Siberian anthracite as a precursor material for microporous activated carbons Piotr Nowicki, Robert Pietrzak * , Helena Wachowska Laboratory of Coal Chemistry and Technology, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan ´ , Poland Received 4 June 2007; received in revised form 12 October 2007; accepted 16 October 2007 Available online 8 November 2007 Abstract The technology of obtaining active carbon from anthracite mined in Siberia is described. The effect of the activating agent, anthracite/ activator ratio and activation temperature has been tested. The activation either with KOH or NaOH has been found to lead to micro- porous active carbon samples of well-developed surface area reaching from 588 to 2260 m 2 /g and pore volume from 0.29 to 1.12 m 3 /g. The structural properties of the active carbons obtained have been found to depend first of all on the anthracite/activating agent ratio, on the kind of activating agent and finally on the temperature of activation. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Anthracite; Carbonaceous materials; Microporous carbons 1. Introduction Growing interest in the sorption materials has been a result of development of new industrial technologies and the necessity of satisfying increasing demands on the pro- tection of the natural environment. From among many products used for this purpose, of greatest importance are the sorbents made of carboniferous materials. Carbon adsorbents occur as a wide range of materials characterised by different surface area development, depending on the type of the raw material. Of greatest application are active carbons, and activated carbon fibres used e.g. for adsorp- tion of pollution from gas and liquid phases, in catalysis, in electrochemistry or for gas storage [1–4]. Active carbons can be obtained from coals of different degree of metamorphism. Recently, much interest has been paid to the active carbons obtained from anthracites [5,6]. The main reasons for this interest are the high content of carbon and their primary microporous structure, which permit getting materials of well-developed porous struc- ture. The porous structure can be developed by way of physical activation using gas agents such as steam or car- bon dioxide [7,8] or by chemical activation in which the precursor impregnated or mixed with an activating agent e.g. KOH, ZnCl 2 ,H 3 PO 4 , is subjected to the process of pyrolysis [9,10]. The chemical method has become more popular as it is a single-stage process, more effective, taking place in shorter time and in lower temperatures than that of physical activation. The main aim of the study presented is to check the effect of the chemical activation parameters such as the type of activating agent, the ratio of activating agent to precursor and temperature on the porous structure of the active carbons obtained from anthracite. 2. Materials and methods 2.1. Materials The starting sample (S) was prepared from a Siberian anthracite (Moisture = 0.4 wt%, Ash d = 1.6 wt%, VM daf = 6.1 wt%, C daf = 93.9 wt%, H daf = 1.8 wt%, N daf = 0.8 wt%, S daf = 0.1 wt%, O daf = 3.4 wt%). The precursor was 0016-2361/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2007.10.008 * Corresponding author. Tel.: +48 618291476; fax: +48 618291505. E-mail address: pietrob@amu.edu.pl (R. Pietrzak). www.fuelfirst.com Available online at www.sciencedirect.com Fuel 87 (2008) 2037–2040