Installation and method for the liquefaction of hydrogen

Abstract

The invention relates to an invention for the liquefaction of hydrogen, comprising a supply circuit for supplying hydrogen to be cooled, a plurality of heat exchangers arranged in heat exchange with the supply circuit, a first pre-cooling device, a second pre-cooling device and a cooling system in heat exchange with the set of exchangers, to reduce the temperature of the hydrogen to a temperature below the critical temperature of hydrogen, the first pre-cooling device comprising a refrigerator having a closed refrigeration cycle for a first cycle gas comprising at least three components, a first centrifugal compressor, a cooling member, three phase separators configured to separate the two-phase fluid, the refrigerator having a refrigeration cycle of the first pre-cooling device comprising a first expansion member configured to expand the liquid produced by one of the phase separators and to return this fluid to a first centrifugal compressor via a passage through a heat exchanger of the set of exchangers.

1 . An installation for the liquefaction of hydrogen, the installation comprising:
 a supply circuit ( 3 ) for supplying hydrogen to be cooled, having an upstream end designed to be connected to a source ( 2 ) of gaseous hydrogen under pressure at a first initial temperature and a downstream end ( 23 ) designed to be connected to at least one liquefied hydrogen collection member ( 30 );   a plurality of heat exchangers ( 4 ,  5 ,  6 ,  7 ,  17 ) arranged in series in heat exchange with the supply circuit ( 3 );   a first pre-cooling device ( 8 ) in heat exchange with a first set ( 4 ,  5 ) of the heat exchanger(s), the first pre-cooling device ( 8 ) being configured to reduce the temperature of the hydrogen from the first initial temperature to a second temperature, which is below the first initial temperature, and is between 120 K and 163 K;   a second pre-cooling device ( 9 ) in heat exchange with a second set ( 4 ,  5 ,  6 ) of the heat exchangers, the second pre-cooling device being configured to reduce the temperature of the hydrogen from the second temperature to a third temperature, which is below the second temperature, and is between 103 K and 80 K,   a cooling system ( 10 ) in heat exchange with a third set ( 4 ,  5 ,  6 ,  7 ,  17 ) of the heat exchangers, the cooling system being configured to reduce the temperature of the hydrogen from the third temperature to a fourth temperature below the critical temperature of the hydrogen,   wherein the second pre-cooling device ( 9 ) comprises a second refrigeration cycle for a second cycle gas consisting of nitrogen,   wherein the first pre-cooling device ( 8 ) comprises a closed refrigeration cycle for a first cycle gas comprising at least three components including at least one first component that is more volatile than at least one second component, the at least one second component being more volatile than at least one third component,   wherein the second refrigeration cycle of the first pre-cooling device ( 8 ) comprises:
 a first centrifugal compressor ( 18 ) for the first cycle gas; 
 a cooling member ( 180 ) for the compressed first cycle gas configured to produce a two-phase fluid; 
 a first phase separator ( 28 ) configured to separate the two-phase fluid; 
 a pair of second compression members ( 38 ,  58 ) configured to compress a gas and liquid from the first phase separator ( 28 ); 
 a second phase separator ( 48 ) configured to separate the two-phase fluid produced by the pair of second compression members ( 38 ,  58 ); 
 a first duct ( 68 ) in heat exchange with the first set ( 4 ,  5 ) of the heat exchangers and configured to cool and partially condense gas produced by the second phase separator ( 48 ) and to transfer this partially condensed gas to a third phase separator ( 88 ); 
 a first expansion member ( 78 ) configured to expand a liquid produced by the second phase separator ( 48 ); 
 a fourth phase separator ( 108 ) configured to recover the liquid produced by the second phase separator ( 48 ) and expanded by the first expansion member ( 78 ) and to be additionally supplied with a liquid produced by the third phase separator ( 88 ); and 
 a return passage configured to transfer fluid from the fourth phase separator through the first set of heat exchangers and into an inlet of the first centrifugal compressor ( 18 ). 
   
     
     
         2 . The installation according to  claim 1 , wherein the refrigerator having a refrigeration cycle of the first pre-cooling device ( 8 ) comprises a fifth phase separator ( 118 ), configured to receive the gas produced by the third phase separator ( 88 ) of the refrigerator and expanded in an expansion member ( 128 ) of the refrigerator of the first pre-cooling device ( 8 ). 
     
     
         3 . The installation according to  claim 1 , wherein the first cycle gas consists of a mixture of three to six components chosen from among nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, and pentane. 
     
     
         4 . The installation according to  claim 1 , wherein the refrigerator of the second pre-cooling device ( 9 ) comprises, arranged in a cycle circuit, at least two centrifugal compressors ( 19 ) in series, configured to compress the second cycle gas, at least one expansion turbine ( 29 ) of the second cycle gas coupled to a rotating shaft which is preferably also coupled to one of the compressors ( 19 ), the cycle circuit further comprising a thermosiphon device comprising a phase separator reservoir ( 39 ) configured to receive at least one flow of the second cycle gas expanded by the at least one expansion turbine ( 29 ) and to return cycle gas to the compressors ( 19 ). 
     
