SU430052A1 - METHOD OF OBTAINING NITROGEN OXIDE - Google Patents

Description

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This invention relates to a method for producing nitrous oxide by catalytic oxidation of ammonia.

A method is known for producing nitrous oxide by oxidizing ammonia on a catalyst, which is manganese oxide or cobalt oxide. However, the reaction according to a known method is carried out in the case of incomplete conversion of ammonia: at the outlet of the reactor, in addition to nitrous oxide and nitrogen, there is 8-14% unreacted ammonia. This means that nitrous oxide is contaminated with ammonia and cannot be used as anesthetic in medicine; the output of nitrous oxide is small.

In order to increase the yield and purity of the product, it is proposed to carry out the process on an oxide catalyst containing manganese oxide or cobalt monoxide promoted with platinum additives.

When the process is carried out on a promoted manganese oxide catalyst, the yield of pure nitrous oxide at 200 ° C is 76%, and when using a promoted oxide-cobalt catalyst, the yield of pure nitrous oxide is 60%.

Example 1. Manganese dioxide powder obtained by decomposing manganese nitrite at 400 ° C is mixed with barium sulphate powder, on which 0.1 weight is applied. % platinum. The application is carried out by impregnation of barium sulfate with a solution of hydrochloric acid of the corresponding concentration, after which the substance is carried out at 100 ° C and calcined at 585 ° C until the acid is completely converted to platinum metal. Manganese dioxide and platinized barium sulphate are mixed in a 1: 1 ratio by weight, carefully ground in a mortar and stirred to obtain a homogeneous mixture, then the catalyst is tableted and crushed into 2 mm grains.

In the reactor (quartz tube with an inner diameter of 15 mm and a length of 20 cm) load

7.2 g of catalyst, to which quartz glass is added. The reaction mixture consists of ammonia and oxygen entering the reactor from the cylinders through a purification system, measuring gas flow rates and mixing them. The analysis of the products is carried out chromatographically. The initial mixture contains 10 vol. % ammonia, the rest is oxygen. Before catalytic oxidation, the catalyst is heated in a stream of oxygen at 200 ° C in

for 2 hours

At 200 ° C and a gas mixture flow rate of 50 ml / min, the catalytic conversion of ammonia is 100%; the output of nitrous oxide 76%. No higher oxides of nitrogen are formed.

Example 2. Powder of nitrous oxide of cobalt, obtained by decomposition of cobalt nitrite at 400 ° C, is mixed with barium sulfate powder, on which 0.1 weight is applied. % platinum. The application is carried out by impregnating the barium sulfate with a solution of hydrochloric acid of the corresponding concentration, after which it is dried at 100 ° C and calcined at 595 ° C until the acid is completely converted to platinum metal. Cobalt hydroxide and platinized barium sulphate are mixed in a 1: 1 ratio by weight, thoroughly ground in a mortar and stirred to obtain a homogeneous mixture, then the catalyst is pelletized and crushed into 2 mm grains.

6.2 g of catalyst are loaded into a reactor (a quartz tube with an inner diameter of 15 mm and a length of 20 cm), to which quartz glass is added. The reaction mixture consists of ammonia and oxygen entering the reactor from the cylinders through a cleaning system, measuring the flow rates of gases and mixing them. The analysis of the products is carried out by chromatography. The initial mixture contains 10 vol. % ammonia, the rest is acidrrDg Before

the catalytic catalyst is heated in a stream of oxygen at 500 ° C for 2 hours. At a gas mixture flow rate of 12.5 ml / min, the catalytic conversion of ammonia is

100%; yield of nitrous oxide 60% Higher oxides of nitrogen are not formed.

Subject matter, eni.

A method of producing nitrous oxide by oxidizing ammonia with oxygen on an oxide catalyst selected from the group of oxides containing manganese oxide and cobalt oxide, characterized in that, in order to increase the yield and purity of the product, the process is carried out on a catalyst promoted with plat.in1 additives: | one.