Process for producing liquid hydrogen

Abstract

The invention relates to an integrated process for continuous production of liquid hydrogen, comprising (a) producing gaseous hydrogen by electrolysis; and (b) liquefying said gaseous hydrogen in a hydrogen liquefaction unit, which liquefaction unit is powered by energy essentially from renewable sources; and, (c) when additional power is needed, using electrical energy generated in a process in which electrical energy and hydrogen are co-generated by an integrated electrolysis process comprising: (d) electrolysing a metal salt or mixture of metal salts and water into the corresponding metal or metals, acid or acids, and oxygen (electricity storage phase), and (e) producing gaseous hydrogen and recovering electricity in a regeneration reaction of the metal (s) and acid(s) of step (d) (regeneration phase); wherein at least part of the gaseous hydrogen generated in step (e) is used in step (b) of the process.

1 . An integrated process for continuous production of liquid hydrogen, comprising: (a) producing gaseous hydrogen by electrolysis; (b) liquefying said gaseous hydrogen in a hydrogen liquefaction unit, which liquefaction unit is powered by energy essentially from renewable sources; and, (c) when additional power is needed, using electrical energy generated in a process in which electrical energy and hydrogen are co-generated by an integrated electrolysis process comprising:
 (d) electrolysing a metal salt or mixture of metal salts and water into the corresponding metal or metals, acid or acids, and oxygen (electricity storage phase), and   (e) producing gaseous hydrogen and recovering electricity in a regeneration reaction of the metal(s) and acid(s) of step (d) (regeneration phase);   
       wherein at least part of the gaseous hydrogen generated in step (e) is used in step (b) of the process. 
     
     
         2 . The process of  claim 1 , wherein the metal salt or mixture of metal salt is/are selected from ZnSO 4 , MgSO 4 , and/or MgCl 2 , and the like. 
     
     
         3 . The process of  claim 2 , wherein the metal salt is ZnSO 4 . 
     
     
         4 . The process of  claim 1 , wherein the hydrogen and electricity products of step (e) are individually produced as needed “on-demand”. 
     
     
         5 . The process of  claim 1 , wherein additional sources of electricity supply are used as back-up when the renewable power source is not available and/or electricity regenerated in step (e) is not enough. 
     
     
         6 . The process of  claim 1 , wherein gaseous hydrogen is stored after step (e) and before liquefying the hydrogen. 
     
     
         7 . An integrated system for continuously producing liquid hydrogen, comprising an energy inlet for feeding energy from renewable sources into an electrolysis system for co-generation of electrical energy and hydrogen, which comprises an energy storage part and a regeneration part, wherein the regeneration part of the electrolysis system has an outlet for hydrogen that is connected to a hydrogen liquefaction unit and wherein the regeneration part of the electrolysis system has an outlet for electricity produced in the electrolysis system that is connected to an energy inlet into the hydrogen liquefaction unit for power supply. 
     
     
         8 . The integrated system of  claim 7 , further comprising a hydrogen storage unit for intermittent storage of gaseous hydrogen. 
     
     
         9 . The integrated system of  claim 7 , further comprising a battery for storage of power, 
     
     
         10 . The process of  claim 2 , wherein the hydrogen and electricity products of step (e) are individually produced as needed “on-demand”. 
     
     
         11 . The process of  claim 2 , wherein additional sources of electricity supply are used as back-up when the renewable power source is not available and/or electricity regenerated in step (e) is not enough. 
     
     
         12 . The process of  claim 2 , wherein gaseous hydrogen is stored after step (e) and before liquefying the hydrogen. 
     
     
         13 . The process of  claim 3 , wherein the hydrogen and electricity products of step (e) are individually produced as needed “on-demand”. 
     
     
         14 . The process of  claim 3 , wherein additional sources of electricity supply are used as back-up when the renewable power source is not available and/or electricity regenerated in step (e) is not enough. 
     
     
         15 . The process of  claim 3 , wherein gaseous hydrogen is stored after step (e) and before liquefying the hydrogen.