Method for processing high-purity low-dew point hydrogen-nitrogen mixture gas

Abstract

The invention relates to a method for processing hydrogen-nitrogen mixed gas with high purity and low dew point. The hydrogen-nitrogen mixed gas processed by the method has stable yield and low dew point. The method is characterized in that liquid ammonia is sent to an evaporator through a filter; after gaseous ammonia comes out from the evaporator, the pressure of the gaseous ammonia is controlled at 0.05 Mpa through an adjusting valve; heat of pyrolysis gas is absorbed through a rotor flowmeter and a heat exchanger, is preheated and enters a cracking furnace; ammonia gas is heated to a temperature between 800 and 850 DEG C and is decomposed into the hydrogen-nitrogen mixed gas under the action of nickel as a catalyst; the hydrogen-nitrogen mixed gas is cooled through the heat exchanger and a water cooler and enters a purification system; an adsorption tower of the purification system is provided with two sets of towers in parallel connection; each set of the towers is formed by two stages of the adsorption towers in serial connection; the mixed gas passes through a primary adsorption tower and a secondary adsorption tower; and moisture and residual ammonia are removed through molecular sieves in the adsorption towers.

Description

technical field [0001] The invention relates to the technical field of ammonia decomposition processing, in particular to a processing method of high-purity low dew point hydrogen-nitrogen mixed gas. Background technique [0002] In stainless steel processing, one of the processes is solution treatment of steel pipes. In solution treatment, hydrogen and nitrogen mixed gas must be passed through the furnace to protect the steel from oxidation. The existing processing method of hydrogen-nitrogen mixed gas is that liquid ammonia comes out of the storage tank and directly enters the decomposition furnace. When the ammonia gas is heated to 800-850 degrees Celsius, it is decomposed into hydrogen-nitrogen mixed gas under the action of a nickel catalyst. Enter the purification system, and the purification system consists of two sets of adsorption towers connected in parallel, one set of towers works, and the other set of regeneration, the molecular sieve in the adsorption towers rem...

AI Technical Summary

Problems solved by technology

The disadvantage of the above process is that the gas production is unstable, there is a trace of residual ammonia, the purity is low, and the gas dew point is high, and the high dew point is easy to affect the surface finish of the steel