Integrated anaerobic digester system

An integrated system for converting cellulose-containing feedstock into useful materials, wherein the integrated system comprises:

• a feedstock slurry feeder system that forms an aqueous slurry of cellulose-containing feedstock;
• an anaerobic digester system directly or indirectly connected to the feeder system and comprising two or more pressurizable anaerobic digesters connected in parallel, wherein each anaerobic digester receives the aqueous slurry of cellulose-containing feedstock and converts it into a discharge gas and an enriched effluent;
• and
• a discharge gas processing system that is directly or indirectly connected to the anaerobic digester system and that at least separates methane from the discharge gas;
• wherein the headspace of each anaerobic digester is pressurizable to about 10 psi or more to form the enriched effluent and a discharge gas comprising at least methane during anaerobic digestion of the feedstock slurry.

An integrated anaerobic digester system comprising:

• a single-stage anaerobic digester system comprising two or more pressurizable anaerobic digesters connected in parallel, wherein each anaerobic digester receives an aqueous slurry of cellulose-containing feedstock and converts it into a discharge gas and an enriched effluent;
• a discharge gas processing system that is directly or indirectly connected to the anaerobic digester system and that at least separates methane from the discharge gas;
• and
• an enriched effluent processing system that is directly or indirectly connected to the anaerobic digester system;
• wherein the headspace of each anaerobic digester is pressurizable to about 10 psi or more to form the enriched effluent and a discharge gas comprising at least methane during anaerobic digestion of the aqueous slurry of cellulose-containing feedstock.

An integrated anaerobic digester system comprising:

• a single-stage anaerobic digester system comprising two or more pressurizable anaerobic digesters connected in parallel, wherein each anaerobic digester receives an aqueous slurry of cellulose-containing feedstock and converts it into a discharge gas and an enriched effluent;
• a discharge gas processing system that is directly or indirectly connected to the anaerobic digester system and that at least separates methane from the discharge gas;
• an enriched effluent processing system that is directly or indirectly connected to the anaerobic digester system;
• a feedstock slurry feeder system that forms an aqueous slurry of cellulose-containing feedstock;
• a pressurizer system;
• a gas recirculation system that recirculates gas from the headspace of an anaerobic digester to the slurry of the digester;
• and
• a fluid recirculation system that recirculates the scum, supernatant, effluent, or sludge of an anaerobic digester;
• wherein the headspace of each anaerobic digester is pressurizable to about 10 psi or more to form the enriched effluent and a discharge gas comprising at least methane during anaerobic digestion of the aqueous slurry of cellulose-containing feedstock.