Purely Physical Demulsification, Zero Chemicals: An Oily Wastewater Solution for Heavy-Oil Power Plants
In the daily operation of a heavy-oil power plant, a seemingly unremarkable stream - fuel oil tank washing water, oil pump and pipeline seepage and flushing water - often becomes a major environmental headache for managers. Although its instantaneous volume is small, it contains a proportion of emulsified oil that is extremely difficult to settle and separate, and its quality fluctuates sharply, placing a huge shock load on the downstream central wastewater treatment plant and seriously affecting the stability and final compliance of the plant's wastewater system.
Conventional treatment processes - whether chemical-dependent 'composite settling tank + high-density filter' or 'oil interceptor + conventional flotation + filtration' combinations - often fall short when facing the difficult, highly variable oily wastewater of a heavy-oil power plant. They generally occupy large areas, carry high civil works costs, tolerate shock loads poorly, have low automation and clog easily and, most critically, struggle to stably meet the strict requirements for feeding the downstream wastewater plant, while potentially generating oily sludge and other secondary pollutants.
Facing this shared industry challenge, SINOKLE draws on its deep core technology base to deliver an efficient, economical and environmentally friendly innovative solution.
The core of SINOKLE's solution is purely physical separation technology. It abandons the conventional reliance on chemicals and is built mainly around the CDFU (swirl dissolved-air flotation unit) and the KFM activated filter media filter.
CDFU The swirl dissolved-air flotation unit is a high-efficiency oil-water separator independently developed by SINOKLE. It innovatively combines swirl centrifugal separation, dissolved-air flotation and ultra-fine nano-bubble technology. Its core working principle: the wastewater to be treated mixes with dissolved-air water rich in micro-bubbles (5-30 μm in diameter) and enters the unit tangentially along the vessel wall, forming a stable swirl field. Under centrifugal force, micro-bubbles collide with, attach to and coalesce with emulsified oil droplets; the resulting floating oil rises to the central oil collection zone and is discharged, while treated clear water flows out from the bottom.
The unit features a unique structural design with dual tangential inlets, inner and outer flotation zones and bottom swirl desanding, giving it clear technical advantages: single-stage deoiling efficiency above 90%, hydraulic retention time as short as 1-5 minutes, and a footprint only one third that of conventional flotation. The whole process requires no chemicals and produces no oily sludge, achieving efficient, compact and eco-friendly physical separation.
The downstream KFM activated filter media filter is a high-precision filtration unit modified with atomic deposition technology. Its core media is a silicate-based activated material with a negatively charged surface and a unique triple mechanism of physical interception, charge adsorption and catalytic oxidative sterilisation, with filtration precision down to 1 micron.
The filter reliably achieves fine targets of effluent oil content ≤ 6 mg/L and suspended solids ≤ 2 mg/L, and is especially suited to difficult scenarios such as oilfield produced water and power plant oily wastewater. With a compact, skid-mounted design and a high degree of automation, its backwash efficiency reaches 100%. The media has high mechanical strength and wear resistance and a theoretical service life of up to 15 years, greatly reducing long-term O&M costs.
The advantages of this combined process are obvious:
· Highly efficient, stable and shock-tolerant: purely physical demulsification and deoiling is efficient and stable, tolerating wide swings in influent quality, and both effluent oil content and suspended solids can be stably held at very low levels (for example oil ≤ 5-10 mg/L, SS ≤ 5 mg/L), truly easing the burden on the downstream wastewater treatment plant.
· A win-win for the environment and the bottom line: no chemicals are needed at any stage, which avoids secondary pollution and allows high-quality light waste oil to be recovered and returned directly to the production system for resource utilisation. Because no oily sludge (hazardous waste) is produced, solid waste disposal costs and environmental risk are also greatly reduced.
· Compact, intelligent and quick to build: the equipment uses a highly integrated skid-mounted design with a compact structure occupying only about one tenth of the footprint of conventional processes, greatly saving land and civil works costs. The whole system can run automatically in an enclosed mode with simple O&M, short construction periods and even online retrofits without disrupting normal plant production.
SINOKLE's technology is not confined to the laboratory; its excellent performance has been proven in many heavy-oil power plant projects worldwide. In a heavy-oil power station project in Sierra Leone, Africa, for example, the 'two-stage CDFU + KFM filter' process supplied by SINOKLE successfully treated oily wastewater to compliant discharge, providing solid support for the plant's long-term environmental compliance.
Similar core processes have been used in overseas projects such as Mirsarai in Bangladesh and the captive power station at an iron ore mine in Guinea, all achieving stable and excellent treatment results - proof of the technology's strong adaptability to different regions and environmental conditions.
Behind these successful applications is SINOKLE's continued deep engagement in difficult industrial wastewater treatment. It has built four core technology platforms, including ultra-fine nano-bubble generation, super-hydrophilic material modification and high-gravity intensified mass-transfer demulsification. This strong independent innovation capability is exactly what allows SINOKLE to tailor a genuinely effective solution to the characteristics of heavy-oil power plant oily wastewater.
As global environmental standards tighten and power plants increasingly seek cost savings, efficiency gains and sustainable development, efficient and clean pretreatment technology will become standard for heavy-oil power plants. With its technological leadership, operating economy and environmental friendliness, SINOKLE's purely physical oily wastewater solution is becoming the reliable choice for more and more plant managers pursuing a green transition and better operational quality.
