimination of MgO and the strong dehydration effect of MgCl2 on WPT.