Reply to Comment on “Determination of Mass Transfer Rates of 3-Pentanone into Crude Oil at High Temperatures”

Abstract

The main objective of our previous study (Rezk et al. Energy Fuels 2026, 40, 11799) was to investigate mass transfer of 3-pentanone (3P) from the aqueous phase to the oil phase. Experiments were conducted at high temperatures using aqueous 3P solution and oil phases. Gas chromatography mass spectrometry (GC-MS) was employed to quantify the 3P concentration at various times during the tests. The measured concentration profiles were matched using a developed mass transfer model. Additionally, molecular dynamics (MD) simulations and COSMO-RS calculations based on density functional theory (DFT) were performed to describe the mass transfer of the 3P in the brine–oil system. A comment was subsequently received regarding the boundary condition imposed at the brine-oil interface in the mathematical model. In this reply, we justify the selected interface boundary condition and validate it further through comparison with published studies that solve analogous mass transfer problems using the same governing equations. We compare our model predictions with those reported in the Comment by Chen and Zhang at corresponding locations adjacent to the oil–brine interface. The predicted concentration profiles are nearly identical despite the different treatments of the interfacial boundary conditions. Additionally, we discuss the limitations of enforcing flux continuity at the brine–oil interface for describing the experimental concentration data and estimating mass transfer parameters. The limitations of the experimental measurements are also highlighted.