Denitrification device for supercritical water oxidation of high-concentration nitrogen-containing organic wastewater

Abstract

The invention discloses a denitrification device for supercritical water oxidation of high-concentration nitrogen-containing organic wastewater, belonging to the technical field of environmental protection and organic wastewater harmless treatment devices. According to the invention, a liquid oxygen supply unit is connected with a supercritical water oxidation reaction unit through a pipeline; a material conveying unit is connected with the supercritical water oxidation reaction unit after passing through an organic wastewater pretreatment unit; a methanol supply unit is respectively connectedwith the organic wastewater pretreatment unit and the supercritical water oxidation reaction unit through pipelines; the supercritical water oxidation reaction unit and the heat exchange unit are respectively connected with a cooling and depressurizing unit through pipelines; and a softened water conveying unit and a gas-liquid separation unit are respectively connected with the heat exchange unit. The device provided by the invention can effectively degrade nitrogen-containing organic wastewater which is difficult to degrade and high in concentration, and realizes separation of gaseous nitrogen, liquid nitrogen and solid nitrogen (mainly nitrate and nitrite) and zero-pollution emission of products.

Description

technical field [0001] The invention belongs to the technical field of environmental protection and organic wastewater harmless treatment devices, and relates to a denitrification device for supercritical water oxidation of high-concentration nitrogen-containing organic wastewater. Background technique [0002] Supercritical water (SCW for short) refers to water whose temperature and pressure are higher than its critical value (Tc=647.15K, Pc=22.12MPa), which has low viscosity, low electrostatic dielectric constant, and continuously variable density. , High diffusion coefficient, so that organic matter and SCW can be miscible in any ratio, so that the heterogeneous reaction becomes a homogeneous reaction, reducing the interphase resistance of the phase interface to heat and mass transfer. Inorganic substances, especially salts, have extremely low solubility in SCW and can be easily separated. [0003] Supercritical water oxidation (SCWO) technology is considered to be a pro...

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Problems solved by technology

At present, in industrial supercritical water oxidation treatment of ammonia nitrogen, due to the stability and refractory nature of ammonia nitrogen, the current industrialization often uses 316 stainless steel materials with limited ability to withstand high temperatures, and the price of steel made of precious metals is too high to be practical.

On the one hand, increasing the temperature will easily cause problems such as corrosion of the reactor and salt deposition blockage. On the other hand, since the properties of water change greatly near the critical point, heat transfer must also be considered in the supercritical water oxidation process. However, there is currently no suitable denitrification device that can realize the denitrification treatment of high-concentration nitrogen-containing organic wastewater.

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