Producing ammonia using ultrapure, high pressure hydrogen
In various implementations, feed streams that include ultrapure, high-pressure hydrogen streams and ultrapure, high-pressure nitrogen streams are reacted to produce ultrapure, high-pressure feed gas in a stoichiometric ratio to an ammonia synthesis reactor loop without or independent of including a methanol loop purge gas.
1. A method for producing ammonia comprising;
exothermically reacting a first portion of a hydrocarbon feed stream with an oxidant gas comprising molecular oxygen to produce an exothermically generated syngas product, wherein the step of reacting occurs in a partial oxidation reactor (POX) or an autothermal reforming reactor (ATR);
endothermically reforming a second portion of the hydrocarbon feed stream with steam over a catalyst in a heat exchange reformer to produce an endothermically-reformed syngas product, wherein at least a portion of heat used in generation of the endothermically-reformed syngas product is obtained by recovering heat from the exothermically-generated syngas product and the endothermically reformed syngas product;
combining the exothermically generated syngas product and the endothermically-reformed syngas product to produce a combined syngas stream
cooling the combined syngas stream to produce steam in a heat recovery boiler;
catalytically reacting the combined syngas stream in one or more catalytic carbon monoxide shift reactors to generate a shifted stream including additional H 2 and CO 2 ;
cooling the shifted stream to near ambient temperature in a heat exchanger by transferring heat to water for steam production in syngas generation;
removing CO 2 from the shifted syngas stream to produce a CO 2 -depleted stream;
removing a high pressure, substantially pure H 2 stream from the CO 2 -depleted stream, wherein the high pressure, substantially pure H 2 stream is produced independent of a compressor; and
combining the high pressure, substantially pure H 2 stream with a high pressure, substantially pure N 2 stream to produce ammonia.
2. The method of claim 1 , wherein impurities included in the ammonia are about 50 parts per million (ppm) or less.
3. The method of claim 1 , wherein the combined high pressure, substantially pure H 2 stream and high pressure, substantially pure N 2 stream have a pressure in a range about 100 to 300 bars.
4. The method of claim 1 , wherein the high pressure, substantially pure H 2 stream comprises about 20 parts per million (ppm) by total volume of other components different than H 2 .
5. The method of claim 1 , wherein the high pressure, substantially pure H 2 stream has a pressure of about 60 bars or greater.
6. The method of claim 1 , wherein the exothermically-generated syngas product is generated using a partial oxidation burner followed by a catalytic reforming section in a convectively heated steam plus hydrocarbon reformer.
7. The method of claim 1 , wherein the feed stream includes methane.
8. The method of claim 1 , wherein the CO 2 is removed using at least one of a conventional physical scrubbing process or a conventional chemical scrubbing process.
9. The method of claim 1 , wherein the high pressure, substantially pure H 2 stream is separated from the CO2-depleted stream using one or more pressure swing adsorption systems.
10. The method of claim 9 , wherein the one or more pressure swing adsorption systems comprises two pressure swing adsorption systems.
11. The method of claim 10 , wherein H 2 produced from the two pressure swing adsorption systems are at substantially a same pressure.
12. The method of claim 9 , wherein at least a portion of waste gas from the one or more pressure swing absorption systems is used as fuel for a gas turbine.