Hydrogen-rich Gas Production From Biomass Catalytic Gasification Over Fe-Ce/olivine Catalyst

Serious environmental issues promote the application of clean and renewable energy as the significant strategy of world energy consumption structure reforming. Hydrogen is a relative clean and efficient energy compared to other energy types, and biomass gasification technology provides a new method to produce it. But in direct biomass gasification process, hydrogen in gaseous products is in low content, and tar generation also cause lots of negative effects including damaging equipments, influencing downstream operations, reducing overall energy conversion efficiency. To solve these problems, an efficient and low-cost catalyst, Fe-Ce/olivine catalyst was prepared in this work to improve hydrogen production and reduce tar generation at the same time in biomass gasification.Natural olivine was pre-treated by calcinations at high temperature to improve its properties as catalyst support. Compared to natural olivine, calcined catalyst possesses higher surface area, which was benefit for the doping of metals. Iron oxides content on olivine surface increased due to iron ions come out from the silicate tetrahedral structure, and partial iron state converted from Fe(II) to Fe(III), which will improve olivine catalytic activity. The effect of different calcination temperature(800-1000?) on olivine catalytic activity was studied.By using calcined olivine as catalyst support, Fe-Ce/olivine catalysts were prepared by deposition-precipitation(DP) method. XRF, BET, XRD, FTIR and SEM/EDX were adopted to characterize catalyst. Catalyst activity was tested in biomass gasification process with dry gas yield, hydrogen yield and tar removal efficiency as gasification indicators. The catalytic mechanism in gasification process was also discussed. Experiment results showed that Fe-Ce/olivine catalyst demonstrated effective activity to promote hydrogen concentration in final gaseous product, with tar removal efficiency above 90%. Experiments results showed that Fe-Ce/Olivine catalyst has good stability and coke resisting ability and the coke deposit rate was 3.75%.The application of Fe-Ce/olivine on biomass steam catalytic gasification was conducted in a self-made lab-scale two-stage fixed bed. The effects of catalyst addition, steam to biomass ratio(S/B), solid residence time, gasification temperature and catalytic temperature on gasification performance were investigated. The optimum parameters were studied under the experimental conditions to provide reference data for further research or practical application of Fe-Ce/olivine catalyst.