SU831152A1 - Method of separating blowing gas at ammonia synthesis - Google Patents

Description

(54) THE METHOD OF SEPARATION OF AMMIAK SYNTHESIS BLOW GASES

in a water absorber, afterburning of methane in a contact furnace with copper oxide and absorption of carbon dioxide in the absorber with ammonia water, followed by argon, in which desorption from argon, methane and ammonia is carried out by heating to 430-480 ° C, the resulting gas the mixture is sent to the iron oxide reduced sorbent.

At the same time, as the iron oxide reduced sorbent, a sorbent of the following composition was used, wt.%:

EgOz64-54

FeO29-36

KjO0.7-1.0

ABOS3-4

CaO2-3,

MgO + SiQj Else

A distinctive feature is that argon methane and ammonia desorbed from coal at 450-480 ° C are purified from nitrogen impurity by its adsorption on an iron oxide sorbent at a pressure of 280-320 atm.

The adsorption of nitrogen on this sorbent is activated and selective, and argon, methane, and ammonia present in the mixture besides nitrogen do not affect the amount of nitrogen adsorption. Argon, methane and ammonia are desorbed from coal as the temperature rises to 450480 ° C while maintaining a pressure of 280-320 atm, in order to create the best conditions for adsorbing nitrogen impurities on the iron oxide reduced sorbent.

The process technology is as follows.

The purge gas separation scheme for an ammonia synthesis shop with a capacity of 25 tons of ammonia per hour per nitrogen-nitrogen mixture. argon and ammonia include argon adsorbers,

miak and methane, oil filter, ammonia absorr, meta-oxidation contact furnace, carbon dioxide absorber, nitrogen re-absorption adsorbers.

The purge gases enter the absorber filled with KAU or AP-3 activated carbon, where argon, ammonia and methane are adsorbed at

0-40-C. pressure 280-320 atm and temperature The nitrogenous mixture is returned to the ammonia synthesis cycle through an oil filter. When the coal is saturated in the adsorber to create a continuous process, the purge gases are sent to the parallel adsorber and the saturated adsorber is placed in the desorption mode. Desorption of argon, ammonia and methane is carried out with increasing temperature to 450 °. heating. The desorbing gases enter the nitrogen impurity adsorber, filled with the iron oxide reduced adsorbent. Here, at a temperature of 400-450 ° C and a pressure of 300 atm, nitrogen impurity is absorbed. When the adsorbent is saturated with nitrogen, the carbon dioxide adsorber is shut off and nitrogen is desorbed from it during pressure throttling.

To carry out the process continuity, the gases from the argon, ammonia and methane adsorber are at this time purified from nitrogen in the ammonia adsorber, then methane is oxidized to carbon dioxide in one of the copper oxide contact furnaces (regeneration is underway in another furnace). After the contact furnace, argon is cleaned of carbon dioxide in a carbon dioxide absorber with ammonia water. Pure argon comes out of this absorber.

The table shows the material flows of the purge gas processing at the synthemmiak plant with a capacity of 25 tons per hour.

.11,8 -173

Claims (2)

11.8 173 Thus, the proposed method makes it possible to improve the quality of argon as compared with the known one, which makes it possible to bring it up to commercial standard and expand the sources of obtaining commercial argon for the national economy. DETAILED DESCRIPTION OF THE INVENTION The method for separating the purge gases from the synthesis of ammonia involves the adsorption of argon, methane and ammonia with activated carbon at a pressure of 280-320 atm. and temperature O-40 C, return to the cycle of synthesis of a nitrogen-hydrogen mixture, desorption from argon coal, methane and ammonia, separation of ammonia in a water-absorber, afterburning of methane in a contact furnace with copper oxide and absorption of carbon dioxide in an absorber with ammonia water obtaining argon, characterized in that, with improved quality of argon, desorption from argon, methane and ammonia is carried out by heating to 430-480 ° C, the resulting gas mixture is directed to a reduced oxide sorbent. 2. A method according to claim 1, characterized in that a sorbent of the following composition is used as the reduced oxide sorbent: wt.% (Before reduction):. EvgOz64-54 FeO- 29-36 KjO0.7-1.0 АЬ.ОЗ3-4 СаО2-3 MgO + SiOi Others Sources (information taken into account during the examination 1. Author's certificate of the USSR N 362178, cl. 01 D 53 / 00, 1973. 2. Nitrogen and Oxygen Industry I. B., 1964, p. 8 (prototype).