System and Method for Cooling Fluids Containing Hydrogen or Helium

Abstract

A system for cooling a feed stream including hydrogen or helium with a mixed refrigerant includes a pre-cooling heat exchanger. A compression system has an inlet in fluid communication with the pre-cooling heat exchanger and receives and increases a pressure of a refrigerant vapor stream including hydrogen and/or helium mixed with at least one other refrigerant such that the molecular weight of the mixture is greater than 6 kg/kgmol. The compression system has an outlet in fluid communication with the pre-cooling heat exchanger. A first refrigerant separation device receives fluid from the pre-cooling heat exchanger and has a liquid outlet in fluid communication with the pre-cooling heat exchanger and a vapor outlet. A refrigerant purifier has a purifier inlet in fluid communication with the vapor outlet of the first refrigerant separation device and an outlet in fluid communication with the pre-cooling heat exchanger.

What is claimed is: 
     
         1 . A system for cooling a feed stream including hydrogen or helium with a mixed refrigerant comprising:
 a. a pre-cooling heat exchanger having a feed stream cooling passage, a first refrigerant cooling passage, a second refrigerant cooling passage and a refrigerant warming passage;   b. a compression system having an inlet in fluid communication with the refrigerant warming passage and configured to receive and increase a pressure of a refrigerant vapor stream comprised of hydrogen and/or helium mixed with at least one other refrigerant such that the molecular weight of the mixture is greater than 6 kg/kgmol., said compression system having an outlet in fluid communication with the first refrigerant cooling passage;   c. a first refrigerant separation device configured to receive fluid from the first refrigerant cooling passage in the pre-cooling heat exchanger, said first refrigeration separation device having a liquid outlet in fluid communication with the refrigerant warming passage and a vapor outlet;   d. a refrigerant purifier having a purifier inlet in fluid communication with the vapor outlet of the first refrigerant separation device and an outlet in fluid communication with the second refrigerant cooling passage, said second refrigerant cooling passage having an outlet in fluid communication with the refrigerant warming passage.   
     
     
         2 . The system of  claim 1  wherein the compression system includes a first interstage compressor having an inlet in fluid communication with the refrigerant warming passage and an outlet, a first interstage aftercooler having an inlet configured to receive fluid from the first interstage compressor and an outlet, a high-pressure accumulator having an inlet in fluid communication with the first interstage aftercooler outlet, said high-pressure accumulator having a vapor outlet and a liquid outlet, said vapor outlet in fluid communication with the first refrigerant cooling passage and said liquid outlet in fluid communication with the compression system. 
     
     
         3 . The system of  claim 2  further comprising an interstage separation device having an inlet in fluid communication with the first interstage aftercooler outlet having a vapor outlet in fluid communication with the high-pressure accumulator and a liquid outlet in fluid communication with the compression system. 
     
     
         4 . The system of  claim 3  wherein the refrigerant warming passage includes a low-pressure refrigerant warming passage and an intermediate-pressure refrigerant warming passage and wherein the compression system includes a mixed gas compressor having an inlet configured to receive fluid from the low-pressure refrigerant warming passage, a mixed gas aftercooler having an inlet configured to receive fluid from the mixed gas compressor, a mixing device having a first inlet configured to receive fluid from the mixed gas aftercooler, a second inlet configured to receive fluid from the intermediate-pressure refrigerant warming passage, a third inlet, a mixing device vapor outlet in fluid communication with the first interstage compressor, a second interstage compressor configured to receive fluid from the vapor outlet of the interstage separation device, a second interstage aftercooler configured to receive fluid from the second interstage compressor and to direct fluid to the high-pressure accumulator,
 and further comprising a simultaneous heat and mass transfer control system which maintains control of a composition and thermal properties of a mixed refrigerant vapor exiting the mixing device vapor outlet, said simultaneous heat and mass transfer control system including at least one of:
 i) a mixing vessel valve having a valve inlet configured to receive fluid from the interstage separation device liquid outlet and the high pressure accumulator liquid outlet and a valve outlet configured to direct fluid to the third inlet of the mixing device when the mixing vessel valve is open; 
 ii) the mixed gas aftercooler; and/or 
 iii) the first and/or second interstage aftercooler. 
 
