Hydrogen energy offers a carbon-free alternative for the most polluting sectors such as road transport, heating and industry (cement works, steelworks, etc.). Several methods of producing hydrogen exist, but some still emit CO2. Biomass gasification captures and stores carbon and produces hydrogen without emissions.
Achieving the famous “zero emissions” represents much more than the transition to renewable or low-carbon electricity production. The entire economy must be transformed. This of course includes heavy industries, such as cement and steel works, and heavy goods vehicles which transport goods, but also heating in private homes.
While hydrogen is a carbon-free fuel, its production methods can be very emitting. In this context, biomass, organic matter of plant or animal origin, or even bacterial or fungal origin, with or without carbon capture and storage (BECCS or Bioenergy with carbon capture and storage), can play a major role.
Last January, the British government launched a vast innovation program of five million pounds sterling (nearly six million euros) for hydrogen produced by BECCS. The objective is to develop technologies for the production of hydrogen in the most polluting sectors, and to remove CO2 of the atmosphere. This program highlights the connection between biomass and hydrogen, and how these two assets together can support the UK’s goal of zero emissions.
Producing hydrogen on a large scale using biomass
Hydrogen is the lightest and most abundant element in the universe. But, on Earth, it is found associated with oxygen, in the form H2O. Closely associated with other elements, pure hydrogen must be manufactured and not extracted like oil or natural gas.
Every year, nearly 70 million tonnes of hydrogen are produced around the world, mostly to make ammonia and methanol, or for oil refining. Of these 70 million tonnes, 96% are made from fossil fuels, primarily natural gas. However, without the use of technologies to capture and store CO2carbon is released into the atmosphere, thus acting as a greenhouse gas (GHG).
The other method to produce hydrogen is electrolysis which separates hydrogen and oxygen molecules. This method is low carbon if it uses electricity which is also low carbon. It is zero carbon if the electricity comes from renewable sources, such as solar, wind or biomass.
Biomass gasification is a process by which biomass (organic materials) is subjected to very high temperatures, but with minimal oxygen to prevent complete combustion.
This process breaks down the biomass and transforms it into a gaseous mixture known as “syngas” which can be used as an alternative to methane (from natural gas) to produce heat or electricity or make fuels. This “syngas” can be converted into pure hydrogen or carbon dioxide.
With BECCS technology, the process is even more “green”. Let’s imagine that BECCS starts with biomass from forests. Wood that cannot be processed or used in supplies and construction is often considered just waste. But this wood can be used as biomass and therefore generate energy.
When biomass is used with the gasification process, the CO2 absorbed by trees throughout their life is released. The BECCS process makes it possible to capture this CO2 and transport it to a place where it will be stored permanently.
This process prevents CO2 escapes into the atmosphere during hydrogen production. So-called negative emissions technologies, such as BECCS, are considered essential by many countries. This is particularly the case of the United Kingdom which is investing in this sector.
Hydrogen in a low carbon economy
Will hydrogen play a big role in the future? In 2018, the Climate Change Committee (CCC) published a report (“Hydrogen in a low-carbon economy”) which proposed several production estimates in 2050 ranging from less than 100 terawatt hours (TWh) to more than 700 TWh.
Likewise, the report estimates that in 2050, hydrogen production using BECCS technology will be between 50 TWh and 300 TWh. This very significant gap is due to several factors, including for example the level of improvement of the biomass gasification technique.
Volumes will also depend on the commitments made by States in the BECCS and sustainable biomass sector. Another report, “Biomass in a low-carbon economy”, also published by the CCC, proposes a scenario making the United Kingdom a “hub” for BECCS technology. If London invests massively in this sector, the country would become a world leader in supply chaininfrastructure and geological storage capacities linked to BECCS. In doing so, biomass and BECCS technology would become the engine of a hydrogen economy in the UK.
