Experimental reactor for the conversion of biomass (in this case woodchips) into methane-rich gas, a substitute natural gas. Pictured is the disengager which seperates the product gas from the sand used in the combustor. The process employed is called Multi-Solid Fluidized-Bed gasification, it involves the wood feedstock being steam reformed with a chemical catalyst. Wood as a fuel is neither easy to transport nor practical to use, conversion to fuel gas allows it's energy content to be utilised in a form that is readily incorporated into existing natural gas systems. This photo was taken at the Battelle Mem. Institute in Columbus, Ohio, USA.