Fraunhofer develops synthetic fuels from paper residues
The Fraunhofer Institute UMSICHT is producing a sustainable fuel from paper residues in the "Reststoff2Kraftstoff" project. Together with seven partners from industry and science, 50 tonnes of feedstock from the paper and pulp industry are being processed into CO2-neutral crude oil and further into standard-compliant petrol and diesel. This is then tested in series-production trucks.
Every year, about four million tonnes of fibre residues from the paper and pulp industry are produced in Germany. Disposal costs the industry a total of 160 million euros per year. The thermal utilisation of this waste also releases 500 kilogrammes of fossil CO2 per tonne, a total of about 1.5 million tonnes per year.
The aim of the research project Reststoff2Kraftstoff is to first convert this residual material into a crude oil equivalent with the help of a novel thermo-chemical conversion process (TCR process) and then to process it into sustainable standard fuels in a refinery.
Synthetic fuels from residues
Synthetic fuels from residues and waste products could play an important role in the mobility mix of the future, especially for sectors that are difficult to electrify, such as freight and air transport.
Dr Robert Daschner, head of the Energy Technology department at Fraunhofer UMSICHT Sulzbach-Rosenberg says: "To achieve the climate targets in the mobility sector, we need CO2-neutral fuels quickly. If only to make the thousands of trucks that will still have to be operated for decades climate neutral as quickly as possible."
In total, fuels based on residues from the pulp and paper industry alone could save up to one million tonnes of CO2 emissions annually. An additional 1.5 million tonnes would be eliminated because the residues would no longer have to be burned.
Project manager at Fraunhofer UMSICHT, Dr. Andreas Apfelbacher, says: "Biogenic residues from industry or agriculture are ideal input materials, as there is definitely no competition with the agricultural industry in terms of land use. Up to now, these waste materials have mostly rotted unused, thus releasing CO2. We convert them into climate-neutral fuels."
From residual material to renewable fuel
In the Reststoff2Kraftstoff project, 50 tonnes of fibre residues from the paper manufacturer LEIPA are first pre-treated, i.e. dried and pelletised.
The feedstock is then converted into a crude oil in the technical centre of Fraunhofer UMSICHT Sulzbach-Rosenberg using the patented thermo-catalytic reforming (TCR) technology. In the process, the fibre residues are first pyrolysed in a screw reactor (intermediate pyrolysis). In the second stage, catalytic reforming, the resulting coal and vapours are selectively combined, which improves the gas yield and quality. Through condensation, the process water and oil are separated from the gas phase, and the gas is purified and used for energy. In this way, a total of 2000 litres of crude oil are produced from fibre residues in the project.
The crude oil is then sent to the Bavarian Gunvor refinery in Ingolstadt. Laboratory tests and simulations are used to determine how the regenerative TCR oil can be used as a "drop-in fuel" to substitute fossil crude oil 1:1 in a conventional refinery. The product quality of the oil, especially its thermal stability, is crucial for this. Preliminary tests with TCR crude oil promise high potential on the way to defossilising existing refineries.
After the oil has been qualified, refining will be carried out on a pilot plant scale at Fraunhofer UMSICHT, in which the crude oil will be refined into renewable fuels according to DIN EN 228 (gasoline) and EN 590 (diesel). For this purpose, Clariant provides the project partners with bio-ethanol from the sunliquid® demonstration plant in Straubing.
The finished fuels are then tested on BMW test engines on roller dynamometers at the OTH Amberg-Weiden. The measurement results can be used to further optimise the parameters of crude oil production and refining.
In addition, the renewable diesel fuel will be tested in road use and under real conditions by the company MAN Truck und Bus SE. A production model of an MAN tractor unit will be used for this purpose. With the help of a PEMS (Portable Emission Measurement System), the emissions will be analysed.
In addition to the technical feasibility and evaluation of the overall efficiency of the recycling chain, the project also looks at the legal framework conditions for a fuel made from paper residues. The project partners from the Friedrich Alexander University of Nuremberg are analysing in particular the applicable relief options under the Energy Tax Act as well as the tax incentives for biofuels and other renewable energy sources.
The technical, economic and legal results from the project serve as a starting point for the conception of a large-scale plant for the utilisation of fibre residues and the production of renewable crude oil.
The Reststoff2Kraftstoff project started in spring 2021 and will run until 2024. It is funded by the Federal Ministry of Economics BMWi in the funding area "Energetic Biomass Use".
Synthetic fuels of the next generation
Synthetically produced fuels from residual and waste materials have significantly lower equivalent CO2 emissions than fossil fuels. Their production does not compete with the use of agricultural land and thus with the production of food. The potential of biomass from residual and waste materials is limited in principle, but in Germany alone there is a technical potential of over 20 million tonnes of unused biogenic residual and waste materials that could in principle be used for the production of synthetic fuels.
With the possibility of sequestering the carbon produced in the TCR process, even negative CO2 emissions become possible in balance, i.e. the CO2 bound in the biogenic feedstock is not completely released again, but stored.
Partners in the project
The research project Reststoff2Kraftstoff is an overall project between seven industrial companies and the Fraunhofer Institute UMSICHT, Sulzbach-Rosenberg branch. The cooperation partners include:
Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Sulzbach-Rosenberg branch.
Gunvor Refinery Ingolstadt GmbH
Bayerische Motoren Werke Aktiengesellschaft
Friedrich-Alexander University Erlangen-Nuremberg, Chair of Economics, in particular Economic Theory, and Chair of Tax Law and Public Law
LEIPA Georg Leinfelder GmbH
East Bavarian Technical University Amberg-Weiden
MAN Truck & Bus SE
Clariant Products (Germany) GmbH
Institute for Heat and Mobility e. V. (associated partner)
