Electrolyzer

How Does an Electrolyzer Function and What are the Benefits?

There are many ways in which green technology has already begun to transform our daily lives. A sizable portion of these are associated with novel ways to produce reliable sources of energy without harming the environment. The use of an apparatus known as an electrolyzer is a prime example.

However, the majority of consumers are relatively unaware of this technique. It is therefore important to discuss how an electrolyzer functions. We can then move on to discuss the associated benefits and applications.

What is an Electrolyzer?

An electrolyzer is a system that uses the electrolysis of water to separate hydrogen and oxygen atoms. This is why the overall method is sometimes referred to as "hydrogen electrolysis".^[1]

A typical electrolyzer is therefore capable of tapping into a (theoretically) limitless source of energy. Interestingly enough, the roots of this technique can be traced as far back as 1800. A scientist named Alessandro Volta discovered that passing an electric current through water produced hydrogen gas as a byproduct.^[2] Thus, the first electrolyzer was born.

The components of an electrolyzer are rather straightforward. This machine consists of a stack of electrodes that is separated by a thin membrane. A high voltage current is then passed through the stack; causing water molecules to break down into hydrogen and oxygen atoms. While novel at the time when it was first discovered, the applications of an electrolyzer were not yet fully appreciated or understood.^[1]

A Look at the Different Types of Electrolyzers

It is possible to categorise an electrolyzer in accordance with its size, components and function. There are two primary types and each of these is associated with a handful of unique characteristics.

PEM Electrolysis

PEM is an acronym for Proton Exchange Membrane. In some cases, it may also refer to "polymer electrolyte membrane". A PEM electrolyzer employs a thin membrane that is used to direct hydrogen gas ions onto a cathode (a positively charged electrode). The main benefit of this type of PEM water electrolysis is that the electrolyzer is easy to cool and it is extremely efficient.^[3]

There are still some possible drawbacks associated with this type of electrolyzer. As noble metals (such as gold) are employed, the unit can be rather expensive. Another issue is that this membrane offers only moderate levels of durability. In other words, it will need to be replaced from time to time.^[4]

AEM Electrolysis

AEM is an abbreviation for Anion Exchange Membrane.^[5] An AEM hydrogen electrolyzer functions in a similar way to the PEM systems mentioned above. One main benefit is that noble metal electrocatalysts can be replaced with transition metals. This helps to significantly reduce costs; enabling the electrolyzer to be more affordable.

Having said this, the technology itself is still rather new. It is not yet known which applications it is suited for. There are also questions in regard to the complexity of the electrolyzer itself.^[6]

Alkaline Electrolysis

An alkaline electrolyzer uses solutions such as sodium hydroxide in combination with water. When a current is applied, hydroxide ions pass through the water. This produces small bubbles of hydrogen and oxygen which can then be collected at the anode and the cathode. This process has been used for over 100 years and it is arguably the most understood.^[7]

However, this type of electrolyzer uses expensive noble metals and it is quite large. These features may detract from the levels of efficient electrolysis that have been attributed to the PEM process mentioned earlier.^[1]

What are the Applications of an Electrolyzer?

There are many ways in which hydrogen production electrolysis can benefit individuals as well as businesses. Perhaps the main advantage of this technique involves the production of green hydrogen as opposed to relying upon blue hydrogen (a product derived from traditional fossil fuel sources such as natural gas). In other words, an electrolyzer offers a renewable means to produce energy.^[8]

It is therefore clear to see why an electrolyzer is often used within the hydrogen fuel cell industry. This gas can be collected and stored in order to recharge cells once they become depleted; dramatically extending their lifespan while ensuring reliable sources of energy.

Another interesting application involving hydrogen storage involves how it can be integrated into existing green technologies. For example, there can be times when wind turbines are unable to produce sufficient levels of power due to weather conditions. An on-site electrolyzer can be employed as a redundant system.

Another instance involves situations when an excess amount of mains electricity is produced. As opposed to curtailing production, this power can be redirected to an electrolyzer; resulting in more adequate stores of hydrogen for future use.^[9]

The Humble Electrolyzer: A Familiar Technology with a Promising Future

While not everyone is familiar with how an electrolyzer functions, there is no doubt that the applications are being felt across countless industries. It is still important to mention that research is ongoing. The chances are quite high that even more innovative approaches will be discovered in the not-so-distant future.

It is also likely that electrolyzer technology will begin to make its way into the consumer sector; especially in terms of real-world applications such as hydrogen-powered vehicles. Of course, other factors such as cost and viability remain to be seen in terms of large-scale production and distribution.

Might we witness the day when an electrolyzer is present within every home? Although the verdict is still out, there is no doubt that this technology represents yet another powerful facet within the renewable energy sector as a whole.