Contents lists available at ScienceDirect Journal of CO 2 Utilization journal homepage: www.elsevier.com/locate/jcou Performance of non-aqueous amine hybrid solvents mixtures for CO 2 capture: A study using a molecular-based model Ismail I.I. Alkhatib a,b,c , Luís M.C. Pereira a,b , Ahmed AlHajaj a,c , Lourdes F. Vega a,b,c,d, ⁎ a Chemical Engineering Department, Khalifa University of Science and Technology, P.O. 127788, Abu Dhabi, United Arab Emirates b Gas Research Center, Khalifa University of Science and Technology, P.O. 127788, Abu Dhabi, United Arab Emirates c Research and Innovation Center on CO2 and H2(RICH), Khalifa University of Science and Technology, P.O. 127788, Abu Dhabi, United Arab Emirates d Center for Catalysis and Separation (CeCaS), Khalifa University of Science and Technology, P.O. 127788, Abu Dhabi, United Arab Emirates ARTICLE INFO Keywords: Soft-SAFT predictive models Non-aqueous amines Hybrid chemical-physical solvents CO 2 capture ABSTRACT We present here results regarding the chemisorption of CO 2 in non-aqueous hybrid solvents of mixtures of amines and physical solvents such as glycols or glymes as alternatives to aqueous amines for CO 2 capture and separation, using the molecular-based equation of state, soft-SAFT, as a modelling tool. The reactive nature of the CO 2 absorption process in non-aqueous amines was implicitly considered through the formation of CO 2 - amine physical aggregates bounded by strong and localised intermolecular interactions, with the efect of non- aqueous solvents on the reactivity included in these interactions. With such a modelling framework, only VLE data on the absorption of CO 2 in amine solvents is required, without any need for additional information such as speciation reactions or equilibrium constants, thus decreasing the number of adjustable parameters needed to accurately model the absorption process. Subsequently, the developed models were used to examine the CO 2 capture performance of these hybrid solvents in terms of absorption cyclic capacity and heat of regeneration as key performance indicators using a simple and short-cut estimation method. Results show that for the same total amine mass concentration, non-aqueous amine solvents possess a 30–40% decrease in total heat of regeneration compared to their aqueous counterparts at the expense of a 10–50% reduction in cyclic capacity. These results validate the reliability of the molecular modelling approach as an attractive and valuable tool for the screening of chemical solvents and process modelling. 1. Introduction It is acknowledged that the increasing levels of anthropogenic CO 2 emissions is the primary contributor to global warming and climate change, requiring immediate mitigation and control [1–3]. With the emergence of stringent environmental legislations on climate change mitigation, signifcant eforts have been exerted to the development of CO 2 capture technologies that limit the degree of future climate change, deeming CO 2 capture as a global engineering project [4]. Although various strategies are available to curtail anthropogenic CO 2 emissions, Post-Combustion Carbon Capture (PCCC) is the most suitable choice for retroftting existing fossil fuel combustion and power-generation facil- ities [1,3]. Among the wide variety of available PCCC technologies, the physical or chemical absorption of CO 2 from large-scale emission sources, such as power-generation facilities, are considered the most viable and close-to-market approaches to be deployed at a large in- dustrial scale. More specifcally, chemical solvents, mainly aqueous solutions of amines, are regarded as the most technically proven and industrially feasible technology for carbon capture at large scale [4,5]. Since their emergence, as early as the 1930s, several amines have been developed and patented, owing to their selectivity for CO 2 over other species present in fue gases and ease of solvent regeneration through heating [5]. Aqueous solutions of amines, primarily monoethanolamine (MEA), are the most mature technology for CO 2 absorption due to their high afnity and reactivity with CO 2 and relatively low costs of production. Still, a signifcant barrier to their full-scale deployment or “Achilles’ heel” as dubbed by Heldebrant et al. [6], is the high energy requirement associated with solvent regeneration (usually done at high tempera- tures of 373–393 K) [7–12]. This energy penalty adds a parasitic load on power-generation facilities to burn more fossil fuels, resulting in more CO 2 emissions to compensate for the energy consumed for solvent regeneration, in addition to dropping overall efciency of these facil- ities by approximately 30% [4,12]. The regeneration energy (reboiler, https://doi.org/10.1016/j.jcou.2019.09.010 Received 25 June 2019; Received in revised form 12 September 2019; Accepted 16 September 2019 ⁎ Corresponding author at: Chemical Engineering Department, Khalifa University of Science and Technology, P.O. 127788, Abu Dhabi, United Arab Emirates. E-mail address: lourdes.vega@ku.ac.ae (L.F. Vega). Journal of CO₂ Utilization xxx (xxxx) xxx–xxx 2212-9820/ © 2019 Elsevier Ltd. All rights reserved. Please cite this article as: Ismail I.I. Alkhatib, et al., Journal of CO₂ Utilization, https://doi.org/10.1016/j.jcou.2019.09.010