Supercritical water oxidization treatment system for high-salinity organic waste water

Abstract

The invention discloses a supercritical water oxidization treatment system for high-salinity organic waste water. The high-salinity waste water is subjected to cooling crystallization through cold energy of liquid oxygen to reduce mass concentration of inorganic salt in the waste water; a large amount of solid salt grains separated out from the waste water are removed by using a hydraulic cyclone device under a supercritical water condition to effectively prevent a subsequent pipeline and a reactor of the hydraulic cyclone device from plugging; and a desalting device is arranged at the lower part of the hydraulic cyclone device to continuously remove the inorganic salt from the system. In addition, excessive oxygen and CO2 product gas are recovered through a separation recovery part; the reaction time and the reaction temperature of supercritical water oxidization are reduced through arranging a simple subsequent treatment unit; and the system recovers heat energy of the reacted high-temperature fluid in a steam mode through the arrangement of a water softening device, so that the operation cost of the system is reduced. The system can be widely applied to the innocent treatment process of the high-salinity organic waste water.

Description

technical field [0001] The invention relates to a system for harmlessly treating organic wastewater with high salt content (inorganic salt content is 5wt% to 30wt%) by using supercritical water as a reaction medium. Background technique [0002] Supercritical water refers to water in a special state whose temperature and pressure are higher than its critical point (T=374.15°C, P=22.12MPa). Supercritical water has the properties of both liquid and gaseous water. In this state, only a small amount of hydrogen bonds exist. The dielectric constant is similar to that of polar organic solvents. It has a high diffusion coefficient and low viscosity. Organic matter, oxygen and supercritical water are mutually soluble, so that the heterogeneous reaction becomes a homogeneous reaction, which greatly reduces the mass transfer resistance, while the solubility of inorganic salts in supercritical water is extremely low and can be easily separated. [0003] Supercritical Water Oxidation (...

AI Technical Summary

Problems solved by technology

The viscous salt precipitated during the supercritical water oxidation of organic wastewater aggregates and deposits on the inner surface of the reactor. When the salt deposition is out of control, the reactor will be blocked, especially when larger particles of viscous salt are precipitated under low flow rate conditions. More likely to cause clogging of the reactor

When blockage occurs, the entire device must be shut down, flushed and restarted, which reduces the reliability of SCWO device operation and increases operating costs

In addition, the deposition of inorganic salts, especially inorganic salts containing chloride ions, will also accelerate the corrosion rate of reactors, transportation pipelines and other parts, resulting in the deterioration of heat transfer on the heat exchange surface of the heat exchanger

The high-temperature, high-pressure, oxygen-enriched reaction environment leads to high operating costs of SCWO devices, which greatly limit the popularization and application of SCWO

[0005] In view of the complex feed characteristics and harsh reaction conditions in the organic wastewater SCWO process, the existing desalination methods (electrodialysis, reverse osmosis, ion exchange, electrosorption, etc.) are difficult to use in the high-salt organic wastewater SCWO system. The reliable operation of the salt organic wastewater SCWO system requires simpler, more efficient and more convenient desalination equipment and desalination methods

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