Crude oil is a kind of complicated

Crude oil is a kind of complicated mixture and
commonly contains water and a large quantity of salts
[1-3]. Water in crude oil makes the pipeline and the
refining processes to be costly and even may cause oil
refining process unsteady. Salts, such as sodium,
magnesium, and calcium chlorides, in crude oil may
corrode the downstream equipments, obstruct the
pipes and make the catalysts poison. The main purpose
of desalting in the refinery is to avoid the harms
mentioned above. Some of the oil fields around the
world have already got into the stage of secondary or
tertiary oil recovery. The crude oil recovered in this
way tends to become ropier and heavier, containing
more salts. Current methods as electric desalting and
dewatering processes for these oils may be hard to
meet the need of the refinery.
Researches [4-7] had shown that the crude oil
pretreatment by ultrasound can agglomerate the tiny
water particles scattered in the oil, demulsify the oil,
and enhance the dewatering and the desalting process.
All the researches that have been reported are batch
and discontinuous processes [8-10]. The aim of this
present research is to study the continuous ultrasonic-
electric united process for crude oil desalting
and dewatering. The results in our research can be
compared with those of the refinery process. The
study presented in this article is based on our lab
works.