Patent ID: 7332146

Claim:
A cryogenic method for hydrogen cryogenic liquefaction and hydrogen separation for liquid hydrogen (LH 2 ) production comprising the steps of: (a) producing a hydrogen rich gas mixture containing H 2 , CO, CO 2 , CH 4 , H 2 O and trace amounts of hydrocarbons; (b) cryogenically separating the gas mixture of step (a) resulting in H 2 O, and liquid carbon dioxide (LCO 2 ); (c) separating low temperature gaseous H 2 and gas mixture of CO and CH 4 ; (d) recycling the CO and CH 4 of the gas mixture to further produce hydrogen rich gas; (e) mixing the hydrogen rich gas from step (d) with the hydrogen rich gas mixture in step (a) to form a closed loop for CO and CH 4 gas mixture; (f) further cooling the low-temperature gaseous hydrogen until it is liquefied; and (g) producing LH 2 without CO 2 emission.