Crushed coal pressurized gasification gas-water separation and recycling system and method

Abstract

The invention provides a crushed coal pressurized gasification gas-water separation and recycling system and method, and belongs to the field of coal gas separation and recycling. According to the invention, different types of coal gas water are respectively separated and recycled, so that the whole system is small in occupied area, low in investment, low in operation cost, short in treatment flow, less in equipment, less in pollutant discharge points and not easy to cause environmental pollution. By arranging a medium-pressure flash evaporator, a vacuum flash evaporator, a vacuum flash separator, an ammonia distillation tower and the like and arranging a settling tank and the top of a coal gas water tank to be connected with an inert gas pipeline, and the whole system and the separation and recycling process keep micro-positive pressure operation greater than 0.2 kPa, thereby being capable of guaranteeing that VOCs and odor exhausted from the system can be treated in a centralized mode. The coal gas water treated by a deacidification tower is fed into the ammonia distillation tower, so that the coal gas water going to the biochemical treatment equipment can be subjected to ammoniadistillation, the ammonia content in the coal gas water going to the biochemical treatment equipment can be reduced, and the problem that a biochemical system is difficult to operate stably due to change of different feed coals is solved.

Description

technical field [0001] The invention relates to the technical field of coal gas separation and reuse, in particular to a system and method for gas water separation and reuse of crushed coal pressurized gasification. Background technique [0002] Crude gas produced by pressurized gasification of crushed coal contains a large amount of water vapor, dust and carbonized by-products, such as tar, light oil, naphthalene, phenol, fatty acid, dissolved gas and inorganic salts, etc., and the temperature is relatively high . Therefore, it needs to be cooled and washed to reduce the temperature and remove harmful substances in the crude gas. During the washing and cooling process of crude gas, these impurity components enter the water, forming gas water with various components in three states of gas, liquid and solid. The content of various ingredients is also not the same. Gas water cannot be directly treated by conventional methods such as biochemistry, filtration, and reverse osm...

AI Technical Summary

Problems solved by technology

[0004] However, with the development of coal gas technology, it is gradually developing in the direction of large-scale, energy-saving, environmental protection, high efficiency and stability. The current gas-water separation and recovery process of the pulverized coal pressurized gasification technology commonly used cannot meet modern requirements, mainly reflected in:

[0005] 1. The existing gas water treatment system collects different types of gas water from different equipment for gas water separation and recovery. There are multiple separators and buffers in the device process, which not only causes the entire gas water separation And the recovery system occupies a large area, high investment, high operating cost, and the process is long, and there are many equipments, so that there are many pollutant discharge points, which is easy to cause serious environmental pollution

[0006] 2. Multiple buffers and separators are used in the existing gas-water separation and recovery system. These devices are operated under normal pressure, which is likely to cause the discharge of VOCs (Volatile Organic Compounds, volatile organic compounds), odor, etc. Centralized processing after collection makes the site environment harsh

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