Equilibrium and transport properties of CO2+N2O and CO2+NO mixtures: Molecular simulation and equation of state modelling study

Abstract

In the present study, the thermodynamic behaviour and transport properties of CO 2 +N 2 O and CO 2 +NO mixtures have been investigated using molecular simulation and equation of state modelling. Molecular simulations were based on Monte Carlo and Molecular Dynamics calculations using force fields calibrated from pure component properties and no adjustment of mixture properties was performed. Original force fields were proposed for N 2 O, NO and N 2 O 2 molecules. Special attention must be paid when studying nitric oxide containing systems because this compound can exist as a mixture of monomers (NO) and dimers (N 2 O 2 ) under certain pressure and temperature conditions. Liquid-vapour coexistence properties of the reacting NO-N 2 O 2 system were thus first investigated using combined reaction ensemble and Gibbs ensemble Monte Carlo methods. Using the new force fields proposed, phase compositions, phase densities and phase viscosities were determined for CO 2 +NO x mixtures. Due to the strong similarities between carbon dioxide and nitrous oxide (T c (CO 2 ) = 304.21 K; T c (N 2 O) = 309.57 K; P c (CO 2 ) = 7.38 MPa; P c (N 2 O) = 7.24 MPa), the obtained thermodynamic and transport properties for a CO 2 +N 2 O mixture with 10 mol% of N 2 O are similar to pure CO 2 properties in the whole range of studied temperatures (273 -293 K), in agreement with available experimental data. Calculations of CO 2 +NO equilibrium and transport properties were also performed at three different temperatures in the range of 253 -273 K. At these temperatures, only the monomer form of the nitric oxide (NO) has to be accounted for. The performed calculations are pure predictions since no experimental data are available in the open literature for this system. For a mixture containing 10 mol% of NO, the simulation results show a decrease of the liquid densities and viscosities of 9% and 24% with respect to corresponding pure CO 2 values, respectively. The new pseudo-experimental data generated in this work were finally used to calibrate binary interaction parameters required in standard cubic equations of states. Both Peng-Robinson and Soave-Redlich-Kwong equations of state have been considered and after the regression, they display a decent match with experimental and pseudo-experimental data of the vapour-liquid equilibrium for the two studied mixtures.

Chemoinformatics at IFP Energies Nouvelles: Applications in the Fields of Energy, Transport, and Environment

“…[17,34] Similarly, numerical simulations are interesting tools when the considered molecules are toxic for human, which is typically the case of systems containing H 2 S. [35,36,37] In numerous studies we have reported the use of molecular simulation techniques to obtain pseudo experimental data for gas mixtures. [38,39,40,41,42,43,44] In these studies, simulated vapour-liquid equilibrium data were compared to corresponding experimental data points, and scaling laws together with additional molecular simulation results were used to calculate critical point coordinates. [39,40,42] The so obtained phase envelops can then be used to optimize binary interaction parameter values to feed EoS.…”

“…[38,39,40,41,42,43,44] In these studies, simulated vapour-liquid equilibrium data were compared to corresponding experimental data points, and scaling laws together with additional molecular simulation results were used to calculate critical point coordinates. [39,40,42] The so obtained phase envelops can then be used to optimize binary interaction parameter values to feed EoS. [44] Moreover, it has been shown that molecular simulation results can be used to determine association scheme and association parameters of a SAFT (Statistical Associating Fluid Theory) type EoS.…”

Equilibrium and Transport Properties of Primary, Secondary and Tertiary Amines by Molecular Simulation

“…They have found that the TIP4P/2005 model corresponds to the one that best predicts on average the water behavior for all these properties. For N 2 O and N 2 , the molecular models proposed by Lachet et al [25] and Delhommelle [26] were chosen respectively. Table 6 summarizes the force field parameters used for water and for the two studied gases.…”

Vapor-phase chemical equilibrium and combined chemical and vapor–liquid equilibrium for the ternary system ethylene+water+ethanol from reaction-ensemble and reactive Gibbs-ensemble molecular simulations

“…The reactive Gibbs-ensemble Monte Carlo (RxGEMC) method [18,30,31] is a combination of the reaction-ensemble (RxMC) [17][18][19] and the Gibbs-ensemble (GEMC) [32][33][34][35][36][37][38][39] methods, and it has already been used for the computation of the combined ChVLE of dimerization and combination reactions [18,30], the etherification reaction of isobutene and methanol to yield methyl-tertbutyl ether [31], and the dimerization reactions of nitrogen dioxide [40] and nitric oxide [41]. In this work, the RxGEMC method was implemented in order to compute the combined ChVLE for the hydration of ethylene to ethanol and compare the simulation predictions with those previously obtained [1] from the thermodynamic model.…”