NPG production process wastewater recycling treatment method and device

Abstract

The invention relates to a method for recycling and treating an NPG production process wastewater. The method comprises the following steps: a, feeding process wastewater in NPG production to a methanol distillation tower, circularly heating and distilling at 85-95 DEG C; distilling and condensing partial methanol to a methanol receiving tank; b, feeding the wastewater from the distillation tower to a stripping tower to spray downwards, carrying out blast countercurrent contact in the tower, blowing and removing formaldehyde in the wastewater, wherein the water temperature of the spray wastewater is 75-80 DEG C, the blast volume is 100-150sq / c; the COD of the wastewater is within 2,000mg / L; and the formaldehyde concentration is less than 20mg / L; c, discharging the treated wastewater into a stirring tank, dropwise adding a catalyst and 27.5% of hydrogen peroxide to react at 60-70 DEG C; and d, cooling the treated wastewater to 20-25DEG C, and returning to a production system to use. The method has the advantages that the wastewater in the complete set of NPG production can be fully recycled; the wastewater treatment cost is reduced; and the cost of a neopentyl glycol material is reduced.

Description

Technical field: [0001] The invention relates to an NPG production method, in particular to a process wastewater recycling treatment method in NPG production and a device for realizing the method. Background technique: [0002] Neopentyl glycol (scientific name 2,2-dimethyl-1,3-propanediol, referred to as NPG) is mainly used in the production of high-grade alkyd resin, and its consumption accounts for 75% of the total consumption; in addition, it is also used in lubricating oil , plasticizers, polyester polyols, flame retardants, pharmaceuticals and pesticides, etc. [0003] There are two industrialized production routes for NPG, namely, the halogenated propanol route and the isobutyraldehyde route. At present, the industrial production of NPG at home and abroad basically adopts the isobutyraldehyde route, that is, isobutyraldehyde and formaldehyde are used as starting materials, and alkali is used as a catalyst. Catalyzed condensation to generate intermediate 2,2-dimethyl-...

AI Technical Summary

Problems solved by technology

However, the activity of biological treatment is greatly affected by the initial concentration of formaldehyde. It is generally believed that the allowable concentration of formaldehyde in biological treatment poisons is 100-150mg / L

[0006] Neopentyl glycol production wastewater is a high-concentration organic wastewater containing high concentrations of harmful substances such as alcohols and aldehydes. It is not easy to biodegrade, and cannot be directly anaerobic biological treatment combined with aerobic biological treatment.

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