We aim at developing new applications of CO2 and water, at near-critical or supercritical conditions, in chemical processes. These environmental-benign fluids, when brought at near-critical or supercritical conditions, acquire special properties that make them suitable for replacement of conventional organic solvents used in separation units or as reaction media in chemical reactions. They can be applied in a wide range of industries, enabling innovative process solutions, increasing the quality of the products, or lowering the environmental footprint of conventional processes. The group is currently focusing on the following actions:

- Production of fuels and chemicals from lignin. Lignin is the most abundant natural polymer constituted of aromatic building blocks. It is a by-product of the pulp and paper industry and of the lignocellulosic-to-ethanol processes. There is potential for utilizing this by-product for the renewable production of fuels and chemicals currently produced from petroleum. In this context, our research focuses on the hydrothermal conversion of lignin, which is to say the depolymerization and conversion of this biopolymer into value-added products by chemical reactions in water at high-pressure and high-temperature. We are currenlty doing research in collaboration with Chalmers University of Technology (Sweden) on the conversion of Kraft lignin in near-critical water in the presence of capping agents for preventing re-polymerization reactions. This research is enabled by a customized batch injection high-pressure high-temperature reactor available at Esbjerg campus.

- Upgrading of lignocellulosic biocrudes. Lignocellulosic biocrudes are raw oils that can be produced by liquefaction of lignocellulosic biomass applying processes such as pyrolysis or hydrothermal liquefaction (HTL). These biocrudes can be used for producing renewable liquid fuels, thus substituting part of the fuel production based on petroleum. However, the quality of the raw biocrudes is not high enough for application and these biocrudes need to undergo extensive upgrading. Within this area we are researching on the application of supercritical carbon dioxide (sCO2) as a solvent for upgrading biocrudes produced by HTL of lignocellulosic biomass. The aim is to generate a new process routes for upgrading, without using any petroleum-based or toxic solvent while improving the quality of the refined biocrude in order to allow blending with conventional liquid fuels. In this context, we have recently ran run one PhD project (2018-2020) focused on upgrading of pinewood HTL biocrude using sCO2 and we are currently exploring the technology on nitrogen-rich biocrudes derived from HTL on mixtures of sewage sludge and lignocellulosic biomass. This research is enabled by a supercritical CO2 extractor available at Esbjerg campus.  

- Cleaning of wastewaters by hydrothermal oxidation (HTO). Some wastewaters are difficult to clean with conventional biological processes, due to, e.g., high toxicity of the pollutants. In these cases the application of water at high-pressure and high-temperature in the presence of an oxidant (e.g., air, oxygen-enhanced air, oxygen) can be a valid alternative for degrading toxic organic pollutants from wastewaters converting them into harmless species and ensuring clean water discharge. The process also allows recovering energy form the oxidation reactions, which can be used for heating purposes. We are currently focusing on the application of this technology for treating difficult wastewaters in the oil and gas and pharmaceutical industry. In this context, we are currenlty running a research project (ZeroH2S) funded by the Danish Offshore Technology Center which aims at cleaning the wastewater which derives from the hydrogen sulfide (H2S) scavenging operation applied in offshore oil and gas. The research is based on the combination of membrane technology, for recovering the unspent H2S scavenger (MEA-triazine), and hydrothermal oxidation (HTO), which is applied for cleaning the spent scavenger. Two postdoctoral researchers are hired on this project, whcih will be completed in 2024. The HTO part of the project is enabled by a customized batch injection high-pressure high-temperature reactor available at Esbjerg campus.