Jn. Kristensen et al., A COMBINED SOAVE-REDLICH-KWONG AND NRTL EQUATION FOR CALCULATING THE DISTRIBUTION OF METHANOL BETWEEN WATER AND HYDROCARBON PHASES, Fluid phase equilibria, 82, 1993, pp. 199-206
With the purpose of achieving a thermodynamic capable of calculating t
he distribution of methanol between oil, gas and water phases when met
hanol is being used as a hydrate inhibitor in offshore multi phase flo
w pipelines, parameters for methanol-hydrocarbon and methanol-water in
teractions have been estimated in a model suggested by Huron and Vidal
. The applied model takes the general' form of the Soave-Redlich-Kwong
(SRK) equation but uses an NRTL type mixing rule for the a-parameter.
For hydrocarbons the mixing rule reduces to the ordinary SRK mixing r
ule. This is advantageous because it makes the obtained calculation re
sults consistent with those obtained for methanol free mixtures using
SRK and because an already existing C-7+ characterization procedure fo
r use with the SRK equation does not have to be modified. Experimental
data for the methanol distribution between water and the oil and gas
phases of a North Sea reservoir fluid have been used to test the model
and it is found that the predicted results agree very well with the e
xperimental ones.