Coal gasification wastewater phenol and ammonia recovery process

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a coal gasification wastewater phenol and ammonia recovery process. The process comprises the following steps that feeding wastewater is divided into cold feeding materials and hot feeding materials to respectively enter an acid water stripping tower from the tower top and the tower middle upper part; the tower top pressure is set to be 0.9 to 1.2MPa; the tower top temperature is 50 to 80 DEG C; the tower kettle pressure is set to be 0.92 to 1.25 MPa; the tower kettle temperature is 178 to 188 DEG C; acid gas is produced at the tower top; ammonia water vapor is produced at the lateral line; the ammonia water vapor is sequentially used as a heat source of a phenol tower and a solvent stripping tower, and then enters a three-stage segregated system to be concentrated into crude ammonia gas; kettle liquid of the acid water stripping tower enters an extraction device to be subjected to phenol removal; an extraction phase enters the phenol tower; an extracting agent and crude phenol are separated through rectification; a raffinate phrase enters a solvent steam extraction tower; the extracting agent dissolved in the wastewater is stripped out and returns to an extraction tower. By using the process provided by the invention, the steam consumption can be greatly reduced; in addition, the good treatment effect can be ensured.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a process for recovering phenol and ammonia from coal gasification wastewater. Background technique [0002] Coal gasification is one of the key links in coal chemical industry and coal gas production. Among them, technologies such as Lurgi pressurized gasifier, pulverized coal pressurized gasifier, Yunmei furnace, and BGL gasifier have achieved great success in converting low-rank coal. widely used. Due to the difference in conversion process and raw materials, for every ton of coal converted, 0.2-1.2 tons of phenolic wastewater will be produced. The main components of the wastewater are phenol, ammonia, carbon dioxide, hydrogen sulfide, etc., which belong to high-concentration refractory organic industrial wastewater. Among them, acid gases, ammonia, and phenolic substances affect the biochemical treatment process, and must be removed and recovered before they ca...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the defect of large steam consumption in the above-mentioned coal gasification wastewater phenol ammonia recovery process existing in the prior art, and provide an energy-saving coal gasification wastewater phenol ammonia recovery process, which can greatly save steam consumption, and Can guarantee better treatment effect

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