Hydrogen - How Can It Be Created?
Hydrogen is becoming an increasingly common energy source that promises to power the world’s future economies. But many people still wonder how this chemical element can be created. In this article we’ll take you through the varied ways in which hydrogen can be generated – from Steam Methane Reforming (SMR) to Electrolysis to Biomass Gasification.
Steam Methane Reforming (SMR)
The most common way of generating hydrogen is called Steam Methane Reforming (SMR). This is a process in which methane is heated to a very high temperate (700 °C to over 1000 °C), and then mixed with a catalyst (usually nickel) in order to produce hydrogen, carbon monoxide and carbon dioxide. This process relies on natural gas to generate the methane needed to produce hydrogen, and is therefore not a renewable way of creating hydrogen.
While hydrogen generators that use Steam Methane Reforming are able to produce hydrogen of high quality and purity, they can also have a negative impact on the environment. The process of SMR also creates carbon dioxide, a harmful greenhouse gas. According to a report by researchers at Macquarie University, the carbon dioxide released accounts for 99.8% of the global warming impact from SMR hydrogen production.
A potentially far cleaner way of producing hydrogen is through electrolysis. This involves splitting water molecules into hydrogen and oxygen using an electrical current. If this electricity is produced from renewable sources like solar or wind power, the hydrogen created is completely carbon neutral and sustainable.
Hydrogen generators that produce this type of hydrogen are known as ‘green’ hydrogen generators and are becoming increasingly popular around the world – producing clean hydrogen with zero greenhouse gas emissions.
Hydrogen can also be produced from Biomass Gasification. Wood, certain plants, or even waste from industry and households can be used to create hydrogen with very low or even zero greenhouse gas emissions. This biomass is then heated with steam and combined with oxygen to produce hydrogen – all without combustion taking place.
While there are some small amounts of greenhouse gasses created using biomass gasification – these are usually offset by the production of biomass. Growing trees, energy crops or other biomass removes carbon dioxide – so the net carbon emissions are extremely low.
Water Thermolysis (also called Thermochemical Water Splitting) is an interesting new technology that generates hydrogen by splitting water molecules using high-temperature heat (up to 2,500 °C).
Water Thermolysis is very similar to electrolysis in that water is split water into hydrogen (H2) and oxygen (O2). The difference is that with this technology, instead of electricity splitting the water into oxygen and hydrogen, it’s done through high-temperate heating.
This form of hydrogen generation has been subject to much research recently. Achieving the temperatures needed for water thermolysis can be costly – that’s why researchers are looking at ways to achieve water thermolysis by using the heat produced from nuclear power plants or other heat-producing industries.
Hydrogen generators make use of a variety of different means of achieving their goal. While Steam Methane Reforming is currently the most common way to produce hydrogen, new technology offers the possibility to create clean, green, sustainable hydrogen. Biomass gasification along with electrolysis and water thermolysis promise to revolutionize the hydrogen industry, with millions of kilograms of green hydrogen produced every year.
Interested in learning more about how hydrogen can be used in fuel cells? Check out our Ultimate Guide to Fuel Cells to learn more.