Sofía T. Blanco

Water dew points of binary nitrogen+water and propane+water mixtures. Measurement and correlation

Abstract A water dew point generation bench has been built and tested. Experimental measurements of dew point for binary nitrogen+water and propane+water were carried out between 1.01×105 Pa and 109.61×105 Pa and temperatures from 249.80 to 283.93 K. An excess function–equation of state method reproduces quite accurately the experimental curves independently of the pressure range.

Accurate values of some thermodynamic properties for carbon dioxide, ethane, propane, and some binary mixtures.

Quasicontinuous PρT data of CO(2), ethane, propane, and the [CO(2) + ethane] mixture have been determined along subcritical, critical, and supercritical regions. These data have been used to develop the optimal experimental method and to determine the precision of the results obtained when using an Anton Paar DMA HPM vibrating-tube densimeter. A comparison with data from reference EoS and other authors confirm the quality of our experimental setup, its calibration, and testing. For pure compounds, the value of the mean relative deviation is MRD(ρ) = 0.05% for the liquid phase and for the extended critical and supercritical region. For binary mixtures the mean relative deviation is MRD(ρ) = 0.70% in the range up to 20 MPa and MRD(ρ) = 0.20% in the range up to 70 MPa. The number of experimental points measured and their just quality have enable us to determine some derivated properties with satisfactory precision; isothermal compressibilities, κ(T), have been calculated for CO(2) and ethane (MRD(κ(T)) = 1.5%), isobaric expasion coefficients, α(P), and internal pressures, π(i), for CO(2) (MRD(α(P)) = 5% and MRD(π(i)) = 7%) and ethane (MRD(α(P)) = 7.5% and MRD(π(i)) = 8%). An in-depth discussion is presented on the behavior of the properties obtained along subcritical, critical, and supercritical regions. In addition, PuT values have been determined for water and compressed ethane from 273.19 to 463.26 K up to pressures of 190.0 MPa, using a device based on a 5 MHz pulsed ultrasonic system (MRD(u) = 0.1%). With these data we have calibrated the apparatus and have verified the adequacy of the operation with normal liquids as well as with some compressed gases. From density and speed of sound data of ethane, isentropic compressibilities, κ(s), have been obtained, and from these and our values for κ(T) and α(P), isobaric heat capacities, C(p), have been calculated with MRD(C(p)) = 3%, wich is within that of the EoS.

Excess enthalpies of dibromoalkane + tetrachloromethane mixtures. Measurement and analysis in terms of group contributions (DISQUAC)

Abstract Blanco S.T. Munoz Embid J. and Otin S., 1993. Excess enthalpies of dibromoalkane + tetrachloromethane mixtures. Measurement and analysis in terms of group contributions (DISQUAC). Fluid Phase Equilibria , 91: 281-290. Excess enthalpies at 298.15 K and atmospheric pressure are reported for binary liquid mixtures of dibromomethane, 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 1,5-dibromopentane and 1,8-dibromooctane + tetrachloromethane (CCl 4 ). These experimental results, along with literature data, on liquid-vapor equilibria (excess Gibbs energies) are interpreted in terms of the DISQUAC group contribution model. The systems are characterized by three types of contact surfaces: bromine (Br) and alkane, in α,ω-dibromoalkanes, and solvent CCl 4 . The interchange energies of the alkane/CCl 4 and alkane/Br contacts were determined independently from the study of n -alkane + CCl 4 , and α,ω-dibromoalkane + n -alkane systems, respectively. The interchange energies of the alkane/Br contact of dibromomethane and of the Br/CCl 4 contact were estimated in this work. The Br/CCl 4 parameters of α,ω-dibromoalkanes are entirely dispersive and increase regularly with increasing separation u of the two bromine atoms in the molecule (proximity effect) in the same regular manner as observed previously for α,ω-dichloroalkane + CCl 4 , mixtures, and reach the values of 1-bromoalkanes when u ≧ 5. In general, the model provides a fairly consistent description of H E and G E as a function of composition and dibromoalkane chain length.

Influence of Methane in CO2 Transport and Storage for CCS Technology

CO(2) Capture and Storage (CCS) is a good strategy to mitigate levels of atmospheric greenhouse gases. The type and quantity of impurities influence the properties and behavior of the anthropogenic CO(2), and so must be considered in the design and operation of CCS technology facilities. Their study is necessary for CO(2) transport and storage, and to develop theoretical models for specific engineering applications to CCS technology. In this work we determined the influence of CH(4), an important impurity of anthropogenic CO(2), within different steps of CCS technology: transport, injection, and geological storage. For this, we obtained new pressure-density-temperature (PρT) and vapor-liquid equilibrium (VLE) experimental data for six CO(2) + CH(4) mixtures at compositions which represent emissions from the main sources in the European Union and United States. The P and T ranges studied are within those estimated for CO(2) pipelines and geological storage sites. From these data we evaluated the minimal pressures for transport, regarding the density and pipelines capacity requirements, and values for the solubility parameter of the mixtures, a factor which governs the solubility of substances present in the reservoir before injection. We concluded that the presence of CH(4) reduces the storage capacity and increases the buoyancy of the CO(2) plume, which diminishes the efficiency of solubility and residual trapping of CO(2), and reduces the injectivity into geological formations.

Volumetric behavior of the {CO2 (1) + C2H6 (2)} system in the subcritical (T = 293.15 K), critical, and supercritical (T = 308.15 K) regions.

