Comprehensive utilization method for tributoxy ethyl phosphate wastewater

Abstract

The invention discloses a comprehensive utilization method for tributoxy ethyl phosphate wastewater. The method comprises the following steps: carrying out a saponification reaction between TBEP alkali washing wastewater and an alkaline solution, enabling residual phosphate in the wastewater to completely react and produce sodium phosphate so as to obtain saponification wastewater, adding an acidic solution into the saponification wastewater, reacting, standing and layering, and separating the lower acidic aqueous phase and the upper oil phase; neutralizing the lower acidic aqueous phase, anddistilling so as to obtain an industrial salt and distilled water; distilling and dehydrating the upper oil phase, continuously distilling to obtain crude ethylene glycol monobutyl ether and a distilled base solution, performing cyclic dehydration on the crude ethylene glycol monobutyl ether by a molecular sieve packing tower, and collecting; neutralizing the distilled base solution, distilling and dehydrating, thereby obtaining the TBEP (Tributoxy Ethyl Phosphate) sodium salt. According to the comprehensive utilization method disclosed by the invention, the problems of production and treatment of hazardous solid wastes in the wastewater treatment method in the prior art are solved, and the problem that a high-efficiency distillation system cannot be normally used due to scaling blockage of sodium phosphate in an MVR (Mechanical vapor recompression) pipeline can be completely solved.

Description

Technical field [0001] The invention relates to a comprehensive utilization method of tributoxyethyl phosphate wastewater. Background technique [0002] Tributoxyethyl phosphate flame retardant, English name Tris (2-butoxyethyl) pHospHate, referred to as TBEP, also known as ethylene glycol monobutyl ether phosphate triester, molecular formula is C18H42O10P, molecular weight is 449.4955. It is a flame-retardant plasticizer, mainly used for flame-retardant and plasticizing of polyurethane rubber, cellulose, polyvinyl alcohol, etc. It has good low temperature characteristics. The product has a wide range of uses, the market demand continues to increase, and has the characteristics of low smoke, halogen-free, non-toxic, etc., in line with the development direction of flame retardant halogen-free environmental protection, so it has a good development prospect. In the process of generating flame retardant TBEP, every 1 ton of TBEP product produced can produce about 0.5 ton of alkaline...

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Problems solved by technology

[0004] 1. Pre-distillation pretreatment measures such as oxidation of TBEP wastewater, flocculation and precipitation to remove phosphorus cannot remove phosphorus in the water, and phosphorus is still dissolved in the wastewater in the form of TBEP sodium salt. On the contrary, the pretreatment caused by the addition of flocculants and other agents Increase in Hazardous Solid Waste

[0005] 2. When TBEP wastewater is continuously distilled and dehydrated to separate chlorine and phosphorus elements in the water, the TBEP sodium salt in the wastewater will precipitate as the water decreases, and its shape is similar to high-viscosity sludge, which cannot be centrifugally separated by the general crystalline sodium chloride method. Cause scaling on the inner wall of the equipment, blockage of the material transfer and return pipeline, resulting in extremely poor steam heating effect, low distillation efficiency, high equipment failure shutdown rate, etc.

[0006] 3. The content of sodium chloride in TBEP wastewater is extremely low, and when TBEP wastewater is pretreated by the environmental protection station and combined with other phosphate wastewater for MVR dehydration, the industrial salt separated by salt will make the appearance of the large amount of TBEP sodium salt and sodium chloride content does not meet the industrial salt quality standards

[0007] 4. The recyclable ethylene glycol monobutyl ether in wastewater has no effective recovery process, resulting in waste

The mass content of ethylene glycol monobutyl ether phosphate diester sodium salt in TBEP production wastewater is more than 75%. Since the company's original process did not separate inorganic salts and organic salts, the final wastewater obtained by distillation and dehydration Phosphate sodium salt solid contains nearly 1 / 3 of the mass of sodium chloride, and its active ingredient ethylene glycol monobutyl ether phosphate diester sodium salt has a mass content of less than 50%. sale, but can only be treated as hazardous solid waste

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