Efficient Demulsification and Separation: An Innovative Process for Refinery Acidic Wastewater
Facing the many challenges of treating high-emulsification, high-acid wastewater in the refining and petrochemical industry, an innovative physical demulsification process integrating cyclonic flotation, fine filtration and high-efficiency coalescence has emerged. The solution requires no chemicals and, through multiple purely physical stages, achieves efficient separation of oil and suspended solids from wastewater, safeguarding stable effluent quality and reliable operation of downstream units.
1. Three-stage treatment process
Process flow diagram for refinery acidic water treatment
The process has three core stages that form a complete stepwise purification chain:
Pretreatment (efficient demulsification and oil removal): wastewater first enters thecyclonic dissolved gas flotation (CDFU) unit. Combining cyclonic centrifugal force with the adhesion of micro-nano bubbles, the unit rapidly breaks the oil-water emulsion and efficiently removes most suspended solids, free oil and emulsified oil.
Advanced treatment (precise solid-liquid separation): the pretreated water enters thefine filter. This unit further intercepts residual trace suspended solids and dispersed oil droplets, preparing the water for final polishing.
Final treatment (refined oil-water separation): the flow finally passes through theKHC high-efficiency coalescing separator. Exploiting the density difference between oil, gas and water and the coalescing action of special coalescing media, it delivers deep oil-water separation and ensures clear effluent.
2. Technical advantages of the core units
CDFUCyclonic dissolved gas flotation unit: as the core demulsification unit, it integrates ultra-fine bubble generation, cyclonic centrifugation and dissolved gas flotation for high separation efficiency. It offerspurely physical demulsification, no chemical dosing, low energy consumption and a high degree of automation, and its effluent directly meets the requirements for feeding a stripping tower.
Fine filter: playing the "gatekeeper" role, it provides high filtration accuracy and stable operation, effectively protecting downstream units and improving overall effluent quality.
KHC high-efficiency coalescing separator: as terminal polishing equipment, it delivers powerful coalescing separation, high treatment load and stable, reliable operation, and is particularly suited to high-emulsification conditions.
Case study: acidic water treatment at a petrochemical plant in Henan
3. Process features and practical results
The integrated process has been successfully applied at several refining and petrochemical enterprises (for example, a petrochemical project in Henan) and shows clear advantages:
Purely physical, green and safe: no chemicals are added throughout the process, fundamentally avoiding secondary pollution and chemical costs.
High separation efficiency and strong adaptability: significant removal of emulsified oil and suspended solids, with the ability to accommodate a certain degree of influent fluctuation.
Stable operation, easy maintenance: integrated equipment design, a small footprint, automatic operation and high reliability.
Excellent effluent quality, high reuse rate: final effluent oil and suspended solids content are extremely low, allowing direct reuse in the stripping unit or meeting stringent environmental discharge requirements, unifying environmental and economic benefits.
This innovative process provides an efficient, reliable and economical solution for treating difficult acidic wastewater in the refining and petrochemical industry.
