Method and apparatus for compression of ammonia synthesis gas and recycle gas for the production of ammonia by screw compressors

Abstract

A method for producing ammonia may be provided. The method may include supplying ammonia synthesis gas to a synthesis gas screw compressor and compressing the synthesis gas. The compressed synthesis gas may be joined with a flow of recycle gas compressed in a recycle gas screw compressor. The compressed combined flow may then be introduced to an ammonia reactor. The ammonia reactor may discharge ammonia, purge gas, and unconverted gas, which may be the recycle gas.

What is claimed is: 
     
         1 . A system for producing ammonia comprising:
 at least one screw compressor; and   an ammonia reactor, wherein the at least one screw compressor compresses at least one of ammonia synthesis gas and recycle gas and supplies a compressed gas flow to the ammonia reactor, and wherein the ammonia reactor discharges produced ammonia, purge gas, and recycle gas.   
     
     
         2 . The system of  claim 1 , comprising one screw compressor configured to receive and compress ammonia synthesis gas and recycle gas, and supply a compressed flow of combined synthesis gas and recycle gas to the ammonia reactor. 
     
     
         3 . The system of  claim 1 , comprising a first screw compressor configured to receive ammonia synthesis gas and discharge a flow of compressed ammonia synthesis gas and a second screw compressor configured to receive recycle gas and discharge a flow of compressed recycle gas, wherein the flows of compressed synthesis gas and compressed recycle gas are combined and supplied to the ammonia reactor. 
     
     
         4 . The system of  claim 3 , wherein the first screw compressor and the second screw compressor are disposed on a single shaft. 
     
     
         5 . The system of  claim 3 , wherein the first screw compressor and the second screw compressor are disposed on separate shafts. 
     
     
         6 . The of  claim 1 , wherein the ammonia reactor is configured to supply the recycle gas to the at least one screw compressor. 
     
     
         7 . A method for producing ammonia comprising:
 supplying ammonia synthesis gas to a screw compressor;   compressing the ammonia synthesis gas in the screw compressor;   discharging a flow of compressed ammonia synthesis gas;   combining a flow of compressed recycle gas with the flow of compressed ammonia synthesis gas, forming a compressed combined gas flow;   supplying the compressed combined gas flow to an ammonia reactor, wherein the ammonia reactor discharges a produced ammonia, purge gas, and recycle gas;   supplying the recycle gas to a screw compressor;   compressing the recycle gas; and   supplying the compressed recycle gas to the flow of compressed ammonia synthesis gas.   
     
     
         8 . The method of  claim 7 , wherein the synthesis gas and recycle gas are compressed in a single screw compressor. 
     
     
         9 . The method of  claim 7 , further comprising a first screw compressor and a second screw compressor, wherein the synthesis gas is compressed in a first screw compressor and the recycle gas is compressed in a second screw compressor. 
     
     
         10 . The method of  claim 9 , wherein the synthesis gas screw compressor and recycle gas screw compressor are disposed on a single shaft. 
     
     
         11 . The method of  claim 9 , wherein the synthesis gas screw compressor and recycle gas screw compressor are disposed on separate shafts.