Utilising micro-bubbles for oil in water separation
Published: 23 February, 2018
Transvac Systems from Derbyshire, UK, is a leading supplier of Ejector solutions, committed to pushing the boundaries of Ejector performance and finding ways to apply the technology to new applications.
Ejectors are well known in the Oil & Gas industry as devices capable of boosting production, recovering flare or waste gas and handling sand. With environmental impact in mind, Transvac says it has developed liquid driven Ejectors that are capable of entraining gas to produce ultra-fine bubbles, known as Micro-Bubbles, at targeted size ranges. Transvac Ejectors can be used in produced water treatment to improve the efficiency of oil in water separators.
The management of produced water in the Oil & Gas industry is increasingly becoming a burden to the industry, with stringent discharge contaminant levels having a considerable impact on the operating costs of managing multi-phase wells. Operators are welcoming new technology that can swiftly and efficiently remove oil from process streams, to reduce the impact these constraints are having. Using a Micro-Bubble Ejector as a secondary stage oil in water separation offers a simple, low maintenance solution that can provide a significant reduction in running costs.
By generating a plume of Micro-Bubbles, the Ejector can be used within an Induced Gas Flotation Unit (IGF) to improve the efficiency of oil in water separation. Thanks to the extremely large surface area to volume ratio created by the micro-bubbles, the oil more readily attaches to the bubble surface, improving the rate of removal. This can reduce the time taken to process the contaminated water, increasing the capacity of an existing system or can reduce the size of new systems which is key for offshore and subsea installations. It also results in cleaner water to meet the tight, allowable discharge contamination levels. To minimise the CAPEX and OPEX of the equipment, the Ejector can be driven by an existing recycle pump with gas entrained from the top of the vessel to create the Micro-Bubbles, making it a very efficient system.
Gary Short, design & innovation director said “The key to our technology is control over bubble size, and bubble size distribution. In simple terms, the closer to the optimum designed bubble size, the better. Transvac have run multiple tests on our state-of-the-art R&D Micro-Bubble rig to optimise and characterise the effects process conditions have on bubble size and distribution; to minimise coalescing, be as efficient as possible and design against blockages.”
