SINOKLE Achieves a Breakthrough in Purely Physical Demulsification and Separation of Coking Sour Water
1. What is coking sour water?
Coking sour water is the industrial wastewater formed when refining high-sulphur crude oil and related by-products (such as coke, coal gas and tar). Such water dissolves a large amount of acidic components, including hydrogen sulphide and sulphuric acid, and is rich in sulphides, ammonia, phenols, cyanides and oils. Its composition is complex, covering phenols, oils, naphthalene, pyridine, quinoline, anthracene and other heterocyclic and polycyclic aromatic compounds, and it is widely regarded as a major challenge in current industrial wastewater treatment.
Coking oily sour water at a refinery is severely emulsified
2. What are the difficulties in coking sour water treatment?
The difficulties of coking sour water treatment are mainly reflected in the following aspects:
Coking sour water has a high concentration of acidic substances and a low pH value, making it difficult to treat. Acidic substances are highly toxic to the environment and to living organisms, so they must be treated effectively.
Some streams are severely emulsified, and conventional methods find it difficult to achieve demulsification and oil removal.
Coking sour water contains large amounts of suspended solids and oily contamination, which make the water turbid and even harder to treat. The presence of suspended solids and oil not only affects treatment performance but may also cause equipment blockage and damage.
Coking sour water contains various organic substances and heavy metal ions that are harmful to the environment and to ecosystems. When treating coking sour water, therefore, in addition to removing acidic substances and suspended solids, organics and heavy metals must also be removed effectively.
3. What processes are currently available for coking sour water?
3.1 The activated sludge process, as a commonly used aerobic biological treatment technology, can reduce oil, some organics, ammonia nitrogen and total nitrogen in wastewater to a certain extent. However, because coking wastewater contains large amounts of refractory macromolecular organics, the conventional activated sludge process finds it difficult to remove them completely, so the organic content in the effluent remains high and cannot meet discharge or reuse standards, requiring further advanced treatment.
3.2 Chemical methods neutralise acidic substances by dosing chemical reagents to achieve the treatment goal. However, this method produces large amounts of chemical sludge and oily waste residue during production, easily causing secondary pollution, and reagent costs are relatively high.
3.3 Biological methods use microbial communities to degrade organics and purify the water. Biological methods offer good treatment performance and little secondary pollution, but the operation process is relatively complex and the growth environment of the microbial community must be strictly controlled and maintained.
4. The latest treatment process for coking sour water
In response to the treatment difficulties described above, SINOKLE has developed a patented process system centred on CDFU cyclonic dissolved gas flotation, fine filters and the KHC high-efficiency coalescing de-oiler. This technical solution has significant advantages: the whole treatment process is purely physical demulsification and separation and does not rely on the addition of chemical reagents, eliminating the generation of scum and oily sludge and fundamentally avoiding secondary pollution. Its demulsification performance is stable and reliable, and the separated waste oil can be effectively recovered, with good oil quality and low water content, suitable for reprocessing. The process combines energy saving and environmental protection with economic benefit, providing an ideal solution for coking sour water treatment.
Coking sour water CDFU treatment unit at a petrochemical plant
Treatment process: coarse filter + CDFU cyclonic dissolved gas flotation + fine filtration + KHC high-efficiency coalescing de-oiling
Capacity: 15 m³/h;
Inlet wastewater oil content: ≤150,000 ppm (15%);
Effluent oil content: ≤50 ppm (average)
Project treatment performance
