Annual Report 2022

14 Sustainability Project to recover blown-off natural gas Transitgas has successfully completed the project to recover blown-off natural gas at the Ruswil compressor station. As part of ongoing initiatives to reduce methane emissions from its natural gas transmission network, last December 2022 Transitgas successfully commissioned a new gas recovery system at the Ruswil compressor station. The Ruswil compressor station is equipped with four turbo compressor units. Two units were supplied by the companies Solar Turbines SA (USA) and Dresser Rand (FR) in 1998; these can compress up to 890’000 Nm3/h of natural gas. The other two units were supplied by Baker Hughes in 2001 and can compress up to 1,800,000 Nm3/h of nat- ural gas. With the new gas recovery system, the nat- ural gas emitted during the plant’s operation can be recovered. The Gas recovery at the compressor station is achieved by collecting, in a common head- er, each natural gas emission point: • while purging the compressor piping and gas turbine fuel gas piping during start and stop sequences • during compressor operation (emissions through the compressor sealing system “Dry Gas Seal Primary Vent” and through the operation of the gas-operated valves) • in the course of maintenance work (gas filter cartridge replacement , gas tanks inspection , station or unit’s maintenance , metering units replacement , etc.) The collected natural gas is led to the stor- age pipeline and from there it is compressed back to the station’s main pipeline using the CUBO-GAS (reciprocating compressor) so that the methane is not released into the atmosphere. From the data collected during commission- ing, Transitgas estimates that it is able to recover 100% of the methane emissions