Sustainable oil production of the future

Sustainable oil production of the future

Fuel for transport – such as ships, cars and airplanes – currently uses around two thirds of the annual production of fossil fuels globally. New types of sustainable transportation, such as electric or hydrogen-driven cars, are emerging, but they are still very far from capable of fully taking over from fossil-fuel driven transportation – if, indeed, they will ever be able to do so.

There is a need for alternative types of sustainable fuel to fulfil the extensive fuel consumption all over the world – and the AAU researchers believe they have found a possible solution. Kasia Arturi explains:

“The C3BO project is an extensive project, funded by the Council for Strategic Research, that includes several partners in Denmark and internationally. The focus is the use of Hydrothermal liquefaction – HTL – for transforming biomass at high temperatures and high pressure into a bio-crude which resembles crude oil to a very high degree.”


Kasia Arturi and her research colleagues in Esbjerg, Aalborg, and Aarhus are currently working on refining and optimising the HTL process. They are researching feasible ways of carrying out the process at a small scale and subsequently running tests at a pilot-plant scale in the new advanced bio-oil facility at the Department of Energy Technology at AAU in Aalborg. This will prove to potential investors and industry that the process and products are feasible and should be considering as a valuable fuel source of the future.

- “A great advantage to this technology is that we can use a wide range of biomass as feedstock for the process – which means that different bio-refineries in different countries will be able to use the type of biomass they have available, such as wooden waste from forests or algae – but in all instances get the same output: A bio-crude that can substitute the fossil fuels that are used now” Kasia Arturi explains. “At the same time, since the process takes place in a water base, it is environmentally preferable to traditional ways of processing biomass, which include the use of powerful chemicals, acids and alkalis” she adds.

Another advantage of HTL processing is that it can utilize surplus energy from other sustainable energy sources like wind and wave power for creating the temperatures and pressures needed.


In addition to the optimisation of the HTL process, the research group at AAU Esbjerg is also heading the work within finding a new way of purifying the water used during the HTL process, in principle enabling infinite recycling of this water. In order to do this, they have looked in a completely new direction.

- “We are working with a method called supercritical water oxidation that is currently being used for purifying wastewater at space stations. In both a space context and in our context, the success of the process is critical for the subsequent use of the water, so it made good sense to us to adapt that method. We are currently aiming at refining the purification to the level acceptable at wastewater treatment plants” Kasia Arturi explains and adds:

“The recycling of the water used during the HTL process is a crucial part of the sustainability of the project. We do not just want to make more sustainable products – we want the entire process to be sustainable.”


Kasia Arturi is in no doubt that the project may come to play a crucial part in solving a range of the environmental problems that the world is facing.

- “We believe this bio-crude can be a sustainable substitute for crude oil. In my opinion, in the future we will not see one energy/fuel solution that works for everyone, but rather a range of different solutions complementing each other in a coherent system. Different countries have different resources of biomass, water or wind, so there is a need for solutions that are applicable in each context” she explains and finishes:

- “A huge advantage of our solution is that, contrary to electric or hydrogen-fuelled cars, the end product can be used in the current fuel infrastructure – there is no need for modification of for instance motors. Furthermore, bio refineries will be able to use the bio-crude the way that crude oil is used today, to produce a series of important products such as chemicals or plastic. In short, we will be able to substitute crude oil in any way necessary – and at the same time use a much more environmentally friendly process.”