| Biomass is renewable and abundantly available in the world.Biomass gasification to synthesis gas is the most promising approach to share renewable energy,compared with its use as a combustion fuel.The limitation of the gasification makes the difficult to attain an overall efficiency.To solve this problem,Ni catalysts supported on titanium dioxide and porous ceramics are prepared and studied.In this paper it is studied that influence on character of catalysts by preparation parameters such as calcination time,calcinations temperature and Ni content.The titanium dioxide loading 5wt.%Ni obtains the best catalytic performance when prepared at the following conditions:the NiO/TiO2 is calcined at 900℃for 3h.The porous ceramics loading 5wt.%Ni calcined at 1000℃for 3h obtains the best catalytic performance.For NiO/TiO2,reaction temperature,S/B(stearn/biomass)ratio and catalyst/biomass ratio have been studied.The results show that H2 concentration(40.13%),syngas yield(0.718m3·kg-1),H2 yield(26.72g·kg-1)and H2 potential yield(75.33g·kg-1)are obtained at 850℃,S/B ratio 3.27 and catalyst/biomass ratio 2%.For NiO/porous ceramics,reaction temperature,S/B(steam/biomass)ratio and catalytic reaction temperature have been studied. The results show that H2 concentration(46.81%),syngas yield(0.740m3·kg-1),H2 yield(30.93 g·kg-1)and H2 potential yield(73.12g·kg-1)are obtained at 800℃,S/B ratio 1.17 and catalytic reaction temperature 800℃.The NiO/TiO2 and NiO/porous ceramics catalysts are analyzed by SEM.The results show that the interaction between Ni and support is proper and there is no agglomeration of Ni.By means of thermogravimetric analysis,a series of pine sawdust catalytic gasification experiments are performanced on the big quantity material thermogravimetric analysis experimental device.The mechanism functions,the activation energy and pre-exponential factor of sawdust and sawdust+Ni-based catalyst isothermal gasification are numerated.It is propitious to research reaction mechanism. |
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