Oxidative steam reforming of ethanol over Ni/CeO2-ZrO2 catalyst

Catalytic steam reforming of ethanol for hydrogen production in presence and absence of oxygen has been studied over Ni-CeO2-ZrO2 catalyst. The effect of oxygen addition and space time on conversion and product selectivities has been investigated in a down-flow tubular fixed bed reactor at atmospheric pressure with an ethanol/water molar ratio of 1:8, over a temperature range of 400-650 degrees C. The O-2/EtOH molar ratio was varied from 0.5 to 1.5. In the presence of oxygen, the catalytic activity was significantly higher and the effect was more at lower temperature (<450 degrees C). Hydrogen yields and selectivities as well as the coke deposition were significantly affected by addition of oxygen. At a temperature <= 500 degrees C, hydrogen yield was highest at an O-2/EtOH molar ratio of 0.5, whereas at higher temperatures, higher hydrogen yields were obtained in absence of oxygen. Higher oxygen content in the feed (O-2/EtOH >= 0.5) reduced the hydrogen yield. (C) 2007 Elsevier B.V. All rights reserved.