Breakthrough in Advanced Treatment of Coking Acidic Water: SINOKLE Purely Physical Process Achieves Efficient Purification
Characteristics of coking acidic water and treatment challenges
Coking acidic water is highly difficult wastewater generated in coking production. Its main sources include moisture carried in with the coal blend, wastewater from coking reactions, distilled ammonia liquor and gas condensate, and it can be divided into excess ammonia liquor, phenol-cyanide wastewater, dust-removal wastewater, gas seal water and desulfurization waste liquor. This wastewater features complex and variable quality, huge volumes and high pollutant concentrations: oil content can reach 13.3%-16%, COD is extremely high, and it also contains complex components such as ammonia nitrogen, sulfides and volatile phenols.
Compared with conventional industrial wastewater, the difficulty of treating coking acidic water is mainly reflected in four aspects:
First, high coke powder content leads to a high suspended solids concentration;
Second, it contains large amounts of refractory organics such as phenols and cyanides, with poor biodegradability;
Third, the oils are highly emulsified, forming a stable oil-water mixture;
Fourth, water quality fluctuates greatly, placing extreme demands on the shock resistance of the treatment system.
These characteristics make it difficult for conventional processes to achieve stable compliance, and innovative technology is urgently needed for a breakthrough.
Innovative process technology system
For the special properties of coking acidic water, SINOKLE has developed a multi-technology collaborative treatment process centered on cyclonic dissolved-air flotation and KHC coalescing oil-water separation.
Coking acidic water treatment process flow diagram
The system comprises a multi-stage treatment flow:
In the pretreatment stage, a coarse filter removes large suspended particles, creating favorable conditions for subsequent processes.
The core treatment unit, the CDFU cyclonic dissolved-air flotation unit, combines centrifugal separation, dissolved-air flotation and ultrafine bubble generation technology, achieving >90% oil removal and >80% suspended solids removal within a residence time of ≤5 minutes. Its 5-30 μm microbubbles, compared with the 300-1,000 μm bubbles of conventional flotation, have a stronger capability to capture pollutants.
The polishing stage is equipped with a KHC high-efficiency coalescing de-oiler that uses special fiber materials for 0.1 μm precision filtration, reducing effluent oil content to below 10 ppm.
Technical innovation advantages and engineering performance
This process system has significant technical advantages: purely physical demulsification without chemical addition avoids oily sludge (hazardous waste) generation at the source. The CDFU unit is compact in structure, occupying only 10% of the footprint of conventional flotation, with a single-unit capacity of up to 500 m³/h. The fully enclosed pressurized operation design completely eliminates hydrogen sulfide and oil vapor leakage, achieving intrinsic safety.
Case study: high-emulsification acidic water treatment project at a petrochemical company in Luoyang
In engineering practice at the Luoyang petrochemical company, the process delivered excellent treatment results: influent oil dropped from 2,000 ppm to below 50 ppm, and the suspended solids removal rate exceeded 98%. The effluent is clear and transparent, with oil content and suspended solids stably below 20 mg/L, fully meeting reuse standards. Notably, the system has strong shock-load resistance and remains stable even with 50% fluctuations in water quantity and quality.
Economic and environmental benefits analysis
In terms of environmental benefits, the process makes wastewater treatment greener: no chemical addition avoids secondary pollution; the purely physical separation technology achieves a waste oil recovery rate of 99%; and the enclosed operation design eliminates exhaust gas leakage. In an application case at a chemical company in Henan Province, highly emulsified acidic water was treated to produce clear, transparent effluent, achieving truly clean production.
Application prospects and development direction
As environmental requirements become increasingly strict, SINOKLE's coking acidic water treatment technology has been successfully applied at many large petrochemical companies. Its modular, skid-mounted design is particularly suitable for retrofitting old plants, shortening construction schedules by more than 50%, and the intelligent control system supports remote monitoring and unattended operation, greatly reducing O&M costs.
Engineering practice has verified that this coking acidic water treatment technology not only solves the bottleneck problems of conventional processes but also unifies economic and environmental benefits, providing reliable technical support for the sustainable development of the coking industry.
