• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.559-567
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• 2011

This paper deals with an economic evaluation of domestic low-temperature water electrolysis hydrogen production. We evaluate the economic feasibility of on-site hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ by the alkaline and the polymer electrolyte membrane water electrolysis. The hydrogen production prices of the alkaline water electrolysis, the polymer electrolyte membrane water electrolysis, and the steam methane reforming hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ were estimated as 18,403 $won/kgH_2$, 22,945 $won/kgH_2$, 21,412 $won/kgH_2$, respectively. Domestic alkaline water electrolysis hydrogen production is evaluated as economical for small on-site hydrogen fueling stations, and we need to further study the economic evaluation of low-temperature water electrolysis hydrogen production for medium and large scale on-site hydrogen fueling stations.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.155-162
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• 2018

In this paper, the reliability of the numerical analysis using the two phase flow on the behavior of the hydrogen bubbles in the alkali electrolysis stacks was investigated by comparing the results obtained from numerical analysis and flow visualization experiments. As the results, through comparison with results gotten to visualization experiments, it is possible to approximate analysis for the flow of hydrogen bubbles in the stacks by numerical analysis using the two-phase flow. Also, the flow of hydrogen bubbles around the electrodes could be similarly analyzed by numerical analysis using the two-phase flow.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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• pp.121-128
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• 2017

For an investigation on the effect of the shape of electrodes in alkaline water electrolysis, two kinds of stack with circular and square electrode array are used to visualize both for behaviors of hydrogen bubble around the electrodes and for measurements of hydrogen production from these two stacks. The electrolytes for the hydrogen production experiment were applied for 20 wt%, 25 wt%, 30 wt% and 35 wt% of KOH alkaline aqueous solutions. As a result, the adhesion length of bubbles attached around the square electrode in the visualization experiment was found to be 1.7 times longer compared with the attached around the circular electrode. In the hydrogen production experiments, the volume of hydrogen production of the stack by using circular electrode array was approximately 3% more than that of the stack with square electrode array. These observations may be caused by the effect of the bubbles attached to the around the electrodes obstructing mass transfer such as hydrogen exhaust and electrolyte supply.