Biofuels’ role in the green energy transition

Imagine yourself in 2050, almost 30 years from now, standing in the middle of a larger city. What does the world look like? What powers everything around you? The cars driving by you on the streets? The airplanes above you? The ships sailing in the harbour? What kind of materials is the fashion made of? And which food can you buy in the supermarket?

Whether you imagine a world that has transitioned far, or one that is still on the journey, the strides we need to make towards this sustainable society are large and full of complexity.

One aspect of the green energy transition that is regularly discussed is the role of biomass and biofuels in the future society. Can we use biological material for the energy and other products we need, without impacting food prices, biodiversity and soil quality? The short answer is yes we can, if we do it intelligently – and NIRAS is deeply involved in projects that do just that.

What do we mean by biomass, and will we have enough for the green energy transition?

Biomass is a broad group of materials, from used cooking oil through animal manure, wheat straw, leaves, and waste wood. The question is if we have enough of these combined to drive the green transition – to which the short answer is no, we unfortunately don’t. Researchers estimate that, in 2050, humanity will be able to use 50 to 150 exajoule (10¹⁸ joule) of biomass per year for our societies, sustainably. This covers only between one fourth to one twelfth of our current global energy use of 600 EJ per year – and that doesn’t include materials, chemicals and other products that are produced with fossil carbon today. Power-to-x will be able to cover some of this gap, but its high energy demand and costs means it cannot cover all and not rapidly enough. Therefore, even though biomass cannot cover the entire global energy and carbon need, it does have a core role to play in supplying carbon, molecules and energy into the transition.

Today, biofuels are already produced at scale using easy-to-convert biomass such as used cooking oil, or energy crops such as vegetable oils. These are challenging to scale either because they are scarce, which is the case for used cooking oil, or have unclear and difficult to convey climate improvements which is the case for as biodiesel from vegetable oil and ethanol from corn. To scale biofuels to make a real impact, we will need to address the more difficult ones to degrade biomasses, most of which fall into the category “lignocellulose” – a word which might be unfamiliar to most, but which is actually all around us.

Converting lignocellulose to biofuels

Most biomass available globally consists primarily of lignocellulose. Lignocellulose is the main constituent of e.g. wood, grasses, straw and other plant products, and consists of a complex structure of biopolymers giving the plant strength and protecting it from attack.

The lignocellulose structure is expensive to break and prepare for conversion, but also holds potential for valorising the individual components of the biomass once the separation has been done. Several technologies able to convert lignocellulose are nearing technical and market maturity. Examples are 2^nd generation ethanol, where the lignocellulose is broken down and the sugars converted to ethanol, and thermal conversion processes such as pyrolysis, gasification and hydrothermal liquefaction where the biomass is converted to a bio-oil or a gas at high temperatures.

Biogas can also convert some lignocellulose, though it requires a thorough breakdown of the structures before entering the biogas plant. Most of these technologies have been available for a long time, though the financial performance or incentives have not been present to warrant rolling them out. Recent changes in regulatory support form EU and US and customer willingness to pay for a more climate friendly product are creating a pull to for these on the market – though the transition is still happening slowly often driven by a high investment cost and limited profitability. So, how do we inject value into the biomass value chain to accelerate the transition?

Producing high value products from biomass

Though we can convert biomass to energy and fuels, these are generally low value products with fluctuating market price. Additional regulatory support may make this more profitable, which would benefit the roll-out of the fuel technologies. However, some companies are having success in creating even more societal and monetary value from the biomass, by extracting or producing high value products from the biomass before using the rest for energy.

Examples of this is recovering proteins for feed or food, natural waxes to replace fossil waxes or dietary fibres for food. Extraction of valuable compounds injects much needed value into the biomass value chain, leaving the remainder to be converted to lower value products such as energy and fuels. It does, however, also mean that an entire value chains must be established to utilize every component of the biomass, which takes time and puts high pressure on the first valorisation step to secure a business case before the next steps of the value chain steps are established. We call it “utilization in a cascade.”

So, how do we get to the future of biofuels and other bio-products?

It will require large strides before we reach a society where we utilize the biomass intelligently to cover our needs for energy, molecules and biogenic carbon. From where we are sitting, some of the necessary strides are:

• Supporting upscaling of new technologies: Many innovative companies struggle to develop biomass utilisation technologies past the pilot scale. Reaching demonstration scale and then full scale is therefore aptly called “the valley of death”. A solution to crossing the valley of death is establishing central pilot and upscaling facilities for biorefining technologies. Baltic Plant Solutions, (BPS) which NIRAS has been part of developing, is an example of an upscaling plant that would help develop the technologies we need for our future society.

• Focus on establishing value chains for cascade use of biomass: Companies and regulators should focus on creating several steps of the value chains needed to utilize every component of the biomass.

• Additional regulatory support for biofuels and other bio-products: Though the US and the EU are taking strides in supporting greener products, we need more and broader support if we want to see the transition happening fast enough. Increasing the value of biomass products will also have a great effect on the biomass availability. We have spent many years minimizing biomass production in e.g. agriculture, where long wheat straw and corn stover were a nuisance more than a product opportunity. Increasing the support and value of using biomass will see us shift back towards biomass production, thus securing much needed carbon, molecules and energy for the transition.  

In conclusion, biomass can be a central resource in the future society. It can supply carbon, molecules and energy to produce some of the fuels, materials and chemicals we need in the future.

However, we need to support technologies that use broadly available biomasses, and technologies that produce high value products from said biomass. With these technologies we can build a green society using biomasses in amounts and origin that have sustainable impacts on the climate and biodiversity.