METHOD FOR PREPARING ACESULFAME POTASSIUM

20240083863

18/519151

November 27, 2023

Described herein is a method for preparing acesulfame potassium, comprising: pressing an acetoacetamide-N-sulfonic acid triethylamine salt solution and a cyclizing agent solution into a Venturireactor via different inlets, mixing same at a mixing section and a diffusion section of the Venturireactor, and then injecting the obtained mixture into a flow reactor, wherein the cyclizing agent solution is formed by dissolving sulfur trioxide in a first organic solvent; subjecting the mixture passing through the flow reactor to a sulfonation cyclization reaction under the action of a supported solid base heterogeneous catalyst preset in the flow reactor, and entering the obtained sulfonated cyclized product into a hydrolysis reactor; subjecting the sulfonated cyclized product and a hydrolysis agent preset in the hydrolysis reactor to a hydrolysis reaction to obtain a hydrolysis product solution; and adding potassium hydroxide into an organic phase of the hydrolysate solution for a salt-forming reaction to obtain the acesulfame potassium.

1. A method for preparing acesulfame potassium, wherein the method is implemented by using a combined reactor, the combined reactor comprises a Venturi reactor, a flow reactor and a hydrolysis reactor, the outlet of a diffusion section of the Venturi reactor is connected to the inlet of the flow reactor, and the flow reactor is connected to the inlet of the hydrolysis reactor; and the method comprises: a mixing step: pressing an acetylacetamide-N-sulfonic acid triethylamine salt solution and a cyclizing agent solution from different inlets of the Venturi reactor, after mixing in a mixing section and the diffusion section of the Venturi reactor, injecting the obtained mixture into the flow reactor, wherein the cyclizing agent solution is formed by dissolving sulfur trioxide in a first organic solvent; a sulfonation cyclization step: subjecting the mixture passing through the flow reactor to a sulfonation cyclization reaction under the action of a supported solid base heterogeneous catalyst preset in the flow reactor, and entering the resulting sulfonated cyclized product into the hydrolysis reactor; a hydrolysis step: carrying out a hydrolysis reaction with the sulfonated cyclized product and a hydrolysis agent preset in the hydrolysis reactor to obtain a hydrolysate solution; and a salt forming step: adding potassium hydroxide into the organic phase of the hydrolysate solution, and carrying out a salt forming reaction to obtain acesulfame potassium.

2. The method according to claim 1, wherein the acetylacetamide-N-sulfonic acid triethylamine salt solution is prepared by the following method: dissolving sulfamic acid in a second organic solvent, then adding triethylamine into the second organic solvent, and carrying out an amination reaction to generate an ammonium sulfamate solution; and adding diketene to the obtained ammonium sulfamate solution, and carrying out an acylation reaction to obtain an acetylacetamide-N-sulfonic acid triethylamine salt solution.

3. The method according to claim 2, wherein the molar ratio of sulfamic acid to the second organic solvent is 1:3-5, preferably 1:4; the molar ratio of diketene to sulfur trioxide is 1:2-15, preferably 1:4; the reaction temperature of the sulfonation cyclization reaction is −20 to 40° C., preferably 10 to 30° C., and more preferably 15 to 25° C.; and the reaction time is 1 s-30 min, preferably 2 s-2 min.

4. The method according to claim 2, wherein the first organic solvent is pentane, hexane, heptane or dichloromethane; and the second organic solvent is pentane, hexane, heptane or dichloromethane.

5. The method according to claim 1, wherein the supported solid base heterogeneous catalyst is a K2O/-γAl2O3 catalyst, and preferably, the K2O/-γAl2O3 catalyst is added with organic silicon.

6. The method according to claim 1, wherein the hydrolysis agent is an ethanol aqueous solution, wherein the mass fraction of ethanol in the ethanol aqueous solution is 60-85%.

7. The method according to claim 1, wherein the reaction temperature of the hydrolysis reaction is −10 to −20° C.

8. The method according to claim 1, wherein the acetylacetamide-N-sulfonic acid triethylamine salt solution is used as a working fluid, the working fluid is pressed in from the nozzle of the Venturi reactor, the cyclizing agent solution is used as an ejecting fluid, and the ejecting fluid is pressed in from the suction chamber of the Venturi reactor; and the pressure of the working fluid is controlled to be greater than the pressure of the ejecting fluid.

9. The method according to claim 8, wherein the pressure of the working fluid is 0.4-1.6 MPa, the pressure of the ejecting fluid is 0.2-1.4 MPa, and the pressure of the working fluid is 0.2-0.4 MPa higher than the pressure of the ejecting fluid.

10. The method of claim 1, wherein the flow reactor is a fixed bed reactor or a tubular reactor.

07; 01; 01

edspap.20240083863