Breaking the Oily Wastewater Challenge at Light Oil Depots: SINOKLE's Purely Physical Process Delivers Both Environmental and Economic Gains
In the refined oil storage sector, periodic water draining from light oil (gasoline) tank farms is a key operation for safeguarding product quality, but draining inevitably entrains oil products, forming high-concentration oily wastewater. If discharged directly, this wastewater not only causes serious water pollution but also leads to the loss of large amounts of light oil products - crossing environmental red lines while causing significant economic losses. How to treat oily wastewater from light oil depots efficiently while recovering valuable oil and meeting reuse standards has become a core issue in the green transformation of oil depots.
For a long time, oily wastewater treatment at domestic oil depots has relied mainly on conventional processes, with many pain points:
Physical methods such as gravity oil separation remove only floating oil and are helpless against emulsified and dissolved oil, making stable compliance of effluent oil content difficult;
Chemical methods achieve oil-water separation by dosing flocculants and demulsifiers. Although they improve treatment performance, chemical costs are high, sludge output is large, secondary pollution is likely, and the recovered oil is of poor quality and hard to reuse directly;
Biological methods can deeply degrade organics, but they require a large footprint and long construction periods and have weak shock-load tolerance, making them unsuitable for the intermittent draining and highly variable water quality at oil depots.
These processes either have limited treatment performance or high operating costs, and struggle to meet the dual needs of oil depots: environmental compliance plus resource recovery.
Addressing the characteristics of oily wastewater from light oil depots, SINOKLE has innovatively introduced a CDFU swirl dissolved-air flotation process plus KHC high-efficiency coalescing oil separators. This purely physical process offers the industry a more efficient and more economical solution. The process adds no chemicals at all and achieves efficient oil-water separation by physical means. It has been widely applied in draining treatment at crude oil tank farms, refined product tank farms and heavy oil power plant tank farms at PetroChina, Sinopec, China Power and other enterprises, becoming a benchmark technology for oily wastewater treatment at light oil depots.
The core technical advantages of SINOKLE's purely physical process lie in precise design and efficient coordination throughout the flow:
CDFU swirl dissolved-air flotation unit: integrating swirl separation and dissolved-air flotation, it uses nitrogen flotation to form fine bubbles that efficiently capture floating oil, emulsified oil and fine suspended solids, achieving over 90% oil removal in a short time while avoiding the risk of oil oxidation caused by oxygen and safeguarding the quality of recovered oil.
Fine filter unit: performs advanced filtration of the flotation effluent, intercepting residual fine oil droplets and solid impurities to provide stable feed for subsequent coalescing separation. It also has a backwash function for self-cleaning, reducing maintenance costs.
KHC high-efficiency coalescing oil separator unit: using patented coalescing media and a coalescence-separation mechanism, it coalesces residual fine oil droplets in the water into larger oil globules for thorough oil-water separation. Effluent oil content is stably controlled below 10 mg/L, meeting wash-water reuse standards while recovering high-quality light oil.
Oily wastewater treatment project at a power plant light oil depot (KHC coalescing oil-water separator)
Compared with conventional processes, SINOKLE's purely physical process delivers clear technical and economic advantages:
Zero pollution: no chemicals are added throughout the process - no sludge, no secondary pollution - fully resolving the environmental risks of chemical methods and meeting green production requirements.
High resource recovery: light oil products in the wastewater are efficiently recovered at a rate of over 95%, and the recovered oil is close in quality to virgin light oil and can be directly refined or sold, creating significant economic value for the depot.
Low operating cost: the equipment has a small footprint, a high degree of automation and low energy consumption, with no frequent replacement of chemicals or media, bringing operating costs more than 30% below chemical methods.
Strong adaptability: it handles the intermittent draining and highly variable water quality typical of oil depots, with strong shock-load tolerance and stable compliant effluent that can be reused directly for tank farm cleaning, achieving water recycling.
Against the backdrop of the dual carbon goals and tightening environmental supervision, oily wastewater treatment at light oil depots has shifted from a cost item to a value item. With the dual value of environmental compliance and resource recovery, the purely physical process not only solves depots' environmental pain points but also turns waste into value through oil recovery, providing a replicable and scalable model for the industry's green transformation.
