Hydrogen’s ability to combine with oxygen was first noted by Henry Cavendish in 1766. The first electrolyzer subsequently appeared in 1800, when Nicholson and Carlisle induced a static charge into water. More than 200 years later, Cummins is continuing to evolve these fundamental discoveries
In alkaline electrolysis, a reaction occurs between two electrodes in a solution composed of water and liquid electrolyte. When sufficient voltage is applied, water molecules take electrons to make OH⁻ ions and an H2 molecule. The OH⁻ ions travel through the solution toward the anode, where they combine and give up their extra electrons to make water, electrons, and O2.
Recombination of hydrogen and oxygen at this stage is prevented by means of our patented IMET® ion-exchange membrane. The IMET® membrane is made of highly resistant, inorganic materials and does not contain asbestos. The electrolyte remains in the system owing to a closed-loop, pump-free recirculation process.
PEM electrolysis creates a reaction using an ionically conductive solid polymer, rather than a liquid. When voltage is applied between two electrodes, negatively charged oxygen in the water molecules gives its electron, resulting in protons, electrons, and O2 at the anode.
The H+ ions travel through the proton-conducting polymer towards the cathode, where they take an electron and become neutral H atoms. These combine to make H2 at the cathode. The electrolyte and two electrodes are sandwiched between two bipolar plates, which transport water to them, transport product gases away from the cell, conduct electricity, and circulate a coolant fluid to cool down the process.