Patent ID: 9321655
Filing Date: 2016-04-26
CPC Classification: C01B,C01C,Y02P

Claim Text:
1. A method for producing ammonia, comprising: reforming a hydrocarbon comprising methane in a first reaction zone in the presence of one or more first catalysts and steam at conditions sufficient to produce an effluent comprising about 10 mol % to about 40 mol % non-reformed methane, about 5 mol % to about 20 mol % carbon monoxide, about 10 mol % to about 20 mol % carbon dioxide, and about 40 mol % to about 60 mol % hydrogen; reforming the effluent in a second reaction zone in the presence of one or more second catalysts and nitrogen at conditions sufficient to produce a syngas comprising about 10 mol % or less non-reformed methane, about 40 mol % to about 80 mol % hydrogen, about 20 mol % to about 40 mol % nitrogen, about 5 mol % to about 20 mol % carbon monoxide, and about 5 mol % to about 20 mol % carbon dioxide; introducing an oxidant into the second reaction zone; converting at least a portion of the nitrogen and hydrogen in the syngas to ammonia to produce an ammonia effluent; separating the ammonia effluent to produce an ammonia product and a purge gas comprising nitrogen; separating the purge gas comprising nitrogen to produce a hydrogen-rich recycle gas and a hydrogen-lean recycle gas; comparing a temperature associated with the oxidant with a predetermined temperature; and recycling a first portion of the hydrogen-lean recycle gas to the effluent from the first reaction zone separately from the oxidant introduced into the second reaction zone and only if a temperature associated with the oxidant is above the predetermined temperature, wherein the hydrogen-lean recycle gas comprises 10 mol % to 70 mol % nitrogen.