Advanced Slagging Gasifier for Biomass Wastes

Gasification provides a potential means of deriving clean energy from biomass waste materials. One of the greatest obstacles to the effective gasification of animal and farm waste is the slagging behavior of the residual ash at temperatures that yield the most efficient gasification performance. Many wastes particularly are problematic for dry ash gasification processes, especially waste from concentrated animal feeding operations or CAFOs (e.g., poultry litter and other animal manures) because these wastes combine high ash content with low ash fusion temperatures. This Phase I project will address the development of an advance counter-rotating vortex (CVR) slagging gasifier for the processing of animal and farm wastes. Specific attention will be directed toward poultry litter (a CAFO waste). The advanced gasification technology being developed represents modifications to a previously developed vitrification technology for the processing of carbon- and ash-containing industrial wastes to operation under reducing conditions for the gasification of animal and farm wastes. The proposed gasification technology operated reliably and efficiently above the ash fusions temperature, thus avoiding ash slagging problems while achieving improved H2 and CO yields. Tar formation also is mitigated by the disassociation of higher molecular weight hydrocarbons at these higher operating temperatures. The great degree of turbulence and high mixing rates achieved within the gasification reactor result in very high heat release rates (> 100,000 °C/second), which in turn promote the rapid disintegration of the biomass feedstocks. This results in improved carbon conversion efficiency and reduced wall heat transfer losses. The net result is the achievement of very high gasification efficiencies with improved product yields and quality. The robust nature of the proposed technology can be applied to the gasification of a wide range of animal and farm wastes, as well as other biomass materials.