Gas use can be made more efficient in many areas
in Gas Utilisation Technologies
The diversification of gas procurement, in particular due to high-calorific LNG and the integration of renewable gases into our gas system, may increasingly lead to fluctuations in gas quality. This has repercussions for different application technologies, for example for special combustion and production processes. Adaptation strategies for standard application technologies, for example on the heat or mobility market, are available but in particular in the commercial and industrial sector a research requirement continues to exist.
Research aims at increasing the robustness of application technologies with respect to fluctuating gas qualities by means of the dynamic combustion control approach. At the same time, the focus is on broad areas of application, not on individual technologies. Research also comprises novel control concepts, which are based on the external provision of information, for example by a grid-side gas procurement information system, but with a rather medium-term focus.
The requirements on the saving of energy are laid down in different regulations and standards. They encompass a large scope with partly differing conditions at regional and federal level. Their joint denominator is the fact that increasingly more stringent parameters and indicators for energy efficiency and emission reduction are defined.
Within the scope of energy conservation legislation, the Energy Conservation Ordinance has evolved into the central control element. It is based on primary energy factors as far as the climate protection-relevant assessment of energy sources is concerned. These in turn flow into other rules and regulations and constitute a guide parameter. Current research has revealed that the basis of calculation for primary energy factors has over the years developed such that there is no steering effect with regard to climate protection and other increasingly more important factors such as system and grid stability, resource consumption, life cycle considerations, etc.
The research cluster CHP / application technology therefore is to enhance the existing systematics of primary energy factors and supplement these with new indicators. At the same time, experience gained in other European countries outside Germany is to be taken into account. Here, advanced approaches, for instance with regard to the incorporation of CO2 emissions or biomass sustainability indicators, were developed.
The combination of fossil gas with natural gas to lastingly reduce CO2 emissions does not only constitute a cost-efficient solution for the heat market. Large potentials are also available both in the industry, trade and services sector (ITS-sector). Owing to the flexibility of the energy source gas, it can be ideally combined with regenerative energies, in particular in view of EEC-subsidised plants.
Hybrid systems, for example consisting of biomass base load plants and natural gas peak load plants, lend themselves for commercial but also for industrial heat production. In this field there are identifiable development needs as far as system integration and standardisation are concerned. As these are as a rule case-related solutions, such research projects must be developed and implemented together with the partners involved, where necessary within the scope of regional or local programmes.
Fuel cells convert energy that is chemically bound in natural gas into power and heat by electrochemical means. With this direct conversion step, very high electrical efficiencies can be achieved. In recent years, extensive research and development work has been done. Two fuel cell system principles – polymer electrolyte membrane fuel cells (PEMFC), solid oxide fuel cells (SOFC) – have turned out to be sustainable. These essentially differ in the required gas processing methods at respectively different operating temperatures. Although the SOFC technology works with very high operating temperatures of up to 750 °C, it achieves electrical efficiencies of up to 60 percent. This demonstrates the considerable potential of this type of fuel cell in an impressive manner.
A need for technological research lies in the improvement of the range of functions such as long-term stability and operational reliability, but also in system integration in the building energy sector. Attendant accompanying scientific research on the market launch is necessary to spread this climate-friendly and system-stabilising application technology. The enhancement of fuel cell technology in particular in the power range up to 50 kW for the district power supply is essential to achieve a market penetration also in superordinate sectors.
A great potential in helping to achieve the objectives of the energy transition is ascribed to highly efficient gas application technologies, as these lead to distinct CO2 reductions. In this connection, the combined heat and power generation in power-optimised or power-controlled plants is of special importance, for instance to use it in virtual power plants. Apart from system and technology research, for example in the course of the market launch of linked CHP systems based on ICT technology, accompanying scientific research in the field of emission improvements of motor-driven combined heat and power plants and their behaviour in case of more strongly fluctuating gas qualities is also necessary to that end.
Basic requirement for a power-optimised or power-controlled CHP plant operation is a heat management that is optimised for this purpose. Because this is the only manner in which an operation that is temporarily decoupled from the building’s heat requirement can be implemented. Novel storage concepts and operating strategies have to be developed, including the research work on novel storage materials exhibiting clearly higher intake capacities.
Low energy buildings place high requirements on the power supply because, as a rule they exhibit low and continuous load profiles, but nevertheless also require high peaks of demand, for example for hot water generation, to be covered. Further questions arise with regard to the technical-economical role of gas technologies in this sector. Similar research requirements arise with regard to the use and approval of regenerative gases on the heat market and for rehabilitations, for instance as accompanying research with the purpose of transferring country regulations to a federal level.
The research cluster CHP/Application Technology, headed by Dirk Hunke (Stadtwerke Neuss), is responsible for the topic of efficient gas utilisation.
The CHP/Application Technology research cluster is part of the Gas Innovation Circle. The Innovation Circle's task is to initiate, evaluate and prioritise as well as to ensure communication of the respective research topics.