Bio-ethanol steam reforming and autothermal reforming in 3-¦Ìm channels coated with RhPd/CeO₂ for hydrogen generation

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• 作者：Nú ; ria J. Divins^a ; ^b ; Eduardo Ló ; pez^a ; ^c ; Á ; ngel Rodr&#237 ; guez^d ; Didac Vega^d ; Jordi Llorca^a ; ^b ; ^{jordi.llorca@upc.edu}
• 关键词：Hydrogen ; Microreactor ; Silicon microchannel ; Ethanol ; Bio-ethanol ; Steam reforming ; Autothermal reforming
• 刊名：Chemical Engineering and Processing
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：64
• 期：Complete
• 页码：31-37
• 全文大小：769 K

文摘

A silicon micromonolith of 7 mm diameter and 0.2 mm length containing 1.5 million regular channels with a diameter of 3.3 ¦Ìm was used for obtaining hydrogen through ethanol or bio-ethanol steam reforming (ESR) and oxidative steam reforming (OSR). The microchannels were coated with RhPd/CeO₂ catalyst by a two-step method. First a CeO₂ layer of ca. 100 nm thickness was deposited from cerium methoxyethoxide over a SiO₂ layer, which was previously grown over the silicon microchannels by oxidation. Then, noble metals were grafted over the CeO₂ support from chloride precursors. The unit was successfully tested for hydrogen production, achieving hydrogen rates of for the steam reforming of bio-ethanol at 873 K, S/C = 2 and 0.009 s contact time. Reaction yields of 3.8 and 3.7 mol hydrogen generated per mol ethanol in feed were measured for ESR and OSR, respectively. A performance comparison was performed with a conventional cordierite monolith with the same catalyst formulation. Results show for the silicon microreactor an outstanding improvement of the specific hydrogen production rate, operating at considerably reduced residence times, due to the increase in contact area per unit volume.