Method for preparing hydrogen from ammonia by using pressure swing adsorption
A method for preparing hydrogen from ammonia by using pressure swing adsorption (PSA) is provided. The method for preparing hydrogen from ammonia, of the present invention, comprises the steps of: generating hydrogen and nitrogen from ammonia gas through a high-temperature reaction by using a catalyst; performing purification by selectively adsorbing unreacted ammonia gas from a gas containing unreacted ammonia and low-purity hydrogen and nitrogen, which are supplied through the high-temperature reaction and cooled; and performing purification by separating high-purity hydrogen from the gas consisting of low-purity hydrogen and nitrogen, wherein purification is carried out by using a carbon molecular sieve (CMS) adsorbent so as to desorb the unreacted ammonia gas through PSA.
1 . In a method for manufacturing hydrogen from ammonia, the method comprising steps of:
generating hydrogen and nitrogen from ammonia gas through a high-temperature reaction by using a catalyst;
performing primary purification by selectively adsorbing undecomposed ammonia gas from a gas containing undecomposed ammonia and low-purity hydrogen and nitrogen, which are supplied through the high-temperature reaction and cooled; and
performing secondary purification by separating high-purity hydrogen from a gas comprising low-purity hydrogen and nitrogen,
wherein primary purification is carried out by using a carbon molecular sieve (CMS) adsorbent so as to desorb the undecomposed ammonia gas through PSA,
wherein the CMS loaded with metal halide is used as the adsorbent.
2 . The method for manufacturing hydrogen from ammonia of claim 1 , wherein the metal halide is one or more selected from MgCl 2 , CaCl 2 ), SrCl 2 , MgBr 2 , CaBr 2 , and SrBr 2 .
3 . The method for manufacturing hydrogen from ammonia of claim 1 , wherein the adsorbent is applied to undecomposed ammonia having an ammonia decomposition rate of 80 to 99% by volume %, a concentration of undecomposed ammonia of 0.5 to 11%, pressure of 3 barg to 9 barg, and a temperature of 20 to 50° C.