Influence of oxygen on adsorption of elemental mercury vapors onto activated carbon D. Karatza a , A. Lancia b , M. Prisciandaro c,⇑ , D. Musmarra a , G. Mazziotti di Celso d a Dipartimento di Ingegneria Civile, Design, Edilizia e Ambiente, Seconda Università degli Studi di Napoli, Real Casa dell’Annunziata, Via Roma 29, 81031 Aversa (CE), Italy b Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli ‘‘Federico II’’, P.le Tecchio 80, 80125 Napoli, Italy c Dipartimento di Ingegneria Industriale, dell’Informazione e di Economia, Viale Giovanni Gronchi 18, 67100 L’Aquila, Italy d Dipartimento di Scienze degli Alimenti, Università degli Studi di Teramo, Via Carlo R. Lerici, 64023 Mosciano S. Angelo (TE), Italy highlights  We studied Hg 0 adsorption on activated carbon in different O 2 /N 2 streams.  The experiments led to the determination of the breakthrough curves for fixed bed.  The influence of oxygen during pre- treatment and during adsorption is studied.  Experiments showed that O 2 in the gas phase increases the adsorption capacity.  Oxygen has a twofold effect, increasing active sites and modifying carbon surface. graphical abstract Activated carbon adsorbate loading at equilibrium (x  ) as a function of initial mercury concentration (c 0 ), temperature and oxygen partial pressure. Symbols: experimental results; lines: model results.e p O2 = 99.3 kPa, h p O2 = 20.8 kPa, s p O2 = 4.9 kPa, + p O2 = 0 kPa (100% N2). Activated carbon adsorbate loading at equilibrium (w*) as a function of initial mercury concentration (c0), temperature and oxygen partial pressure . Symbols: experimental results; lines: model results. ◊ pO2 = 99.3 kPa, □ pO2 = 20.8 kPa, ○ pO2 = 4.9 kPa, + pO2 = 0 kPa (100% N2). article info Article history: Received 2 August 2012 Received in revised form 24 March 2013 Accepted 25 March 2013 Available online 11 April 2013 Keywords: Mercury Adsorption Modeling Oxygen Activated carbon abstract The main purpose of this paper is the study of elemental mercury adsorption phenomena on a commer- cially available activated carbon in different oxygen/nitrogen streams. A laboratory-scale apparatus with a fixed bed was used to adsorb elemental mercury vapors in an oxygen/nitrogen stream (synthetic gas). Temperature was varied from 90 to 150 °C. The inlet gas stream was a nitrogen/oxygen mixture with oxy- gen partial pressures varying from 4.9 to 99.3 kPa, in this gas stream elemental mercury vapors was added spanning the mercury concentration from 0.3 to 3 mg/m 3 . A commercial activated carbon (Darco G60 from BDH) was utilized as sorbent. The experiments led to the determination of the breakthrough curves for the fixed bed. Saturation data allow determining the adsorption isotherms for the temperatures tested, at the different oxygen partial pressures investigated. Experiments showed that the presence of oxygen in the gas phase increases the adsorption capacity of the sorbent and the higher the oxygen concentration the higher the adsorption capacity; however an unusual trend of the adsorption capacity as a function of the temperature was observed, suggesting the occurrence of different phenomena. In order to explain this trend a set of ad hoc experiments was realized pre-treating the carbon in oxygen/nitrogen gas phase and performing 0016-2361/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fuel.2013.03.068 ⇑ Corresponding author. Address: Dipartimento di Ingegneria Industriale, dell’Informazione e di Economia, University of L’Aquila, Via Giovanni Gronchi,18 – Zona Industriale Campo di Pile, 67100 L’Aquila (AQ), Italy. Fax: +39 0862 434203. E-mail address: marina.prisciandaro@univaq.it (M. Prisciandaro). Fuel 111 (2013) 485–491 Contents lists available at SciVerse ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel