Ecosense installs a Fuel Cell Training System at PDEU

The operating principle of the proton-exchange-membrane-hydrogen-based fuel cell is relatively simple. The fuel cell as a whole is made up of several stacked cells (similar to the cells of a car battery). A cathode and an anode, which are separated by a proton exchange membrane, make up each cell in the stack. The PEM provides a channel for the migration of the hydrogen protons generated during the process while acting as an insulator between the adjacent "half cells." Each cell has an anode fed with hydrogen and a cathode fed with air or oxygen. On the anode side, hydrogen releases electrons that are guided through an external circuit before returning to the system on the cathode side, where they combine with oxygen and hydrogen ions to generate water. The process is described in a bit more detail below.

Hydrogen at the anode side of the cell starts the power generation process. The proton exchange membrane has a specific platinum catalyst coating that allows hydrogen molecules to split into two H+ ions when they come into contact with it (hydrogen ions). Each hydrogen atom from the initial hydrogen molecule needs to surrender an electron in order for the positive hydrogen ion to arise. Here's where graphite comes into play: the highly conductive graphite anode conducts these newly "free" electrons away, where they are then routed through an external circuit to generate energy. Hydrogen undergoes oxidation at the anode (its electrical charge is increased due to the shedding of electrons which results in an increased positive charge). While on the cathode side of the cell, oxygen molecules moving into the surface of the proton exchange membrane are cleaved into two highly reactive oxygen atoms, the newly created hydrogen ions (protons) continue to pass across the proton exchange membrane (the oxygen molecule, O2, is relatively stable while oxygen atoms are not). The electrons released from the hydrogen molecules at the anode during this entire process return from the external circuit via the extremely conductive graphite cathode. One oxygen atom, two hydrogen ions, and two returning electrons come together to form a water molecule at the interface between the proton exchange membrane and cathode. The overall reaction at the cathode is a reduction (electrons are added to oxygen reducing its charge). In the cell stack as a whole, hydrogen is oxidised, oxygen is reduced, electrons are released and reunited, and the resulting "chemical pressure" is used to generate power. This electrolytic "combustion" produces water as a by-product, which is released into the atmosphere. Every cell in the stack goes through the aforementioned process as long as fuel is available. A total stack pressure, or voltage, equal to the voltage of each cell times the quantity of cells in series is created by each cell pumping electrons emitted from the previous cell (the total number of cells in the stack).