UA68638A - Method for synthesizing hydroxylaminesulfate - Google Patents

Abstract

The method for synthesizing hydroxylaminesulfate (HAS) consists in preparing the reaction mixture comprising ammonia, oxygen, and water vapor, the catalytic oxidation of ammonia, the concentration of the nitrose gas employing the condensation of the water vapor, the mixing of the concentrated nitrose gas with hydrogen and the mixture of sulfuric acid, water, the condensate obtained upon concentration of the nitrose gas, and the catalysate upon the catalytic hydration of the nitric acid, and finally, the catalytic hydrogenation of the nitric acid and HAS synthesis. The catalytic oxidation of ammonia is performed under the pressure exceeding 0.3 MPa. The heat of the nitrose gas is used for concentrating the nitric condensate and HAS solution. The nitric condensate is concentrated until the content of not less than 40% is obtained. Then the condensate is subjected to the catalytic hydrogenation. HAS solution is concentrated until the content of not less than 38% is obtained employing the condensation heat of the distillate vapors produced upon the concentration of the nitric condensate.

Description

Description of the invention

The invention relates to the chemical industry, namely to the method of obtaining hydroxylamine sulfate, which is used in the production of caprolactam.

The production of hydroxylamine sulfate (HAS) requires concentrated nitrogen monoxide, the production of which by catalytic oxidation of ammonia in the presence of water vapor is inevitably accompanied by the formation of dilute solutions of nitric acid. The disposal of dilute solutions of nitric acid leads to significant capital and operating costs. 70 There is a known method of obtaining GAS, which includes the preparation of a reaction mixture of ammonia, oxygen and water vapor, catalytic oxidation of ammonia, stabilization of the composition of nitrous gas by hydrogenation on a silver-manganese catalyst, its two-stage concentration by condensation of water vapor, purification of concentrated nitrous gas from nitrogen oxide (IM ), mixing it with hydrogen, a mixture of sulfuric acid, water, condensate of the first stage of nitrous gas concentration and synthesizing hydroxylamine sulfate | see stalemate. RF Mo2045471, IPC 5 12. СО1821/14, op. 10.10.1995, Bull. Mo28). At the first stage of nitrous gas concentration, about 7095 condensate containing nitric acid with a mass fraction of up to 0.395 is released, in the second - nitric acid is formed with a mass fraction of up to 5-690o. The condensate of the first stage is directed to the dilution of sulfuric acid. The condensate of the second stage, after evaporation to 40-45 mass.bo, is heated to 300"C and mixed with the main stream of nitrous gas, which enters for stabilization, and water vapor is directed to the preparation of a mixture of ammonia, oxygen, and steam.

The specified method allows for the disposal of diluted solutions of nitric acid, providing a waste-free technology for the production of GAS, but it is difficult to manage and insufficiently reliable in operation. In addition, in the process of two-stage condensation of water vapor contained in nitrous gas, the heat released at the same time is irreversibly lost.

The method for obtaining hydroxylamine sulfate, which includes the preparation of a reaction mixture of ammonia, oxygen and water vapor, catalytic oxidation of ammonia, "concentration of nitrous gas due to condensation of water vapor, mixing of concentrated nitrous gas with hydrogen, a mixture sulfuric acid, water, condensate of the first stage of nitrous gas concentration, catalyst after catalytic hydrogenation of nitric acid, catalytic hydrogenation of nitric acid and synthesis

GAS | see EPO application Mo945401, IPC9 СО1821/14, op. 09/29/1999 - prototype). At the same time, after the catalytic co-oxidation of ammonia, stabilization of the composition of nitrous gas is also carried out by hydrogenation on a co-silver-manganese catalyst and its two-stage concentration. It differs from the above in that the condensate of the second stage of nitrous gas concentration is hydrogenated in the presence of a platinum catalyst. The resulting catalyst containing nitric acid with a mass fraction of more than 0.4595 is also used for the dilution of sulfuric acid. In this way, waste-free production technology is achieved

KEROSENE. As in the above method, the heat released during the condensation of water vapor of nitrous gas is irreversibly lost. In addition, the oxidation of ammonia at pressure close to atmospheric leads to the need to compress nitrous gas, which increases the cost and complicates the management and regulation of the production process

KEROSENE. The difficulty of disposal is usually associated with a relatively low mass fraction of nitric acid in the condensate of the second stage. The consequence of this is a significant fluctuation of the concentration of the catalyst in the hydrogenation reactor, because it is continuously removed from the reactor together with the catalyst, and returned to it from the filter periodically. :z» And, because the productivity of the reactor is proportional to the concentration of the catalyst, the amount of nitrogen monoxide entering the gas synthesis stage also fluctuates, and this complicates the regulation of the process.

The purpose of the claimed invention is to improve the method of obtaining GAS by changing the scheme and parameters of the process so as to reduce the capital and energy costs for the manufacture of the product, as well as to simplify the management and regulation of the process. (ee) The problem is solved by the fact that in the method of obtaining hydroxylamine sulfate, which includes preparation of a reaction mixture of ammonia, oxygen and water vapor, catalytic oxidation of ammonia, concentration of nitrous gas due to condensation of water vapor, mixing of concentrated nitrous gas with hydrogen, (95 ) 50 with a mixture of sulfuric acid, water, nitrous gas condensate, catalyst after catalytic hydrogenation of nitric acid, catalytic hydrogenation of nitric acid and synthesis of HAS, according to the invention, catalytic oxidation of ammonia is carried out under a pressure of more than 0.3MPa, the heat of nitrous gas is used to concentrate nitric acid condensate and GAS solution, while the nitric acid condensate is concentrated to a mass fraction of nitric acid of at least 4095, which is then subjected to catalytic hydrogenation, and the GAS solution is concentrated to a mass fraction of 3895 due to the heat of condensation of distillate vapors formed at concentration of nitric acid condensate.

