Oxygen recovery control system and method for treating refractory nitrogen-containing concentrated organic wastewater by scwo

Abstract

The invention discloses an oxygen recovery control system and an oxygen recovery control method in hard-biodegradable?high-nitrogen concentration organic wastewater SCWO treatment. The oxygen recovery control method comprises the flowing steps that: the temperature of gas at the upper part of a vapor liquid separator is decreased to about 10 DEG C through adjusting liquid oxygen flow; the liquid level of a purification tower is controlled and made to be a mediate level, and the pressure of liquid carbon dioxide at the outlet of the purification tower is reduced to 2MPa through a pressure reducing valve; the flow of a high-pressure compressor is interlocked with the liquid level of the vapor liquid separator, and the liquid level of the vapor liquid separator is controlled in a set range; the flow of the high-pressure compressor achieves a maximum value, a vent valve on a second buffer is opened so as to perform exhaust slowly, after the exhaust, the flow of a low-temperature liquid oxygen pump is continuously maintained, and when the compensation of loss amount of exhausted oxygen is completed, the liquid oxygen flow is returned to normal; the fluctuation of system operating pressure is controlled in a small error range through utilizing a counterbalance valve, such that relative stability of the system working pressure can be maintained.

Description

technical field [0001] The present invention relates to an oxygen recovery method for harmless treatment of high-concentration nitrogen-containing organic wastewater that is difficult to biodegrade (the content of organic matter is 5wt% to 10wt%; the content of organic nitrogen and ammonia nitrogen is 2000mg / L) by using supercritical oxidation technology SCWO. Control Method. Background technique [0002] Supercritical water means that the temperature and pressure are higher than its critical point (T c =374.15°C, P c =22.12MPa) special state of water. It has the characteristics of high diffusion coefficient, low viscosity, low dielectric constant, etc., similar to a non-polar organic solvent, which can dissolve oxygen, nitrogen, organic matter and other substances, while the solubility of inorganic salts in supercritical water is extremely low. Supercritical Water Oxidation (SCWO for short) utilizes the special properties of supercritical water. Organic matter undergoes ...

AI Technical Summary

Problems solved by technology

Although a small number of supercritical water oxidation treatment systems for high-concentration, biodegradable organic wastewater have appeared, the problem of efficient, continuous and stable recycling of oxygen has not been effectively solved, especially there is no supercritical water oxidation system for high-concentration, biochemically refractory nitrogen-containing organic wastewater. Report on Oxygen Recovery Control Method in Critical Water Oxidation Treatment System

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