Chemical Engineering Communications, Vol.163, 97-109, 1998
A two stage PSA for argon and hydrogen recovery from ammonia purge gas
A two stage PSA process for argon and hydrogen recovery from ammonia purge gas was developed. Appropriate adsorbents were selected by considering adsorption equilibrium and regeneration possibility. A continuous process, which can treat about 100 Nm(3)/h of ammonia purge gas, was designed by applying the adsorption equilibrium and breakthrough test results. The continuous process consists of 2 stage PSA with 4 beds respectively. Product hydrogen (>99%) can be obtained from the first stage during first period of adsorption step, and also from the second stage. An intermediate product, argon and hydrogen mixture, is obtained from the first stage during the second period of adsorption step, and this is sent to the second stage to be separated into high purity argon and hydrogen respectively. From the raw purge gas containing about 6% argon, argon is concentrated upto 14% through the first stage, and upto 97% through the second stage PSA.