Continuous preparation method of N-methylimidazole
A technology of methylimidazole and methylamine, which is applied in the field of preparation of N-methylimidazole, can solve the problems of long cycle, many processes, and high energy consumption, and achieve the effects of reduced waste water, simple process flow, and reduced ammonia consumption
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0030] First, add 60-80 mesh Hβ molecular sieves to the tubular reactor with a stainless steel jacket, wherein the volume ratio of the Hβ molecular sieve to the tubular reactor tube is 0.52:1; : 1 is pumped into the mixer by a metering pump, wherein the mass ratio of ammonia water to methylamine in the mixed ammonia is 0.53:1, and the mass ratio of formaldehyde to glyoxal in the mixed aldehyde is 0.62:1.0; the raw material mixed ammonia and mixed aldehyde are passed through After the mixer is mixed, it enters the preheater, is heated and vaporized by the heating furnace, and then enters the tubular reactor for reaction. The mixed gas generated by the reaction enters the collector after being condensed by the condenser. The crude imidazole product (excluding water content) has a yield of 97.07%; the N-methylimidazole crude product extracted from the bottom of the collector is added to the vacuum side rectification tower, separated by vacuum rectification, and vacuum side stream ...
Embodiment 2
[0046] The pressure of the tubular reactor was changed, and the gas-phase catalytic reaction was carried out under the same conditions as in step (1) in Example 1. Controlled in the tubular reactor, when the filling amount of Hβ molecular sieve and the tube volume ratio of the tubular reactor are 0.52:1, and the mass ratio of mixed ammonia / mixed aldehyde is 0.89:1, the mass of formaldehyde / glyoxal in the mixed aldehyde The ratio is 0.62:1.0, the mass ratio of ammonia / methylamine in mixed ammonia is 0.53:1, and the space velocity ratio is 1.11h -1 When the reaction temperature is controlled to be 125.1° C., the influence of pressure on the conversion rate of glyoxal and the purity of N-methylimidazole crude product (excluding water content). See figure 2 As shown, when the pressure is 0.15-0.25MPa, the conversion rate and the purity of the crude product increase, and when the pressure continues to increase, the conversion rate and the purity of the crude product decrease, mai...
Embodiment 3
[0048] The pressure of the tubular reactor was changed, and the gas-phase catalytic reaction was carried out under the same conditions as in step (1) in Example 1. In the tubular reactor, the ratio of Hβ molecular sieve filling to the inner tube volume of the tubular reactor is 0.52:1, and the mass ratio of mixed ammonia / mixed aldehyde is 0.89:1, the mass ratio of formaldehyde / glyoxal in the mixed aldehyde is 0.62:1.0, the mass ratio of ammonia / methylamine in mixed ammonia is 0.53:1, and the space velocity ratio is 1.11h -1 , the control reactor pressure is 0.25MPa, the impact of temperature glyoxal conversion and N-methylimidazole crude product purity (excluding water content) see image 3 As shown, when the temperature was at 110.0-120.1, the conversion rate and the purity of the crude product increased. When the temperature continued to increase, the conversion rate and the purity of the crude product decreased, mainly due to the generation of derivative products and furthe...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More