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ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
WATER-ALCOHOL-HYDROCARBONS VLE AND VLLE: PREDICTION OF ALCOHOL PARTITION COEFFICIENT
Submission Author:
Moisés Marcelino Neto , PR
Co-Authors:
Felipe Cesar Jacomel, Thales Sirino, Moisés Marcelino Neto, Dalton Bertoldi, Rigoberto Morales
Presenter: Moisés Marcelino Neto
doi://10.26678/ABCM.ENCIT2018.CIT18-0517
Abstract
Clathrate hydrates are compounds of great interest in oil industry. They are crystalline structures formed by water and gas molecules at high pressure and/or low temperature. Formation of hydrate blockages represents both an economical loss and a safety concern in operation of a pipeline. Thermodynamic inhibitors (usually alcohols, such as methanol) change the thermodynamic equilibrium itself, avoiding the hydrate zone. Accurate results for the loss of volatile inhibitor in the gas phase (partition coefficient) are of major importance for the oil and gas industry. In this work, a flash algorithm was developed using the Cubic Plus Association (CPA) equation of state to estimate the partition coefficients of each component (water, hydrocarbon and hydrate inhibitor) in any phase over a wide range of temperature and pressure in vapor-liquid equilibrium (VLE) and vapor-liquid-liquid equilibrium (VLLE). The binary interaction coefficients were optimized as a linear function of temperature. The flash was applied to various systems with water, methane, ethane, propane, isobutane, carbon dioxide, nitrogen, hydrogen sulfide, methanol, ethanol, monoethylene glycol, sodium chloride, calcium chloride and potassium chloride. The results were then compared with experimental data and satisfactory results were obtained.
Keywords
vapor-liquid equilibrium, vapor-liquid-liquid equilibrium, CPA, inhibitor, partition
