A hydrogen generator’s primary purpose is to produce hydrogen gas using water as raw material through a proton exchange membrane (PEM). The proton exchange membrane was first introduced by NASA in the 1960s. Hydrogen gas generators are the most cost-effective, safe, and efficient alternative to the use of H2 high-pressure cylinders.
As compared to a cylinder, a gas generator produce gas on demand 24 hours a day, meaning you don’t have to worry about exhausting your existing resource of gas at any point in time. In comparison, hydrogen generators can be maintained anywhere with the need of few to no safety measures. To know more about our hydrogen generator, view the ThalesNano Energy hydrogen generator.
What is PEM?
PEM is an abbreviation for the proton exchange membrane, also known as a polymer electrolyte membrane. The purpose of a PEM is to conduct protons while acting as a reactant barrier and electronic insulator.
Proton exchange membranes are made of ionomers (polymers). The characteristics of PEM to act like a reactant barrier and an electronic insulator is of great importance in proton exchange membrane fuel cells; more known merely as hydrogen generators.
What is Hydrogen Gas?
Hydrogen is one of the most abundant elements found in the entire universe. However, hydrogen is not found in its gaseous state on earth and needs to be manufactured using hydrocarbons by separation of the hydrogen and carbons. More efficient and effective ways of producing hydrogen to meet the growing demands have been made, such as the hydrogen generators. This hydrogen is used in a number of sectors such as agricultural, chemical, and industrial.
The most common usage of hydrogen is in;
- Nitrogen fixation in the Haber process.
- Producing hydrochloric acid (HCl)
- Gas chromatography
- Transport vehicle fuel
How Does a Hydrogen Generator Work?
The manufacture of hydrogen takes place in a hydrogen generator, otherwise known as a proton exchange membrane cell. This cell consists of;
- Hydrogen proton exchange membrane electrode (cathode)
- Proton exchange membrane
- Oxygen electrode (anode)
- Continuous supply of voltage
The production takes place via the electrolysis of water. The manufacturing takes place in steps, and reactions occur at the respective electrode.
Reaction one: At the anode, which is the positively charged electrode, oxidation occurs. Water molecules lose two electrons forming an oxygen molecule and four ions of hydrogen.
Reaction at anode: 2H2O – 4e = O2 + 4 H+
The oxygen produced in this step is extracted out through vents into the atmosphere. The hydrogen ions produced in reaction one is attracted to the cathode.
Reaction two: At the cathode, which is the negatively charged electrode, the four hydrogen ions are attracted (opposite charges attract). Here the hydrogen ions undergo a reduction reaction by gaining four electrons to form four molecules of hydrogen.
Reaction at Cathode: 4H+ + 4e = 2H2
The hydrogen gas produced in the reduction reaction is kept separated from the oxygen by means of the proton exchange membrane.