operating a combustion system furthermore the gasifier of the present invention is designed to operate at significantly lower temperatures than a conventional combustion system in a preferred embodiment the gasifier operates at temperatures below the melting temperature of ash this is significant because the combustion of solid fuel produces both bottom ash and fly ash when a combustion system operates at high temperatures the ash can melt and cause slag formation on the moving grate components which may require substantial maintenance thus by sustaining an operating temperature below the melting point of ash the gasifier of the present invention limits the potential for slagging this reduces the overall maintenance costs associated with converting waste or solid fuel to energy and makes it more practical to use conventional moving grate technology the low temperature gasification of solid fuel is also advantageous because it produces less particulate emissions and noxious gases such as nox than conventional high temperature combustion according to the present invention the syngas produced during gasification flows out of the gasifier and into a post combustor where the syngas undergoes combustion the post combustor subjects the syngas to turbulent air flow that is only slightly in excess of stoichiometric conditions and thus.