 
     
     
         5 . The system of  claim 4  wherein the mixing device includes a liquid outlet in fluid communication with the low-pressure refrigerant warming passage and/or the intermediate-pressure refrigerant warming passage. 
     
     
         6 . The system of  claim 5  further comprising a pump having a pump inlet in fluid communication with the mixing device liquid outlet and a pump outlet in fluid communication with the low-pressure refrigerant warming passage and/or the intermediate-pressure refrigerant warming passage, said pump being included in the simultaneous heat and mass transfer control system. 
     
     
         7 . The system of  claim 4  wherein the mixing device contains a heating coil and the heating coil is included in the simultaneous heat and mass transfer control system. 
     
     
         8 . The system of  claim 1  in which the refrigerant purifier is selected from the group consisting of an adsorbent, a freeze-out device, and a distillation column. 
     
     
         9 . The system of  claim 1  in which a first refrigerant purifier regeneration stream is recycled to the compression system. 
     
     
         10 . The system of  claim 9  in which a second refrigerant purifier regeneration stream is removed from the liquefaction process by rejecting it or recycling it upstream of the feed stream cooling passage of the pre-cooling heat exchanger. 
     
     
         11 . The system of  claim 1  in which the pre-cooling heat exchanger has at least one supplemental refrigerant cooling passage and at least one supplemental refrigerant warming passage. 
     
     
         12 . The system of  claim 11  in which at least a portion of the supplemental refrigerant is used to provide refrigeration to an outside process or system. 
     
     
         13 . The system of  claim 1  in which the feed stream and the mixed refrigerant are purified in a combined purifier and the resulting purifier product is split with a portion of the purifier product being directed to the feed stream cooling passage and another portion being directed to the compression system. 
     
     
         14 . The system of  claim 1  further comprising an insulating cold box having an interior and an exterior wherein the pre-cooling heat exchanger is positioned within the interior of the cold box and the compression system is positioned exterior to the cold box. 
     
     
         15 . The system of  claim 1  further comprising a primary refrigerant expansion device operating below ambient temperature, said primary refrigerant expansion device configured to receive primary refrigerant from the liquid outlet of the first refrigerant separation device, reduce temperature and pressure of the received primary refrigerant so that an expanded primary refrigerant is provided and to direct the expanded primary refrigerant to the refrigerant warming passage. 
     
     
         16 . A method for liquefying a feed stream containing hydrogen or helium comprising the steps of:
 a. mixing a hydrogen or helium refrigerant with at least one additional refrigerant component having a higher molecular weight than hydrogen or helium to form a mixed refrigerant having a molecular weight of at least 6 kg/kgmol;   b. compressing the mixed refrigerant using a compression system that contains at least one dynamic compressor or dynamic compressor stage;   c. separating the at least one additional refrigerant component from the hydrogen or helium refrigerant at a temperature of at least 75 K to obtain a remaining hydrogen or helium refrigerant;   d. cooling the hydrogen or helium feed stream using the remaining hydrogen or helium refrigerant to produce a liquid hydrogen or helium product from the feed stream containing hydrogen or helium.   
     
     
         17 . The method of  claim 16  wherein the at least one additional refrigerant component is selected from the group consisting of hydrocarbons, partially fluorinated hydrocarbons, and fully fluorinated hydrocarbons that contain at least three carbon atoms or neon. 
     
     
         18 . The method of  claim 16  wherein step c. is accomplished using partial condensation and adsorption. 
     
     
         19 . The method of  claim 16  wherein step c. is accomplished using partial condensation and at least two adsorption steps operating at different temperatures in which the at least one additional component is removed at a first temperature and impurities in the feed stream containing hydrogen or helium are removed at a second temperature that is a lower temperature than the first temperature and further comprising the step of expelling the removed impurities. 
     
     
         20 . The method of  claim 16  further comprising the step of providing refrigeration to the feed stream containing hydrogen or helium in a heat exchanger using the at least one additional refrigerant component separated in step c. 
     
