Recuperation systems for fluorinated gas at the CERN LHC Experiments
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Different families of gaseous detectors used in particle physics experiments are operated with gas mixtures containing fluorinated gases for different purposes. The main gases used in these detectors are tetrafluoromethane (CF4), tetrafluoroethane (C2H2F4), sulphur hexafluoride (SF6), perfluorobutane (C4F10). Given their high Global Warming Potential (GWP) and the increasingly stringent European regulations regarding the use and trade of these gases, different strategies have been adopted by EP-DT Gas Team, in collaboration with the experiments and the CERN Environmental Protection Steering board, for reducing the Green House Gas (GHG) emissions. One of the strategies, currently operating at the LHC Experiments, is the use of gas recuperation systems.
At the CERN LHC experiments four GHG recovery systems are operational: two for the CF4, one for the R134a (C2H2F4), and one for the C4F10. They are industrial-scale systems, each of which relies on different principles of gas separation and purification. Considering the unique gas mixtures used in particle detectors, these recovery systems have been specifically developed as no industrial apparatus currently exists to address the particular requirements of detector gas mixtures.
The goal is to reuse the purified gases within gas mixtures in variable fresh/recovered fractions, depending on the purity of the obtained gas (usually between 90% and 98%). The use of these recovery systems at CERN in recent years has led to significant savings both in terms of economy and emissions.
In this seminar, a complete overview of the working principle of the gas mixture separation processes will be given as well as an overview of the design and operation of the different gas recuperation plants.
Roberto Guida and Burkhard Schmidt (EP-DT)