Method of Hydrogen Liquefaction Using Optimized Claude Refrigeration Cycles

Abstract

Methods and systems providing a process for cooling and liquefying a purified gaseous hydrogen feed stream to a liquid hydrogen stream that may be stored in a liquid hydrogen storage tank, as well as a system wherein ortho-hydrogen (o-H2) contained in the purified gaseous hydrogen feed stream may be converted to para-hydrogen (p-H2) through serial low-temperature catalytic converters along with cooling process from normal ambient temperature (300K) to the liquefied temperature (about 20K) of the hydrogen.

1 . A hydrogen liquefaction method, comprising:
 providing a purified gaseous hydrogen feed stream, wherein the purified gaseous hydrogen feed stream comprises about 75% ortho-hydrogen and 25% para-hydrogen, and further wherein the purified gaseous hydrogen feed stream comprises a pressure within the range of 800 kPa·G to 4,000 kPa·G and a temperature of about 300K;   combining the purified gaseous hydrogen feed stream and a first split gaseous hydrogen stream forming a combined gaseous hydrogen feed stream;   cooling the combined gaseous hydrogen feed stream inside a precooling main heat exchanger to form a first cold gaseous hydrogen stream;   purifying the first cold gaseous hydrogen stream inside a swing hydrogen absorption bed unit to form a deep purified cold gaseous hydrogen stream;   passing the deep purified cold gaseous hydrogen stream through a fixed-bed catalyst ortho-para hydrogen converter, wherein the deep purified cold gaseous hydrogen stream forms a first p-H2 enriched gaseous hydrogen stream, wherein the first p-H2 enriched gaseous hydrogen stream comprises a new equilibrium composition of about 53% ortho-hydrogen and about 47% para-hydrogen, and further wherein the first p-H2 enriched gaseous hydrogen stream increases in temperature due to the exothermic process of the ortho to para hydrogen conversion;   cooling the first p-H2 enriched gaseous hydrogen stream inside the precooling main heat exchanger to form a first cold p-H2 enriched gaseous hydrogen stream, wherein the temperature of the first cold p-H2 enriched gaseous hydrogen stream is reduced to 82K;   cooling the first cold p-H2 enriched gaseous hydrogen stream inside a catalyst filled intermediate-temperature ortho-para hydrogen converter of an intermediate temperature main heat exchanger to form a second cold p-H2 enriched gaseous hydrogen stream, wherein the second cold p-H2 enriched gaseous hydrogen stream comprises a temperature of about 40K;   converting ortho-hydrogen to para-hydrogen in the second cold p-H2 enriched gaseous hydrogen stream inside the catalyst filled intermediate-temperature ortho-para hydrogen converter of the intermediate temperature main heat exchanger, wherein the second cold p-H2 enriched gaseous hydrogen stream comprises a new equilibrium composition of about 11% ortho-hydrogen and about 89% para-hydrogen;   cooling the second cold p-H2 enriched gaseous hydrogen stream inside a catalyst filled low-temperature ortho-para hydrogen converter of a cold temperature main heat exchanger to form a subcooled high-pressure p-H2 enriched liquid hydrogen stream, wherein the subcooled high-pressure p-H2 enriched liquid hydrogen stream comprises a temperature of about 23.5K;   converting ortho-hydrogen to para-hydrogen in the subcooled high-pressure p-H2 enriched liquid hydrogen stream inside the catalyst filled low-temperature ortho-para hydrogen converter of the cold temperature main heat exchanger, wherein the subcooled high-pressure p-H2 enriched liquid hydrogen stream comprises a new equilibrium composition of about 1% ortho-hydrogen and about 89% para-hydrogen;   reducing the pressure of the subcooled high-pressure p-H2 enriched liquid hydrogen stream with a Joule-Thomson valve (J/T valve) to form a low-pressure liquid hydrogen product stream, wherein the low-pressure liquid hydrogen product stream comprises a pressure of about 50 kPa·G and temperature of about 21.7K;   feeding the low-pressure liquid hydrogen product stream into a liquid hydrogen storage tank;   removing a flashed gaseous hydrogen stream from the liquid hydrogen storage tank;   feeding the flashed gaseous hydrogen stream into a liquid hydrogen storage tank pressure control valve, wherein the flashed gaseous hydrogen stream exits the liquid hydrogen storage tank pressure control valve as an optimized hydrogen Claude cycle hydrogen makeup stream; and   combining the optimized hydrogen Claude cycle hydrogen makeup stream with a low-pressure thermosiphon hydrogen vapor stream to form a combined low-pressure cold circulation hydrogen stream, wherein the combined low-pressure cold circulation hydrogen stream enters a pass of the cold temperature main heat exchanger, forming a mixed low-pressure thermosiphon hydrogen stream.   
     
