Abstract: A method of liberating various existing hydrocarbon fractions from emulsified hydrocarbon mixtures without the need of additives, catalysts or heating using ultrasonic cavitation. Ultrasonic energy is provided at a rate sufficient to induce cavitation in the emulsified hydrocarbon mixture without causing cracking. The high temperatures and high pressures resulting from cavitation disrupt the emulsion thereby liberating existing lighter hydrocarbons in the diesel range or lighter for recovery via more traditional separation technologies. The resulting upgraded petroleum product exhibits lower distillation curves and decreased pollution causing components. Further, a wide variety of feedstocks can be treated according to the method of this invention.