Highlights

Alternative Fuels from Biomass

Kerry Dooley, S. Adusumilli, V. Kalakota, Chemical Engineering

For gasification, cleanup is the primary cost Chart is from DOE Biomass Roadmap (2007) for converting poplar to ethanol Effluents from gasifiers – up to 3.5% tars H2S (<0.3%), NOx, NH3, Cl, K Must crack tars, remove S, N etc. Desulfurization and tar removal: Use rare earth oxides CeO2 La2O3 in 2 steps: Syngas Cleanup:  oxide + H2S -> oxysulfide Regenerate Catalyst: oxysulfide à oxide + H2S

Determine the intermediate compounds that form using X-ray Diffraction at CAMD

Mixed rare earth oxides CeO2 La2O3 compared with other oxides	(A) Ce/La = 0.9 (B) Ce/La = 0.65 (C) pure CeO2.
	Ce/Al oxides - greater reduction, if mixture intimate or as monolayer dispersion (here 80 wt% Al2O3).

Ce/LaOx -- S capacity low for biomass gasifier effluents. Addition of 3rd REO to supported Ce/LaOx increases S-capacity and hydrothermal stability.

For supported REOs impregnated with transition metals, S-capacities in order Mn > Fe >> Cu.

For mixed REOs, lack of crystallinity and extent of reduction determine S-capacities.