US 4,289,625 A · Hybrid bio-thermal gasification

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gasification wherein a biological feed is anaerobically digested with product methane and carbon dioxide containing gas withdrawn from the digester and biological residue separately withdrawn from the digester and introduced into a thermal gasifier wherein at least a substantial portion of the biological residue is gasified under elevated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.

Claims28

Dependent claims

A hybrid bio-thermal gasification process for improved carbonaceous gasification comprising:

adding biological feed to an anaerobic digester;
anaerobically digesting said biological feed under thermophilic or mesophilic conditions in an active liquid culture;
introducing a gasification product to said active liquid culture during said anaerobic digesting;
withdrawing product methane and carbon dioxide containing gas from said digester;
separately withdrawing biological residue from said digester and introducing it into a thermal gasifier;
gasifying at least a substantial portion of said biological residue under elevated temperature conditions producing thermal gasifier products and thermal residue, at least a portion of said thermal gasifier products or their derivatives being passed through said digester as said gasification product.

3 more elements

Dependencies are inferred from the claim text.

Hybrid bio-thermal gasification

Life of this patent

Hybrid bio-thermal gasification

Life of this patent

Abstract

Claims28