     
         2 . The hydrogen liquefaction method of  claim 1 , further comprising:
 providing a high-pressure circulation hydrogen stream, wherein the high-pressure circulation hydrogen stream comprises a pressure within the range of about 3,500 kPa·G to 4,400 kPa·G and a temperature of about 313K;   cooling the high-pressure circulation hydrogen stream in the precooling main heat exchanger to form a first cold high-pressure circulation hydrogen stream, wherein the first cold high-pressure circulation hydrogen stream comprises a temperature of about 82K;   further cooling the first cold high-pressure circulation hydrogen stream in the intermediate temperature main heat exchanger, wherein a first hydrogen turbo-expander feed stream is split from the first cold high-pressure circulation hydrogen stream in the intermediate temperature main heat exchanger, wherein the first hydrogen turbo-expander feed stream proceeds to a first hydrogen turbo-expander, wherein a first hydrogen turbo-expander discharge stream exits the first hydrogen turbo-expander;   removing a second cold high-pressure circulation hydrogen stream from the intermediate temperature main heat exchanger;   cooling the second cold high-pressure circulation hydrogen stream in the cold temperature main heat exchanger to form a subcooled high-pressure circulation liquid hydrogen stream, wherein the subcooled high-pressure circulation liquid hydrogen stream comprises a temperature of about 32K;   splitting the subcooled high-pressure circulation liquid hydrogen stream into a first subcooled high-pressure circulation liquid hydrogen stream and a second subcooled high-pressure circulation liquid hydrogen stream;   reducing the pressure of the first subcooled high-pressure circulation liquid hydrogen stream in a first circulation liquid hydrogen pressure let-down valve to about 50 kPa·G, forming the low-pressure thermosiphon hydrogen vapor stream;   reducing the pressure of the second subcooled high-pressure circulation liquid hydrogen stream in a second circulation liquid hydrogen pressure let-down valve to form an intermediate-pressure cold circulation hydrogen stream, wherein the intermediate-pressure cold circulation hydrogen stream comprises a pressure of about 815 kPa·G and a temperature of about 30.7K, and further wherein the intermediate-pressure cold circulation hydrogen stream comprises vapor flash-out; and   totally vaporizing the intermediate-pressure cold circulation hydrogen stream in the cold temperature main heat exchanger.   
     
     
         3 . The hydrogen liquefaction method of  claim 1  further comprising mixing a cold nitrogen turbo-expander discharge stream with an intermediate-pressure cold circulation nitrogen stream to form a combined intermediate-pressure cold circulation nitrogen stream, wherein the combined intermediate-pressure cold circulation nitrogen stream enters the precooling main heat exchanger, forming a first nitrogen mixed stream. 
     
     
         4 . The hydrogen liquefaction method of  claim 1  further comprising providing a low-pressure cold circulation nitrogen stream, wherein the low-pressure cold circulation nitrogen stream enters the precooling heat exchanger. 
     
     
         5 . The hydrogen liquefaction method of  claim 1 , wherein the intermediate temperature main heat exchanger and the cold temperature main heat exchanger are combined into an integrated cold temperature main heat exchanger.