| dc.description.abstract | Produced water, the primary waste product of the petroleum industry, contains harmful components that must be treated before discharge to the sea or reinjection. The focus of treatment has traditionally been on dispersed crude oil, but there is now a growing interest in addressing dissolved organic compounds as well.
Gas flotation is an efficient topside separation method, frequently employed in conjunction with gravity separation and hydrocyclone units. In recent times, subsea produced water treatment has gained increased attention, with gas flotation emerging as a viable candidate for this purpose. The mechanism of gas flotation hinges upon the attachment of oil droplets to nucleated or dispersed gas bubbles, thereby forming aggregates of significantly reduced density that can rise more rapidly to the surface. The efficiency of the process is enhanced when the oil spreads over the surface of the gas bubbles, reducing the possibility of detachment due to shear forces. For the spreading to happen, the thin film between the oil drop and the bubble must thin to a critical thickness, until it ruptures. Fast film drainage and rupture are crucial for achieving a high level of efficiency in removing oil, highlighting the essential role of micro-scale events in the separation process.
The objective of this thesis was to investigate the impact of pressure, temperature, and fluid composition on gas flotation performance, considering both macro- and micro-scale aspects. The research combined flotation experiments conducted in a high-pressure and high-temperature gas flotation setup with microfluidic tests under similar conditions. This approach allowed for a comprehensive examination of gas flotation mechanisms. | en_US |
