Gas: Reduction of emissions at compressor stations
moreGas Connect Austria GmbH contracted ILF to carry out a feasibility study for the reduction of emissions at one of their compressor stations.
In the considered station, three gas compressor units, each with a mechanical shaft power of approx. 11 MW, are installed. Each compressor unit is driven by a gas turbine. For the feasibility study, two approaches were investigated and compared from both an economic and technical point of view. Furthermore, the time required for the implementation of each approach as well as the potential of each approach for reducing emissions were evaluated.
The scope of the reconstruction work and the amount of investment required for each of the two approaches differs.
One approach would entail replacement of one of the gas turbine driven compressor units with a larger electrically driven gas compressor unit, capable of covering the entire basic supply of the station. The remaining two gas compressor units would consequently only be used when needed, enabling CO2 emissions to be reduced by 95% and methane emissions to be reduced by 88%.
The other approach would not entail any major reconstruction works, but would still reduce emissions from the existing plant. Great potential for savings was discovered related to process vent gas. On the basis of these findings, ILF elaborated a solution for the reduction of emissions. When the gas compressor units are switched off, the natural gas remaining in the compressor lines is blown out into the atmosphere; therefore by re-compressing and re-feeding this process vent gas into the gas grid, methane emissions could be reduced by 80%.