Carrying out the catalytic oxidation of ammonia under a pressure of more than O0.3 MPa allows to exclude the compression stage of nitrous gas. At the same time, coordination of the stages of catalytic oxidation of ammonia and synthesis of GAS and automatic regulation of the process is simplified, capital costs are significantly reduced. because thanks to the use of the heat of nitrous gas for the concentration of nitric acid condensate and GAS solution, a reduction in energy costs for the production of the final product is achieved.

Implementation of the claimed method is explained by the scheme presented in Fig.1.

The method is carried out as follows.

To obtain 1 ton of hydroxylamine per hour, a reaction mixture with 678kg/h of ammonia, 17OZkg/h of oxygen and 3352.4kg/h of steam is prepared in mixer 1 and sent to reactor 2, where steam-oxygen conversion of ammonia is carried out on platinum grids under a pressure of more than 0 ,3MPa, for example 0.3-0.35MPa. The heat of the ammonia oxidation reaction is used to produce steam by cooling the nitrous gas in the boiler part of the reactor 2 to a temperature of 260-280"C. The obtained nitrous gas (MOX) then enters the boiler from the nitric acid condensate distillation column 6, where water vapor is condensed with the release of nitric acid condensate (ACC) and nitrous gas is concentrated. The heat of condensation of water vapor is used to concentrate nitric acid condensate from a mass fraction of 7-8.595 to a mass fraction of 4095. The gaseous distillate formed at the same time, containing nitric acid with a mass fraction of up to 0.2595, enters into the heat exchanger 7, where a GAS solution with a mass fraction of about 2495 is supplied as a coolant. The GAS solution, heated due to 7/0 Condensation of water vapor of the distillate, enters the separator 8, where water vapor evaporates from the solution under dilution at a temperature of 60-857C. Concentrated solution contains GAS with a mass fraction of about 3895. Nitrous gas after the boiler From column di of stylation b enters the heat exchanger 4, where condensation of residual water vapor occurs with the formation of nitric acid condensate with a mass fraction of 7-8.5956 and cooling of concentrated nitrous gas to 40"C, then it is cleaned of nitrogen oxide (NO) in scrubber 5 and fed to stage 11 of GAS synthesis in the amount of 9Obkg/h. Condensed distillate with a mass fraction of nitric acid of 0.2595, as well as part of the condensate of the secondary steam (VP) after the separator 8 and condenser 9 are directed to the dilution of concentrated sulfuric acid 10. The cubic residue from the distillation column b with a mass fraction of nitric acid of about 4095 in the amount of 935 kg /h (374 kg/h of nitric acid monohydrate) is sent to unit 12 for hydrogenation in the presence of a platinum catalyst. Nitrogen monoxide 20, which is obtained in this case, in the amount of up to 186 kg/h in a mixture with hydrogen, is also sent to stage 11 of the GAS synthesis. The waste gases of GAS synthesis reactors are sent for burning in recuperative unit 13.

Table 1 shows data illustrating the operation of the GAS installation according to the claimed method and according to the prototype.

As can be seen from the data in the table, the specific costs of raw materials for the production of the product are practically the same. But at the same time, in the proposed method, two stages are excluded: stabilization of nitrous gas and its compression, thereby reducing capital costs and simplifying process regulation. In addition, in the claimed method, the GAS solution is concentrated from a mass fraction of 24.695 to a mass fraction of 3895 without additional energy costs. co

NN ni Os si me in this app. 7 mouth 12 11 hydr. Oz mouth 12/11 established 12 so in pom (with EPO Me945401) so according to the method that 678 )1703 3336 186 | 1092 17.9 | 128.1.) 146 40 38 z re V Y ii oo oi V Pio ONY Po Po oi NBN BIJ F pl. 0, BUT What 5. I I hear. h 2. We are 8 4B&W |. y "p moh 12 to nn, SHCI AkKIpv with NMOI ha GAS pays EV in y

F NN

(Fe) zAGAS in 195 N.O.,

BE

(is) Fig at 50

Claims (1)

The formula of the invention IR e) The method of obtaining hydroxylamine sulfate (HAS), which includes the preparation of a reaction mixture of ammonia, oxygen and water vapor, catalytic oxidation of ammonia, concentration of nitrous gas due to condensation of water vapor, mixing of concentrated nitrous gas with hydrogen, a mixture of sulfuric acid, water, condensate in" concentration of nitrous gas, catalyst after catalytic hydrogenation of nitric acid, catalytic hydrogenation of nitric acid and synthesis of HAS, which is distinguished by the fact that catalytic oxidation of ammonia is carried out under a pressure greater than 0.3 MPa, the heat of nitrous gas is used to concentrate nitric acid brand ndenset and GAS solution, while the nitric acid condensate is concentrated to a mass fraction of nitric acid of at least 40595, which is then subjected to catalytic hydrogenation, and the GAS solution is concentrated to a mass fraction of 38 to due to the heat of condensation of distillate vapors formed during the concentration of nitric acid condensate. Official bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated and microcircuits", 2004, M 8, 15.08.2004. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine.