| abstract |
A hybrid bio-thermal gasification process for improved carbonaceous gasification wherein a biological feed is anaerobically digested with product methane and carbon dioxide containing gas withdrawn from the digester and biological residue separately withdrawn from the digester and introduced into a thermal gasifier wherein at least a substantial portion of the biological residue is gasified under elevated temperature conditions producing thermal gasifier products and thermal residue with at least a portion of the thermal gasifier products or their derivatives being returned to the digester. The process provides high conversion of the carbonaceous material and biological feed stocks to gas products and permits gasification of a wider variety of biological feeds by anaerobic digestion processes while requiring less external nutrient feeding to the process. The process of this invention provides a highly efficient process for production of substitute natural gas. Various advantages of interrelation between the anaerobic digester and thermal gasification are taught. |