Optimization Design Of Treatment Device For Supercritical Water Oxidating Spent Caustic Wastewater

With the rapid development of petroleum refining industry,the total amount of spent caustic wastewater is increasing.Traditional treatment technologies(including biological treatment technology,wet air oxidation,incineration,etc.)can not completely degrade the organic pollutants in these wastewater,and even produce secondary pollution.Supercritical water oxidation technology has the advantages of wide application range,fast reaction rate,high treatment efficiency and without secondary pollution.It has obvious advantages in the treatment of spent caustic wastewater.However,due to the problems of corrosion,salt precipitation and high operation cost,it can not be promoted in large-scale industrialization.Therefore,the gasoline alkaline residue wastewater is taken as the research object in this paper,the existing supercritical water oxidation treatment device is carried out optimal design.The supercritical water oxidation experiment of gasoline alkali residue wastewater from Yanshan Petrochemical Company was carried out with the existing supercritical water oxidation device in the laboratory.The reactor is a continuous tube type,and the oxidant is air.The reaction temperature range is 500～600℃,the pressure range is24～28MPa,the residence time range is 10～30s,and the peroxide coefficient is more than400%.The experiment adopts the form of orthogonal analysis to explore the influence rules of reaction temperature,reaction pressure and residence time on the COD removal rate.The results show that the three factors on the COD removal rate of alkaline slag wastewater are successively influenced by temperature > pressure > residence time.In the comprehensive consideration of product COD and the economy and safety of the device,in the case of sufficient oxidant under the optimal experimental conditions can choose the reaction temperature of 550℃,reaction pressure of 24 MPa,residence time 30 s.To solve the problem of supercritical water oxidation technology corrosion salt precipitation and high running cost problems,put forward a kind of supercritical water oxidation process with energy recovery system and an internal combustion through wall automatic row of salt and integrated reaction and separation of supercritical water oxidat-ion device,and by using the Aspen Plus software using different oxidizer(air of oxygen Finally,it is concluded that all three schemes can effectively reduce the energy consumption during the operation of the supercritical water oxidation system and reduce the operating cost of the system.However,scheme 3 is the optimal scheme when the plant has empty sub-stations.According to the simulation results of Aspen Plus software,the structure of the reaction device in the system is designed,including the multi-hole pipe reaction inclined pipe separator and the equipment head.In addition,the selection and design of the waste heat recovery device and gas-liquid separator in the system are also carried out.Finally,the auxiliary equipment required for each scheme is included the pressurization device valve Selection of measuring device and heating device...