Experimental Resesrch On Supercritical/Superheated Near-critical Water Oxidation Of Cyanobenzene Wastewater

In organic wastewater treatment, Supercritical water oxidation technology with high purification efficiency, water purification rate of organic compounds and does not produce secondary pollution, the characteristics of the reaction completely, is considered by people as a kind of sustainable development of green technology. Supercritical water oxidation technology in practical application will appear in the salt and corrosion problems. In order to solve these problems, equipment tend to use expensive, good quality alloy and catalyst, greatly increasing the cost of such equipment, most enterprise cannot withstand high equipment cost and operation cost. Equipment manufacturing costs and operation costs hindered industrialization process of supercritical water oxidation technology.In the previous experiments subject puted forward " Superheated Near-Critical Water Oxidation technology", Cyanobenzene is the object of study, Using a continuous supercritical oxidation device, choose oxidant oxygen by supercritical/ Superheated NearCritical experimental conditions, oxygen coefficient is 1.5. The main research content is as follows:(1) The experiment studied the reaction temperature, reaction pressure, the initial concentration of organic compounds and the influence of retention time for wastewater removal rate of organic matter. The experimental results show that: in the high temperature of 520℃ pressure under the condition of 18~22 MPa, cyanobenzene pollutants removal rate is over 95%..Within a certain range, when the reaction temperature, reaction pressure and residence time of ascension increases, the wastewater purification rate also increases. In the reaction pressure 18~22 MPa and reaction temperature 400~520℃ range, the effects of reaction temperature on purification rate is greater than the reaction pressure, the influence of the pressure after 500℃ is gradually tending to straight line. This supercritical oxidation equipment to deal in the same processing under the condition of different concentrations of cyanobenzene wastewater effluent CODcr values changed little, and the wastewater removal rate of organic matter in the 100 s after change tending to straight line.(2) According to the experimental results, at about 520 ℃ under 24 MPa Cyanobenzene and the macro dynamic equations of the supercritical water oxidation:At about 520℃ under 20 MPa Cyanobenzene and the macro dynamic equations of Superheated Near-Critical water oxidation:By comparing two dynamic equations can be found that when the concentration of reactants oxidation phase at the same time, cyanobenzene oxidation reaction in supercritical conditions are more likely to happen.(3) To design temperature of 625℃ and the design pressure of 32 MPa reactor material consumption for one, every 2 MPa below the design pressure, reactor material consumption reduced by 7%. In order to further reduce the cost, Using Superheated NearCritical water oxidation technology deal with organic wastewater, and using other economic water treatment method for secondary processing.