Study On The Technology Of Quench Water Purifying And Recycling In Ethylene Unit

The chemical enterprises have always been the super water consumers and polluters,and the composition of petrochemical sewage is complicated,the concentration of pollutants is quite high,which causes serious pollution to the environment.So it’s difficult to achieve water discharge requirements as a single treatment process.In recent years, the new technology of chemical sewage treatment are emerging,Membrane separation technology,called Water treatment technology in 21 th century,is getting more and more attracting.Membrane separation technology is a sewage treating method,using the semi permeable membrane molecular filtration.This membrane can make the water through,but the suspended solids in water and solutes can not.So it can remove the dissolved solids in the water, most of the soluble organic matter and colloidal substances.Nanofiltration is a new type of membrane separation technology,between reverse osmosis and ultrafiltration.It has many functions, such as acid proof,alkali proof,oil resistance,oxidation resistance and chloride resistance,which can improve the separation efficiency and durability.This paper studies the quench water recycling,which discharged by ethylene unit in Daqing Petrochemical Company.Plant No.1 applying oxidation pretreatment technology with membrane technology as the core technology set up a pilot plant and purified the quench water discharged by cracking unit.The technology made processed water to meet to the standards of industrial water recycling with considering operating conditions and process indicators.It ensured that water recovery was greater than 85% and had the requirement of industrial production.