Climate Impacting Gases and Substances

The use of climate-relevant gases and substances at several institutes of the Fraunhofer-Gesellschaft was recorded as part of the preparation of the Fraunhofer GHG balance sheet for the balance sheet year 2021. Particularly noteworthy here are refrigerants and special gases containing fluorine, which are mainly used in semiconductor production.

The combination of the quantities used and the high GWP (Global Warming Potential) values of these substances provides a valuable basis for analyzing their contribution to the overall GHG balance in more detail and identifying optimization potential in a targeted manner.

Information on the quantities of refrigerants procured directly by the institutes and used to fill systems is already available. The contribution of external service providers is also taken into account for further detail.

The collection of specific data on the use of technical gases containing fluorine (e.g. NF3, SF6, CF4) is currently being supplemented by targeted queries to the participating institutes. This enables a continuous expansion of the data basis and creates the basis for precise and comprehensive balancing.

Project goals

1. Recording the status quo: Carrying out a comprehensive analysis of the technical gases and refrigerants currently used within the Fraunhofer-Gesellschaft in order to create a sound basis for optimization measures.
2. Development of precise measurement technologies: Testing innovative hardware and software solutions for the technical readout of mass flow controllers in systems. The aim is to record and log the consumption of greenhouse gases precisely and with process accuracy.
3. Online exhaust gas measurement: Implementation of continuous online measurement of exhaust gases in various phases of technological processes. The aim is to determine what proportion of the greenhouse gases used is released unprocessed or unfiltered into the exhaust air.
4. Climate impact assessment and data collection: Assessment of the potential climate impact of the gases used and development of a comprehensive concept for data collection. The data obtained will be integrated into the greenhouse gas balance (GHG balance) of the Fraunhofer-Gesellschaft.

Initial results

The data on the use of greenhouse gases at the three cleanroom institutes involved (IPMS, IISB, EMFT) is very inconsistent. While it is possible to record consumption on an annual basis at IPMS due to ISO certification and the existing building management system, only average consumption over several years can be determined at EMFT and IISB. The following diagrams show examples of the quantities of greenhouse gases used at Fraunhofer IPMS. A comparison of the corresponding quantities of CO equivalents for IPMS, EMFT and IISB is also shown, based on the assumption that the gases are not consumed in the processes and all escape into the atmosphere.

Outlook

Due to the high GWP factor, even relatively low emissions of a greenhouse gas can have a relevant impact on the environmental footprint of the Fraunhofer-Gesellschaft. A central question of the project is how much of the greenhouse gases used are actually released into the atmosphere, or how much is consumed in the process or removed via burner or scrubber systems. It is becoming apparent that the special gases containing fluorine used in the Fraunhofer-Gesellschaft make a significant contribution to the GHG balance, even if many questions remain unanswered at present.

• Gases that affect the climate = greenhouse gases
• Absorb/reflect long-wave heat radiation
• Additional warming of the earth's surface
• Different long residence times in the atmosphere
• Classic greenhouse gases (unwanted by-products e.g. from combustion processes, animal husbandry, fertilizers, sewage treatment plants and natural emissions e.g. volcanism)
• Carbon dioxide (CO₂)
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Fluorinated/partially fluorinated gases/substances (generally produced in a targeted manner and used as refrigerants, propellants, fire extinguishing agents or corrosive gases, e.g. in semiconductor production)
• Partially fluorinated hydrocarbons (C2HCl2F3 = R123a, Freon)
• Fully fluorinated hydrocarbons (C2H2F4 = R134a; CF4 = R14)
• Sulphur hexafluoride (SF6), nitrogen trifluoride (NF3)