Method and device for treating coal chemical industry production sewage

Abstract

The invention provides a method and a device for treating coal chemical industry production sewage. The method comprises the following steps: allowing medium-pressure overheat steam with the pressure of 3.0 to 4.1 MPa and the temperature of 360 to 420 DEG C to enter a high-pressure steam stripping tower from the bottom of the tower, wherein the medium-pressure overheat steam serves as a heat source; directly heating the coal chemical industry production sewage, which enters the tower from the upper part of the tower and is pressurized to be 3.7 to 4.4 MPa, from bottom to top in a countercurrent manner; resolving soluble gases or volatile substances of the coal chemical industry production sewage; and discharging the generated coal chemical industry treated water from the bottom of the high-pressure steam stripping tower and discharging saturated steam containing resolved gases from the top of the tower. According to the method provided by the invention, an active carbon dephenolizing / CLL ammonia recovering process of coal chemical industry production sewage is changed into a medium-pressure overheat steam stripping process, so the separated pollutants can be recycled and the treated sewage returns a system to be comprehensively utilized.

Description

technical field [0001] The invention relates to a treatment method for coal chemical production sewage, in particular to a clean treatment process for conventional coal chemical sewage and a device suitable for the method. Background technique [0002] Coal chemical production uses coal as raw material, which is converted into gas, liquid and solid fuels and chemicals through chemical processing, specifically including coal gasification, liquefaction, dry distillation and other processing processes. Due to the reaction characteristics of pressurization and heating in the coal processing reaction process, a large amount of coal chemical sewage containing tar, phenols, benzenes, ammonia and other impurities will be produced during the production process. How to treat this part of sewage reasonably and effectively is a thorny problem that needs to be solved in the development of coal chemical industry. [0003] The sewage treatment process widely adopted by coal chemical enter...

AI Technical Summary

Problems solved by technology

[0004] 1. The activated carbon dephenolization / CLL ammonia recovery process is complex in operation and high in maintenance costs, and the ammonia concentration in the sewage entering the process from the upstream often fluctuates, which makes the operation of the process difficult

[0005] 2. Due to the high ammonia content in coal chemical wastewater, the recovery rate of ammonia in the activated carbon dephenolization / CLL ammonia recovery process in the conventional treatment process is not high, which cannot meet the design requirements

[0006] 3. Due to residual CO 2 The presence of ammonia and residual CO recovered from the process 2 A chemical reaction occurs to generate ammonium bicarbonate or ammonium carbonate crystals, which adhere to the equipment and pipeline flow, causing serious blockage of equipment and process pipelines and scaling on the inner wall, which seriously restricts the stable operation of the equipment

[0007] At the same time, the sewage treated by the activated carbon dephenolization / CLL ammonia recovery process cannot meet the requirements of environmental protection

Images