     
         5 . A method for the liquefaction of hydrogen, the method comprising the following steps:
 providing the installation according to  claim 1 ;   cooling a flow of hydrogen, having a pressure of at least 20 bars abs and a first initial temperature, to a second temperature of 163 K or below in the first set of heat exchanger(s);   cooling the hydrogen flow from the second temperature to the third temperature of 103 K or below, in the second set of heat exchangers;   cooling the hydrogen flow from the third temperature to a temperature below the critical temperature of hydrogen in a third set of heat exchangers, and liquefying the hydrogen flow cooled to the temperature below the critical temperature in order to obtain a flow of liquid hydrogen,   wherein the closed refrigeration cycle of the first pre-cooling device comprises the steps of:
 compressing the first cycle gas from a pressure of between 1.1 bara and 10 bara to a pressure of between 7 and 30 bara; 
 cooling the first cycle gas to form a two-phase fluid; 
 separating the two-phase fluid in a first phase separator; 
 compressing a gas from the first phase separator in a second centrifugal compressor, and pressurizing a liquid from the first phase separator to a pressure of between 25 bara and 70 bara; 
 sending the compressed gas and the pressurized liquid to a second phase separator, and separation of the compressed gas and the pressurized liquid in the second phase separator to form a second gas and a second liquid; 
 cooling of the second gas in the first set of heat exchangers to at least the second temperature, in order to condense the second gas partially; 
 sending the partially condensed gas to a third phase separator to form a third gas and a third liquid; 
 cooling and expanding the second liquid via a valve or a turbine to form an expanded fluid; and 
 introducing the expanded fluid and the third liquid from the third phase separator to the fourth phase separator; and 
 withdrawing a fluid from the fourth phase separator and heating the fluid in the first set of heat exchangers before returning the fluid to the inlet of the centrifugal compressor as part of the first cycle gas. 
   
     
     
         6 . The method according to  claim 5 , wherein the installation uses a fifth phase separator to receive the third gas produced by the third phase separator following expansion in a second valve or a second turbine. 
     
     
         7 . The method according to  claim 5 , wherein the first cycle gas comprises a mixture of three to six components chosen from among nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, and pentane. 
     
     
         8 . The method according to  claim 5 , wherein the first cycle gas comprises a mixture composed of at least one light component chosen from the group of: nitrogen and methane, at least one medium component chosen from the group of: ethane, ethylene, propane, propene, butane, butene, and at least one heavy component which is pentane, or butane if the medium component is chosen from the group of: ethane, ethylene, propane, and propene. 
     
     
         9 . The method according to  claim 8 , wherein the first cycle gas comprises, in moles, between 10% and 50% light component(s), between 30% and 70% medium component(s) and 10% and 35% heavy component(s), the total being equal to 100%. 
     
     
         10 . The method according to  claim 5 , wherein the cooling of the hydrogen flow from the second temperature to the third temperature comprises a cooling of the hydrogen flow to an intermediate temperature of between 113 K and 153 K, at which the hydrogen flow is sent to an adsorption purification unit operating at a cryogenic temperature, and then, if necessary, to a catalytic conversion unit for converting ortho hydrogen to para hydrogen, in order to produce a hydrogen flow having a para hydrogen content of between 30% and 55% before being re-cooled. 
     
     
         11 . The method according to  claim 5 , wherein the method comprises producing of pre-cooling power by the second pre-cooling device with the following steps: centrifugal compression of the second cycle gas in at least two compressors arranged in series, from an inlet pressure of between 1 and 5 bara to a pressure of between 10 and 50 bara, and expansion of the compressed second cycle gas at a temperature of between 173 K and 128 K in at least one valve or turbine to a pressure of between 1.1 and 2 bara, at least one expansion turbine providing mechanical work if necessary for driving at least one compressor. 
     
     
         12 . The method according to  claim 11 , wherein the production of pre-cooling power by the second pre-cooling device comprises a transfer of the expanded second cycle gas to a phase separator reservoir of a thermosiphon device and a return of the second cycle gas from the reservoir to an intake of the two compressors. 
     
     
         13 . The method according to  claim 11 , wherein the expansion of the compressed second cycle gas to a pressure of between 1.1 and 2 bara is carried out in two expansion turbines in series, a pressure of the second cycle gas entering a first of the turbines being between 15 and 50 bara, a temperature of the second cycle gas entering a second of the turbines being between 143 K and 103 K. 
     
     
         14 . The method according to  claim 5 , wherein the first cycle gas consists of a mixture of three components: CH4, C2H6 or C3H8, C5H10. 
     
     
         15 . The method according to  claim 5 , wherein the first cycle gas consists of, expressed in moles, 53% CH4, 41% C3H8, 6% C5H10. 
     
     
         16 . The method according to  claim 5 , wherein the first cycle gas consists of a mixture of four components from among: CH4 and/or N2, C2H6 and/or C3H8, C5H10, expressed in moles as 49% CH4, 11% C2H6, 31% C3H8 and 9% C5H10. 
     
     
         17 . The method according to  claim 5 , wherein the first cycle gas consists of a mixture of CH4, C2H4, C3H8 and C5H12, in respective proportions in moles of 24%, 39%, 22%, and 15%, or in respective proportions in moles of 6%, 33%, 26%, 35%. 
     
     
         18 . The method according to  claim 5 , wherein the first cycle gas consists of a mixture of five components: N2; CH4, C2H6; C3H8; C5H10, in respective proportions in moles of 3%; 37%, 32%, 13% and 14% or in respective proportions in moles of 3%, 31%, 34%, 18%, 14%, or in respective proportions in moles of 3%, 33%, 37%, 13%, and 14%. 
     
     
         19 . The method according to  claim 5 , wherein a cut-off temperature between the first pre-cooling device and the second pre-cooling device, which is the temperature of the hydrogen flow between these two pre-cooling portions, is between 148 K and 123 K. 
     
     
         20 . The method according to  claim 5 , wherein a cut-off temperature between the second pre-cooling device and the cooling system, which is the temperature of the hydrogen flow between these two pre-cooling portions, is between 93 K and 73 K.