The fundamental analysis and modeling of kinetics of solvent extraction of rapeseed oil enable the quantification of the “washing” and “diffusion” steps. Both are illustrated through “starting accessibility” and “effective diffusivity”, respectively. This is a relevant way to identify how to intensify and optimize the operating conditions in terms of highest yield and lowest extraction time. Using the instant controlled pressure drop (DIC) expansion as a pretreatment for the intensification of the whole unit operation, the starting accessibility ratio reached a value of 28.69% against 19.03% for the raw material. Effective diffusivity of DIC treated samples reached a value of 2.05 × 10−12 m2/s instead of 0.72 × 10−12 m2/s for the raw material. Regarding oil composition, predominant fatty acids in all extracted rapeseed oils are oleic acid (C18:1 n9) ranged from 57.58 to 59.03%, linoleic acid (C18:2 n6) ranged from 21.23 to 21.89%, and linolenic acid (C18:3 n3) ranged from 9.11 to 9.45%. None of DIC treatment produced a significant variation in relative fatty acid profile.