NO 2 removal on adsorbents obtained by pyrolysis and physical activation of corrugated cardboard Piotr Nowicki a , Marta Supłat a , Jacek Przepiórski b , Robert Pietrzak a,⇑ a Faculty of Chemistry, Adam Mickiewicz University in Poznan ´, Grunwaldzka 6, 60-780 Poznan ´, Poland b West Pomeranian University of Technology, ul. Pułaskiego 10, 70-322 Szczecin, Poland highlights " The alternative method of utilisation of used corrugated cardboard is proposed. " The adsorbents obtained from corrugated cardboard can be used as efficient adsorbents of NO 2 . " The best sorption capacities show the products of pyrolysis process. " Sorption capacity depend on the temperature and time of pyrolysis. article info Article history: Received 28 February 2012 Received in revised form 23 April 2012 Accepted 23 April 2012 Available online 30 April 2012 Keywords: Corrugated cardboard Pyrolysis Physical activation Carbonaceous adsorbents Surface chemistry NO 2 adsorption/reduction abstract A method for obtaining carbonaceous adsorbents from used corrugated cardboard by physical activation with CO 2 is described. The effect of pyrolysis temperature (500–800 °C) and time (30 and 60 min) as well as activation on the adsorbents textural parameters, acid–base character of surface and sorption proper- ties toward nitrogen dioxide have been tested. The products were microporous carbons of rather low sur- face area ranging from 13 to 278 m 2 /g and pore volume from 0.02 to 0.19 cm 3 /g, showing a very strong basic character of the surface. The results have proved that a proper choice of cardboard pyrolysis and activation procedure can produce adsorbents with a high capacity for nitrogen dioxide, reaching to 27.8 and 106.1 mg NO 2 /g in dry and wet conditions, respectively. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Continuous development of industry and increasing urbanisa- tion have unavoidably led to increasing pollution of the natural environment. The post-industrial waste, increasing use of chemi- cals, chemical fertilisers and surfactants pose a serious threat to the soil and surface water. So far in drinking water over 800 organ- ic and inorganic compounds have been identified, many of them show carcinogenic properties [1]. Rapidly increasing number of motor vehicles motor as well as combustion of fossil fuels entail emission of huge amounts of exhaust gases. In effect, considerable volumes of gaseous pollutants, including NO x , SO x , carbon oxides and volatile organic compounds (VOCs) enter the atmosphere. In response, the legal regulations concerning the admissible levels of pollutants (especially air pollutants) get increasingly restrictive, which stimulates development of new technologies of pollutants removal. One of interesting solutions proposed to limit production of pollutants is based on changing the parameters of combustion by the use of clean fuels, catalytic converters as well as by changes in the construction of furnace hearths. Another solu- tion involves purification of exhaust gases by adsorption, absorp- tion or catalytic methods. Particular attention has been paid to activated carbons that can be used as adsorbents, catalysts or reducing agents [2,3]. Removal of hydrogen sulphide, sulphur oxides or nitrogen oxides from gas- eous streams using activated carbons has been a subject of re- search at many centres in the world [3,4]. From among nitrogen oxides present in exhaust gases, the most serious is NO 2 . Neverthe- less removal of NO has been the subject of the majority of studies, while unfairly much less attention has been devoted to removal of NO 2 or N 2 O, which are equally harmful to the human’s health as well as the natural environment. Precursors of activated carbons can be numerous materials con- taining carbon in organic bonds. As yet carbon precursors of indus- trial significance have been wood, peat, brown and hard coals and 1385-8947/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cej.2012.04.073 ⇑ Corresponding author. Tel.: +48 618291476; fax: +48 618291505. E-mail address: pietrob@amu.edu.pl (R. Pietrzak). Chemical Engineering Journal 195–196 (2012) 7–14 Contents lists available at SciVerse ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej