Systematic development of predictive molecular models of high surface area activated carbons for adsorption applications Emanuela Di Biase, Lev Sarkisov * Institute for Materials and Processes, School of Engineering, The University of Edinburgh, EH9 3JL Edinburgh, UK ARTICLE INFO Article history: Received 13 May 2013 Accepted 21 July 2013 Available online 29 July 2013 ABSTRACT Adsorption in porous materials is a promising technology for CO 2 capture and storage. Par- ticularly important applications are adsorption separation of streams associated with the coal power plant operation, as well as natural gas sweetening. High surface area activated carbons are a promising family of materials for these applications, especially in the high pressure regimes. As the streams under consideration are generally multi-component mix- tures, development and optimization of adsorption processes for their separation would substantially benefit from predictive simulation models. Here, we develop a molecular model of a high surface area carbon material based on a random packing of small frag- ments of a carbon sheet. In the construction of the model, we introduce a number of con- straints, such as the value of the accessible surface area, concentration of the surface groups, and pore volume to bring the properties the model structure close to the reference porous material (Maxsorb carbon with the surface area in excess of 3000 m 2 /g). We use experimental data for CO 2 and methane adsorption to tune and validate the model. We demonstrate the accuracy and robustness of the model by predicting single component adsorption of CO 2 , methane and other relevant components under a range of conditions. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Capture and sequestration of carbon dioxide from power plants is an important intermediate strategy towards the reduction of the greenhouse emissions. This approach recog- nizes that power generation will still rely on fossil fuels in the nearest future. However, it allows us to satisfy the current en- ergy demand, while remaining carbon-neutral and providing the necessary time for the technologies based on the renew- able sources of energy to mature [1,2]. A recent article by D’Alessandro and co-authors summarizes the main issues associated with carbon capture on industrial scale [3]. The key bottleneck in the implementation of carbon capture tech- nologies is the additional energy cost of this process. Current conventional post-combustion technologies, based on absorption in amine solutions, consume 25–40% of the energy produced by the power plant, which renders them economi- cally and energetically unviable. Physical adsorption in porous materials is considered to be an energy efficient alternative to absorption processes, as it does not require reboiling and circulating of large amounts of solvent. A substantial research effort has been recently in- vested in systematic search and optimization of porous mate- rials for carbon dioxide separation processes [4–6]. The obvious requirements include affinity and selectivity of the material to- wards carbon dioxide, stability with respect to water vapours and elevated temperatures, cost and so on. The actual choice of the material will also strongly depend on the specific 0008-6223/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbon.2013.07.061 * Corresponding author. E-mail address: Lev.Sarkisov@ed.ac.uk (L. Sarkisov). CARBON 64 (2013) 262 – 280 Available at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/carbon