Multiphase equilibria in aqueous systems containing hydrocarbons and natural gases

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5917582

Anderson, F E

For processing fossil fuels toward thermal and chemical products, economic design requires quantitative information on phase-equilibrium properties for hydrocarbon-water systems. Two hydrocarbon water phase-equilibrium problems are studied in this thesis. The first study presents experimental measurements for liquid-liquid mutual solubilities and vapor pressures of aqueous mixtures containing aromatic hydrocarbons at high temperatures under conditions of three-phase (vapor-liquid-liquid) equilibrium. An apparatus has been constructed in which the phases are equilibrated, sampled and analyzed using gas-liquid chromatography. Measurements are reported for aqueous binaries containing benzene, toluene, m-xylene, and thiophene in the temperature range 100 - to 200/sup 0/C. Comparison of these results with literature data shows good agreement. The second study presents a new correlation for the inhibition effect of methanol on hydrate formation in moist natural gas mixtures applicable between 220 and 320 K. Methanol is commonly used to inhibit hydrate formation by lowering the fugacity of water in coexisting phases. Six phases are potentially present in these mixtures: gas, aqueous liquid, hydrocarbon liquid, ice, and hydrate structures I and II. For given temperature and mixture composition, the molecular-thermodynamic method described here allows computation of the hydrate-formation pressure and the relative amounts and compositions of coexisting phases. This correlation is based on the van der Waals-Platteeuw model for hydrates, a modified Redlich-Kwong equation of state for gases and on the UNIQUAC equation for liquid-phase activity coefficients. The final correlation is presented in a computer program useful for computer-aided process design.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 5917582
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
033000* -- Natural Gas-- Properties & Composition
ALCOHOLS
ALKYLATED AROMATICS
AROMATICS
BENZENE
CALCULATION METHODS
CHROMATOGRAPHY
COMPUTER CODES
CONTROL
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS CHROMATOGRAPHY
GAS FUELS
GAS HYDRATES
GASES
HETEROCYCLIC COMPOUNDS
HIGH TEMPERATURE
HYDRATES
HYDROCARBONS
HYDROXY COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MEDIUM TEMPERATURE
METHANOL
NATURAL GAS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PARTICLE MODELS
PHASE STUDIES
PRESSURE DEPENDENCE
QUANTITY RATIO
SEPARATION PROCESSES
SOLUBILITY
STATISTICAL MODELS
THERMODYNAMIC MODEL
THIOPHENE
TOLUENE
XYLENES