In the effort to reduce climate change and eliminate the abundance of fossil fuels, one particular element has been identified as so promising that it could be the future of clean fuels. That element is hydrogen. Earth has a massive supply of hydrogen. It can be burned in the same way we use oil or gas, but instead of polluting the air, it only emits water. So if there is plenty of it and it’s so clean, why isn’t it more popular?
There’s no chemical element more abundant than hydrogen in the universe, but it’s still difficult to obtain in a pure and ready-to-use form. To use it in the same way we use oil and gas, we must manufacture it. The problem is that the manufacturing process itself usually releases significant climate-warming emissions. There is little point in using clean hydrogen energy if the process to create it negates its benefits.
The problems with manufacturing hydrogen
Data from the International Energy Agency (IEA), shows that 96% of hydrogen fuel production around the world uses fossil fuels — releasing at least nine tons of carbon dioxide (CO₂) per ton of hydrogen, and even up to twelve tons. The various production processes used impact the levels of CO₂ emitted.
Most of the hydrogen used today — including around 95% of projects in the U.S. — is known as gray hydrogen; made by breaking down natural gas using high heat. While this process does produce hydrogen, it also releases about 12 kilograms of CO₂ for every single kilogram of hydrogen. A cleaner option is blue hydrogen, which uses the same method but adds carbon capture technology to trap some of the emissions. Even then, it still releases three to five kilograms of CO₂ per kilogram of hydrogen.
As part of a team researching new ways of creating hydrogen, without direct CO₂ emissions, Professor Graham Hutchings of Cardiff University stated, “Finding sustainable ways of creating the products we need for everyday life and to meet net zero ambitions for the future is a key challenge facing the chemical industry. Hydrogen is widely regarded as one way of achieving these ambitions because it is made from natural gas. However, it is extremely energy intensive and, of course, when created through traditional methods, it produces large amounts of carbon dioxide limiting its environmental benefits.”
Research into cleaner ways to produce hydrogen
One potential process which would be safer for our climate, is an option referred to as green hydrogen. This utilizes clean and renewable energy, like wind or solar power, to manufacture the hydrogen. The process can emit one kilogram or less of harmful emissions, which is significantly less than the current processes in place for gray and blue hydrogen.
Researching the concept at the Massachusetts Institute of Technology (MIT) Energy Initiative, a key stumbling block is the cost of the electrolyzers that are used to split the hydrogen from water. Furthermore, wind and solar power aren’t reliable enough for a continuous manufacturing process. That leaves the options of either stopping production when conditions are not ideal, or having to rely on more traditional methods of producing hydrogen, which is counterintuitive.
Principal research scientist at the MIT Energy Initiative, Emre Gençer, explained, “If we get cheaper electrolyzers, you will definitely see more green hydrogen coming online … The reason we are talking about hydrogen today [is] because there are hard to abate sectors with electrification or other decarbonization options, and that’s why we see hydrogen as a solution. But that completely depends on how clean our hydrogen production is.”
