Synthesis of Cu/Fe/Ti/Al 2 O 3 Composite Granules for SO 3 Decomposition in SI Cycle
- PDF / 315,882 Bytes
- 5 Pages / 595.276 x 790.866 pts Page_size
- 79 Downloads / 180 Views
Synthesis of Cu/Fe/Ti/Al2O3 Composite Granules for SO3 Decomposition in SI Cycle Bhari Mallanna Nagaraja Æ Kwang Deog Jung Æ Kye Sang Yoo
Received: 17 August 2008 / Accepted: 22 October 2008 / Published online: 11 November 2008 Ó Springer Science+Business Media, LLC 2008
Abstract The present paper deals with the catalytic decomposition of SO3 reaction. Cu/Fe/Ti/Al2O3 composite granule catalysts prepared by a combination of Yoldas process and oil-drop method were studied in an attempt to find some suitable catalysts for the decomposition of sulfur trioxide as the oxygen-generating reaction in the thermochemical water splitting process. CuFe/Ti:Al-1:2 shows high SO3 conversion (69%) at 800 °C compared with other catalysts because of the high surface area and the support permitted a better dispersion of Ti. Keywords SO3 decomposition Composite granules Cu/Fe/Ti/Al2O3
1 Introduction The most important fossil fuel is hydrogen that is estimated to become the energy carrier of the future because hydrogen as a fuel will allow sustainable development from the perspective of zero emission energy production systems. Thermo-chemical splitting of water has been proposed as a clean method for hydrogen production. Such hydrogen would be obtained by decomposition of water by using heat
B. M. Nagaraja (&) K. D. Jung Clean Energy Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, South Korea e-mail: [email protected] K. S. Yoo (&) Department of Chemical Engineering, Seoul National University of Technology, 172 Gongreung 2-dong, Nowon-gu, Seoul 139-743, South Korea e-mail: [email protected]
123
energy through a chemical cycle process that consists of several reactions. Among the thermo-chemical cycles, the sulfur–iodine (SI) process [1] has received attention as one of the reliable candidates that exhibits a great potential for the industrialization of hydrogen production by the water splitting. The SI cycle consists of the following reactions: (1) The first step is decomposition of sulphuric acid to form gaseous H2O, SO3 and oxygen at temperature [600 °C, (2) second step is also known as Bunsen reaction proceeds exothermically in liquid phase and produces two immiscible aqueous acid phase viz., sulfuric acid and hydroiodic acid produce in the temperature range 70–120 °C and (3) HI decomposition is slightly endothermic, produces hydrogen and take place in the temperature range of 300– 450 °C. The iodine–sulfur cycle shows the following reaction. H2 SO4 ! H2 O þ SO2 þ 1=2O2
ð1Þ
I2 þ SO2 þ 2H2 O ! 2HI þ H2 SO4
ð2Þ
2HI ! H2 þ I2
ð3Þ
The decomposition of sulfuric acid consists of two reactions in series: H2 SO4 ! H2 O þ SO3
ð4Þ
SO3 ! SO2 þ 1=2O2
ð5Þ
Sulfuric acid can be decomposed with a catalyst or without a catalyst, while the decomposition of SO3 has been known to be a catalytic reaction. Most metal oxides are considered as active catalysts for the sulfuric acid decomposition in the temperature range 600–1,000 °C. Noble metals are reliable as highly active catalys
Data Loading...
