Measurement and Correlation of Phase Equilibria for Water + Hydrocarbon Systems near the Critical Temperature and Pressure of Water

Abstract

An experimental apparatus based on a flow method was constructed in order to measure the phase equilibria for water + hydrocarbon systems near and above the critical temperature of water in the high-pressure region. The phase equilibria were measured for the water + decane system at 573.2 K from 12.1 to 30.3 MPa and at 593.2 K from 15.4 to 25.1 MPa and for the water + toluene system at 553.2 K from 15.1 to 30.1 MPa and at 573.2 K from 17.2 to 30.5 MPa. The phase equilibria of the water + decane system at 573.2 and 593.2 K and of the water + toluene system at 553.2 and 573.2 K are correlated by a modified SRK (MSRK) equation of state, which is modified in the attractive term of the SRK equation of state to calculate well the saturated vapor pressures of many organic and inorganic compounds. An exponent-type mixing rule, which uses empirical exponential parameters showing deviations from random mixing, is applied to the energy parameter a, and a conventional mixing rule is applied to the size parameter b. Good correlation results are obtained.

Impact of non-ideality on mixing of hydrocarbons and water at supercritical or near-critical conditions

“…As a group contribution method, PPR78 yields phase equilibrium results with correct trends and tolerable errors. water at 23MPa (circle sign) and 25MPa (plus sign) [47], and experimental data of toluene and water at 25MPa (cross sign) [48]; (b) PPR78 results of binary HC-water systems at 24MPa: solid blue line for n-decane, dashed blue line for n-hexadecane, dash-dot blue line for n-triacontane, solid red line for benzene, dashed red line for toluene, dash-dot red line for 1,3,5-trimethylbenzene, solid magenta line for 1-butylbenzene, solid black line for 1-decylnaphthalene, and dashed black line for 1-dodecylnaphthalene (color figure online).…”

Development of Predictive Methods of Water–Heavy Oil Phase Equilibrium for Supercritical Water Upgrading Process

“…16 19 , Fig. 7 water decane 8), 14) LLE kij lij AAD Table 5 Table 6 water toluene water decane PR AAD 2.9 % Eq. 21…”

pVTx Properties of Hydrothermal Systems

“…A modifi ed-Soave-Redlich-Kwong (MSRK) EOS with an exponent-type mixing rule (Higashi et al, 1994) for the energy parameter and a conventional mixing rule for the size parameter is applied to correlate the phase equilibria for four binary mixtures of water + hydrocarbon (benzene, n-hexane, n-decane, and dodecane) systems at high temperatures and pressures by Haruki et al (1999Haruki et al ( , 2000. The MSRK EOS is given as follows (Sandarusi et al, 1986):…”

“…The empirical exponents b represent a deviation from random mixing, and it was assumed that b 11 = b 22 = b 21 = 1 (Haruki et al, 1999(Haruki et al, , 2000. Furthermore, the following combining rule is adopted…”

“…Equation (2.38) with mixing rules (2.39) to (2.41) has been used by Haruki et al (1999Haruki et al ( , 2000 to correlate the phase equilibria for water + hydrocarbon binary systems.…”