An Efficient Purification Solution for Coking Sour Wastewater
In petroleum refining, the highly emulsified, strongly acidic wastewater generated during coking has always been a treatment challenge. This wastewater is complex in composition and extremely high in concentration, specifically:
Rich in fine coke particles with a small particle size;
High oil content, with fine emulsification and tiny oil droplets;
High concentrations of sulfur, ammonia nitrogen and phenols;
Variable composition with significant fluctuations in content.
If sent directly to the stripping unit, it can easily cause equipment blockage, reduced stripping efficiency and lower quality of the liquid ammonia product, and may even trigger unplanned shutdowns, resulting in serious economic losses. This problem not only restricts the coking wastewater treatment process but also poses a major challenge to environmental protection and sustainable development. Therefore, effective purification of coking sour wastewater is essential for the stable and reliable operation of downstream process units.
In the past, this kind of wastewater was mostly treated with chemicals, but this approach suffered from high chemical consumption, increased production of scum and oily sludge, fluctuating treatment results, and potential secondary pollution risks.
To break through this technical bottleneck, through continuous R&D and practice, we have successfully developed a coking sour wastewater treatment system based on purely physical demulsification and separation technology. The system takes CDFUswirl dissolved-air flotation, precision filtration equipment and the KHC high-efficiency oil coalescing separator as its core, with no chemical dosing throughout the entire process.
Schematic flow diagram of the coking sour wastewater treatment process
The wastewater first passes through coarse filtration equipment to initially intercept larger particle impurities; it then enters CDFUthe swirl dissolved-air flotation unit, where swirl and dissolved-air action efficiently separate suspended solids and emulsified oil; next, a precision filtration system further removes fine solid particles and residual emulsified oil; finally, the KHC high-efficiency oil-water separator performs deep purification, thoroughly removing trace oil droplets and suspended matter. The effluent is clear and transparent, with an oil removal rate of over 99%.
Compared with conventional chemical treatment methods, this coking sour wastewater treatment system offers the following outstanding advantages:
No chemical dosing is required, avoiding massive chemical consumption and the generation of scum and oil residue, and fundamentally eliminating the possibility of secondary pollution;
The purely physical treatment technology is stable and reliable, with remarkable demulsification results, effectively separating emulsified oil and suspended solids from the wastewater;
The recovered oil is of good quality with a low water content and can be returned to the furnace for reuse, maximizing resource utilization and economic benefits;
The system is fully automated and operates in an enclosed, pressurized mode, ensuring safe, reliable operation with no environmental risk;
Compact footprint and low operation and maintenance costs.
Application case:
The coking sour wastewater treatment system specially designed by SINOKLE for a petrochemical company in Luoyang has been put into stable operation. The influent oil content of the system is as high as 15% (i.e., 150,000 ppm), and after treatment the effluent oil content is steadily controlled below 50 ppm, with an average oil removal efficiency of over 99%, successfully solving the long-standing sour wastewater treatment problem faced by the company.
Coking sour wastewater treatment project site
Coking sour wastewater treatment results (left: influent; right: effluent)
The successful implementation of this project not only provides a practical and feasible treatment path for highly emulsified coking sour wastewater, but also marks an important advance in China's coking wastewater treatment technology, providing solid support for the sustainable operation of petrochemical enterprises and the green transformation of the industry.
