Efficient Treatment Technology and Application of Oily Wastewater from Thermal Power Plants
Thermal power plants generate various oily wastewaters during operation, mainly from fuel oil tank cleaning, oil pump and pipeline leak flushing, lubricating grease mixed in from the coal handling system, and discharges from pumps in the pump house. These wastewaters are complex in composition; the treatment difficulties are: crude oil splits into heavy and light fractions, the small treatment volume makes regeneration difficult, emulsified oil settles poorly, and coal-washing wastewater has low oil but much suspended matter and slag. Even with an oil content of only a few hundred mg/L, improper treatment would severely impact the downstream wastewater treatment plant.
Current common treatment processes have many shortcomings:
1. Composite settling tank + high-clarity filter: large footprint, high cost, poor shock resistance, low automation, difficult oil recovery and tank cleaning, and major safety and environmental risks.
2. Oil separation tank + flotation tank + filtration: conventional flotation struggles with emulsified oil and high-density oil droplets, with poor and unstable effluent; it easily clogs filters and likewise has a large footprint and high cost.
3. Oil-water separator: gravity separation alone performs poorly (especially when oil and water densities are close) and tolerates fluctuations poorly; the long retention time means a large footprint; conventional packing coalesces poorly and clogs easily.
Efficient solution: SINOKLE's oily wastewater treatment process for thermal power plants
To address these challenges, SINOKLE developed an efficient treatment scheme incorporating its core patented products (such as the KHC coalescing oil remover). The process offers strong shock resistance, high efficiency and stable effluent, thoroughly solving the power plant wastewater discharge problem.
Process flow diagram of oily wastewater treatment at a thermal power plant
Its core advantages include:
Short flow, stable results: mainly purely physical, little oily sludge, environmentally friendly.
High automation: fully enclosed operation, small footprint, low labour and maintenance requirements, easy operation.
Advanced technology: applies several domestically leading patented technologies.
Core technology: high-efficiency coalescing pressure oil remover
The patented product integrates the coarse-graining principle, the shallow-pool principle and CFD simulation optimisation; its internal structure (pre-separation cyclone, coalescing packing zones of different specifications, oil collection pockets, high-efficiency sand-flushing and desilting device) is rationally designed to achieve rapid oil droplet accumulation, coalescence and flotation separation. Its technical advantages are significant:
1. Compact structure with a small footprint; oil removal efficiency above 90%.
2. Patented structural packing (stainless steel or reinforced PP) is strong and long-lived.
3. The special sand-flushing and desilting device keeps the packing unclogged and the equipment silt-free, ensuring long-term stable operation with little maintenance.
4. Fully enclosed pressurised automatic operation: stable, safe and reliable, with no environmental risk.
Successful application cases:
In March 2024, a customised oily wastewater treatment unit for a large combined heat and power project in Shaanxi Province was successfully commissioned. The unit adopts a filter + high-efficiency coalescing pressure oil remover combined process with a design capacity of 10 m³/h. The wastewater first passes through the filter to remove suspended solids, then enters the high-efficiency oil remover for oil-water separation; the effluent is clear, stable and compliant.
Multiple cases at home and abroad prove that SINOKLE's thermal power plant oily wastewater treatment process runs reliably, lasts long, removes oil efficiently and performs stably — an effective solution to the power plant oily wastewater treatment problem.
