Method and system for providing upgraded biogas
AssigneeIogen Corporation
InventorsBrian Foody, Patrick J. Foody
Life of this patent
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Abstract
A method for providing upgraded biogas includes feeding a stream of biogas into a biogas upgrading system in order to remove carbon dioxide from the stream of biogas. The biogas upgrading system, which may be based on absorption, adsorption, membrane permeation, and/or cryogenics, provides a stream of upgraded biogas and a tail gas stream. The tail gas stream, which may be CO2-rich, is enriched with natural gas so that it is combustible in medium-BTU equipment. The upgraded biogas is used for transportation use and/or the generation of fuel credits. Accordingly, both the tail gas and the upgraded biogas are used effectively and at lower cost.
Claims20
A method of providing upgraded biogas comprising:
- feeding biogas into a biogas upgrading system, said biogas upgrading system producing upgraded biogas and tail gas;
- enriching the tail gas with natural gas to provide an enriched tail gas, said enriching comprising feeding natural gas withdrawn from a distribution system into at least one of the biogas upgrading system and the tail gas;
- providing at least a portion of the enriched tail gas to a combustion system, said combustion system configured to produce at least one of heat and electricity;
- and
- feeding at least a portion of the upgraded biogas to the distribution system,
- wherein the amount of natural gas withdrawn from the distribution system for said enriching is at least 50% of the amount of upgraded biogas fed into the distribution system, each of said amount of natural gas and said amount of upgraded biogas measured as energy delivered over a period of time.
Dependencies are inferred from the claim text.