Crude oil in addition to oil also includes water, Surface-Active Components (SAC) and other components in small fractions. Such a mixture is a form of an emulsion. These emulsions alongside adsorbed asphalts accumulate leading to a thick dense packed layer (DPL) settling in the front centre part of large separators. The water needs to be removed from the crude oil before it is transported and send it for refining to produce valuable products such as Diesel, Gasoline, etc. Considering crude oil as a complex emulsion consisting of chemical compounds, enormous amount of studies has been conducted to understand the stabilization/destabilization of emulsions in the presence of these chemicals. The focus of these research work has been on accurate estimation of concentration and accurate measurement of rheology and interfacial tension. Currently, a simple strategy of gravity separation and electrical devices (for electrostatic coalescence) is practiced fostering droplet coalescence and separation. But, when these conventional methods fail, energy intensive methods like thermal devices for altering thermos-physical properties of emulsions, centrifugal methods, and injection of de-stabilizer chemicals, microwave radiation and ultrasonic treatment are practiced. In chemical demulsification adding demulsifiers beyond their optimum resulted in an increase of the stability of the emulsion, probably due to the formation of a new stabilizing film in which the excess of demulsifiers. This has led to over usage of energy, chemicals and inefficient recovery. Often when these methods fail DPL are removed through an intermediate outlet and simply disposed of without recovery. IMPOSE proposes that it is necessary to process DPL separately after it comes out of the separator.
The crude oil emulsions are stable due to presence of SAC's and by removing these SAC's the stability of the crude oil can be changed significantly. In IMPOSE, a proposed SAC removal method can lead to a revolutionary change in the oil industry. With this method, even simple gravity separators can be sufficient for efficient separation of oil from the crude oil. Furthermore, IMPOSE will establish new standards in separation technology. So far, the oil industry faces serious challenges in the choice of the separation method. It is difficult to select which de-emulsification method should be used for efficient separation. A common separation method is the use of chemical demulsifiers. The excessive use of chemical demulsifiers is not only costly but also creates environmental issues.
IMPOSE developments:
- Removal of the SAC from emulsion: Various nano particles such as Al2O3, Fe2O3 and SiO2 will be used to understand the absorption behaviour of SAC on particles.
- Design of dynamic emulsion characterization techniques: An advance bottle test (stirred tank cell ) be used that can produce the same level of dissipation as a real separator system. a range of measurement accessories will be utilized to accurately measure emulsion dynamics or relaxation time scales for droplet coalescence. This advanced bottle test can be utilized by oil industry to develop operation regime map for optimised dissipation (flow rate to be maintained), electrical and chemical utilization, etc.
- Development of efficient separation methods: Various separation methods such as chemical demulsification, thermal heating, microwave heating, centrifuge, and electrocoalescence will be studied.