Method for recovering ammonia and synthesis gas from coking wastewater

Abstract

The invention discloses a method for recovering ammonia and synthesis gas from coking wastewater. The method comprises the following steps: (1) entering coking wastewater and a certain amount of alkali into an ammonia evaporator; passing the fluid on the top of the ammonia evaporator through a stronger ammonia water storage tank by virtue of a dephlegmator and a condenser orderly to achieve recovery of ammonia, and entering bottom fluid into a wastewater concentrator; (2) entering the fluid on the top of the wastewater concentrator into a deep treatment section via a heat exchanger, entering the bottom fluid into a supercritical water gasification reactor through a compressor and a heating furnace orderly, and meanwhile, and entering oxygen into the supercritical water gasification reactor via an oxygen compressor; (3) entering the fluid gasified by the supercritical water into s a gas-liquid separator through the heat exchanger and a reducing valve orderly; and (4) entering the bottom fluid of the gas-liquid separator into the deep treatment section, entering the top fluid into a CO2 absorption tower, and meanwhile, diluting a part of fluid in the stronger ammonia water storage tank is together with dilution water in a diluted ammonia water storage tank, and then entering into the CO2 absorption tower via a centrifugal pump, recovering the synthesis gas from the top of the tower, and recycling the ammonium carbonate solution at the bottom of the tower.

Description

technical field [0001] The invention belongs to the resource utilization technology of organic waste liquid, in particular to a method for recovering ammonia and synthesis gas by supercritical water gasification treatment of coking waste water. Background technique [0002] In recent years, the coking industry and coal gasification industry have developed vigorously. However, a large amount of coking wastewater is produced in the process of coke production, gas washing, cooling, purification, recovery and refining of chemical products. The main characteristics of coking wastewater are high concentration of phenol and ammonia and large amount of wastewater discharge. The chemical oxygen demand (COD) in wastewater is as high as 20000mg / L, among which phenolic substances account for more than 70% of COD. Due to the biological toxicity of phenolic substances and the biological inhibition of ammonia nitrogen, the biodegradability of coking wastewater is poor, and its five-day b...

AI Technical Summary

Problems solved by technology

This treatment method is mainly based on the harmless treatment of wastewater. The high concentration of organic matter and ammonia in coking wastewater cannot be effectively utilized, which not only wastes a lot of resources, but also significantly increases the cost of chemicals and energy consumption for the treatment of this refractory substance. Will produce secondary pollution (such as biochemical sludge)

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