Anaerobic digester-based system for rng and hydrogen productions

A method of generating hydrogen comprising:

• cleaning a biogas input to remove impurities from the biogas to produce cleaned biogas;
• employing a catalytic reforming system (CRS) comprising at least one catalytic reactor to process the cleaned biogas into a syngas mixture containing hydrogen;
• and
• employing a hydrogen separation system to separate hydrogen from the syngas mixture.

An integrated carbon recycling system for selective production of biomethane and high-purity hydrogen from biogas, comprising:

• an anaerobic digester configured to produce biogas comprising methane, carbon dioxide, and hydrogen;
• a reforming unit fluidly connected to the anaerobic digester and configured to receive at least a portion of the biogas and convert the portion into a hydrogen-containing reformate stream;
• a hydrogen separation unit configured to separate the reformate stream into a hydrogen-rich product stream and a hydrogen-lean off-gas stream;
• a first recirculation pathway configured to return at least a portion of the hydrogen-rich product stream to the anaerobic digester to enhance in-situ biomethanation through biological conversion of hydrogen and carbon dioxide into methane;
• and a
• second recirculation pathway configured to return at least a portion of the hydrogen-lean off-gas stream to the anaerobic digester to utilize residual hydrogen and carbon-containing species, wherein the coordinated operation of the first and second recirculation pathways forms a closed-loop carbon-recycling architecture configured to selectively increase methane concentration in the biogas or to produce high-purity hydrogen on demand.

A method for selectively producing biomethane and high-purity hydrogen from biogas, comprising:

• generating biogas in an anaerobic digester;
• diverting at least a portion of the biogas to a reforming unit to produce a hydrogen-containing reformate stream;
• separating the reformate stream into a hydrogen-rich stream and a hydrogen-lean stream;
• recirculating at least a portion of the hydrogen-rich stream to the anaerobic digester to enhance biological methanation of carbon dioxide;
• and recirculating at least a portion of the hydrogen-lean stream to the anaerobic digester to utilize residual hydrogen and carbon species, wherein relative flow rates of the hydrogen-rich stream and the hydrogen-lean stream are adjusted to selectively operate the system in a biomethane enhancement mode or a hydrogen production mode.