Flash evaporation-sedimentation-fluidized bed separation combined purification method and device for coal gasification black water

Abstract

The invention relates to a flash evaporation-sedimentation-fluidized bed separation combined purification method and device for coal gasification black water. The flash evaporation-sedimentation-fluidized bed separation combined purification method for the coal gasification black water comprises the following steps: (i) carrying out flash evaporation treatment on the coal gasification black water; (ii) feeding the coal gasification black water having been subjected to flash evaporation treatment into a sedimentation tank, conducting sedimentation and separating, feeding bottom concentrated suspended matters into a vacuum filter pressing system, and feeding a supernatant of the sedimentation tank, namely coal gasification ash water, into an ash water tank; (iii) pumping the coal gasification ash water out of the ash water tank, and sending the coal gasification ash water to a fluidized bed separator to deeply remove fine particles in the coal gasification ash water; (iv) sending the coal gasification ash water purified by the fluidized bed separator to a deaerator for deoxygenation; and (v) after the fluidized bed separator is operated for a period of time and a pressure difference is 0.3 MPa, mixing the coal gasification ash water and nitrogen, and reversely feeding the obtained mixture to regenerate a separation medium of the fluidized bed separator. The invention further provides the flash evaporation-sedimentation-fluidized bed separation combined purification device for coal gasification black water.

Description

technical field [0001] The disclosure belongs to the technical field of refractory sewage treatment and reuse, and relates to a method for purifying coal gasification black water, which is suitable for removing solid particles in coal gasification black water. Specifically, the disclosure provides a combined separation method and device for coal gasification black water purification by combining flash evaporation, sedimentation and ebullating bed separation technologies. Background technique [0002] The coal gasification process uses coal or coal char as raw material, uses oxygen, water vapor or hydrogen as gasification agent, and converts the combustible part of coal or coal char into gas fuel or downstream raw material through chemical reaction under high temperature conditions. . At present, entrained bed is the mainstream coal gasification technology in China. Although the new gasification process has been industrialized on a large scale and can operate stably for a lo...

AI Technical Summary

Problems solved by technology

This method solves the defects in the existing process that a large amount of waste water needs to be discharged outside, fresh water is added, and solid particles are not completely removed.

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