A method of producing hydrogen comprising receiving a sour gas comprising CO2, H2S, and ammonia from a sour water stripper; introducing the sour gas to an absorption system to produce an ammonia rich gas and a sulfide rich gas, wherein the ammonia rich gas comprises ammonia and CO2, and wherein the sulfide rich gas comprises H2S and CO2; compressing the ammonia rich gas in a compressing unit to a pressure of 400-600 psig to produce a compressed ammonia rich gas; introducing the compressed ammonia rich gas to an ammonia cracker unit comprising a catalyst to produce a cracked gas, wherein the ammonia cracker unit is characterized by a cracking temperature of 450-550° C., and wherein the cracked gas comprises hydrogen, nitrogen, and CO2; and introducing the cracked gas to a PSA unit to produce hydrogen and a PSA tail gas, wherein the PSA tail gas comprises nitrogen and CO2.