Refining Sour Water Treatment: Sources, Challenges and SINOKLE's Innovative Solution
Refining sour water has a complex composition and fluctuates widely; coking sour water in particular can have oil content of 500-3,000 mg/L, high coke-fines content (mostly smaller than 20 um) and severe emulsification. Discharging or mishandling such wastewater creates multiple problems:
Production safety impact: emulsified oil and coke fines readily clog the stripper, causing unplanned shutdowns and economic loss.
Environmental and health risks: irritating gases containing sulfides and ammonia nitrogen escape, polluting the environment and harming employee health.
High treatment difficulty: conventional processes struggle to meet standards consistently, and direct discharge to the wastewater plant aggravates downstream loading.
Limitations of Conventional Treatment Processes
Early practice mainly used gravity settling and cyclonic separation:
Gravity settling requires 50-70 hours of retention time, with poor separation and a large footprint.
Although cyclonic processes offer some improvement, they remove emulsified oil (0.1-20 um droplets) poorly, clog easily and consume high energy.
Later attempts with flotation plus inorganic ceramic membrane processes improved precision, but investment is high, membranes foul easily, water recovery is low, and secondary pollution is generated.
SINOKLE's Innovative Process: Purely Physical, Highly Efficient Treatment
To address these pain points, SINOKLE developed a new treatment scheme centred on CDFU (cyclonic dissolved gas flotation) and combined with the KHC high-efficiency coalescing separator to form a multi-stage purely physical treatment flow:
CDFU Cyclonic dissolved gas flotation: through the synergy of cyclonic centrifugation and ultra-fine bubbles (5-30 um), it efficiently adsorbs emulsified oil and coke fines with no chemicals, achieving single-stage oil removal above 90%.
KHC coalescing separator: uses patented hydrophilic modified packing to demulsify deeply and recover high-quality crude oil that can be returned directly to refining. The unit achieves emulsified oil removal precision of 0.1 um, with effluent oil content below 10 ppm (excluding dissolved oil).
Core Advantages of the New Process
The SINOKLE solution is significantly better than conventional technologies:
Highly efficient and stable: effluent oil content reduced to below 100 mg/L, suspended solids removal above 80%, and tolerance to water-quality fluctuations.
Economical and environmentally friendly: purely physical separation with no chemicals, eliminating oily sludge (hazardous waste) at the source, and recovered oil creates economic value.
Compact and intelligent: skid-mounted design occupying only 1/3 of the conventional footprint, fully automatic closed operation with no gas leakage, supporting online implementation.
The process has been successfully applied in Luoyang Petrochemical (15 m³/h capacity), the PetroChina Chad refinery (20 m³/h capacity) and other projects, with effluent oil content stably below the specified standards, making it the ideal choice for refining and chemical enterprises to achieve environmental compliance while cutting costs and raising efficiency.
