NMP waste liquid treatment
Dec 19, 2021
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N-Methyl-Pyrrolidone, N-Methyl-2-pyrrolidone,1-Methyl-2-pyrrolidone, Methylpyrrolidone, NMP also known as 1-methyl2-pyrrolidone, referred to as NMP solvent, is a polar aprotic transport solvent, high boiling point, strong polarity, low viscosity, strong solubility, no corrosion, small toxicity, strong biodegradation, low volatility, chemical stability, excellent thermal stability. Today, we wil talk about how NMP waste liquid treatment works.
Ⅰ. Current situation of DISPOSAL of NMP waste liquid
N-Methyl-Pyrrolidone, N-Methyl-2-pyrrolidone,1-Methyl-2-pyrrolidone, Methylpyrrolidone, NMP can be intersoluble with water with arbitrary ratio, high boiling point, flash point and strong solubility, so it is not easy to be directly separated from the aqueous solution of NMP. Its recovery methods mainly include flash and solvent extraction.
Due to the special physical and chemical properties of NMP, flash extraction of NMP from a solution with high water content will consume a lot of heat energy, resulting in energy waste. Solvent extraction technology has the advantages of simple equipment, large extraction capacity, high separation efficiency and low cost. Therefore, solvent extraction method is suitable for industrial application.
Ⅱ. Principle of NMP wastewater treatment by centrifugal extraction process
N-Methyl-Pyrrolidone, N-Methyl-2-pyrrolidone, 1-Methyl-2-pyrrolidone, Methylpyrrolidone, NMPwaste liquid and extractant are fully mixed in the centrifugal extractant. Because the waste water and extractant are not mutually soluble, there are two liquid phases in the centrifugal extractant and waste water. After mixing, a large phase interface is formed, so that the two phases are in full contact, and NMP is selectively extracted by the extractant (chlorinated hydrocarbon), separated from the wastewater, so as to achieve the purpose of separation and extraction of NMP.
Ⅲ. Working principle and flow of centrifugal extractor
Centrifugal extractor is an efficient equipment for liquid-liquid two-phase extraction and separation by using centripetal force. The equipment can complete a variety of functions, such as liquid liquid two phase mixture mass transfer, reaction, extraction, washing, separation and so on.
The new centrifugal extractor adopts the up-hanging structure and fully sealed design, and the two-phase liquid is fed through the mixing chamber below. The machine above the drum is mainly composed of transmission parts, drum parts, shell and frame.
Insoluble two liquid phases (raw liquid and extractant) enter the drum from the bottom of the two feed ports, and mix rapidly with the rotation of the drum, and then gradually transfer the extraction components in the original liquid phase to the extractant. In the drum, the mixture from the bottom to the top, light to the rotor center movement, heavy to the inner wall of the rotor movement, separation of the light, heavy two liquid phase respectively through the light, heavy phase yan kou gathered to light, heavy phase collection cavity, and discharged from their respective exports.
Ⅳ. Effect of centrifugal extraction process on disposal of NMP waste liquid
Due to the density difference between the waste water and the extractant, stratification will be produced by centrifugation to achieve the purpose of separation. The extraction phase was mainly composed of extractant and dissolved with more NMP, and the raffinate phase was mainly composed of waste water and containing a small amount of NMP.
Normally the NMP manufacturer will second time to use this NMP waste liquid which can save the cost and also can protect the environment,and we can offer the machine and technical supports for them to assist them to do this work.
