NMP synthesis process is introduced in detail

NMP, N-methylpyrrolidone (abbreviated as NMP), mainly uses the BDO synthesis route, synthesis of γ-butyllactone, γ-butyllactone and methylamine reaction to produce NMP. This route is a reliable and mature process production route.

This method has long industrialization time, mature technology and large yield. It mainly adopts copper catalyst, and adds zinc, aluminum, chromium, manganese and other co-catalysts to improve the activity and selectivity of the reaction. The catalyst is easy to use, long service life, low cost, 1, 4-butanediol conversion rate of 98%, selectivity of 95%, yield &gt. 90%, the economic competitiveness of the process depends mainly on the price and source of the raw material 1, 4-butanediol.

The biggest advantage is that it is not limited by hydrogen source, and hydrogen is produced by side. The production scale can be large or small, with the basic organic raw material 1, 4-butanediol as raw material can be produced, for γ-butanolactone as raw material to further produce a variety of fine chemicals manufacturers is more appropriate.

Gamma-butyrolactone process

The raw material, 1, 4-butanediol, is fed into the 1, 4-butanediol heater by the metering pump, heated to a certain temperature by thermal oil, mixed with circulating hydrogen, and then into the static mixer. After being fully mixed, it enters the mixture heater and heated to a certain temperature, so that 1, 4-butanediol is completely vaporized, enters the heavy material separator, and enters the dehydrogenation reactor for dehydrogenation reaction. Control a certain temperature and pressure, after the completion of the reaction product and circulating hydrogen heat exchanger in the product, the product after heat exchange into the product cooler cooled by circulating water into the gas-liquid separator, where the reaction product and hydrogen are separated, the reaction product flows into the crude product storage tank storage, hydrogen separated by the gas-liquid separator, A small amount of high altitude discharge or purification treatment is used in the hydrogen device, and the remaining large amount of hydrogen is pressurized by the pressure regulator into the hydrogen press, and then into the product hydrogen heat exchanger for heat exchange with the reaction product, and into the hydrogen heater, and mixed with hot 1, 4-butaneol into the static mixer for recycling. The crude γ-butyrolactone is driven into the azeotrope tower by the feed pump to remove the light impurities, and then driven into the product rectifying tower by the feed pump to obtain the high purity product, and then pumped into the product storage tank.

NMP process flow

The finished gamma-butyllactone and 40% monomethylamine aqueous solution of raw materials are respectively injected into the steam preheater by the metering pump according to a certain molar ratio, into the static mixer, after full mixing, into the amination reactor, at the high temperature of 230-260℃ and under the pressure of 7.0 ~ 8.0MPa, The reaction product is cooled by the product cooler and then fed into the constant pressure tank. The product is decompressed into the normal pressure at the bottom of the constant pressure tank by the flow limiting orifice plate and then into the crude NMP storage tank. Then it is pumped into the deamination tower for deamination. The effluent from the tower tank enters the dewatering tower for dehydration, the water from the top of the tower goes into the sewage treatment system, the effluent from the tower tank goes into the middle distillate tower for rectification, the liquid from the middle distillate tower tank goes into the product tower for rectification, the produced product is put into the product storage tank and enters the filling workshop for filling, the residual liquid from the bottom of the tower is discharged into the barrel, and there is a qualified recycling company for recycling or incineration.

Domestic and foreign technical situation

Globally, the leading manufacturers of NMP are BASF in Germany, Ashland in the United States, Mitsubishi Chemical in Japan, Leander Bassel in Belgium, etc.

In foreign countries, γ-butyllactone (GBL) and monomethylamine (MMA) are mainly used to synthesize NMP, and γ-butyllactone and mixed methylamine are also used as raw materials to synthesize NMP. Gamma-butyrolactone and methylamine catalyst free synthesis of NMP process was developed by E. path et al in 1936, Germany BASF Company, GAF Company and Japan Mitsubishi Chemical Company have built NMP production units are using this process. The difference is that the raw material gamma-butyllactone production route is different. BASF of Germany and GAF of the United States used 1, 4-butanediol as raw materials to produce gamma-butanolactone. The Japanese Mitsubishi Chemical Company used maleic anhydride high-pressure hydrogenation process to produce gamma-butylactone.

Contact us :

MOB/Whatsapp: +86-13505467767
E-mail: vanessa@sddslchem.com
jinhaova@gmail.com
Linkedin: linkedin.com/in/vanessa-zhang-11521973