A hydrogen-x flow battery system coupled to a hydrogen pipeline network

A flow battery system, comprising:

• a first tank including a hydrogen reactant;
• a second tank including a bromine electrolyte;
• at least one cell including a hydrogen reactant side operably connected to the first tank through an H2 feed and return system and a bromine electrolyte side operably connected to the second tank through a bromine electrolyte feed and return system;
• and
• a crossover return system including (i) a vessel operably connected to the H2 feed and return system and configured to receive an effluent containing a first portion of the hydrogen reactant and a second portion of the bromine electrolyte, the vessel configured to separate the first portion from the second portion, (ii) a first return line operably connecting the vessel to the first tank to return first portion of the hydrogen reactant to the first tank, and (iii) a second return line operably connecting the vessel to the second tank to return the second portion of the bromine electrolyte to the second tank, the flow battery system further comprising:
• a scrubber positioned between the vessel and the second tank for operably connecting the vessel to the scrubber and the scrubber to the second tank and configured to receive an off-gas containing a third portion of the bromine electrolyte and a fourth portion of the hydrogen reactant from the second tank, the scrubber configured to separate the third portion from the fourth portion through contacting the off-gas and the second portion of the bromine electrolyte, and a third return line operably connecting the scrubber to the H2 feed and return system to return the fourth portion of the hydrogen reactant to the first tank, wherein the third portion of the bromine electrolyte from the scrubber is returned to the second tank.