Supercritical water oxidation treatment and generation system of municipal sludge having high-solid content

Abstract

The invention discloses a supercritical water oxidation treatment and generation system of municipal sludge having high-solid content. The municipal sludge having high-solid content orderly enters a filter basin and a homogenizing basin to carry out pretreatment, and then is transported to the system to carry out supercritical water oxidation treatment by using a high-pressure diaphragm pump; high-temperature fluid after reaction is fully utilized to preheat feedstock when the system runs. Surplus heat generates super-high pressure steam to generate electricity by adopting a low oxidation coefficient; a supercritical zone is arranged at the upper part of a reactor; a subcritical zone is arranged at the lower part of the reactor; an inorganic salt separated out from the supercritical zone at the upper part of the reactor falls into the subcritical zone at the lower part of the reactor to be dissolved again by virtue of inertia and gravity; strong brine containing solid (insoluble salt) orderly enters a cooler and a capillary step-down transformer for cooling and decompression.

Description

technical field [0001] The invention relates to a system for harmless treatment and resource utilization of urban sludge with high solid content (6%-15% solid content by mass) by using supercritical water oxidation technology SCWO. 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, and its dielectric constant is close to that of polar organic solvents. Organic matter, oxygen and supercritical water are miscible, while the solubility of inorganic salts in supercritical water is extremely low. Supercritical Water Oxidation (SCWO for short) uses the properties of supercritical water to make organic pollutants undergo a homogeneous reaction in an oxygen-rich supercritical water environment, converting organic matter into H ...

AI Technical Summary

Problems solved by technology

This is because: the reaction conditions of high temperature and high pressure and the corrosive substances contained in the municipal sludge will cause the corrosion of the reactor, reduce the service life of the reactor, and affect the safety of the operation of the SCWO unit

In addition, the solubility of inorganic salts in supercritical water is extremely low, usually less than 100mg / L

Inorganic salts precipitated during the municipal sludge SCWO process will deposit on the inner surface of the reactor, which will gradually lead to blockage of the reactor or outlet pipeline, which will cause the shutdown, flushing and restart of the entire device, affecting the reliability of the device operation

[0005] At present, the municipal sludge supercritical water oxidation treatment system has not yet ideally solved the problems of high operating costs, reactor corrosion and clogging

Therefore, the development of supercritical water oxidation treatment system for municipal sludge is still in development, and there is no supercritical water oxidation harmless treatment and power generation system for municipal sludge with high solid content.

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