Investigations on the Role of Temperature and Applied Power Profiles in
Microwave Demulsification of Crude Oil Emulsions
Montserrat Fortuny1,2, Adriano N. Santos1, Rosana L.F.V. Melo1, Márcio Nele3, Raquel C.C.
Coutinho4 and Alexandre F. Santos1,2*
1
Laboratório de Engenharia de Petróleo, Instituto de Tecnologia e Pesquisa, Aracaju,
49032-490, SE, Brazil.
2
Programa de Engenharia de Processos, Universidade Tiradentes, Av. Murilo Dantas 300,
Aracaju, 49032-400, SE, Brazil.
3
Escola de Química / Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de
Janeiro, 21945-970, RJ, Brazil.
4
CENPES / PETROBRAS, Cidade Universitária Q.7, Rio de Janeiro, 21949-900, RJ, Brazil
*
[email protected]
Applications of the microwave irradiation technology for water-in-oil demulsification have
been developed in the last twenty years. However, the design of microwave irradiation
procedures for demulsification of crude oil emulsions has received little attention, and few
studies are devoted to this subject. One of the reasons for these limitations is that the exact
nature of all factors that determine the demulsification efficiency due to microwave
irradiation is still not totally clear. Recent studies from our group have shown the effect of
aqueous phase properties on the performance of microwave demulsification of crude oil
emulsions.
The main objective of this work is to investigate the role of a set of operation conditions of a
microwave reactor system, including profiles of both temperature and applied power, upon
the microwave demulsification process. A series of batch demulsification runs were carried
out to evaluate the final emulsified water content of emulsion samples after the exposure to
microwaves. Tests were performed at distinct heating temperature profiles, using a
commercial microwave reactor system and water-in-heavy crude oil emulsion samples
containing different salt and water contents and pH. Well-defined temperature programs were
established in order to control the amount of energy applied to the samples. The microwave
power supplied by the instrument was automatically manipulated to assure the temperature
programmed for the samples during the heating ramp. Also, the effect of the microwaves on
the demulsification of freshly made and aged emulsions was investigated. Higher microwave
demulsification efficiencies were achieved when great amounts of energy (around 60% of
total energy) were applied in the very beginning of the demulsification run, for a number of
water-in-crude oil emulsions. In particular, temperature and power profiles considering this
intensive application of energy in the first few minutes yielded high efficient microwave
demulsification results, even when aged and tight emulsions were employed in the process.