GHG CERN/Linde/TEGA meeting

Friday 11 Apr 2025, 11:00 → 13:00 Europe/Zurich

1. Agenda: supply topics and recuperation projects

It has been clearly stated in the beginning of the meeting that no prices will be discussed and that the meeting will be focused on supply chain and circular economy / recuperation

 

1. Supply security R 134a: CERN will require R 134a supply until 2050

Action to Linde: monitoring of regulatory developments in Switzerland about HFC status

Action to TEGA: monitoring of regulatory developments on EU level as well as in China about HFC status  

Actions to Linde and TEGA: keeping CERN updated on regulatory developments for making sure that impacts to future supply availability of R 134a will be recognized early in advance.

 

1. Alternatives to R 134a

CERN is evaluating R 1234ze as an alternative which, however, doesn't show yet promising performance. TEGA asked CERN to check whether R 1224yd would be of interest which TEGA could provide in sample quantities. It will become part of TEGA's refrigerants portfolio when supply chain out of Japan has been fully established.

Action to TEGA: to provide feedback whether HFOs, such as R 1234ze, are subject to quota consideration according to the revised F-Gas Directive of EU.

Feedback from TEGA on this question: in revised F-Gas-Directive (EU) 2024/573, only HFCs and PFCs listed in Annex 1 of this directive are subject to quota consideration, not HFOs listed in Annex 2.

Action to Linde and TEGA: to also monitor Swiss and EU regulations on HFOs and keep CERN updated.

 

1. R 14 supply request: CERN is still interested in another source for R 14.

TEGA explained the difficulty to find a source for a substance with such high GWP but will double-check whether a supply option could be established.

Action to TEGA: to get back to Linde and CERN by mid May whether a supply option can be offered for R 14

 

1. Circular economy of R 134a

From CERN‘s detectors ALICE, ATLAS, CMS and LHCb, two are currently in focus for recuperation of R 134a and R 14

 

ATLAS with Zeolite absorption/desorption

Leakages of R 134a and R 14 are kept in a cavern in which the detector is embedded. The goal is to have the air in the cavern cleaned from R 134a and R 14 by air conditioning via Zeolite which effectively absorbs R 134a and R 14 with the additional property of having R 134a and R 14 desorbed again for recuperation. So incineration of Zeolite with absorbed R 134a/ R 14 is not CERN’s preferred option. The goal is to maximize recuperation of R 134a and R 14.

Action to TEGA: to check whether Zeolite type in use at TEGA also has good desorption capabilities as well as course-grained particles (no powder!) and if so, to send CERN a 1 kg sample for comparative trials vs Z10 and DUT-67 Zeolite types. The latter shows at CERN laboratory promising desorption of absorbed R 14 at room temperature under vacuum and of R 134a at 90 °C under vacuum.

 

CMS with cooling trap

R 134a is currently recuperated by cooling trap. TEGA already received a drum of recuperated gas mixture for re-adjusting concentration of R 134a vs R 600a but couldn't find any SF6. This excercise shall be repeated but with a smaller container size.

Action to TEGA: to send CERN a large recycling cylinder (61 l) for TEGA analysis of recuperated gas mixture and possible adjustment to CERN's needs for re-use.

Action to CERN: to confirm composition of gas mixture (is R 14 (CF4) also part of CMS gas mixture?)

 

1. Other topics

 

TEGA containers for interim storage of recuperated gas mixture

MIDI container currently in use at CERN will be returned to TEGA for regeneration and recertification by TÜV around June/July 2026. Additional MIDI container and large (61 l) cylinder will be provided by TEGA; this time subject to long-term usage agreement and annual rental fee. Also the MIDI container taken back by TEGA in June July will be replaced by MIDI container which will be subject to long-term usage agreement and annual rental fee.

 

Membrane technologies for gas separation

Since CERN is also looking into certain membrane technologies for gas separation, TEGA will provide CERN with info on membranes in use at DEUKUM.

Action to TEGA: to gather information on DEUKUM's membrane types and forward to CERN.

 

CERN team members for further discussion

Action to CERN: please let TEGA know which CERN team members should be copied on our further correspondence regarding recuperation projects and requested TEGA containers.  

11:00 → 11:20 aob