     
         21 . The method of  claim 20  further comprising the step of exporting refrigeration provided by the at least one additional refrigerant out of the heat exchanger to a second process. 
     
     
         22 . The method of  claim 21  in which refrigeration provided by the at least one additional refrigerant is exported out of the heat exchanger using a supplemental refrigerant stream below ambient temperature. 
     
     
         23 . The method of  claim 20  in which the step of providing refrigeration to the feed stream containing hydrogen or helium in a heat exchanger using the at least one additional refrigerant component separated in step c includes removing a two-phase stream from the heat exchanger. 
     
     
         24 . The method of  claim 16  wherein the step of cooling the hydrogen or helium feed stream is performed within a heat exchanger positioned within a cold box and the step of compressing the mixed refrigerant using a compression system is performed exterior to the cold box. 
     
     
         25 . A system for cooling a cryogenic fluid feed stream including hydrogen or helium with a mixed refrigerant comprising:
 a. a pre-cooling heat exchanger having a pre-cool feed stream cooling passage, a low-pressure refrigerant warming passage, an intermediate-pressure refrigerant warming passage, a first refrigerant cooling passage and a second refrigerant cooling passage;   b. a mixed gas compressor configured to receive a mixed refrigerant vapor stream from the low-pressure refrigerant warming passage;   c. a mixed gas aftercooler in fluid communication with the mixed gas compressor;   d. a mixing device having a first inlet in fluid communication with the mixed gas aftercooler, a second inlet and a mixing device vapor outlet, said second inlet configured to receive a mixed refrigerant vapor stream from the intermediate-pressure refrigerant warming passage;   e. a first interstage compressor in fluid communication with the mixing device vapor outlet;   f. a first interstage aftercooler in fluid communication with the first interstage compressor;   g. a high-pressure accumulator in fluid communication with the first interstage aftercooler and having a high-pressure accumulator vapor outlet and a high-pressure accumulator liquid outlet, said high-pressure accumulator vapor outlet in fluid communication with the first refrigerant cooling passage and said high-pressure accumulator liquid outlet in fluid communication with the intermediate-pressure refrigerant warming passage;   h. a first refrigerant separation device in fluid communication with the first refrigerant cooling passage and having a first refrigerant separation device liquid outlet in fluid communication with the low-pressure refrigerant warming passage and a first refrigerant separation device vapor outlet in fluid communication with the second refrigerant cooling passage;   i. a second refrigerant separation device in fluid communication with the second refrigerant cooling passage and having a second refrigerant separation device liquid outlet in fluid communication with the low-pressure refrigerant warming passage and a second refrigerant separation device vapor outlet;   j. a refrigerant purifier having a purifier inlet in fluid communication with the second refrigerant separation device vapor outlet and a purifier outlet where the purifier outlet is in fluid communication with the low-pressure refrigerant warming passage and the intermediate-pressure refrigerant warming passage.   
     
     
         26 . The system of  claim 25  further comprising:
 k. a liquefaction heat exchanger having a liquefaction feed stream cooling passage configured to receive a pre-cooled feed stream from the pre-cool feed stream cooling passage, a liquefaction low-pressure refrigerant warming passage configured to direct refrigerant to the low-pressure refrigerant warming passage of the pre-cooling heat exchanger, a liquefaction intermediate-pressure refrigerant warming passage configured to direct refrigerant to the intermediate-pressure refrigerant warming passage of the pre-cooling heat exchanger, a third refrigerant cooling passage in fluid communication with the purifier outlet and a fourth refrigerant cooling passage configured to receive a first refrigerant portion from the third refrigerant cooling passage; 
 l. a first expansion device configured to receive a second refrigerant portion from the third refrigerant cooling passage and direct an expanded second refrigerant portion to the liquefaction intermediate-pressure refrigerant warming passage; 
 m. a second expansion device configured to receive a cooled first refrigerant portion from the fourth refrigerant cooling passage and to direct an expanded cooled first refrigerant portion to the liquefaction low-pressure refrigerant warming passage. 
 
