US 11,781,229 B2
Hydrogen production from geothermal resources using closed-loop systems
Alvaro J. Amaya, Emeryville, CA (US); and Joseph A. Scherer, Emeryville, CA (US)
Assigned to GreenFire Energy Inc., Emeryville, CA (US)
Filed by GreenFire Energy Inc., Emeryville, CA (US)
Filed on May 13, 2021, as Appl. No. 17/319,999.
Claims priority of provisional application 63/023,894, filed on May 13, 2020.
Prior Publication US 2021/0371990 A1, Dec. 2, 2021
Int. Cl. C25B 1/50 (2021.01); C25B 1/042 (2021.01); C25B 9/67 (2021.01); C25B 9/19 (2021.01); F03G 4/00 (2006.01); C25B 15/02 (2021.01)
CPC C25B 1/50 (2021.01) [C25B 1/042 (2021.01); C25B 9/19 (2021.01); C25B 9/67 (2021.01); C25B 15/02 (2013.01); F03G 4/00 (2021.08)] 9 Claims
OG exemplary drawing
 
1. A system for circulating fluids and applying electrical energy through a closed-loop down bore apparatus having a U-loop configuration, wherein two generally vertical wells are connected by another well, wherein at least a portion of the two generally vertical wells or of the another well is disposed in a geothermal resource from which thermal energy is transferred to circulating fluids and pressure of fluid in the closed-loop down bore apparatus is high, the system comprising:
a circulation system for circulating a fluid containing water from a surface through a well casing or liner by means of a pump and/or thermosiphon, wherein thermal energy from the geothermal resource is transferred to the fluid and pressure of the fluid, down bore, is increased by a weight of the fluid, thermal expansion of the fluid and, for systems including a pump, additional pressure from pumping to cause the fluid circulating to have high pressure;
an electrolysis system configured to apply electrical current to the circulating fluid wherein water having a high temperature and high pressure is used to produce hydrogen and oxygen gases by means of electrolysis using one of AE Down Bore Method, SOEC Down Bore Method or PEM Down Bore Method, which latter two methods may use an electrolysis cell or a zero gap electrolysis cell;
a control system configured to control flow rates of fluid into the closed-loop down bore apparatus and electrolysis reaction rates such that the water is fully converted to hydrogen and oxygen such that there is no, or only intermittent, flow of fluid to the surface for recirculation; and
a gas collection system for collecting the hydrogen and oxygen gases produced by electrolysis and delivering the hydrogen and oxygen gases to the surface under pressure.