Contents lists available at ScienceDirect Journal of CO 2 Utilization journal homepage: www.elsevier.com/locate/jcou Stability and regenerability of acivated carbon used for CO 2 removal in pilot DR-VPSA unit in real power plant conditions Izabela Majchrzak-Kucęba a, ⁎ , Dariusz Wawrzyńczak a , Aleksandra Ściubidło a , Janusz Zdeb b , Wojciech Smółka b , Artur Zajchowski b a Czestochowa University of Technology, Faculty of Infrastructure and Environment, Institute of Advanced Energy Technologies, Dabrowskiego Street 73, 42-201, Czestochowa, Poland b TAURON Wytwarzanie S.A., Promienna Street 51, 43-603, Jaworzno, Poland ARTICLE INFO Keywords: CO 2 Adsorption Activated carbon DR-VPSA unit Flue gas ABSTRACT The world’s first results of stability and regenerability of activated carbon under flue gas conditions using DR- VPSA (Dual-Reflux Vacuum-Pressure Swing Adsorption) method have been presented. Such assessment is ne- cessary in the light of practical applications of adsorbents in numerous adsorption-desorption cycles in a large- scale DR-VPSA adsorption unit. This is due to the fact that the useful life of an adsorbent has an effect of its costs and, as a consequence, the viability of the adsorption plant and its advantage over the absorption method of CO 2 capture using amine solutions. The assessment of the stability and regenerability of adsorbents was based on the analysis of activated carbon derived from a pilot DR-VPSA unit operating on real combustion gas for a period of 808 h. The pilot plant was set up under the Strategic Project in Tauron Wytwarzanie S.A. – The Łagisza Power Plant in Poland. The stability of activated carbon was determined by performing the full analysis of the phy- sicochemical properties on a samples taken from the adsorption column after many working cycles in the DR- VPSA plant under real flue gas conditions. The regenerability of activated carbon was verified by assessing their sorption capacity prior to, and after prolonged use in numerous adsorption-desorption cycles in the DR-VPSA plant. The obtained information provide new knowledge of the CO 2 adsorption behaviour of the activated carbon in response to flue gas exposure in pilot DR-VPSA adsorption units. 1. Introduction The reduction of the anthropogenic emissions of greenhouse gases, including CO 2 , to counteract the climate change, becomes the priority for the actions of not only the EU but also the whole world [1]. One of the technologies that may find application in the reduction of CO 2 emissions from both energy and other industrial plants is the adsorption method. Particularly promising for CO 2 removal from flue gas seems to be the VSA/VPSA technique (Vacuum Swing Adsorption/ Vacuum Pressure Swing Adsorption), as in this method the CO 2 capturing pro- cess is run at a pressure close to ambient pressure, thanks to which there is no need to compress a huge flue gas volume to high pressures. So, this technique provides a preferred method for removing carbon dioxide from low pressure flue gas, due to the absence of excessive pressurizing of the raw gas [2]. Against the adsorption technology ar- gues the fact that, in contrast to the absorption technology, only few pilot post-combustion flue gas CO 2 capture units are known, which operate on real flue gas in power plants and other industrial plants [3–11]. On the other hand, there are a lot of experimental and simu- lation studies being conducted, including the analyses of economic viability of those installations, which indicates a very good develop- ment of the foundations of this technology [12–20]. The development of the adsorption CO 2 capture method is favoured due to the simplicity of operation and low energy consumption, which could be substantially reduced through the selection of the adsorbent and the optimization of the process cycles. The selection of the adsorbent is the one of the important step in the design of a VPSA installation. Currently, only activated carbon and zeolites can be used for a large-scale plant due to availability and low costs. Other adsorbents (impregnated adsorbents, MOFs) are expensive and not checked on a large scale [1–4]. Activated carbon provides lower CO 2 /N 2 selectivity (6.1 [19]) (at 1 bar, 298 K) as compared to other adsorbents: zeolite 13X (17.0 [19]), zeolite Na-Y (14.5 [19]), MOF-5 (17.48 [18]), MOF-177 (17.48 [18]). At low pres- sure (1 bar) activated carbon also shows lower CO 2 sorption capacity (2.4 mol/kg) at 298 K than zeolite 13X (4.0 mol/kg [20]), MOF-74 (4.0 mol/kg [20]) and other adsorbents. In the case of activated carbon https://doi.org/10.1016/j.jcou.2018.11.003 Received 3 August 2018; Received in revised form 9 October 2018; Accepted 3 November 2018 ⁎ Corresponding author. E-mail address: izak@is.pcz.czest.pl (I. Majchrzak-Kucęba). Journal of CO₂ Utilization 29 (2019) 1–11 2212-9820/ © 2018 Elsevier Ltd. All rights reserved. T