Studies related to the development of equations of state (EOS) to represent thermophysical properties of pure compounds are considered as important tools for engineers to design and optimize industrial equipment and processes. Furthermore, these tools also contribute to amplify the researchers' knowledge related to molecular interaction types, in attempting to predict and correlate both energetic and volumetric effects existing in the compounds. From several equations of state existing, the cubic plus association (CPA) EOS are employed in the calculations of thermophysical properties of compounds, in which the molecular interactions occurring are the association type. In spite of good representation of these properties, it is possible to improve the predictive and correlative capability of the CPA EOS by substitution of terms whose physical meaning can be better. In this way, modifications of the cubic plus association equation of state are proposed: the original repulsive term is replaced by the Carnahan-Starling repulsion term; the attractive term is changed to an attraction term similar to the Peng-Robinson EOS. Furthermore, both attraction and repulsion terms are taken to be temperature dependent when alpha and beta functions are employed in calculations. All implementations make the equations of state non-cubic in relation to volume. Vapor pressure and liquid molar volumes of 1-alkanols (C1 to C10) and water were correlated to experimental data using this non-CPA-EOS format, and good agreement is observed. ©2013 International Journal of Thermodynamics.1612027Abbot, M.M., Thirteen ways of looking at the van der waals equation (1989) Chemical Engineering Progress, (2), pp. 25-37Beaton, C.F., Ambrose, D., Brunner, E., Chase, M.W., Downey, J.R., Hobson, G., Humphreys, A.E., Walton, J., Ortobaric densities and molar volumes of liquids, alcohols, engineering sciences data unit - ESDU (1989) Eng. Sci. Data, , Item Nr. 89037Beaton, C.F., Ambrose, D., Foxcroft, H.J., Hobson, G., Jamieson, D.T., Knight, S.R., Rowell, G.M., White Jr., H.J., Vapor pressures and critical points of liquids, alcohols, engineering sciences data unit - ESDU (1989) Eng. Sci. Data, , Item Nr. 89028 Vapor Pressure DataCarnahan, N.F., Starling, K.E., Equation of state for nonattracting rigid spheres (1969) The Journal of Chemical Physics, 51, pp. 635-636Carnahan, N.F., Starling, K.E., Intermolecular repulsions and the equation of state for fluids (1972) AIChE. J, 18, pp. 1184-1189Coquelet, C., Chapoy, A., Richon, D., Development of a new alpha function for the peng-robinson equation of state: Comparative study of alpha function models for pure gases (natural gas components) and water-gas systems (2004) Int. J. Thermophys, 25, pp. 133-158De Santis, R., Gironi, F., Marrelli, L., Vapor-liquid equilibrium from a hard-sphere equation of state (1976) Ind. Eng. Chem. Fundam, 15, pp. 183-189Fuller, G.G., A modified redlich-kwong-soave equation of state capable of representing the liquid state (1976) Ind. Eng. Chem. Fundam, 15, pp. 254-257Haghtalab, A., Mahmoodi, P., Mazloumi, S.H., A modified Peng-Robinson equation of state for phase equilibrium calculation of liquefied, synthetic natural gas, and gas condensate mixtures (2011) Can. J. of Chem. Eng, 89, pp. 1376-1387Hamam, S.E.M., Chung, W.K., Elshayal, I.M., Lu, B.C.Y., Generalized temperature-dependent parameters of the redlich-kwong equation of state for vapor-liquid equilibrium calculations (1977) Ind. Eng. Chem. Process Des. Dev, 16, pp. 51-59Huang, S.H., Radosz, M., Equation of state for small, large, polydisperse, and associating molecules (1990) Ind. Eng. Chem. Res, 29, pp. 2284-2294Koh, C.A., Tanaka, H., Walsh, J.M., Cubbins, K.E., Zollweg, J.A., Thermodynamic and structural properties of methanol-water mixtures: Experiment, theory and molecular simulation (1993) Fluid Phase Equilibria, 83, pp. 51-58Kontogeorgis, G.M., Michelsen, M.L., Folas, G.K., Derawi, S., Von Solms, N., Stenby, E.H., Ten Years with the CPA (Cubic-Plus-Association) equation of state. Part 1. Pure compounds and self-associating systems (2006) Industrial and Engineering Chemistry Research, 45 (14), pp. 4855-4868. , DOI 10.1021/ie051305vKontogeorgis, G.M., Voutsas, E.C., Yakoumis, I.V., Tassios, D.P., An equation of state for associating fluids (1996) Industrial and Engineering Chemistry Research, 35 (11), pp. 4310-4318Kontogeorgis, G.M., Yakoumis, I.V., Meijer, H., Hendriks, E., Moorwood, T., Multicomponent phase equilibrium calculations for water-methanol-alkane mixtures (1999) Fluid Phase Equilibria, 158-160, pp. 201-209. , DOI 10.1016/S0378-3812(99)00060-6, PII S0378381299000606Kuester, J.L., Mize, J.H., (1973) Optimization Techniques, McGraw-Hill, , USAKutney, M.C., Dodd, V.S., Smith, K.A., Herzog, H.J., Tester, J.W., A hard-sphere volume-translated van der Waals equation of state for supercritical process modeling 1. Pure components (1997) Fluid Phase