Hydrogen supply method and system

A method for supplying additional hydrogen from a reservoir of stored hydrogen in a salt cavern supplied at a purity of greater than 99% to an end-user through a hydrogen pipeline, the method comprising:

• removing a first stream from the salt cavern at a first flow rate to discharge crude hydrogen from the salt cavern, the first stream comprising hydrogen and at least one contaminant imparted by the salt cavern such that the crude hydrogen contains the at least one contaminant at a level higher than that allowed by a product purity specification;
• and
• mixing the first stream at the first flow rate with a second stream comprising the at least one contaminant at or within the product purity specification at a second flow rate under flow rate conditions that form a third stream having lower levels of the at least one contaminant than contained in the first stream.

A method for supplying additional hydrogen to a hydrogen pipeline from a salt cavern to assist in meeting end-use demand, the method comprising:

• removing stored hydrogen from the salt cavern at a first flow rate as a crude hydrogen stream containing at least one contaminant comprising carbon dioxide or water vapor contaminants at a level higher than that allowed by a product purity specification for the hydrogen in the hydrogen pipeline;
• and
• mixing the crude hydrogen stream at the first flow rate with a higher purity hydrogen from the hydrogen pipeline having a second flow rate under flow rate conditions to form a hydrogen product stream comprising hydrogen at a purity of greater than 99% with at least the carbon dioxide or the water vapor contaminants at concentrations at or below the product purity specification.