Research On The Hydrogen Production From Bio-oil By Electrochemical Catalytic Steam Reforming Using Ni-Cu-Zn-nano SiO₂

Biomass is a kind of environmentally renewable resource. And re-utilizing of bio-mass is getting more and more attention by now, with the fast increasing demand of energy and raising focus on the environment protection. The approach of Hydrogen producing by bio-mass is still in the early stage. As a result, problems such as enhancing hydrogen yield and energy efficiency, decreasing cost while in hydrogen production, and the deactivation of the catalyst, etc., are needed to be settled.Based on these problems, this paper focus on a further investigation about efficient reforming approach for production of hydrogen by using the electrochemical catalytic reforming (i.e., current passing through the catalyst) method. The main context are included below: (1) An electrochemical catalytic steam reforming method was designed; and the approach of producing hydrogen from bio-oil, reached high hydrogen yield (70%) and high carbon conversion (85%) at middle temperature (500℃); (2) Studied on the connection between the microcosmic structure of the catalyst and conversion of bio-oil, and also investigated the mechanism of the electrochemical catalytic steam reforming; Details are discussed as follow:(1). Efficient electrochemical catalytic reforming of bio-oil to produce hydrogenThe reforming catalyst of Ni-Cu-Zn-nano SiO2 was prepared by the impregnation method. We studied the effects of the reforming experiments, including temperatures, current, S/C, GHSV etc. In this work, it was observed interestingly that the behavior of the reforming was very sensitive to the current through the catalyst. The carbon conversion and hydrogen yield were both remarkably enhanced by the current. The concentrations of H2 and CO rose with increasing the current, accompanied by the content decrease of CO2 and CH4. e.g., The carbon conversion significantly increased from 42.1% to 78.1% and hydrogen yield increased from 26.0% to 50.1% at 500℃(other conditions : S/C=10,GHSV=3000h-1,P=1 atm ) with increasing the current from 0 to 2 A. Without the current, the content of H2,CO,CH4,CO2 was 65.2%,8.1%,3.0% and 25.0% respectively,while those proportions changed to 68%, 9.2%, 1.0% and 23.0%, with increasing the current from 0 to 2 A.(2) The mechanism study on electrochemical catalytic reforming of bio-oilTo make clear the mechanism of the electrochemical catalytic steam reforming, we studied the micro structure of Ni-Cu-Zn-nano SiO2 via XRD, XPS, BET and TPR measurements. And we figured out that current enhanced reforming results. And this can be attributed to the relationship with the thermal electrons on the surface of the catalyst.Based on the above investigation, we discussed the thermal electrons in the reforming and decomposition processes significantly promoted the dissociation of the oxygenated organic compounds in the bio-oil, and enhanced the hydrogen yield and carbon conversion.