Microwave demulsification of heavy crude oil emulsions: Analysis of acid species recovered in the aqueous phase

• Published in: Fuel (Guildford) Vol. 128; pp. 141 - 147
• Main Authors: da Silva, Elisângela B., Santos, Denisson, de Brito, Mayara Paes, Guimarães, Regina C.L., Ferreira, Bianca M.S., Freitas, Lisiane S., de Campos, M. Cecília V., Franceschi, Elton, Dariva, Cláudio, Santos, Alexandre F., Fortuny, Montserrat
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.07.2014; Elsevier
• Subjects: Applied sciences; Emulsions; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; GC/qMS analysis; Microwaves; Petroleum; Emulsions; GC/qMS analysis; Petroleum; Microwaves; Emulsion; Crude oil; Microwave; Heavy oil; Demulsification
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2014.02.076

[Display omitted] •We report the effect of microwaves and conventional heating on the crude oil.•Microwaves allowed us to remove water and acidic compounds from the oil phase.•Temperature and pH can be managed to alter the profile of acids recovered. In this work, the application of microwave technology is investigated for breaking water-in-heavy crude oil emulsions focusing upon the identification of acidic species existing in the aqueous phase recovered by the microwave demulsification process. To accomplish this, a methodology for characterization of acidic species based on GC/qMS (gas chromatography coupled to mass spectrometry quadrupole type) has been developed. An experimental study was conducted to assess the effect of operating conditions, including the heating mode (microwaves/conventional heating), process time (30, 60min), pH of the aqueous phase (pH=2, 6, 10) and temperature (90, 120, 150°C) over the migration of acidic species from the crude oil to the aqueous phase during the demulsification of a heavy crude oil. The most influential variable was the temperature, which favors the partitioning of a larger number of acidic species, including cyclic compounds of low molecular weight that were not extracted at low temperature. The microwave heating allowed a wider distribution profile of monocyclic and bicyclic acids than the conventional heating scheme. Changing the aqueous phase pH from acid to the alkaline range modifies the profile of acidic compounds from predominantly acyclic to monocyclic and bicyclic species.