(317a) Effect of Inorganics in Biomass On Rhodium Catalysts for Millisecond Autothermal Reforming

Authors: 
Chakrabarti, R. - Presenter, University of Minnesota
Schmidt, L. D. - Presenter, University of Minnesota


Biomass can be upgraded to fuels and chemicals by gasification, which produces synthesis gas (commonly referred to as syngas, a mixture of carbon monoxide and hydrogen). Syngas can be converted to fuels and chemicals by the Fischer Tropsch process. Recently, Schmidt et al. have demonstrated that lignocellulosic biomass can be gasified autothermally by a technique called ?Reactive Flash Volatilization' to a product stream containing equilibrium selectivities to syngas.(1-3) This process takes place on Rhodium-based catalysts at high temperatures (~600-1000˚ C) with a residence time on the order of milliseconds. Biomass contains inorganic constituents such as Ca, Na, K, Mg, S, Si, Cl, P which may be present in different forms such as oxides, sulfates, carbonates, sulfates, silicates, phosphates etc.(4) Reactive Flash Volatilization has been demonstrated using feeds which contain low or negligible concentration of inorganics. These inorganics can affect the catalyst activity by acting as promoters or poisons, hence understanding their effect on Rhodium catalysts for catalytic gasification is necessary to design appropriate biomass processing strategies. These inorganics were added to the Rhodium catalyst through precursors and the effect on autothermal reforming was studied by studying the change in reactor performance, product distribution and catalyst microstructure. Inorganic constituents such as Si, P, S acted as strong poisons for the Rh-based catalyst. SEM, XRD, EDS and chemisorption studies were carried out to evaluate the change in catalyst microstrucutre.

REFERENCES

1)Dauenhauer PJ, Dreyer BJ, Degenstein NJ, Schmidt LD. Millisecond Reforming of Solid Biomass for Sustainable Fuels. Angewandte Chemie International Edition. 2007;46:5864-5867. 2)Colby JL, Dauenhauer PJ, Schmidt LD. Millisecond Autothermal Steam Reforming of Cellulose for Synthetic Biofuels by Reactive Flash Volatilization. Green Chemistry. 2008;10:773-783. 3)Salge JR, Dreyer BJ, Dauenhauer PJ, Schmidt LD. Renewable Hydrogen from Nonvolatile Fuels by Reactive Flash Volatilization. Science. 2006;314:801-804. 4)Raveendran K, Ganesh A, Khilar KC. Influence of mineral matter on biomass pyrolysis characteristics. Fuel. 1995;74:1812-1822.

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