A review on current status of hydrogen production from bio-oil

Increase in energy demand and growing environmental awareness has increased interest for alternative renewable energy sources over the last few years. Hydrogen produces only water during combustion, and therefore, it is seen as an alternative fuel for locomotive application. Nonetheless, hydrogen is not an energy source; rather it is an energy carrier. Different techniques are being explored to find an economical way of generating hydrogen from renewable resources. Hydrogen production from water using sunlight is still expensive. Biomass is another alternative to produce hydrogen. Bio-oil derived from biomass using a fast pyrolysis is a potential source for hydrogen production. Although different techniques have been employed to produce hydrogen from bio-oil, significant effort has been put into steam reforming process. This paper reviews major hydrogen production techniques with a great deal of importance given to steam reforming. The important factors that are known to affect hydrogen yield are temperature, steam to carbon ratio, and catalyst type. Literature review of bio-oil steam reforming technique has been done, and a comparison of experimental conditions has been carried out. However, as a major shortcoming, this technique is accompanied by the formation of carbonaceous deposits over the catalyst surface rendering it inactive and requiring frequent regeneration. Coke formation has been cited as the major disadvantage of bio-oil reforming, and it is more pronounced when Ni based catalysts are used. (C) 2012 Elsevier Ltd. All rights reserved.