Investigation of Activation Time on Pore Size Distribution of Activated Carbon Determined with Different Methods

Document Type : Original Research Paper


Chemical Engineering Department, University of Shahid Bahonar, Kerman, I.R. Iran


Three activated carbons are synthesized in a rotary reactor at different activation times. The adsorption isotherms of the samples are measured The pore size distribution of the samples is determined using combined Saito and Foley method, BJH method. An average potential function has been determined inside the cylindrical pores. The effect of activation time on the pore size distribution samples was investigated. In the micropore size range, as the reaction started, the SF method show the initial micropore was generated. As the activation reaction progress, the micropore volume is developed and widened and therefore area under the PSD curve is increased. Improving the reaction, the pore overlapping was carried out and this occurrence causes decreasing in micropore volume. In the mesopore size range, mesopore volume is increased as the reaction progress. It is acceptable because both developing and overlapping of pores causes improvement of mesopore (and macropore) volume


[1] P. Klobes, K. Meyer, Porosity and Specific Surface Area Measurements for Solid Materials, National Institute of Standards and Technology, Special Publication (2006) 960-17.
[2] K. Kaneko, Determination of pore size and pore size distribution1. Adsorbents and catalysts, Journal of Membrane Science 96 (1994) 59-89.
[3] M. Jaroniec, J. Choma, M. Kruk, Assessment of reliability of the Horvath_Kawazoe pore size analysis method using argon adsorption isotherms on ordered mesoporous silicas, J. Colloids and Surfaces A: Physicochem. Eng. Aspects 214 (2003) 263-269.
[4] E.P. Barrett, L.G. Joyner, P.P. Halenda, The Determination of Pore Volume and Area Distributions in Porous Substances. I. Computations from Nitrogen Isotherms, J. Am. Chem. Sot, 73 (1951) 373.
[5] P. Kowalczyk, A.P. Terzyk, P.A. Gauden, L. Solarz , Numerical analysis of Horvath–Kawazoe equation, J. Computers and Chemistry 26 (2002) 125–130.
[6] G. Horvath, K. Kawazoe, Method for the calculation of effective pore size distribution in molecular sieve carbon, J. Chem. Eng. Jpn. 16 (1983) 470–475.
[7] G. Horvath, Energetic interactions in phase and molecular level pore characterization in nano-range, J. Colloids and Surfaces A: Physicochemical and Engineering Aspects 141 (1998) 295–304.
[8] M. Kruk, M. Jaroniec, Critical Discussion of Simple Adsorption Methods Used to Evaluate the Micropore Size Distribution, J. Adsorption 3 (1997) 209-219.
[9] H. Hashemipour Rafsanjani, Study on synthesis activated carbon from Iranian coal, Ph.D. Thesis, Amir Kabir university of technology, Iran, 2001.