Crude oil from sludge should ease the climate footprint from heavy traffic. Wastewater company joins forces with oil refinery in Fredericia in a three-year development project, where crude oil extracted from sewage sludge will make diesel oil greener in order to reduce CO2 emissions from trucks and ships. Large lorries meander through the countryside on European motorways. They cross country border after border, while supplying EU countries with goods.
The highway mastodons symbolize trade, movement and dependence between countries – in a cloud of diesel. Because at the same time as their important role as impulses in Europe’s central nervous system, they emit massive amounts of CO2. In fact, emissions from heavy and light trucks make up almost 40 percent of total emissions from the transport sector in the EU, according to figures from the European Environment Agency. And while the electrification of passenger cars is growing, there are not the same opportunities in freight transport. Here one must not forget shipping, which is also deeply dependent on oil.
To reduce CO2 emissions, the EU has introduced a directive that fuels must contain a certain amount of biofuel under designations such as E10 and B7, which relate to petrol with 10 percent bioethanol and diesel with seven percent biofuel.
Biofuels are one of the keys to a gradually more fossil-free future. And that makes it attractive to be ready with the right technology when the green transition seriously affects freight transport. At the same time, there is also a rift over the green fuels. This has resulted in a sensational collaboration in Fredericia, where the city’s wastewater company and the large oil refinery join forces to produce crude oil, which is then refined together with fossil oil.
Over the next three years, the HTL technology from a third partner in the project, Circlia Nordic, will be tested at Fredericia Spildevand og Energi A / S. An HTL plant, such as the one that would like to be in test operation at the treatment plant in a year and a half, is designed to speed up the natural decomposition process by allowing the sludge to heat up to approximately 325 degrees under 200 atmospheres pressure, whereby the oil in the organic material is being extracted. The entire plant can be in a large container.
If the project is a success both climatically and economically, a great potential opens up, because all treatment plants in principle have the opportunity to produce crude oil, which can then be refined into fuel.
Not just a bucket in a lab
“This is our largest development project in the next three years,” says Søren Hjortsø Kristensen, CEO of Fredericia Wastewater and Energy, as DANVA meets him ahead of the start of the new project. “It’s not just a bucket in a laboratory, we’re talking about several thousand tonnes. And the project goes all the way and investigates how the finished, refined fuel works in diesel engines, ”says Søren Hjortsø Kristensen.
In short, the project will investigate whether it makes sense to extract crude oil from sewage sludge in full scale. Including whether it should be combined with biogas production or not, or which of the two methods utilizes the sludge most optimally. In addition to the wastewater company, the project partners consist of Crossbridge Energy Fredericia, which is a newly established Danish company with American owners who earlier in 2021 bought Shell’s refinery in Fredericia. Crossbridge Energy refines large amounts of oil from the North Sea, but the company’s goal is to become CO2-neutral.
“By utilizing a residual fraction such as sewage sludge, we will be able to make heavy transport more sustainable at the same time as we utilize a waste resource. The Crossbridge Energy A / S refinery has already tested refining other types of crude oil in our facilities. By coming together and contributing with all project participants’ know-how and technical possibilities, we can test things in practice, ”says technology manager Kristen Kristensen from Crossbridge Energy. He is the project manager for Sludge2Fuel, as the project is aptly named.
In addition, the Danish company Circlia Nordic (formerly Bio2Oil) is included, which has developed the HTL plant itself, which will eventually have a place on the treatment plant. Entrepreneur Ib Johannsen is a former associate professor at Aarhus University, where he has developed the HTL reactor that the university has in Foulum. Aarhus University is also involved in the project and contributes knowledge and analyzes within, among other things, climate footprint, residual products and economics.
Finally, Krüger is part of the project with a special focus on the wastewater that comes out of the HTL process. That water must be purified, and it is assumed that it places special demands on the bacteria in the treatment plant, where one will try to accustom the bacteria gradually to this new and concentrated type of wastewater.