List of current fields of research

In order to realise steam power plants with higher efficiencies, designers require components that use appropriate materials of construction that can withstand fresh steam conditions of over 700 °C and pressures of up to 350 bar. New design concepts and joining and sealing techniques need to be investigated to deal with these conditions. This applies to boiler parts, steam turbines, valves and pipes, for example. Read more

The permanent, secure geological storage of CO₂ fulfils an important function as other technologies will not be available on a large-scale for the foreseeable future. Following on from promising pilot tests on geological storage in saline aquifiers (e.g. in the CO₂SINK project in Ketzin), these technologies must now be transferred to larger demonstration systems as the next step. The various separation technologies available result in CO₂-rich gases containing various impurities. A detailed understanding of the interactions of the various gases with the ground will play a significant role in the safe storage of CO₂ in the long term. Read more

The oxyfuel process is based on the steam power process that has been known for decades, which is used in all coal-fired plants for power generation. The only difference is that combustion takes place here with highly concentrated oxygen and without nitrogen. The cryogenic air separation (using extreme refrigeration) that is necessary here involves high energy consumption and therefore requires significant further development of this process, on the one hand, and the development of alternative methods of oxygen production such as membrane technology or the chemical-looping process, on the other hand. Read more

In this way, compressors increase pressure and compress gases using their blades. In contrast, turbines reduce the pressure of flow media such as steam or gases in order to convert the expansion of these media into power that makes the blades rotate. In both cases, the process is carried out more efficiently when losses in the flow due to eddies and flow separation are reduced. Research work is optimising the power transmission between pressurised gas and blades and continually minimising the flow losses. Read more

Researchers are developing the so-called pre-combustion process in order to implement climate-friendly coal-fired power plants that use CO₂ capture and storage. This process is based on a combined gas and steam turbine process, which is used downstream of a coal gasification process. Read more

Turbines that can burn hydrogen-rich gases are also required in the combined gas and steam turbine process, which is used downstream of a coal gasification process (IGCC). The synthesis gas present after the gasifier and the downstream shift converter mainly consists of CO₂ and Hydrogen (H₂). For this reason, one important focus of research is the development of gas turbines that are reliable, offer fuel flexibility and are also low in emissions for this type of H₂-rich synthesis gas. Read more

CO₂ scrubbing is also referred to as the post-combustion capture process. Most common here is scrubbing of the flue gas using a chemical absorption medium or, as an alternative, dry CO₂ adsorption downstream of a conventional fossil-fuelled power plant. Read more

The output of the turbine is improved by increasing the critical parameters of temperature and pressure. This can only be achieved using new materials of construction and optimised cooling and layering technologies for cooling and coatings. Read more

The carbonate looping principle represents an attractive alternative to other systems of CO₂ capture, as the energy consumption associated with it is relatively low and, for this reason, this approach is very well-suited as a retrofit technology for existing plants.

Another alternative is the so-called chemical looping process, an innovative technology for converting fossil fuels for the purpose of energy production. In both processes, carrier materials are circulated in a loop. With carbonate looping, CO₂ is absorbed and then calcinated, and the carrier material (e.g. calcium) is circulated in a loop. In the case of chemical looping, a metal oxide is circulated in a loop as the oxygen carrier (alternating reduction and oxidation). Read more

Membranes have the potential to be used in CO₂ capture from flue gases (post-combustion), in hydrogen/CO₂ separation in synthesis gases after production of combustion gas (pre-combustion) and in oxygen production in the oxyfuel process. Experts believe that the application of membranes in pre-combustion and oxyfuel plants is particularly promising due to the physical and chemical conditions present here. Applications in post-combustion plants are also the subject of intensive research and development work at the moment. Read more

Steam power plants are known for providing stable and reliable electricity generation from coal. They can run for longer periods to meet the base and medium loads. However, in the future the grid will demand more flexibility when onshore and offshore wind power yields change with the weather. If wind turbines, for example, have to be switched off because of high winds, this loss of energy will need to be dynamically compensated for within a very short period of time. That is why it needs to be known whether future power plants that capture CO₂ can also be flexible enough to contribute to a balanced electricity supply. Read more

Pre-drying of raw coal has the potential to increase efficiencies by up to 10% for plants that burn moist lignite with a water content of over 45%.

Two processes for external coal drying are currently being developed. Read more

Extensive research work is currently being carried out worldwide that will make it possible to implement technologies for the capture and storage of CO₂ (CCS technologies) in the near future. Very prominent networks for the process of scientific dialogue have been put in place alongside national and international research programmes. Read more

Researchers are looking for insulators that will make generators more efficient. The improvement of insulation systems by using nanoparticles offers the potential to increase generator output and improve efficiencies without changing the generator size, thermal loads or resulting service life. This opens up the possibility of implementing measures on power station blocks to improve efficiency and output with reduced costs for overhauling generators. Read more

The micro gas turbine has been developed from gas turbine combustion systems in the 200-kilowatt range.

The turbine inlet temperature is to be increased to 1,300 °C from typical current values of 950 °C in order to improve the electrical efficiency. Read more

The technologies that appear to be the most promising based on current knowledge have been identified as part of investigations on CO₂ REduction TEChnologies (COORETEC) in power plants run on fossil fuels.

With a focus on the processes currently being worked on as part of the COORETEC programme, this research project aims to define uniform or comparable constraint conditions for the realistic calculation of efficiencies for the following processes. Read more

Alongside gas and steam turbines as main components, special turbomachinery will also play an important role in air separation and the compression of carbon dioxide in CO₂ capture and storage systems in the low-emission power plant of the future. The reason for this is that turbomachinery of this type consists of compressors and, in certain cases, turbine drives for these compressors. Read more

The turbine inlet temperature must be increased significantly in order to achieve higher efficiencies. To this end, new burner systems have to be developed that will achieve particularly low emissions and comply with broader stability limits even in the case of higher fuel flexibility or of exhaust gas recirculation. The combustion engineering challenges here include changed fuel specifications, higher flame temperatures and the minimisation of harmful substances. In addition, optimal combustion in partial-load operation is required in order to supply balancing energy. Read more

The amount of fluctuating power generated from wind energy is increasing all the time. Compressed air energy storage can be used to balance the oversupply during periods of strong wind with periods of high demand when winds are weak. A compressed air energy storage facility is a system that can store electrical energy in the short term. It uses excess electricity – on windy days, for example – to produce compressed air and then stores this in a cavern. Read more

A high-temperature heat storage system for combined cycle gas turbine (CCGT) plants has been under development since 2009. The integration of such a storage system in the power plant process enables the electricity and heat provision to be decoupled for specific periods. The process therefore enables, for example, the surplus heat produced in addition to customer requirements to be “parked” in the storage system during the day and then made available again at night when the gas turbines are switched off. This form of separation in CCGT plants, which are operated using cogeneration (CHP) and therefore have a high fuel energy utilisation and low CO₂ emissions, was previously not possible. Read more