Physical Demulsification Separation of Highly Emulsified Oil and Suspended Solids in Coking Wastewater
As an important by-product of the coal-chemical industry chain, coking wastewater has long been regarded as a 'hard nut' in industrial water treatment because of its complex composition, high toxicity, and difficulty in biodegradation. The interweaving of high-concentration emulsified oil, fine suspended solids, and characteristic pollutants not only affects stable unit operation but also exerts dual pressure on corporate environmental compliance and environmental safety. Against the background of the state's in-depth promotion of green manufacturing and pollution-prevention tackling, the industry urgently needs solutions that combine high efficiency, economy, and sustainability.
Characteristics and Challenges of Coking Wastewater
Coking wastewater is mainly generated in processes such as coking, gas purification, chemical-product recovery and refining (e.g., high-temperature carbonization, gas cooling, coal washing, wet quenching). It is a highly challenging, toxic, and refractory organic wastewater.
Its core characteristics are marked:
Complex composition, difficult to degrade: many pollutant types, high concentration, extremely poor biodegradability; excess nitrogen further increases treatment difficulty.
High emulsification and suspended solids: contains high-concentration, fine-sized coke powder and severely emulsified tiny oil droplets, which not only affect stripper efficiency and liquid-ammonia quality but also easily cause stripper-tower blockage or even unplanned shutdowns, causing significant economic losses.
Prominent safety and environmental risks: contains irritant gases such as sulfides and ammonia nitrogen, endangering the environment and employee health; refractory carcinogens such as polycyclic aromatic hydrocarbons pose long-term pollution threats to human health; large discharge volume and high treatment difficulty mean non-compliant discharge puts enterprises under huge environmental pressure.
Innovative Technology and Process Flow
In response to its characteristics, SINOKLE Technology innovatively adopts a purely physical demulsification-separation patented technology withCDFU (cyclonic dissolved-air flotation), the SiC filter, and the KHC high-efficiency coalescing deoiler as core equipment.
High-efficiency demulsification separation:CDFUPretreatment uses ultrafine nano-bubble technology to achieve initial demulsification of emulsified oil and rapid oil-water separation; the KHC coalescing deoiler achieves efficient and stable separation through purely physical demulsification, recovering oil with high quality and low water content that can be directly returned to refining.
Safe, environmentally friendly, zero addition: the entire process operates enclosed, pressurized, and automatically, eliminating safety and environmental risks; no chemical agents are used throughout, eliminating secondary pollution from float scum and oily sludge, and reducing operating and downstream-treatment costs.
Stable, reliable, easy to maintain: the equipment is mostly static, highly automated, simple to maintain, with long overhaul cycles and strong shock-load resistance; the treatment effect is stable and reliable, with a small footprint.
Successful Practice and Results
In an application at a petrochemical enterprise in Luoyang, this technology achieved long-term stable compliant treatment of coking acidic wastewater, with an oil-removal rate above 99%, solving its long-standing acidic-wastewater treatment problem. This successful case sets an efficient, clean, and economical benchmark solution for the industry in treating highly emulsified coking acidic wastewater.
