New research looks at SAF production from tomato residues

Waste from tomato processing will serve to power aircraft.
Under the leadership of Graz University of Technology (TU Graz), the EU project ToFuel is developing a new biorefinery concept that will convert tomato residues into sustainable aviation fuel.
The research team is aiming for a waste-free and climate-neutral process that is also economically competitive and thus makes an important contribution to the defossilisation of air transport.
Tomatoes are the second most consumed vegetable in the world after potatoes.
The EU is the third largest producer with around 17 megatonnes of tomatoes harvested.
However, tomato production produces large quantities of residual biomass – plant material such as flowers, leaves and stems, peel, seeds and tomatoes of inadequate quality.
Most of these residues are incinerated as agricultural waste or disposed of at high cost.
At the same time, the goal of European climate neutrality and the associated reduction of CO₂ emissions in the aviation sector is largely dependent on the production of competitive and sustainable aviation fuels (SAF) from renewable raw materials.
In order to turn tomato waste into a high-quality fuel, the biomass must first be processed so that microorganisms can utilise it efficiently.
ToFuel is investigating two modern fractionation technologies. During extrusion, the biomass is treated under heat and pressure and then broken down into its cellular components by an abrupt drop in pressure.
This creates an optimally digested biomass for the subsequent fermentation process, in which microorganisms produce lipids that are later processed into aviation fuel.
In the second fractionation technology, hydrothermal liquefaction, the biomass is converted into bio-oil and biochar under high pressure and at high temperatures. Before the extracted bio-oil can be refined into aviation fuel, it must be purified of mainly nitrogen-containing interfering ions.
These unwanted ions would otherwise have a negative impact on the subsequent conversion into a sustainable aviation fuel. The corresponding fractionation, biotechnological and purification processes are being developed by the Laboratório Nacional de Energia e Geologia (LNEG) in Lisbon, TU Graz and the University of Zagreb in close cooperation.