Method for reducing the pressure of a gas from a primary network

In a method for reducing the pressure of a gas (12) from a primary network, this gas (12) is first fed through a heat exchanger (9) whose temperature potential comes from the exhaust gases (8) of a gas turbine (2), this gas turbine (2) being a constituent part of a gas turbine group (1, 2, 3, 4). Downstream of this heat exchanger (9), the gas (14) is admitted to an expander (10) which drives a compressor (11). The reduced pressure gas (15) from the expander (10) is used to operate the combustion chamber (4) of the gas turbine group. The compressor (11) provides a certain quantity of compressor air (17) which is introduced into the compressor (1) of the gas turbine group. Because both the thermal treatment of the gas (12) from the primary network and the compressor air (17) become available by using internal energy released by the process, the electricity yield from the generator (3) of the gas turbine group is increased in a manner specific to efficiency.