The volumetric behavior for the {CO2 (1) + C2H6 (2)} system has been studied. Density measurements of {CO2 (1) + C2H6 (2)} binary mixtures at 293.15 and 308.15 K, at several pressures and compositions, and density measurements for infinitely dilute solutions at 304.21 and 308.15 K were carried out using an Anton Paar DMA 512-P vibrating-tube densimeter calibrated with the forced path mechanical calibration model. The mean relative standard deviation of density, s(rho)(r), was estimated to be better than 0.1%, and the uncertainties in temperature and pressure were estimated as +/-0.01 K and +/-0.001 MPa, respectively. In the experimental setup, an uncertainty in the mole fraction of u(x(j)) = +/-0.0015 has been achieved. Other properties related to P-rho-T-x data such as the compressibility factor, Z, excess molar volumes, V(m)(E), and partial molar volumes, V(i) and V(i)(infinity) have been calculated. The volumetric behavior has been compared with literature data and with that obtained from the PC-SAFT EoS rescaled parameters; these parameters have been obtained from our previous experimental values for the critical temperature and pressure of pure compounds. The value for the Krichevskii parameter, A(Kr), was obtained from the experimental density data for infinitely dilute solutions measured in this work, and it has been compared with that obtained from critical properties. Structural properties such as direct and total correlation function integrals and cluster size were calculated using the Krichevskii function concept.

Dew points of ternary methane+ethane+butane and quaternary methane+ethane+butane+water mixtures: measurement and correlation

Abstract Dew points for ternary methane+ethane+butane and quaternary methane+ethane+butane+water mixtures were determined experimentally between 4.77×105 and 99.45×105 Pa and at temperatures from 250.92 to 288.54 K. The experimental dew point curves of the mixtures with water were reproduced quite accurately with an excess function–equation of state method, independent of the temperature and pressure ranges.

Discussion of the influence of CO and CH4 in CO2 transport, injection, and storage for CCS technology.

This paper discusses the influence of the noncondensable impurities CO and CH4 on Carbon Capture and Storage (CCS) technology. We calculated and drew conclusions about the impact of both impurities in the CO2 on selected transport, injection, and storage parameters (pipeline pressure drop, storage capacity, etc.), whose analysis is necessary for the safe construction and operation of CO2 pipelines and for the secure long-term geological storage of anthropogenic CO2. To calculate these parameters, it is necessary to acquire data on the volumetric properties and the vapor-liquid equilibrium of the fluid being subjected to CCS. In addition to literature data, we used new experimental data, which are presented here and were obtained for five mixtures of CO2+CO with compositions characteristic of the typical emissions of the E.U. and the U.S.A. Temperatures and pressures are based on relevant CO2 pipeline and geological storage site values. From our experimental results, Peng-Robinson, PC-SAFT, and GERG Equations of State for were validated CO2+CO under the conditions of CCS. We conclude that the concentration of both impurities strongly affects the studied parameters, with CO being the most influential and problematic. The overall result of these negative effects is an increase in the difficulties, risks, and overall costs of CCS.

Critical properties and high-pressure volumetric behavior of the carbon dioxide+propane system at T=308.15 k. Krichevskii function and related thermodynamic properties.

Critical properties and volumetric behavior for the {CO2(1)+C3H8(2)} system have been studied. The critical locus was measured with a flow apparatus and detected by critical opalescence. For the mixtures, repeatabilities in critical temperature and pressure are rTc<or=0.15 K and rPc<or=0.013 MPa, respectively, and the confidence intervals calculated are c.i.(Tc)<0.32 K and c.i.(Pc)<0.034 MPa. The value for the Krichevskii parameter, AKr=-4.12 MPa, was obtained from the experimental critical data in this work. Additionally, the density measurements of 15 {CO2(1)+C3H8(2)} binary mixtures at 308.15 K and pressures up to 20 MPa were carried out using an Anton Paar DMA 512-P vibrating-tube densimeter calibrated with the forced path mechanical calibration model. The mean relative standard deviation of density, srhor, was estimated to be better than 0.1%, and the uncertainties in temperature and pressure are +/-0.01 K and +/-0.001 MPa, respectively. In the experimental setup, an uncertainty in the mole fraction, u(xj)=+/-0.0015, has been achieved. Other properties related to P-rho-T-x data such as saturated densities, rhoL and rhoV, compressibility factor, Z, excess molar volumes,VmE, and partial molar volumes, Vi, have been calculated. Structural properties such as direct and total correlation function integrals and cluster size were calculated using the Krichevskii function concept. Both the critical and volumetric behavior have been compared with literature data and with those obtained from the PC-SAFT and Patel-Teja equations of state.

Dew Points of Binary Nitrogen + Water Mixtures

Abstract Experimental measurements of dew point for binary nitrogen + water were carried out between 5.0105Pa and 100.2105 Pa and temperatures from 263.0 K to 283.7 K. The experimental method is based on the generation of wet gases by water condensation in two temperature-controlled condensers with continuous gas flow at specified pressures.

Dew Points of Binary Methane + Water: Measurement and Correlation

Experimental measurements of dew points for four methane + water mixtures between 2.6 2 10 5 Pa and 100.4 2 10 5 Pa and the temperature range from 225.5 K to 272.7 K were carried out. The experimental results were analysed in terms of both an equation of state model and an excess function-equation of state method, which reproduced the experimental data within AAD from 1.8 to 3.1 K and from 0.9 to 1.8 K, respectively.