Steam reforming has no place in South Africa’s decarbonisation plans
Hydrogen is a fuel source that is a possible alternative to fossil fuels. It can be used in fuel cells and to create heat, and its only by-product is water, meaning it does not release any greenhouse gases when burned. But, not all methods of producing it are clean. So, should South Africa consider steam methane reforming in its green hydrogen plans?
Most hydrogen is manufactured using fossil fuels. Therefore, it is not necessarily a clean source of energy. In fact, the production of hydrogen is responsible for the emission of over 800 million tonnes of carbon dioxide every year.
However, there is a clean way to produce hydrogen. This is called green hydrogen. It is manufactured through the electrolysis of water. The hydrogen is “green” because the electric current is produced through green sources, like wind or solar power. But, green hydrogen is expensive to produce and requires large amounts of renewable energy. This is why the majority of hydrogen still comes from fossil fuels.
Other forms of hydrogen
Grey and blue hydrogen are other forms of the fuel that are not clean. Grey hydrogen is produced by burning fossil fuels, like natural gas and coal. Most of the hydrogen used in 2021 was produced this way. Blue hydrogen is also produced through fossil fuel sources of energy, but the carbon emissions are captured and stored through carbon capture and storage technology.
Steam methane reforming
Also known as steam methane reforming, this produces hydrogen using a methane source, like natural gas. Steam at high temperatures between 700°C and 1,000°C reacts with the methane to produce hydrogen, carbon monoxide and carbon dioxide.
How it works
A hot furnace heats water to form steam, which is mixed with methane-containing natural gas. This mixture is kept at a high temperature, causing the methane to react with the steam to produce hydrogen. Nickel is used as a catalyst to speed up the process and to ensure that even more hydrogen is retained. A combination of hydrogen and carbon monoxide is released. The hydrogen can then be used as a fuel. However, carbon monoxide is highly damaging to the environment.
The carbon monoxide enters a reactor filled with water and an iron-chrome based substance, used as a catalyst. This reaction causes steam, which is further broken down into oxygen and hydrogen. The hydrogen is captured, and the carbon monoxide joins with the oxygen to form carbon dioxide. This is less harmful to the environment than carbon monoxide, but carbon dioxide is still a dangerous greenhouse gas.
Steam methane reforming emissions
Unfortunately, the hydrogen produced using this method is not green. It is grey or blue because of the carbon dioxide that is released. About seven kilograms of carbon dioxide is released into the atmosphere for every kilogram of hydrogen produced.
Managing carbon dioxide
Hydrogen produced through steam reforming can be blue and, therefore, slightly more sustainable than grey hydrogen. This is because with blue hydrogen, carbon dioxide is captured and stored underground, or reused using carbon capture and storage or usage technologies. In this way, carbon dioxide can be transported underground and stored, for example. But, this method is costly and requires extra infrastructure, making it more expensive than grey hydrogen.
Green hydrogen and South Africa’s energy plans
Green hydrogen could play an important role in South Africa’s energy future and help South Africa reach its carbon emission reduction targets. German green energy think-tank Agora Energiewende says that South Africa could cut its greenhouse gas emissions by 70 per cent by investing in green hydrogen technology.
Besides being a clean source of energy, the development of green hydrogen energy sources, like fuel cells, could also create jobs and develop the country’s platinum belt. Investing in hydrogen fuel cells is a national priority for South Africa, according to President Cyril Ramaphosa.
This is according to a feasibility study done by the South African government and some private sector partners. It showed that the country could successfully develop a “hydrogen valley”. This involves setting up nine pilot projects to develop green hydrogen fuel cells and eventually integrate the use of this energy source into local economies. The government will start rolling this out in the Limpopo province, the so-called “platinum belt” where mines produce much of South Africa’s platinum. Hydrogen manufacturers will use this metal to make fuel cells, and heavy transporters in the Durban area will use them. The government will also use green hydrogen for the greening of buildings in Johannesburg.
Steam methane reforming and South Africa’s decarbonisation goals
As the feasibility study by the Department of Science and Technology and its private sector partners suggests, South Africa’s hydrogen plan is overwhelmingly a green one.
Various private sectors in the country are already investing in green strategies that rely on green hydrogen. This includes the steel and construction industries. Green hydrogen also aligns with another huge priority for South Africa: a just transition away from fossil fuels like coal. The feasibility study notes the possibility for green jobs through the development of green hydrogen technologies. Furthermore, green hydrogen will help the government to reduce air pollution in some of the country’s industrial centres, like Johannesburg.
Therefore, investing in grey or blue forms of hydrogen production does not align with the country’s decarbonisation and economic goals. Steam reforming does not make sense if South Africa wants to follow a green hydrogen path.