Deep eutectic solvents (DESs) are a new class of green solvents that open a whole new world of opportunities for separation challenges. This book comprehensively provides a detailed discussion of their application as an extractive solvent in separation processes, adopting molecular dynamics (MD) simulations for atomistic insight into the solute transfer across bi-phasic systems. Furthermore, it explains ternary and quaternary mixtures, including MD simulation of relevant DES systems. Features in this volume include the following: Applications of DESs in the extraction of aromatics and polyaromatics from fuel oil by liquid–liquid extraction Eutectic behavior with respect to hydrocarbon and aqueous solutions MD insights on extraction using DESs Possible industrial applicability of potential DESs Results from Gaussian, NAMD, and PACKMOL software packages This book is aimed at researchers and graduate students working in the field of fuels and petrochemicals, separation science, chromatography, and chemical processing and design.