Emulsified Acidic Water Treatment in Coking Plant
Process Overview
Process Introduction
Petroleum and its products contain sulfur-containing and nitrogen-containing compounds. During processing operations such as atmospheric and vacuum distillation, catalytic cracking, delayed coking, and catalytic hydrogenation, these compounds undergo high-temperature cracking, catalytic cracking, hydrocracking, and other reactions to generate H2S and NH3-N, which enter the product streams. When these streams undergo condensate dewatering or water washing, sulfur- and ammonia-containing wastewater is produced — commonly known as sour water.
Among refinery sour waters, the sour water generated from coking operations is particularly complex in composition and high in contaminant concentrations. Its main characteristics include:
High coke powder content with small particle size distribution
High oil content, small oil droplet size, and severe emulsification
High sulfide, ammonia-nitrogen, and phenol concentrations
Complex composition with significant content fluctuations
Employs CDFU (High-Efficiency Compact Cyclone DAF) + Fine Filtration + KHC High-Efficiency Coalescing Separator as the core technology, with emulsified oil removal precision down to 0.1 um and effluent oil content below 10 ppm. This technology is proven, reliable, and delivers excellent environmental and economic benefits, ranking at a domestic leading level compared with conventional technologies.
Schematic Diagram of Coking Highly Emulsified Sour Water Treatment Process Flow
Technological Advantages
Technological Advantage
CDFU organically integrates cyclone centrifugal force and dissolved-air flotation; the triple action of cyclone + dissolved air + flotation work synergistically, delivering far superior oil removal efficiency compared to conventional DAF
Retention time less than 5 minutes — only 1/8 to 1/3 of conventional DAF — equipment volume dramatically reduced, extremely small footprint
Bubble diameter 5–30 um with good uniformity, capable of capturing fine oil droplets and suspended solids, removing particles down to below 3 um
KHC high-efficiency coalescing separator with emulsified oil removal precision of 0.1 um and effluent oil content below 10 ppm, thoroughly resolving emulsification challenges
Single-stage suspended solids removal rate exceeding 80%, effectively removing fine suspended solids such as coke powder, preventing clogging of downstream equipment
No or minimal chemical dosing, purely physical separation, operating cost far below conventional DAF processes, no secondary pollution
Fully automated control system, no manual supervision required, stable and reliable operation, dramatically reducing manual workload
CDFU + fine filtration + KHC coalescing integrated process, at the domestic leading level, successfully applied in multiple large-scale projects
Technical Comparison
Technical Comparison
| Comparison Item | Conventional DAF | CDFU |
|---|---|---|
| Principle | Dissolved air + flotation | Cyclone + dissolved air + flotation |
| Retention Time | 15–40 min | <5 min (only 1/8 to 1/3) |
| Oil Removal Efficiency | 60%–85% | >90% |
| SS Removal Rate | 50%–70% | >80% |
| Removal Particle Size | >5 um | <3 um |
| Bubble Diameter | 5–100 um | 5–30 um (good uniformity) |
| Operating Cost | Higher | Lower (no or minimal chemicals) |
| Automation | Manual | Fully automated |
Application Cases
Application Case
Sinopec Luoyang Petrochemical — Coking Sour Water Treatment Project
