Abstract
A new comprehensive semiempirical approach (CSA) has been developed to calculate three-phase water/hydrocarbons equilibria. It uses both laboratory data (stagewise isochoric distillation data) and Peng-Robinson EOS. It considers mutual solubility between water and hydrocarbons. The CSA calculates phase equilibria by applying the thermodynamic equalities between phases and material balance of the systems. The CSA also includes a self-tuning algorithm that allows the user to tune the input parameters, i.e. vapor phase composition (vi). In this study, the CSA has been used to run the data from Billman (1989) and Beladi (1995). These data include two ternary systems of n-heptane/n-dodecane/water, for which their initial overall compositions are different, and one ternary system of n-decane/n-pentadecane/water. The vapor phase composition (yi) data has been tuned to satisfy the following material balance equation: [] The approachhas been verified by comparing the calculated vapor phase composition (yi calc ) with yi data and yi tuning value. They all matched each other in some range of data uncertainty. The data uncertainty ranges from 0.62 to 60.6%. The oleic phase composition can be used to show that solubility of water in oleic phase cannot be neglected. It is shown in this study that vapor-oleic three-phase K-values are slightly dependent upon composition. It is also shown that the lighter the hydrocarbon component, the higher the vapor-oleic three-phase K-values are. The aqueous phase composition in this study shows that solubility of hydrocarbons in the aqueous phase is insignificant,
Tandia, Bagus Krisna (1995). A new comprehensive semiempirical approach to calculate three-phase water/hydrocarbons equilibria. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -T362.