Treatment Solution for Hydrogen-Nitrogen Compressor Wastewater
Hydrogen-nitrogen compressor wastewater comes mainly from the compressor section of an ammonia synthesis plant, in particular from coke-oven gas compressors and nitrogen-hydrogen compressors. In normal operation these machines discharge a certain amount of oil-water mixture every hour. The mixture contains not only the water and other impurities separated from the process gas, but also the lubricating oil from the cylinders and packing. Because this oily water is discharged directly into the plant drainage network without treatment, it is the main reason why the oil content of that network exceeds the limit.
Characteristics of the Wastewater
The main characteristics are a high oil content, the presence of suspended solids and potentially complex chemical constituents. The large amount of entrained lubricating oil makes treatment difficult and poses a potential threat to the environment. The wastewater may also contain fine particles worn from cylinders and packing, which must also be removed effectively.
Treatment Difficulties
Difficult oil-water separation. The oil is present in complex forms — both free oil droplets and emulsified oil — which makes separation particularly hard.
Hard-to-remove suspended solids. The particles are fine and cannot be removed effectively by conventional filtration.
Demanding process requirements. Ensuring that treated water meets discharge standards requires an efficient and stable process, which places high demands on both technology and equipment.
New Process: the KHC Coalescing Oil Separator
To address these difficulties, SINOKLE developed the KHC coalescing oil separator, a new-generation oil-water separation unit. Through a series of advanced technical measures, the equipment achieves efficient coalescence, separation and removal of emulsified oil from the wastewater.
In the process, the wastewater first passes through a precision filter that removes most suspended solids and impurities, then enters the KHC coalescing oil separator for deoiling. Once the effluent meets the required standard it is sent to the stripping unit.
Working Principle
The KHC coalescing oil separator uses super-oleophilic, hydrophobic coalescing fibre material and an internal structure that integrates cyclone centrifugal separation, wetting coalescence, collision coalescence and interception filtration. When the wastewater enters the unit, cyclone centrifugal separation first separates oil droplets and suspended particles. The flow then enters the coalescing zone, where the super-oleophilic, hydrophobic fibre material coalesces fine emulsified oil droplets into large droplets that settle out under gravity. Finally, the interception filter layer removes residual suspended solids and fine oil droplets, keeping the effluent reliably within standard.
Technical Advantages
High deoiling efficiency. Emulsified oil droplets larger than 0.1 micron are removed with an oil removal rate above 95%, so the oil content of the treated water is far below the discharge limit.
Short residence time. Hydraulic retention time is less than 3 minutes, which saves time and improves overall throughput.
Small footprint. The skid-mounted design takes up little space and is easy to install and relocate, suiting a wide range of site conditions.
Stable and reliable operation. The specially modified, reinforced super-oleophilic hydrophobic fibre does not break or age easily and is highly corrosion-resistant, ensuring stable operation in harsh conditions. It also tolerates impurities well and removes suspended solids effectively, avoiding the clogging problems typical of conventional cartridge coalescers.
Automatic operation. Fully enclosed automatic operation reduces manual intervention and improves safety and environmental performance.
In summary, SINOKLE's KHC coalescing oil separator provides an efficient, stable and reliable solution for hydrogen-nitrogen compressor wastewater. It brings the effluent within standard, lowers treatment cost and improves both the environmental and the economic performance of the plant.
