Catalysis is an enabling technology that facilitates chemical transformations. Chemical transformations are used throughout our society and are key in the transition to sustainable systems for transportation, chemical and materials production, and energy conversion. The Competence Centre for Catalysis collects and coordinates academic and industrial expertise to unlock the potential of catalytic techniques for the transformative needs of society.
Heterogeneous catalysis is key in the formation of sustainable, energy-efficient, and fossil-free energy systems. The centre contributes to establish new energy-efficient processes and increase the energy efficiency of existing processes. The targeted energy systems are sketched in the figure.
The centre targets sustainable systems for transportation, chemical and materials production, and energy conversion. The feedstocks for energy carriers and chemicals in the centre are biomass, plastics, carbon dioxide and hydrogen. Sustainable hydrogen is produced by electrolysis of water using electricity from renewable sources such as wind, solar, and hydropower. Biomass is converted to biooil, which needs to be catalytically processed for use as fuels or feedstocks for chemical production. One key process is hydrodeoxygenation where oxygen is removed from the biooil in a thermal catalytic process. The products from these processes are stock chemicals or fuels for transportation. The fuels are different depending on the mode of transport.
Using hydrogen in fuel cell applications yields electricity through an electrocatalytic process with only water as reaction product. Emissions from hydrocarbon-based fuels in lean-burn and hybrid electric applications contain carbon dioxide and toxic gases such as nitrogen oxides. The toxic gases are controlled using thermal catalysis. Carbon dioxide can be captured and hydrogenated to methanol and longer hydrocarbons using thermal catalysis or electrocatalysis. Moreover, carbon dioxide is captured in plants and through photosynthesis photo-catalytically converted to biomass. The sketched energy system is circular without net formation of greenhouse gases.
Catalysis is fundamental in the future energy system as described in the figure. Efficient catalysts are needed in production of fuels, in fuel cell-based production of electricity, in production of chemicals and materials, and for control of greenhouse gases and emissions. To achieve the future sustainable energy system, there is a need for new, energy-efficient catalysts. As compared to existing materials, the new catalytic materials must have higher activity (lower energy consumption), higher selectivity (improved yield with less by-products), and higher durability (higher utilization of resources).
The targeted energy systems in the figure concern the catalytic control of greenhouse gases and emissions, the catalytic transformation of biomass to energy carriers and stock chemicals, the electrocatalytic conversion of hydrogen to electricity in fuel cells, and catalysis for energy-efficient chemical processes. The project portfolio within the centre is selected from an energy systems analysis perspective. Energy systems analyses, including energy-economy modelling, are useful to identify the environmental performance and cost-competitiveness of future energy carriers such as electrofuels, biofuels and hydrogen used in fuel cells. In the centre, the targeted catalytic processes, and energy carriers, are studied from a global perspective to assess their role in future energy systems. The project portfolio includes research projects within four main research areas:
– Catalysis for reduction of greenhouse gases and emissions
The transition to a fossil-independent transport sector generates new challenges with respect to greenhouse gases and emissions. The use of bio-based fuels and electrofuels in hybrid electric engines, and electric engines with electricity from fuel cells and batteries, for transportation will substantially increase during the upcoming years.
The transition to electrification and increasingly more fuel-efficient internal combustion engines that produce colder exhausts increases the demands on the exhaust after-treatment systems. As fuel efficiency increases, the exhaust gas temperature decreases and the critical operating temperature of the catalyst (below which it does not work satisfactorily) must be lowered. The use of biogas is expected to increase and, thus, also the need for efficient emission control of methane, which has a high global warming potential. Correspondingly, the requirements for aftertreatment systems for emissions from stationary plants for energy-efficient treatment increase. In both cases, catalyst-based systems that are efficient at low temperatures are required to meet both current and future legal requirements, and to increase engine efficiency. In the centre, strategies and materials to increase low-temperature catalytic activity are studied.
Catalysts are needed to improve methods to reduce nitrogen oxides with ammonia selectively to nitrogen in excess oxygen, so-called lean conditions. This is important for current and future engine concepts, based on an increasingly more fuel-efficient combustion of renewable fuels in excess oxygen. Selective catalytic reduction is presently the preferred method to reduce nitrogen oxides. Thermally stable, poison-resistant, low-temperature active zeolite-based catalysts are studied for this application. At low temperatures, hydrolysis of urea is limiting for ammonia formation. Interesting here is to accelerate the formation of ammonia by catalysis. For marine applications, the need to develop poison resistant selective catalytic reduction catalysts is of high importance. It is particularly interesting to produce catalysts with high activity and high selectivity towards nitrogen to avoid formation of the potent greenhouse gas N2O and prevent slip of ammonia after the NOx reduction catalyst.
