Technical Breakdown: Three Hard Problems of Refinery Sour Water (Coke Fines, Emulsified Oil and Sulfide-Ammonia-Phenol) and How a Combined Process Solves Them One by One
1. Why Sour Water Is So Hard to Treat
Refinery sour water originates from atmospheric and vacuum distillation, catalytic cracking, delayed coking, catalytic hydrogenation and other processing units: sulfur and nitrogen compounds in the feedstock are cracked at high temperature or converted through catalytic cracking and hydrocracking to form H2S and NH3-N, which become sulfur- and ammonia-bearing wastewater after condensation and dehydration or water washing of the product stream. Coking sour water is especially troublesome: high coke-fines content with small particle size, high oil content and severe emulsification, and high concentrations of sulfur, ammonia nitrogen and phenols with wide compositional fluctuation.
2. Process Countermeasures for the Three Problems
For the coke-fines problem, fine filtration acts as the interceptor, trapping fine coke particles in the middle stage so they cannot enter downstream units; for the emulsified-oil problem,the KHC high-efficiency coalescing separator works at the tail end, letting fine emulsified oil droplets coalesce and grow for efficient separation; against compositional fluctuation, CDFU the high-efficiency compact cyclonic flotation unit responds rapidly at the front end, offsetting influent shocks with stable flotation separation. Three stages in combination, each layer guarding the next.
3. Performance Indicators and Leadership
Emulsified oil removal precision reaches 0.1 um, with effluent oil content below 10 ppm — the core indicators of this combined process. From a process-logic perspective, flotation, filtration and coalescence each specialise in one mechanism yet connect with each other, together holding effluent oil content firmly at a low level. The technology is feasible and reliable, delivers good environmental and economic benefits, and ranks at the domestic leading level compared with conventional technologies.
4. Value and Outlook
For refining and chemical enterprises, the value of this solution goes beyond mere compliance: 0.1 um removal precision leaves no hiding place for micro-emulsified oil, and effluent oil content below 10 ppm creates stable conditions for downstream stripping and biological treatment, thereby safeguarding smooth operation and compliant discharge of the plant-wide wastewater system.
In terms of technical maturity, CDFU the combination of cyclonic flotation, fine filtration and the KHC high-efficiency coalescing separator is not a simple stacking of units but a precise configuration matched to the pollutant forms in sour water. In sour-water management, refining and chemical enterprises would do well to seriously evaluate this domestically leading technical route.
Zoom out a little: sour water is only one link in the refinery wastewater system, yet it often affects the whole chain. If front-end oil removal is incomplete, emulsified oil travels along the process, aggravating the risk of foaming and scaling in the stripper, increasing chemical dosing and even disturbing biological-system stability. SINOKLE addresses the problem at the source with 0.1 um precision, which is equivalent to lifting the heaviest burden off the entire downstream chain.
From an operational perspective, coking sour water, with its 'complex composition and wide content fluctuation', imposes hard requirements on the process's shock resistance. The advantage of the combined process is that buffers form naturally between stages: CDFU cyclonic flotation absorbs influent shocks, fine filtration stabilises mid-stage water quality, and the KHC high-efficiency coalescing separator secures the final output; the three stages share the load, so the whole system maintains deterministic effluent performance even under fluctuating influent.
Regarding the 'domestically leading' claim, it can be understood this way: it is not the leadership of a single piece of equipment but the leadership of combined-process logic — for the complex form in which coke fines, emulsified oil and high-concentration pollutants coexist in sour water, three mechanisms of flotation, filtration and coalescence are precisely assigned and applied in progressive stages, striking a balance between feasibility and reliability. This solution is precisely the technical option worth attention in sour-water management for refining and chemical enterprises.
Looking at industry trends, the focus of sour-water management is shifting from 'end-of-pipe compliance' forward to 'front-end purification': solving emulsified-oil and coke-fines problems before they enter stripping and biological units, relieving the whole flow in the most economical way. This SINOKLE combined process, benchmarked by 0.1 um removal precision and effluent oil content below 10 ppm, fits this trend closely and provides refining and chemical enterprises with a quantifiable, verifiable basis for comparison and selection.
