What is biological hydrogen?

Biological or fermentative hydrogen is a little-known means of producing green hydrogen. It involves bacteria consuming hydrocarbons to yield hydrogen, CO2, and an acidic slurry for biorefining. The process, which is also called Dark fermentation, because it happens without light, is a type of anaerobic digestion (AD). AD being well known as the methodology behind biogas production. And identified by its dome shaped reactors in the countryside.

Fermentation is a naturally occurring process and part of a regenerative cycle where organic material grows, degrades, and evolves into other material to be used again in the cycle. Fermentation has many commercial applications, the most well known of which is probably making beer.

Why is hydrogen important?

Hydrogen is a powerful, transportable energy carrier that can be used to produce electricity or heat. It has a high-power output but crucially when hydrogen is burned, it generates only water as a by-product, meaning no harmful greenhouse gas emissions. Energy Department-funded analysis has shown that hydrogen and fuel cells have the potential to achieve significant reductions in emissions whilst supporting future energy demand.

The dichotomy is that most hydrogen is currently produced from fossil fuels, meaning any emission saving through burning hydrogen has already been lost during its manufacture. The solution therefore is to switch to low or no emissions production methods.

How is hydrogen typically made?

Hydrogen extraction methods like Electrolysers or Pyrolysis involve splitting molecules to release hydrogen. Both involve intense heat or high voltage electricity to split molecules and separate the hydrogen. Currently methane (CH4) from fossil fuel is used as the raw material, making hydrogen a high energy, high emissions fuel. This double negative is driving innovative production methods seeking to ultimately find green production alternatives. Ones which use both green electricity and a sustainable non-CO2 emissive feedstock. Hence the focus on electricity from solar and wind to manufacture the hydrogen.

What is the future of green hydrogen?

Hydrogen production technology is still developing but its production sites are currently coalescing around sources of green energy like wind and solar. Taking the hydrogen plants to the green energy source rather waiting for a distribution network is a logical first step to achieve proof of concept. However, given the location of UK offshore wind farms and the current lack of onward distribution beyond the Scottish islands and highlands this limits the commercialisation of hydrogen plants.

Biological hydrogen generation is at the other extreme. The reaction that produces the hydrogen requires little or no outside energy. Relying instead on bacteria to do the work. It makes production facilities highly mobile, but with smaller gas generation volumes, it may be less suited to heavy industry applications. The search for low carbon, high energy hydrogen is ongoing and production model is still to be defined. However, it will most likely be a matrix with production methods aligned to different sectors. Steel, which uses lots of hydrogen potentially requires generation close to production, so could sit at the point offshore energy comes to land. Other sectors may suit a more distributive model.

However, presently compression and distribution of pure hydrogen over distance is a challenge as its molecular size is so small it would simply leak out the joints in existing gas pipelines. Blending hydrogen with biogas could provide a transitional solution to leverage existing gas infrastructure. This is not in fact a new solution. Prior to the discovery of north sea oil, and the adoption of natural gas in the 1970’s, an artificial gas made from coal called “town gas” was in use. This was a blend of methane, hydrogen and CO2. Half a century later a hybrid gas containing sustainable biohydrogen and biogas merits serious consideration as a stepping stone on the path to a green energy economy.

Where does biological hydrogen sit in the future energy supply chain?

Biological hydrogen with its lower volume, localised production may find its place as a dispersed green power solution. Helping with district electricity power generation or rural mobility, where upgrading the grid or extending a pipeline is uneconomic. At Alps Ecoscience we believe biological hydrogen production should develop as an addition to current biogas production. Our research shows the production processes are symbiotic, resulting in biological, process and economic advantages. Potentially it is truly a case that the whole is greater than the sum of the parts when it comes to biological hydrogen production.

Dark Fermentation is a low energy means of producing hydrogen gas from organic material. The energy to extract the gas comes from the process itself and the feedstock is often waste from landfill or sewage. Trials suggest this production method yields lower volume of gas per tonne than electrolysis but requires no external energy from wind or solar and depending on feedstock can be carbon negative.

Biological hydrogen production methods are in their infancy and yet to commercialise. The alignment with waste processing, synergy with biogas and decentralised production facilities offer different applications within the hydrogen supply chain. Aligning biological hydrogen with district energy systems, local electricity production for manufacturing and propulsion for agricultural and construction vehicles seems a good place to focus. Which is why Alps Ecoscience is seeking to develop the UK’s first fermentative hydrogen reactor.

About Alps Ecoscience

Alps Ecoscience is a British biological engineering company specialising in the production of energy from organic biomass. In addition to R&D work into future fuels, Alps helps clients in the biogas industry to optimise the biological performance of their digesters to maximise energy output.

We are perpetually curious. Our research facility delivers innovation in green fuel production, nutrient recovery, and emissions reduction. Current projects include contracts from Department for Energy Security & Net Zero to develop novel technologies for the Dark Fermentation of biohydrogen from OFMSW and to extract bioethanol from organic waste. We collaborate with academia and industry in equal measure.

We focus our efforts on developing ways organic waste can be processed to replace hydrocarbons and lower primary resource usage. In so doing, Alps Ecoscience believe that, “we can change the world together” and preserve our precious, life-giving resources for future generations.