Crude Oil Storage Tank Area Wastewater Treatment
Process Overview
Process Introduction
During operation of crude oil storage tanks, water contained in the crude oil and natural sedimentation cause oily water cut to continuously accumulate at the tank bottom. This water cut contains large amounts of emulsified oil, dissolved oil, and suspended solids, with extremely high oil content (potentially exceeding 100,000 mg/L) and a high degree of emulsification. Conventional treatment approaches such as API separators and chemical flocculation are ineffective, and can lead to environmental pollution and oil resource waste.
Sinokle employs a purely physical separation process centered on CDFU cyclone dissolved-air flotation + HCC high-efficiency cyclone coalescer, requiring no chemical additives. Through the synergistic action of micro-bubble flotation and coalescing separation, emulsified oil and suspended solids in the water cut are efficiently removed, producing compliant effluent, while the recovered oil is directly returned to the crude oil tank.
CDFU cyclone dissolved-air flotation + HCC high-efficiency cyclone coalescer — two-stage purely physical separation, recovered oil directly reused, no secondary pollution, water cut discharged in compliance with standards.
| Water Quality Parameter | Process Influent | Process Effluent |
|---|---|---|
| Oil in Water | ≤100000mg/L | ≤100mg/L |
| Suspended Solids | ≤2000mg/L | ≤100mg/L |
Schematic Diagram of Crude Oil Tank Farm Water Cut Treatment Process Flow
Technological Advantages
Technological Advantage
Stable and reliable with oil removal efficiency above 95%, no chemical demulsification required
Recovered oil returned directly to the crude oil tank for reuse, no secondary pollution, no oily sludge (hazardous waste) generated, solving environmental challenges while creating economic value
Short process flow, compact equipment, small footprint, saving space and capital investment
Skid-mounted design with simple automated O&M, short construction period, can be retrofitted online without production shutdown
Stable operation capable of handling large fluctuations in water quality and oil content, adapting to the complex operating conditions of tank farm water cut
Fully enclosed pressurized operation, no odor, no leakage, no oily sludge generated, inherently safe and environmentally compliant
Technical Comparison
Technical Comparison
| Comparison Item | API Separator + Chemical Flocculation | CDFU + HCC Coalescing Separation |
|---|---|---|
| Oil Removal Efficiency | Can only remove floating oil and part of dispersed oil; low emulsified oil removal rate; overall oil removal efficiency below 60% | Micro-bubble flotation + coalescing separation synergy; efficient emulsified oil removal; oil removal rate above 95% |
| Chemical Usage | Requires demulsifiers, flocculants and other chemicals; high operating cost; oily sludge (hazardous waste) generated | Purely physical separation, no chemicals required, no oily sludge generated, low operating cost |
| Oil Recovery | Chemicals worsen oil emulsification, making oil recovery impossible, resulting in resource waste | Purely physical separation recovers oil directly for reuse in crude tank, delivering significant economic benefits |
| Footprint | Large API separator volume, long retention time, large footprint | Compact equipment, short retention time, footprint only 1/3 to 1/5 of conventional process |
| Shock Resistance | Treatment performance degrades sharply under large influent oil content fluctuations; unstable operation | Strong shock resistance, capable of handling large oil content fluctuations from thousands to 100,000 mg/L |
| Safety & Environment | Open facilities, strong on-site odors, high risk of sludge leakage, safety hazards present | Fully enclosed pressurized operation, no odor, no leakage, no hazardous waste generated, inherently safe and environmentally compliant |
Application Cases
Application Case
PetroChina — Oil Storage Depot Water Cut Treatment Project