– Catalysis for synthesis and production of renewable energy carriers
The transition to a fossil-independent transport sector is key in counteracting global warming. To realize this climate policy goal, progress is made in the transport sector to replace the present large-scale use of fossil fuels with different biobased fuels and electrification. By using biofuels and electrification it has been estimated that the emissions of GHG can 2040 be reduced by 90% with respect to the levels 2018. In this scenario, 75% of the reduction is thanks to biofuels. Catalytic technologies are required to upgrade renewable raw materials to fuels such as bio-gasoline, biodiesel, and renewable jet fuels. Most of the globally produced biofuels originate presently from hydrogenated vegetable oils and fats. However, due to the limited amounts of available oils and fats, it is critical to include biomass as a feedstock, to reach a fully sustainable transport system. Biomass contains cellulose, hemicellulose, and lignin. All these components contain a large amount of oxygen, which makes biomass different from crude oil. To produce a biofuel, the biomass must be depolymerized yielding a biooil, which thereafter can be upgraded to a fuel. One important method for renewable fuel production is fast pyrolysis giving pyrolysis oil. Pyrolysis oil is not suitable directly as a fuel, as it contains a high amount of oxygen making it highly reactive and corrosive. The pyrolysis oils must, therefore, be hydrogenated using an efficient catalyst to produce fuel components. At the centre, we explore catalytic hydrodeoxygenation of oxygenates for production of fuels from biobased raw materials. The control of selectivity towards the desired products in the catalytic hydrogenation is of major importance to cost-effectively produce bio-based fuels. Other key issues are to minimize char formation and catalyst deactivation, which is crucial to make a cost-efficient bio-refinery, that enables the sustainable transition.
Another area of increasing importance is materials recycling. The society has currently large issues with plastic waste, which could be utilised as a feedstock, thereby reducing pollution and introduce a circular materials flow. Renewable plastics are anticipated to increase. After the plastics have been recycled and the quality has reached its end of lifetime, it could be a suitable feedstock for renewable fuel production. Pyrolysis is one efficient method for converting plastics to fuels. The pyrolysis oils need to be catalytically upgraded to produce a hydrocarbon mixture suitable for fuels. In the centre, we study catalytic recycling of waste plastics to renewable fuels.
– Catalysis for fuel cells and electrocatalysis
Fuel cells convert chemical energy stored in a fuel directly to electricity and are projected to become key components in future sustainable fossil-free energy systems thanks to their high efficiency and potential for zero emissions. Today, the first generations of fuel cell vehicles are in use and fuel cells are expected to provide CO2-free and clean energy in several transport applications, such as heavy-duty and marine. However, for large-scale use, the fuel cells need to become cheaper, become more durable and be composed of sustainable materials. To a large extent, these issues are related to the catalysts on the electrodes of the fuel cell. In the centre, we develop new and sustainable catalyst electrode materials and study life-time degradation in fuel cells.
A current line of development is to produce energy carriers with fossil-free electricity from primarily weather-dependent intermittent power sources, such as wind and solar. Hydrogen can be produced in this way by electrolysis of water. In the transport sector, hydrogen can be used as fuel in combustion engines or fuel cells. By allowing gaseous hydrogen, produced by electrolysis of water, to catalytically react further with carbon dioxide, e.g. methane, methanol or other types of fuels with higher energy density and better storage properties than hydrogen can be produced. Future challenges in this area are to increase the activity and selectivity of the catalyst making the process more energy efficient.
– Catalysis for energy-efficient chemical processes
Catalysis means that activation barriers for chemical reactions are lowered and that the reactions in this way take place in a more energy-efficient manner. Catalytic technology is of central importance for environmentally friendly energy technologies and industrial chemical processes. New, more efficient catalysts for industrial processes and for environmentally friendly technologies are expected to reduce energy use, since less energy is needed for heating up the reactants. In the chemical industry, catalysis is a key component to produce many chemicals. However, the catalytic process may also result in biproduct formation. The biproducts can often be used in other processes but must be separated and purified. There are different separation techniques, but common for all of them are that they require large amounts of energy. If the catalytic process could be made more efficient with higher selectivity, there would be less need for separation and thereby large energy savings could be made. It is also critical to use renewable feedstocks for chemical production, which requires that new catalytic routes are developed. In the centre, we study reactions important in the chemical industry, with the aim to increase the low-temperature activity as well as selectivity using renewable feedstocks