Equilibria, 128 (1-2), pp. 149-171Mathias, P.M., Copeman, T.W., Extension of the peng-robinson equations of state to complex mixtures: Evaluation of the various forms of the local composition concept (1983) Fluid Phase Equilibria, 13, pp. 91-108Nasrifar, Kh., Moshfeghian, M., A new cubic equation of state for simple fluids: Pure and mixture (2001) Fluid Phase Equilibria, 190 (1-2), pp. 73-88. , DOI 10.1016/S0378-3812(01)00592-1, PII S0378381201005921Nath, A., Bender, E., On the thermodynamics of associated solutions. I. An analytical method for determining the enyhalpy and entropy of association and equilibrium constant for pure liquid substances (1981) Fluid Phase Equilibria, 7, pp. 275-287Palombo, F., Sassi, P., Paolantoni, M., Morresi, A., Cataliotti, R.S., Comparison of hydrogen bonding in 1-octanol and 2-octanol as probed by spectroscopic techniques (2006) Journal of Physical Chemistry B, 110 (36), pp. 18017-18025. , DOI 10.1021/jp062614hPeng, D.-Y., Robinson, D.B., A new two-constant equation of state (1976) Ind. Eng. Chem. Fundam, 15, pp. 59-64Perakis, C.A., Voutsas, E.C., Magoulas, K.G., Tassios, D.P., Thermodynamic modeling of the water + acetic acid + CO2 system: The importance of the number of association sites of water and of the nonassociation contribution for the CPA and SAFT-type models (2007) Industrial and Engineering Chemistry Research, 46 (3), pp. 932-938. , DOI 10.1021/ie0609416Queimada, A.J., Miqueu, C., Marrucho, I.M., Kontogeorgis, G.M., Coutinho, J.A.P., Modeling vapor-liquid interfaces with the gradient theory in combination with the CPA equation of state (2005) Fluid Phase Equilibria, 228-229, pp. 479-485. , DOI 10.1016/j.fluid.2004.08.011, PII S0378381204003802, Proceedings of the Tenth International Conference on Properties and Phase Equilibria for Product and Process DesignRavagnani, S.P., D'Avila, S.G., VLE of polar mixtures: A new generalized correlation (1985) Proceedings of IV International Chemical Engineering Conference, CHEMPOR'85, 5, pp. 01-05. , Coimbra, PortugalRosenbrock, H.H., An automatic method for finding the greatest or least value of a function (1960) Computer Journal, 3, pp. 175-184Sadus, R.J., Equations of state for fluids: The Dieterici approach revisited (2001) Journal of Chemical Physics, 115 (3), pp. 1460-1462. , DOI 10.1063/1.1380711Soave, G., Equilibrium constants from a modified Redlich-Kwong equation of state (1972) Chem. Eng. Sci, 27, pp. 1197-1203Toghiani Hossein, Viswanath Dabir, S., Cubic equation of state for polar and apolar fluids (1986) Industrial & Engineering Chemistry, Process Design and Development, 25 (2), pp. 531-536Trebble, M.A., Bishnoi, P.R., Development of a new four-parameter cubic equation of state (1987) Fluid Phase Equilibria, 35, pp. 1-18Vargaftik, N.B., (1975) Handbook of Physical Properties of Liquid and Gases (Pure Substances and Mixtures), , 2nd Edition, John Willey, D.CVon Solms, N., Michelsen, M.L., Passos, C.P., Derawi, S.O., Kontogeorgis, G.M., Investigating models for associating fluids using spectroscopy (2006) Industrial and Engineering Chemistry Research, 45 (15), pp. 5368-5374. , DOI 10.1021/ie051341uWei, S., Shi, Z., Castleman, A., Mixed cluster ions as a structure probe: Experimental evidence for clathrate structure of (H2O)20 H+ and (H 2O)21 H+ (1991) J. Chem. Phys, 94, pp. 3268-3270Wei, Y.S., Sadus, R.J., Equations of state for the calculation of fluid-phase equilibria (2000) AIChE Journal, 46 (1), pp. 169-196Wei, Y.S., Sadus, R.J., Franck, E.U., Binary mixtures of water + five noble gases: Comparison of bimodal and critical curves at high pressures (1996) Fluid Phase Equilibria, 123, pp. 1-15Wertheim, M.S., Fluids with highly directional attractive forces. I. Statistical thermodynamics (1984) Journal of Statistical Physics, 35 (1-2), pp. 19-34Wertheim, M.S., Fluids with highly directional attractive forces. II. Thermodynamic perturbation theory and integral equations (1984) Journal of Statistical Physics, 35 (1-2), pp. 35-47Wertheim, M.S., Fluids with highly directional attractive forces. III. Multiple attraction sites (1986) J. Stat. Phys, 42, pp. 459-476Wertheim, M.S., Fluids with highly directional attractive forces. IV. Equilibrium polimerization (1986) J. Stat. Phys, 42, pp. 477-492Wertheim, M.S., Fluids of dimerizing hard spheres and mixtures of hard spheres and dispheres (1986) J. Chem. Phys, 85, pp. 2929-2936Wertheim, M.S., Thermodynamic perturbation theory of polymerization (1987) J. Chem. Phys, 87, pp. 7323-7331Xu Zhong, Sandler Stanley, I., Temperature-dependent parameters and the peng-robinson equation of state (1987) Industrial and Engineering Chemistry Research, 26 (3), pp. 601-606Zhong, C., Masuoka, H., An EOS/GE type mixing rule for perturbed hard-sphere equation of state and its application to the calculation of solid solubility in supercritical carbon dioxide (1997) Fluid Phase Equilibria, 141 (1-2), pp. 13-23. , PII S0378381297001891