In view of the activated carbon pore-forming mechanism, the fractal hypothesis of pore interior growth was proposed by optimizing the structure of Sierpinski sponge. Based on the hypothesis and the definition of fractal dimension, the function relationship between the reaction degree, reaction step length, specific surface area and pore volume was deduced, and the pore fractal growth model of activated carbon activation process was established. Semi-coke, apple charcoal and lychee charcoal were used to prepare activated carbon. The pore size distributions of the activated carbons are in accordance with the fractal growth hypothesis. Further, the reaction degree and reaction step length can be determined by the experimental data of pore and surface structure, which verified the feasibility of the pore fractal growth model.

    Abstract
    1 Introduction
    2 Establishment of pore fractal growth model of activated carbon
        2.1 The hypothesis of fractal growth
        2.2 Calculation of fractal dimension, pore volume and surface area of activated carbon pores
    3 Preparation and characterization of pore structure of activated carbon
        3.1 Preparation of activated carbon
        3.2 Characterization of pore structure
    4 Calculation of fractal dimension of pores
    5 Determination of reaction degree and step length
    6 Conclusion
    Acknowledgements 
    References

• Junzhe Wang(College of Chemistry and Chemical Engineering, Xi’an University of Science and Technology, Shaanxi Coal Industry New Energy Technology Co., Ltd.)
• Anning Zhou(College of Chemistry and Chemical Engineering, Xi’an University of Science and Technology, Key Laboratory of Coal Resources Exploration and Comprehensive Utilization)
• Guoyang Liu(College of Chemistry and Chemical Engineering, Xi’an University of Science and Technology)
• Zongxing Song(College of Chemistry and Chemical Engineering, Xi’an University of Science and Technology)
• Chao Ma(Shaanxi Coal Industry New Energy Technology Co., Ltd.)
• Dan Wang(Shaanxi Coal Industry New Energy Technology Co., Ltd.)