Novel method of coking residual ammoniacal liquor deamination, dephenolization, denitrification and utilization

Abstract

The invention aims to provide a novel method of coking residual ammoniacal liquor deamination, dephenolization, denitrification and utilization, namely a processing method of twin-tower dual-purpose distillation of coking residual ammoniacal liquor, dual-tower oxidation air-stripping to remove ammonia and nitrogen and COD reduction. The method provided by the invention has characteristics of low energy consumption, high deamination and dephenolization efficiency. And processed water can be separately used as circulating cooling water. The method comprises the following five processes: ammonia distillation for deacidification, air stripping for dephenolization, extraction for dephenolization, oxidation treatment and wastewater utilization. Residual ammoniacal liquor is processed and utilized through the above five processes. According to the above novel residual ammoniacal liquor processing method, ammonia distillation for deacidification requires no live steam, anddephenolization requires no biochemical treatment. Compression stripping dephenolization wastewater undergoes compression stripping and hydrogen peroxide two-stage oxidation and normal-pressure stripping cooling without membrane separation deep processing and then can be directly used as circulating cooling water. The method provided by the invention has protrude advantages of short flow, less investment, low cost, energy conservation and environmental protection, and can be adopted to realize zero discharge of coking wastewater and remarkable water-saving purpose for coking production.

Description

technical field [0001] The invention relates to a method and a device for treating residual ammonia water in coking, which belongs to the fields of energy saving, water saving and environmental protection, and is suitable for the coking industry. Background technique [0002] The residual ammonia water produced in the coking process contains free ammonia, fixed ammonia and phenol, as well as acid gases such as H2S, HNC and CO2. The traditional treatment method first adopts steam direct stripping or steam indirect heating, atmospheric distillation, deacidification and ammonia distillation. In order to achieve zero discharge of ammonia distillation wastewater, there are two main subsequent treatment methods: the first is that ammonia distillation wastewater is passed through A biochemical treatment device that occupies a large area is used for wet coke quenching. At present, most independent coking enterprises adopt this method. Although zero discharge of coking wastewater ha...

AI Technical Summary

Problems solved by technology

The advantage of this method is that most of the ammonia distillation wastewater can be recovered and can be supplemented to the circulating cooling water system, but there are disadvantages such as long process, large area occupation, large investment, high energy consumption, easy blockage of filter membrane and immature technology.

In addition, the traditional ammonia distillation method has a relatively large vapor-liquid ratio, and the large amount of latent heat of water vapor escaping from the top of the ammonia distillation tower has not been recycled, resulting in high energy consumption and high water consumption in the ammonia distillation process.

Furthermore, due to the low temperature in the atmospheric pressure ammonia distillation process, phenol and light tar with higher boiling points in the remaining ammonia water cannot be effectively evaporated from the top of the ammonia distillation tower, resulting in higher phenol and organic matter in the ammonia distillation wastewater, which is sent to biochemical When the system is processed, it is necessary to add nearly double the dilution water

It is even more regrettable that the valuable phenol in the remaining ammonia water is not effectively recovered, but forms worthless biochemical sludge in the process of biochemical treatment

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