The Potential Of Biomass In Enabling A Hydrogen Economy

Hydrogen as a fuel provides a carbon-free substitute for hard-to-abate sectors like heavy road transport, domestic heating, and industries such as steel and cement.

FREMONT, CA:  The development of BECCS and hydrogen technologies will determine how intrinsically connected the two are in a net zero future.

Reaching zero means more than just transitioning to renewable and low-carbon electricity generation. The whole economy must transform where its energy comes from to low-emissions sources. This incorporates ‘hard-to-abate’ industries like steel, cement, heavy goods vehicles (HGVs), and domestic heating.

One solution is hydrogen. The ultra-light element can be utilized as a fuel that, when incinerated in air, produces only heat, water vapor, and nitrous oxide. As hydrogen is a carbon-free fuel, a nominal ‘hydrogen economy’ has the potential to decarbonize hard-to-abate sectors.

While hydrogen is a zero-carbon fuel, its manufacturing methods can be carbon-intensive.

Producing hydrogen at scale

Hydrogen is the lightweight and most abundant element in the universe. Still, it rarely exists on its own. It’s more generally found alongside oxygen in the common form of H2O. Because it tends to form tight bonds with other elements, pure hydrogen streams must be manufactured rather than extorted from a well, like oil or natural gas.

Approximately 70 million tonnes of hydrogen are generated worldwide to make ammonia fertilizer and chemicals such as methanol or eliminate impurities during oil refining. Of that hydrogen, 96% belongs to fossil fuels, mainly natural gas, through steam methane reforming, of which hydrogen and CO2 are products. Without using carbon capture, utilization, and storage (CCUS) technologies, CO2 is released into the atmosphere, where it acts as a greenhouse gas and imparts to climate change.

Another method of generating hydrogen is electrolysis. This process utilizes an electric current to break water into hydrogen and oxygen molecules. Similar to charging an electric vehicle, this method is just low carbon if the electricity sources powering it are also.

For electrolysis to encourage hydrogen production at scale depends on a net zero electricity grid built around renewable electricity sources like wind, solar, hydro, and biomass.

Still, bioenergy with carbon capture and storage (BECCS) offers another way of producing carbon-free renewable hydrogen while also eliminating emissions from the atmosphere and storing it – forever.

Producing hydrogen and negative emissions with biomass

Biomass gasification is subjecting biomass (or any organic matter) to high temperatures but with a minor amount of oxygen added that hinders complete combustion.

The process breaks the biomass into a gaseous mixture called syngas, which can be employed as a substitute for methane-based natural gas in heating and electricity production or to make fuels. Through a water-gas conversion reaction, the syngas can be transformed into pure streams of CO2 and hydrogen.

Ordinarily, the hydrogen could be utilized while the CO2 is released. In a BECCS process, still, the CO2 is captured and stored safely and permanently. The result is negative emissions.

BECCS commences with biomass from sustainably managed forests. Wood that is unsuitable for uses like furniture or construction – or wood chips and residues from these industries – is usually considered waste. Sometimes, it’s simply burnt to dispose of it. Still, this low-grade wood can be used for energy generation as biomass.

When biomass is utilized in a process like gasification, the CO2 absorbed by trees as they grow and subsequently stored in the wood is released. Still, in a BECCS process, the CO2 is captured and transported to locations where it can be stored permanently. The overall process eliminates CO2 from the atmosphere while producing hydrogen.