     
     
         27 . The system of  claim 26  wherein the liquefaction heat exchanger includes a first liquefaction heat exchanger including the third refrigerant cooling passage and a second liquefaction heat exchanger including the fourth refrigerant cooling passage and wherein the liquefaction feed stream cooling passage, the liquefaction low-pressure refrigerant warming passage and the liquefaction intermediate-pressure refrigerant warming passage pass through both the first and second liquefaction heat exchangers. 
     
     
         28 . The system of  claim 26  further comprising a recycle passage running through the liquefaction heat exchanger and the pre-cool heat exchanger and further comprising a product expansion device and a product separation device, said product expansion device configured to receive a liquid product stream from the liquefaction feed stream cooling passage and direct a resulting expanded product fluid stream to the product separation device, said product separation device having a product separation device vapor outlet in fluid communication with the recycle passage and a product separation device liquid outlet. 
     
     
         29 . The system of  claim 25  further comprising a refrigerant expansion device having an inlet in fluid communication with the liquid outlet of the high-pressure accumulator and an outlet in fluid communication with the intermediate-pressure refrigerant warming passage. 
     
     
         30 . The system of  claim 25  wherein the mixing device contain a sparger and/or a heating coil. 
     
     
         31 . The system of  claim 25  wherein the pre-cooling heat exchanger further includes a first supplemental refrigerant warming passage, a second supplemental refrigerant warming passage and a supplemental refrigerant cooling passage and further comprising:
 k. a first supplemental refrigerant compressor configured to receive a first supplemental refrigerant vapor stream from the first supplemental refrigerant warming passage; 
 l. a first supplemental aftercooler in fluid communication with the first supplemental refrigerant compressor; 
 m. a second supplemental refrigerant compressor in fluid communication with the first supplemental after cooler and configured to receive a second supplemental refrigerant vapor stream from the second supplemental refrigerant warming passage; 
 n. a second supplemental aftercooler in fluid communication with the second supplemental refrigerant compressor, said second supplemental aftercooler having a second supplemental aftercooler outlet configured to direct fluid to the supplemental refrigerant cooling passage; 
 o. a third expansion device having a third expansion device inlet in fluid communication with the supplemental refrigerant cooling passage and a third expansion device outlet in fluid communication with the second supplemental refrigerant warming passage; 
 p. a fourth expansion device having a fourth expansion device inlet in fluid communication with the supplemental refrigerant cooling passage and a fourth expansion device outlet in fluid communication with the first supplemental refrigerant warming passage. 
 
     
     
         32 . The system of  claim 25  wherein the mixed gas compressor and the first interstage compressor are dynamic compressors or stages of a dynamic compressor. 
     
     
         33 . The system of  claim 25  wherein said mixing device includes a mixing device liquid outlet and further comprising:
 k. an interstage separation device in fluid communication with the first interstage compressor and having an interstage separation device vapor outlet and an interstage separation device liquid outlet; 
 l. a second interstage compressor in fluid communication with the interstage separation device vapor outlet; 
 m. a second interstage aftercooler having an inlet in fluid communication with the second interstage compressor and an outlet in fluid communication with the high-pressure accumulator; 
 n. said mixing device liquid outlet, said interstage separation device liquid outlet and said high-pressure accumulator liquid outlet configured to combine liquid exiting the mixing device, the interstage separation device and the high-pressure accumulator so that a combined refrigerant liquid stream is formed and directed to the low-pressure refrigerant warming passage and the intermediate-pressure refrigerant warming passage. 
 
     
     
         34 . The system of  claim 33  wherein the pre-cool heat exchanger includes a combined refrigerant liquid stream cooling passage and wherein the combined refrigerant liquid stream is cooled in the combined refrigerant liquid stream cooling passage prior to being directed to the low-pressure refrigerant warming passage. 
     
     
         35 . The system of  claim 33  wherein the mixed gas compressor, the first interstage compressor and the second interstage compressor are dynamic compressors or stages of a dynamic compressor. 
     
     
         36 . The system of  claim 25  wherein the first refrigerant separation device liquid outlet is also in fluid communication with the intermediate-pressure refrigerant warming passage. 
     
