title: Thermodynamic analysis of fuels in gas phase: ethanol, gasoline and ethanol - gasoline predicted by DFT method.
abstract: This paper presents a theoretical study using density functional theory to calculate thermodynamics properties of major molecules compounds at gas phase of fuels like gasoline, ethanol, and gasoline-ethanol mixture in thermal equilibrium on temperature range up to 1500 K. We simulated a composition of gasoline mixture with ethanol for a thorough study of thermal energy, enthalpy, Gibbs free energy, entropy, heat capacity at constant pressure with respect to temperature in order to study the influence caused by ethanol as an additive to gasoline. We used semi-empirical computational methods as well in order to know the efficiency of other methods to simulate fuels through this methodology. In addition, the ethanol influence through the changes in percentage fractions of chemical energy released in combustion reaction and the variations on thermal properties for autoignition temperatures of fuels was analyzed. We verified how ethanol reduces the chemical energy released by gasoline combustion and how at low temperatures the gas phase fuels in thermal equilibrium have similar thermodynamic behavior. Theoretical results were compared with experimental data, when available, and showed agreement. Graphical Abstract Thermodynamic analysis of fuels in gas phase.
authors.affiliation: Laboratory of Preparation and Computation of Nanomaterials (LPCN), Federal University of Pará, C. P. 479, 66075-110, Belém, PA, Brazil. abelfgn@yahoo.com.br.|Postgraduate Program in Chemical Engineering, ITEC, Federal University of Pará, C. P. 479, 66075-900, Belém, PA, Brazil. abelfgn@yahoo.com.br.
authors.forename: A F G
authors.initials: AF
authors.lastname: Neto
authors.affiliation: Laboratory of Preparation and Computation of Nanomaterials (LPCN), Federal University of Pará, C. P. 479, 66075-110, Belém, PA, Brazil.
authors.forename: F S
authors.initials: FS
authors.lastname: Lopes
authors.affiliation: Laboratory of Preparation and Computation of Nanomaterials (LPCN), Federal University of Pará, C. P. 479, 66075-110, Belém, PA, Brazil.
authors.forename: E V
authors.initials: EV
authors.lastname: Carvalho
authors.affiliation: Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, USA.
authors.forename: M N
authors.initials: MN
authors.lastname: Huda
authors.affiliation: Laboratory of Preparation and Computation of Nanomaterials (LPCN), Federal University of Pará, C. P. 479, 66075-110, Belém, PA, Brazil.
authors.forename: A M J C
authors.initials: AM
authors.lastname: Neto
authors.affiliation: Laboratory of Separation Processes and Applied Thermodynamic (TERM@), Faculty of Chemical Engineering-UFPA, Rua Augusto Corrêia N°. 1, CEP: 66075-900, Cx. P. 8619, Belém, Pará, Brazil.
authors.forename: N T
authors.initials: NT
authors.lastname: Machado
mesh_terms: D000431:Ethanol / Q000737:chemistry*; D005742:Gasoline / Q000032:analysis*; D008962:Models, Theoretical; D011312:Pressure; D013696:Temperature; D013816:Thermodynamics; D014835:Volatilization
chemical_list: D005742:Gasoline; D000431:Ethanol
keywords: DFT; Ethanol; Gasoline; Semi-empirical methods; Thermodynamics properties