Solubility of carbon monoxide in bio-oil compounds Muhammad Saad Qureshi a,⇑ , Tom Le Nedelec b , Hernando Guerrero-Amaya a , Petri Uusi-Kyyny a , Dominique Richon a , Ville Alopaeus a a Aalto University School of Chemical Technology, Department of Biotechnology and Chemical Technology, P.O. Box 16100, Aalto FI-00076, Finland b Department of Chemistry and Process, Institut National des Sciences Appliquées de Rouen, Rouen, 76800 Saint-Étienne-du-Rouvray, France article info Article history: Received 15 February 2016 Received in revised form 19 September 2016 Accepted 21 October 2016 Available online 22 October 2016 Keywords: PC-SAFT Polar PC-SAFT Bio-oil SRK PR Oxygenated compounds abstract The solubility of carbon monoxide is measured in four different bio-oil compounds (furan, diacetyl, 2-methylfuran, and trans-crotonaldehyde) at temperatures (273.15, 283.15, 298.15, and 323.15 K) and pressures up to 8 MPa using a static-analytical VLE measurement method. The equipment was validated by measuring the solubility of CO 2 in methanol at 298.15 K and pressures (P = 2.9–5.7 MPa). The results were compared with the abundantly available literature values. PC-SAFT, Polar PC-SAFT (PPC-SAFT), and Cubic (SRK, PR) EoS, part of commercial process simulator Aspen Plus V. 8.6, are used here for modelling purpose. The pure component parameters needed for PC-SAFT and PPC-SAFT EoS models, are regressed using the experimental liquid density and vapour pressure data of the pure components. It was observed that furan, 2-methylfuran and diacetyl, having weak dipole moments (l < 1.0 D), could be modelled rea- sonably well without the addition of polar contribution using conventional PC-SAFT, while it is recom- mended to use PPC-SAFT for the description of a polar compound like trans-crotonaldehyde (l  3.67 D). It was observed that SRK and PR EoS have similar predictive ability in comparison to PC-SAFT for a mix- ture of CO with weakly polar compounds in this study. A comparison between the performances of EoS models was made in two ways: first by setting the binary interaction parameter k ij to zero, and second by adjusting a temperature-dependent binary interaction parameter (k ij ). All the models perform with com- parable accuracy with adjusted binary interaction parameters. However, due to the large differences between the chemical and physical properties of the compounds in this study, it is challenging to make a general statement on which is the best model. Ó 2016 Elsevier Ltd. 1. Introduction Thermodynamic data concerning bio-refining processes are both important and scarce. These data, especially gas solubilities in bio-based compounds, generate considerable interest not only in expanding academic research but also in designing separation processes for industrial use. However, despite the importance of such data, not much thermodynamic research is dedicated to acquire them. In the context of bio-based fuels, ‘‘pyrolysis oil” or ‘‘bio-oil” is an important candidate. It is a thermal decomposition product of lingo-cellulosic biomass and finds particular importance in regions where there is an abundance of biomass. Bio-oil is produced from fast pyrolysis, a process in which biomass is pyrolyzed for a short time (2–3 s) at high temperatures (600–800 °C), resulting in vapors that are condensed afterwards. The condensed vapors forms thick dark brownish liquid termed as bio-oil. For detailed information on pyrolysis technologies, readers are directed to some excellent reviews available in the literature [1–3]. Bio-oil represents a complex mixture of a variety of organic compounds consisting of several different functional groups including aldehydes, alcohols, acids, ketones, and furans, to men- tion only a few. The major constituents of bio-oil besides these compounds are water and sugars. The presence of water (in the mixture) is detrimental because it reduces the heating value of bio-oil, rendering it less appropriate for direct use as fuel. More- over, the oxygenated compounds present in bio-oil also deterio- rates the heating value [4]. Therefore, in order to increase the heating value of bio-oil to make it into a viable fuel, it is necessary to remove water and oxygenated compounds. The commonly used industrial processes for removing oxygen are Hydrodeoxygenation (HDO) and cracking. Cracking involves the treatment of bio-oil under high pressures over special catalysts [5]. HDO and cracking are accompanied by several complex reactions including decarbonylation, decarboxylation, hydrocracking, http://dx.doi.org/10.1016/j.jct.2016.10.030 0021-9614/Ó 2016 Elsevier Ltd. ⇑ Corresponding author. E-mail addresses: muhammad.qureshi@aalto.fi (M.S. Qureshi), tom.le_nedelec@ insa-rouen.fr (T. Le Nedelec), hergueam@gmail.com (H. Guerrero-Amaya), petri. uusi-kyyny@aalto.fi (P. Uusi-Kyyny), richon.dominique@gmail.com (D. Richon), ville.alopaeus@aalto.fi (V. Alopaeus). J. Chem. Thermodynamics 105 (2017) 296–311 Contents lists available at ScienceDirect J. Chem. Thermodynamics journal homepage: www.elsevier.com/locate/jct