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 natural gas.

With the new gas recovery system, the natural gas emitted during the plant’s operation can be recovered.

The Gas recovery at the compressor station is achieved by collecting in a common header each natural gas emission point during:

• Purging of compressor piping and gas turbine fuel gas piping during start and stop sequences
• Compressor operation (emissions through the compressor sealing system (Dry Gas Seal Primary Vent and through the operation of the gas operated valves)
• 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 storage pipeline and from there it is compressed back to the station’s main pipeline by means of the CUBO-GAS (reciprocating compressor) so that the methane does not released into the atmosphere.

From the data collected during commissioning, Transitgas estimates that it is able to recover 100% of the methane emissions during the start and stop phase of the operation (primary seal vent) of the compression units and about 98% of the methane during the depressurisation of the turbo compressors. This corresponds to an avoidance of about 54,000 Nm³ of natural gas emissions per year, which is equivalent to 997.5 tonnes of CO₂ equivalents (the above figures refer to the com-pression units total operation time of 5,200 hours per year).

This project represents an important step for Transitgas who is committed to reduce the carbon footprint in all its activities.

In line with the Swiss Confederation’s goals to reduce greenhouse gas emissions, Transitgas, in addition to its existing sustainability development programmes, continue to engage and increase its investment in low-carbon technologies, as well as launching an aggressive campaign aimed to drastically reducing emissions.