Exploring Study On Disposal Of Ethylene Spent Caustic In A Rotating Packed Bed(RPB) By Water Air Oxidation(WAO)

Refinery spent caustic is a kind of spent alkali liquor produced in refineryindustry of petroleum.It is composed of a mass of dissociative sodium hydroxide,sulphide of high concentration,phenol, sodium naphthenate and neutral oils.these compounds must be disposed before discharge or biological treatment because of their toxicity and serious pollution on the environment.Among the many disposal methods for ethylene spent caustic, water air oxidation(WAO) is widely used at the present time.However, WAO have some defects such as a long time of disposal,low efficiency of mass and heat transfer,high temperature and pressure and high costs for equipments and operatation.So we apply RPB to WAO of refinery spent caustic improve the mass and heat transfer for lowering temperature and pressure. Simultaneously, ferric chelated and 888 catalysts are added to lower temperature and pressure for better oxidation. The conclusions of the paper were as follows:1 In the rotating packed bed(RPB),the optimus condition for WAO and CAO was obtained. The condition for WAO was as follows:liquid flow rate is 120L/h, air flow rate is 20m3/h, rotor speed is 800r/min, temperature is 110℃,pressure is 0.3MPa, circulation time is 1.5h; The condition for ferric chelated CAO was as follows:liquid flow rate is 200L/h, air flow rate is 15m3/h, rotor speed is 900r/min, temperature is 80℃, circulation time is 1.5h,the concentration of ferric chelated is 10mg/L; The condition for 888 CAO was as follows:liquid flow rate is 200L/h, air flow rate is 10m3/h,rotor speed is 900r/min, temperature is 80℃, circulation time is 1.5h,the concentration of ferric chelated is 30mg/L.2 In WAO,ferric chelated CAO,888 CAO three systems, the effect of CAO is better than WAO and the effect of ferric chelated CAO is better than 888 CAO in the same condition.In some condition,the removal rate of sulphion by CWO can reach above 99%.