Supercritical water oxidation system taking air as oxidant and starting method thereof

Abstract

The invention relates to a supercritical water oxidation system taking air as an oxidizing agent, which comprises an oxidizing agent feeding device, an organic waste liquid feeding device, an auxiliary fuel feeding device, a feeding softened water device, a dividing wall softened water feeding device, a pressure reducing device, a gas-liquid separator and a controller which are connected with a reactor. The oxidant feeding device comprises an oxidant source, an air compressor and an air preheater, the oxidant source is air, the air compressor and the air preheater are connected to a pipeline for connecting the oxidant source and the reactor, the controller is electrically connected with each feeding detection adjusting device, and an organic waste liquid structure, an auxiliary fuel structure and a softened water structure are not provided with preheating devices. When the reactor is started, air is preheated to a set temperature by the air preheater outside the reactor and then entersthe reactor. The system has the beneficial effects of safety, reliability, continuous and stable operation, low cost and easiness in operation, does not generate the problem that organic waste liquidis heated outside the reactor to generate coke, tar and salt, and is particularly suitable for industrial devices for continuous and stable production.

Description

technical field [0001] The invention belongs to the technical field of chemical machinery, and in particular relates to a supercritical water oxidation system for treating organic waste liquid. Background technique [0002] Supercritical water oxidation technology has the advantages of many types of organic waste that can be treated, high decomposition efficiency, no secondary pollution, rapid response, high efficiency and energy saving, etc., and has broad application prospects in the field of refractory organic waste treatment. [0003] In the prior art, the supercritical water oxidation system includes a material feeding structure, a reactor, a decompression structure, a gas-liquid separator and a controller, and the material feeding structure includes an oxidant feeding pipeline, an organic waste feeding pipeline, an auxiliary The fuel feeding pipeline and the demineralized water feeding pipeline are connected with corresponding ports on the reactor. The reactor is a cl...

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Problems solved by technology

[0004] 1. When liquid oxygen is used as the oxidant, the system needs to add air separation, gasification and other equipment, and the investment cost is high, and once it leaks, it is easy to cause oxygen poisoning of the operator, and it also has the danger of forming an explosive environment as a combustion aid

When high-purity oxygen is used as the oxidant, the number of oxygen tanks is large, the volume is large, and the investment cost is high, and the pure oxygen environment will accelerate the corrosion rate of the equipment

When hydrogen peroxide is used as the oxidant, the operating cost is high

[0005] 2. The auxiliary fuel or organic waste liquid is heated outside the reactor to the set temperature and then enters the reactor. During the heating process of the auxiliary fuel or organic waste liquid, organic matter is prone to degrade, and coke and tar are formed, and some salt will also be caused by When the temperature rises and crystallizes out, the generated coke, tar and salt will cause deposition and scaling, which will reduce the heat transfer coefficient of the heater

After long-term operation, it is difficult for the outlet of the heat exchanger to reach the preheating temperature, resulting in difficulty in starting the system or failure to operate normally

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