ASTM D3827 Test Method for Estimation of Solubility of Gases in Petroleum and Other Organic Liquids
1. Scope
1.1 This test method covers a procedure for estimating the equilibrium solubility of several common gases in petroleum and synthetic lubricants, fuels, and solvents, at temperatures between 0 and 488 K.
1.2 This test method is limited to systems in which polarity and hydrogen bonding are not strong enough to cause serious deviations from regularity. Specifically excluded are such gases as HCl, NH3, and SO2, and hydroxy liquids such as alcohols, glycols, and water. Estimating the solubility of CO2 in nonhydrocarbons is also specifically excluded.
1.3 Highly aromatic oils such as diphenoxy phenylene ethers violate the stated accuracy above 363 K, at which point the estimate for nitrogen solubility is 43 % higher than the observation.
1.4 Lubricants are given preference in this test method to the extent that certain empirical factors were adjusted to the lubricant data. Estimates for distillate fuels are made from the lubricant estimates by a further set of empirical factors, and are less accurate. Estimates for halogenated solvents are made as if they were hydrocarbons, and are the least accurate of the three.
1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D1218 Test Method for Refractive Index and Refractive Dispersion of Hydrocarbon Liquids
D1250 Guide for Petroleum Measurement Tables
D1298 Test Method for Density, Relative Density (Specific Gravity) or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
D2502 Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils from Viscosity Measurements
D2503 Test Method for Molecular Weight (Relative Molecular Mass) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
3. Terminology
3.1 Definitions:
3.1.1 Bunsen coefficient - the solubility of a gas, expressed as the gas volume reduced to 273 K (32°F) and 0.10 MPa (1 atm), dissolved by one volume of liquid at the specified temperature and 0.10 MPa.
3.1.2 Ostwald coefficient - the solubility of a gas, expressed as the volume of gas dissolved per volume of liquid when both are in equilibrium at the specified partial pressure of gas and at the specified temperature.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 distillate fuel - a petroleum product having a molecular weight below 300 g/mol.
3.2.2 halogenated solvent - a partially or fully halogenated hydrocarbon having a molar volume below 300 mL/mol.
3.2.3 solubility parameter - the square root of the internal energy change (heat absorbed minus work done) of vaporization per unit volume of liquid, at 298 K.
3.2.3.1 Discussion - For gases in Table 1, the liquid is hypothetical and the values were calculated from actual solubility data.
3.3 Symbols:Symbols:
B = Bunsen coefficient at the specified condition,
ρ = density of liquid at 288 K (60°F), g/mL,
ρt = density of liquid at specified temperature, g/mL,
G = solubility in mg/k,
H = Henry's law constant, MPa,
M1 = molecular weight of liquid, g/mol,
M2 = molecular weight of gas, g/mol,
nD = refractive index of liquid, sodium D-line at 298 K,
p = partial pressure of gas, MPa,
pv = vapor pressure of liquid, MPa,
T = specified temperature, K,
L = Ostwald coefficient at T,
X = mole fraction of gas in equilibrium solution,
δ1 = solubility parameter of liquid, (MPa) 1/2,
δ2 = equivalent solubility parameter of gas, (MPa) 1/2, and
Φi = volume fraction of component i in a mixture of liquids.
