Hydrogen Production by Solar Thermochemical Water-Splitting/Methane-Reforming Process

Author(s):  
Tatsuya Kodama ◽  
Yoshiyasu Kondoh ◽  
Atsushi Kiyama ◽  
Ken-Ich Shimizu

Two different routes of solar thermochemical hydrogen production are reviewed. One is two-step water splitting cycle by using a metal-oxide redox pair. The first step is based on the thermal reduction of metal oxide, which is a highly endothermic process driven by concentrated solar thermal energy. The second step involves water decomposition with the thermally-reduced metal oxide. The first thermal reduction process requires very-high temperatures, which may be realized in sun-belt regions. Another hydrogen production route is solar reforming of natural gas (methane), which can convert methane to hydrogen via calorie-upgrading by using concentrated solar thermal energy. Solar reforming is currently the most advanced solar thermochemical process in sun belt. There is also possibility for the solar reforming to be applied for worldwide solar concentrating facilities where direct insolation is weaker than that in sun belt. Our experimental studies to improve the relevant catalytic technologies are shown and discussed.

Author(s):  
Hiroshi Kaneko ◽  
Hideyuki Ishihara ◽  
Takao Miura ◽  
Hiromitsu Nakajima ◽  
Noriko Hasegawa ◽  
...  

CeO2-MOx (M = Mn, Fe, Ni, Cu) reactive ceramics, having high melting points and high conductivities of O2−, were synthesized with the combustion method from their nitrates for solar hydrogen production. The prepared CeO2-MOx samples were solid solutions between CeO2 and MOx with the fluorite structure through XRD. Two-step water splitting reactions with CeO2-MOx reactive ceramics proceeded at 1573–1773K for the O2 releasing step and at 1273K for the H2 generation step by irradiation of infrared imaging furnace as a solar simulator. The amounts of O2 evolved in the O2 releasing reaction with CeO2-MOx and CeO2 systems increased with the increase of the reaction temperature. The amounts of H2 evolved in the H2 generation reaction with CeO2-MOx systems except for M = Cu were more than that of CeO2 system after the O2 releasing reaction at the temperatures of 1673 and 1773K. The largest amount of H2 was generated with CeO2-NiO after the O2 releasing reaction at 1573, 1673 and 1773K. The O2 releasing reaction at 1673K and H2 generation reaction at 1273K with CeO2-Fe2O3 were repeated four times with the evolving of O2 (1.3cm3/g-sample) and H2 (2.3cm3/g-sample) gases, respectively. The possibility of solar hydrogen production with CeO2-MOx (M = Mn, Fe, Ni) reactive ceramics system by using concentrated solar thermal energy was suggested.


RSC Advances ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 12582-12597 ◽  
Author(s):  
Enkhbayar Shagdar ◽  
Bachirou Guene Lougou ◽  
Yong Shuai ◽  
Enkhjin Ganbold ◽  
Ogugua Paul Chinonso ◽  
...  

Integrating solar thermal energy into conventional SRM technology is a promising approach for low-carbon hydrogen production based on fossil fuel in near and midterm.


2008 ◽  
Vol 10 (5) ◽  
pp. 592 ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Afaf Abdel Hameed ◽  
Kamal Usef Sadek

2008 ◽  
Vol 19 (7) ◽  
pp. 788-790 ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Mohamed Abdallah Ameen ◽  
Kamal Usef Sadek

2007 ◽  
Vol 129 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Hongguang Jin ◽  
Jun Sui ◽  
Hui Hong ◽  
Zhifeng Wang ◽  
Danxing Zheng ◽  
...  

This paper manufactured an original middle-temperature solar receiver/reactor prototype, positioned along the focal line of one-axis parabolic trough concentrator, representing the development of a new kind of solar thermochemical technology. A 5kW prototype solar reactor at around 200–300°C, which is combined with a linear receiver, was originally manufactured. A basic principle of the design of the middle-temperature solar reactor is identified and described. A representative experiment of solar-driven methanol decomposition was carried out. Experimental tests were conducted from 200°C to 300°C under mean solar flux of 300–800W∕m2 and at a given methanol feeding rate of 2.1L∕h. The conversion of methanol decomposition yielded up to 50–95%, and the efficiency of solar thermal energy conversion to chemical energy reached 30–60%. The experimental results obtained here prove that the novel solar receiver/reactor prototype introduced in this paper can provide a promising approach to effectively utilize middle-temperature solar thermal energy by means of solar thermochemical processes.


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