Reactive Flash Volatilization of Sustainable Feedstocks for Alternative Fuels

Alternative feedstocks such as lignocellulosic biomass and municipal solid waste provide a realistic source for sustainable production of carbon-based fuels and chemicals. Using RhCe/Al_2 O_3 catalysts at millisecond residence times and temperatures of ~1000 °C, these feedstocks can be directly converted to near equilibrium synthesis gas products through a process referred to as reactive flash volatilization. Autothermal conversion occurs by coupling the endothermic polymer decomposition process with highly exothermic catalytic partial oxidation. By directly contacting solid particles with a hot catalytic surface capable of providing high heating rates, the solid particles form volatile compounds which flow into a catalyst bed and undergo oxidation and reforming chemistry to form a clean synthesis gas product. High speed photography was used to gain insight into the solid feedstock behavior in the pyrolysis zone. Alternatively, high selectivities to potentially valuable liquid products can be obtained by reducing the oxygen concentration in the feed, providing only enough to maintain autothermal reactor operation.