     
         37 . The system of  claim 36  further comprising a fifth expansion device configured to receive fluid from the first refrigerant separation device liquid outlet and direct expanded fluid to the intermediate-pressure refrigerant warming passage and a sixth expansion device configured to receive fluid from the first refrigerant separation device liquid outlet and direct expanded fluid to the low-pressure refrigerant warming passage.’ 
     
     
         38 . The system of  claim 25  further comprising a refrigerant purifier line in fluid communication with the refrigerant purifier and the mixed gas compressor and configured so that a refrigerant purifier regeneration stream is recycled from the refrigerant purifier to the compression system. 
     
     
         39 . The system of  claim 25  wherein the pre-cooling heat exchanger further includes a supplemental refrigerant warming passage and a supplemental refrigerant cooling passage and further comprising:
 k. a supplemental refrigerant compressor configured to receive a first supplemental refrigerant vapor stream from the supplemental refrigerant warming passage; 
 l. a supplemental aftercooler having an inlet in fluid communication with the supplemental refrigerant compressor and an outlet in fluid communication with the supplemental refrigerant cooling passage; 
 m. a third expansion device having an inlet in fluid communication with the supplemental refrigerant cooling passage and a third expansion device outlet in fluid communication with the supplemental refrigerant warming passage. 
 
     
     
         40 . The system of  claim 39  wherein the mixed gas compressor, the first interstage compressor and the supplemental refrigerant compressor are dynamic compressors or stages of a single dynamic compressor. 
     
     
         41 . The system of  claim 25  in which the refrigerant purifier is selected from the group consisting of an adsorbent, a freeze-out device, and a distillation column. 
     
     
         42 . The system of  claim 25  in which the refrigerant purifier is a freeze-out device. 
     
     
         43 . The system of  claim 42  further comprising a refrigerant purifier line in fluid communication with the freeze-out device and the mixed gas compressor and configured so that a refrigerant purifier regeneration stream is recycled from the freeze-out device to the compression system. 
     
     
         44 . The system of  claim 42  wherein the refrigerant purifier is a purifier heat exchanger. 
     
     
         45 . The system of  claim 44  in which the purifier heat exchanger is a brazed aluminum heat exchanger or a tubular heat exchanger. 
     
     
         46 . The system of  claim 44  wherein the purifier heat exchanger includes a filter configured to capture frozen high molecular weigh substances. 
     
     
         47 . The system of  claim 25  wherein the refrigerant purifier is a first refrigerant purifier having a first refrigerant purifier outlet, and further comprising a second refrigerant purifier having a second refrigerant purifier inlet in fluid communication with the first refrigerant purifier outlet, wherein the first refrigerant purifier is configured to remove higher molecular weight impurities with boiling points above 80 K and the second refrigerant purifier is configured to remove lighter molecular weight impurities. 
     
     
         48 . The system of  claim 47  wherein the higher molecular weight impurities include hydrocarbons and the lighter molecular weight impurities include nitrogen and/or argon. 
     
     
         49 . The system of  claim 48  further comprising a refrigerant purifier line in fluid communication with the first refrigerant purifier and the mixed gas compressor and configured so that a refrigerant purifier regeneration stream including the higher molecular weight impurities is recycled from the freeze-out device to the compression system. 
     
     
         50 . The system of  claim 49  wherein the second refrigerant purifier is configured to vent the lighter molecular weight impurities to atmosphere. 
     
     
         51 . The system of  claim 47  further comprising a purified refrigerant cooling passage in the pre-cooling heat exchanger configured to receive fluid from the first refrigerant purifier outlet and to direct cooled fluid to the second refrigerant purifier inlet. 
     
     
         52 . The system of  claim 25  wherein the refrigerant purifier is configured to remove nitrogen and/or argon impurities and hydrocarbon impurities from a refrigerant stream. 
     
     
         53 . The system of  claim 52  further comprising a refrigerant purifier line in fluid communication with the refrigerant purifier and the mixed gas compressor and configured so that a refrigerant purifier regeneration stream including nitrogen and/or argon impurities and hydrocarbon impurities is recycled from the freeze-out device to the compression system.