HEAT EXCHANGER FOULING MITIGATION BY BLENDING AND ULTRASONIC

Fouling is a major economic problem faced in petroleum industry. The presence of
paraffin wax deposition causes ineffective heat transfer and cost increment, since it
creates a new resistance to the heat flow. Many people keeps thinking and moving
forward in their effort to reduce the fouling, which encourages them to focus on the
mitigation and cleaning techniques. The objective of this study is to investigate the
fouling characteristics of pure and mixed crude oil on heat exchanger surface. In
addition, the study also investigated the effect of ultrasonic application for fouling
mitigation. The specified parameters were varied in each set of experiment, followed
by monitoring the rate of deposition for 3 hours. The experiments were mainly
carried out using cold fmger unit, cooling bath circulation system and ultrasonic bath
unit. Besides, the effects of each run were observed by varying 3 different crude oil
samples (TAPIS, MASSA and MIRl), wall temperatures, crude oil temperatures and
ultrasonic application. Ultrasonic wave was generated at the lowest frequency
(28kHz) and highest power (600W), since this condition is proved to give the highest
mitigation. TI1e result shows that the deposition increases as times increases. In
addition, deposition favors at low crude oil and wall temperature, because it depends
on the temperature differences and amount of crude oil temperature below the cloud
point. Apart from that, it was found that the amount of deposition is directly
dependant to the amount of paraffin wax in each sample. However, after introducing
the blending options, deposition of higher paraffin wax content sample was lowered
down because the wax content has been reduced. Finally, the combination of
ultrasonic and blending was proved to give very high and effective reduction of
deposition for all samples namely TAPIS-MASSA (50%), MASSA-MIRI (50%) and
TAPIS-MIRl (60%). In short, crude oil blend and ultrasonic application were proved
as an effective method of fouling mitigation.