Renewable fuels set to take off
Plant oils are typically made in a plant’s seeds or fruit: think canola oil from seed or palm oil from fruit.
But through recent scientific breakthroughs by the CSIRO, we have been able to revolutionise the way plants produce triglyceride oils. Triglyceride oils contain high-energy fats that are ideal to create fuels.
CSIRO scientist Dr Thomas Vanhercke, explains.
“Instead of getting oil from a plant’s seeds or fruits, we have engineered plants to synthesise and accumulate large amounts of oil throughout their vegetative biomass — through their leaves and stems,” Dr Vanhercke said.
The plants in this study are now known as Biomass Oil plants.
“Biomass Oil plants have the potential to massively increase oil crop productivity and expand the production base of renewable raw materials (feedstocks) used for conversion to fuels such as biodiesel, renewable diesel and jet fuel.”
From a farm-to-fuel perspective, triglyceride oils are the preferred feedstock for these renewable fuels. But their supply is heavily constrained by the limited number of highly productive oil crops, and the priority for those oils in the food supply. The current availability of plant oils is insufficient to meet the massive supply needed to replace petroleum-derived diesel and jet fuels.
Our demand for fuel
Currently, over five billion tonnes of petroleum are used globally every year. That’s around 100 million barrels each day! Around three-quarters of this is converted to petrol and diesel fuels for the road transport sector. However, in the road transport sector, renewable electrical and hydrogen alternatives energy systems are already providing a promising path to decarbonisation at scale.
The remaining quarter of oil barrels are refined into either petrochemicals or fuels for aviation and marine transportation. It is generally recognised that aircraft and ships will continue to have a heavy reliance on liquid fuels for the foreseeable future. Bio-based renewable fuels will likely play a major role in decarbonising these transport sectors into the future.
Transition to renewables
The aviation industry has been introducing sustainable aviation fuel into its supply chains for the past several years; marine fuels (fuel for ships) are starting to follow that lead. Renewable diesel offers a pathway to meeting sustainability goals and new industry standards in both sectors. But replacing all of this fuel — around 600 million tonnes — with renewable liquid fuels is a daunting task as has been documented in recent IEA reports by the International Energy Agency and the World Economic Forum.
After the stop-start of the early days, the renewable fuels industry is now gaining momentum. Early pioneers such as Neste from Finland are expanding their production facilities globally, and new entrants are emerging and consolidating. Likewise in the petroleum sector, with global majors, such as BP and Total, and Eni, migrating parts of their refinery operations to renewable feedstocks.
These projects are being established on currently available oil feedstocks that are either unsuitable for human consumption (such as used cooking oil, tallow and Carinata oil), or are traded food oils (such as palm, canola and soy). It is widely recognised that these feedstocks cannot be expanded sufficiently to enable the full-scale transition to renewable aviation and marine fuels at a global level. As such, new and more scalable feedstocks are needed to underpin further expansion of renewable fuels to meet the goal of complete petroleum replacement. This is where Biomass Oil crops could become a game-changer.
Switching on the good oil
Plant leaf cells normally store their carbon and energy as low value starch and sugars. With the addition of Biomass Oil technology, the leaf cells can be converted into biofactories producing large amounts of high energy density oils. Using tobacco as a model plant, CSIRO researchers have engineered up to 33 per cent oil in leaves and stems than unmodified plants.
The technology is being proven in leaf, stem and root tissues of a range of other biomass plants, including sugarcane, sorghum and potato, and is expected to be broadly deployable across a wide range of other plant species. Oil yields of five to six tonnes per hectare can be anticipated when optimally deployed in high biomass crops grown at high density, making it equivalent to commonly used oil palm in productivity.
Biomass oil production could be readily integrated into existing agricultural systems, either as dedicated rotational oil biomass crops or as a valuable co-product in the crop residue of food and feed crops. This would complement rather than compete with land needed to grow food crops.
Biomass Oil production also has economic benefits. Recent modelling demonstrates that the technological step-change will reduce the cost of renewable oils and fuels to below that of renewable jet fuel produced from existing oil crops and algae.
Biomass Oil offers promise for the future transition to renewable fuels. This new product can increase plant oil productivity and profitability through the supply chain, all the while minimising the displacement of current land use or farm practices.
AGRENEW is an agbiotech consultancy focussed on rethinking the design of plant oil production systems for new and improved food and industrial products.
Spiegare is a specialist advisory service that works with a range of partners undertaking technology transfer and commercialisation of research.