Hydrogen: Fuel of the Future?

Hydrogen. The most abundant element in our universe. It is a building block for life and forms an integral part of many compounds we find in nature. Much like electricity, hydrogen is an energy carrier, meaning it stores and delivers energy that can later be transformed to other usable forms, like mechanical work and heat.

Given hydrogen’s abundance in our planet, it would make sense to take advantage of this element to power the global economy.

The problem? On Earth, pure hydrogen is very scarce. It mainly exists in compounds, like in water, where it is combined with oxygen. So the question is: how do extract hydrogen? Is it a viable alternative fuel source for the future of our planet?

CREATING HYDROGEN GAS

Let’s get into it: how do we break up compounds containing hydrogen? Well, simple. We have to split these molecules.

Extracting hydrogen can be done in a number of ways, but steam-methane reforming is currently the most commonly used process, due to being the most cost-effective method of hydrogen production. Steam-methane reforming involves combining high-temperature steam with natural gas to extract hydrogen, a process which produces hydrogen gas, carbon monoxide and CO2.

Hydrogen can also be produced through electrolysis. You may (vaguely) remember this term from your high school science class, but it essentially just involves using an electric current to split hydrogen from water.

Electrolysis does not produce any by-products or emissions other than hydrogen and oxygen, but it is a much more energy intensive method. However, this energy need can be met with renewable sources of energy, including solar, wind and nuclear, to reduce any associated emissions during the production process.

New and even more environmentally-conscious methods of producing hydrogen are currently under development, including using light-dependent microbes to make hydrogen gas; converting biomass into compounds and separating the hydrogen content; and using solar energy technologies to split hydrogen from water.

THE SAFETY ISSUE: FACT OR FICTION?

Hydrogen can either be burned directly or mixed with oxygen in a fuel cell once it is extracted. The caveat? Hydrogen is extremely flammable and there are specific requirements for its storage, transport and use. This leads to yet another question: is hydrogen safe to use as an alternative fuel source?

Is it worth the risk?

Vocal critics of hydrogen as a fuel source will often cite the Hindenburg Disaster as a main pillar of their argument. A brief history lesson: the Hindenburg was a hydrogen airship that caught fire in 1937 and caused 35 deaths. 80 years of research and scientific tests support the same conclusion made by on-site investigators that the disaster was caused by a spark that ignited leaking hydrogen gas from the ship.

Some may see this as the proverbial nail in the coffin for hydrogen gas, but this is not the case. After all, even petroleum is flammable- this just means we need to carefully consider and develop protocols for the proper storage, transport and use of hydrogen gas, much like we have with other flammable materials.

Besides, hydrogen has been used safely- and extensively- in many industrial processes for decades. NASA began using hydrogen in the 1950s as a rocket fuel and was one of the first companies to use hydrogen fuel cells to power electrical systems. Hydrogen is also used in industry to refine petroleum, treat metals and produce fertilizers, among many others.

CELLS, CHUTES AND CARS: HYDROGEN USAGE

Many industrial processes use hydrogen and many more ways to use hydrogen are emerging. From cells, to power plants, to hydrogen vehicles: the demand for hydrogen as a fuel source is at an all-time high.

Hydrogen can be used in fuel cells to produce electricity when combined with oxygen. In this process, hydrogen and oxygen atoms react across an electrochemical cell (very similar to that of a battery), producing electricity along with heat and water as by-products.

Many different types of fuel cells are available for a wide range of applications. Smaller cells can power laptops and cell phones, while larger cells supply electricity to power grids, supply backup power systems in buildings and supply electricity to remote areas.

The interest in using hydrogen gas to fuel power plants is also growing in an attempt to decarbonize processes to reduce greenhouse gas emissions, so much so that hydrogen producers, industry professionals and government bodies alike have developed different categories of hydrogen depending on the energy sources used in the production process:

• Renewable hydrogen or green hydrogen: hydrogen gas produced using renewable sources of energy, like solar and wind energy
• Pink hydrogen or clean hydrogen: hydrogen gas produced using nuclear energy. exists for any gas produced using nuclear energy
• Grey hydrogen: hydrogen gas produced using natural gas
• Brown hydrogen: hydrogen gas produced using coal
• Blue hydrogen: hydrogen gas produced using fossil fuels, like natural gas and coal, coupled with carbon capture and storage/sequestration

Hydrogen use as an alternative transport fuel comes mainly from the fact that it is able to power fuel cells in zero-emission vehicles and is much more energy dense; hydrogen uses up much less space in a high-pressure storage system in order to make a vehicle go a certain distance, making hydrogen fuel cells up to 3x more efficient than internal combustion engines running on gasoline.

The only issues? Fuel cells and hydrogen fueling infrastructure are incredibly expensive. In a way, this is a circular problem: consumers won’t purchase hydrogen-fuelled vehicles if hydrogen refuelling stations are few and far in between, but producers won’t build the necessary infrastructure if customers aren’t purchasing hydrogen-fuelled vehicles.

These are certainly obstacles to overcome before hydrogen truly becomes a viable mainstream fuel source, but as we’ve seen with solar and wind technologies, more and more research into renewable sources of energy results in better and more cost-effective technologies.

THE SUSTAINABILITY ISSUE

How sustainable is hydrogen, really? Despite advances in production technologies, hydrogen still requires energy intensive processes fuelled largely by either fossil fuels or electricity.

The only way to make truly green hydrogen is to produce it using renewable energy.

An overwhelming amount of hydrogen used globally is made from natural gas, which results in greenhouse gas emissions. It can be easy to look at this as terrible- but we can also choose to look at it as a necessary evil for the time-being.  

Current methods are simply temporary bridges helping to build the market for renewable technologies, which will inevitably take over once they become more efficient and more cost-effective.

There’s also the problem of renewable hydrogen. If renewable energy is used to produce hydrogen using electrolysis, the resulting energy produced is less than the energy input. Some critics use this to argue that hydrogen is a waste of renewable energy.

They have a point.

For many applications, electricity remains the best energy carrier to use, either due to being more cost-effective or more efficient. But for other applications, especially in heavy industry and long distance transportation, hydrogen has the potential to occupy a very specific niche- and quite a big niche at that.

THE FUTURE OF HYDROGEN

Hydrogen fuel is here to stay, and it’s not smoke and mirrors this time.

Along with technological advances that are making production methods more efficient and cheaper, governments all over the world are increasingly committing to a decarbonized future and helping drive a new hydrogen economy.

Entrepreneurs and venture capitalists are even buying into the hydrogen hype- literally and figuratively! Because of investment, scientific ideas are quickly moving from laboratories, to pilot plants and ultimately to the marketplace. The reason? There is a market that will pay for low-carbon approaches.

In addition, there continues to be improvements in vehicles and processes that use hydrogen, and even more sophistication among companies using hydrogen. According to a study by McKinsey, more than 350 large-scale global projects are currently underway involving hydrogen, with the projected total investment in the hydrogen sector amounting to an estimated $500 billion.

When we think about the tools needed to get to net zero, there’s no doubt that hydrogen will play a significant role.