Hydrogen is a non-toxic colourless gas, even when it’s referred to as green hydrogen. It’s the most abundant element – it’s estimated that 90% of all atoms are hydrogen atoms, comprising around three quarters of the total mass in the universe.
But you might be wondering how green hydrogen is produced, and whether green hydrogen represents a real opportunity to revolutionise the way we produce and use energy, especially as we continue to strive towards becoming more environmentally friendly by reducing carbon emissions.
How is hydrogen generated?
There are no natural hydrogen deposits on earth, it has to be extracted from other compounds by a chemical process. The vast majority of industrial hydrogen is currently produced from natural gas through a process known as steam methane reforming or SMR. Producing hydrogen in this way is sometimes referred to as brown or grey or even blue hydrogen!
Green hydrogen production
Hydrogen can also be produced by the electrolysis of water (using an electric current to break water, H2O, into its component elements of hydrogen and oxygen). If this electric current is produced by a renewable source (e.g. Solar PV or a wind turbine), the clean hydrogen produced is known as green hydrogen.
What are the by-products of hydrogen generation?
Steam methane reforming (SMR) reacts the methane in natural gas with high-temperature steam in the presence of a catalyst. This produces hydrogen, and ultimately carbon dioxide, CO2. As natural gas is relatively cheap, the hydrogen produced is also relatively cheap. However, the standard SMR process has the considerable disadvantage of releasing large quantities of CO2 into the atmosphere, CO2 is well known to be a highly significant greenhouse gas. It’s less well known that methane itself has a global warming potential that is 85 times higher that CO2, so any small gas leakage of methane from its source and on through the process is also a significant contributor to climate change. The unlimited production of hydrogen using SMR is a major issue in our attempts to avoid climate disaster.
Carbon Capture and Storage – CCS
Versions of steam methane reformation where the CO2 is captured and stored in a stable form elsewhere (Carbon Capture and Storage – CCS) has been proposed as a better alternative. CCS may well be workable, however there are doubts around our ability to manage and finance the storage of captured carbon through future decades and probably centuries or even millennia. Unfortunately we don’t have a good track record for managing the massive captured carbon deposits we’ve inherited. The UK’s peat bogs and moorland are vast carbon stores and emissions and our management are causing considerable concern: https://www.bbc.co.uk/news/uk-49074872
Definition of green hydrogen
If renewable energy (e.g. from Solar panels) is used to generate electricity for electrolysis of water then the green hydrogen can be generated without any harmful emissions.
Our ability to produce large quantities of green hydrogen will play a major role in providing an alternative to fossil fuels as we transition to low emissions and work towards a clean, healthy environment. With electric cars becoming more and more popular, we need to rethink our strategy for electricity generation if we are going to support the increased amount of EV drivers that will be on the road needing to charge their electric cars. Through the use of green hydrogen, we can foresee a sustainable future in handling this increased demand.
Find out how GeoPura can make a difference in providing EV charging solutions and how we promote total zero emissions through the use of hydrogen, to solve the issue created by the increase in electric car owners and their need for electricity for years to come.