(599a) Overview of Caustic Aqueous Phase Electrochemical Reforming (CAPER) Technology for Process Intensified Hydrogen Production

The efficient generation of compressed pure hydrogen (H₂) is a critical milestone for sustaining H₂ in the energy network. Many of the traditional methods for compressed H₂ production are hindered by high operating temperatures, high energy costs, low efficiency, and complex unit operations. For example, the current water electrolysis technology requires a large energy of ~55 kWh to produce 1 kg of H₂ due to its high cell operating voltage of 1.9 V. Furthermore, the cost of liquifying, transporting, and storing H₂ from a large centralized source is approximately $14/kg, which must be significantly reduced to be market competitive. To address this H₂ production and distribution challenges, our Caustic Aqueous Phase Ethanol Reforming (CAPER) technology offers a novel electrochemical reforming reaction requiring a low thermoneutral cell voltage of 0.3V along with an in-situ CO₂ separation and its conversion to value-added product scheme enabling affordable, efficient, reliable, and secure either carbon neutral or carbon negative H₂ production for various fuel cell applications. The CAPER process reduces H₂O at the cathode to produce a high-pressure and high-purity H₂ at ≤80 ^oC while it oxidizes the ethanol at the anode using renewable electrical energy. The CO₂ produced by ethanol oxidation is also captured within the caustic electrolyte solution. The electrolyte can be refreshed to release compressed and pure CO₂ in a regenerator unit. Without needing downstream separation, compression, or membranes, the CAPER process achieves process-intensified H₂ production at high efficiency. For example, our CAPER flow reactor produces pure H₂ at 80 bar and 80 ^oC applying voltages at ≤ 0.5 V. The only gas-phase product detected was H₂ and any carbonaceous products were contained in the liquid phase. The H₂ was produced with 100% faradaic efficiency. The compressed H₂ was produced at ≤ 20 kWh kg^–1, which is much lower than electrolysis systems that require upwards of ~55 kWh kg^–1.