Hydrogen production system and a method for producing hydrogen

PROBLEM TO BE SOLVED: To reduce energy which is invested in separation and recovery of COperformed accompanying hydrogen production.SOLUTION: A hydrogen production device 1 comprises: a reformer 3; a heating device 4 for heating the reformer 3; a transformer 6; a hydrogen separation device 8 for separating and taking out hydrogen from transformed gas; a COseparation device 22 for separating and taking out COfrom off gas from which hydrogen has been separated by the hydrogen separation device 8; a heat recovery device 11 for recovering heats of reformed gas and transformed gas, and exhaust heat from the heating device 4; and a heat medium supply device 21 for supplying a heat medium which absorbs heat recovered by the heat recovery device 11 to the COseparation device 22. The COseparation device 22 comprises: an absorption processing part 24 for causing an absorption liquid to absorb COcontained in the off gas; and a heating part 73 for heating the absorption liquid which has absorbed CO, using heat of the heat medium supplied from the heat medium supply device 21, for causing the absorption liquid which has absorbed COto release COand taking out it.SELECTED DRAWING: Figure 1