A method includes compressing an air flow to a first pressure, transferring heat from the air flow to a liquefaction fluid via an intercooler heat exchanger, compressing the air flow to a second pressure greater than the first pressure, combusting the air flow and a fuel to generate a combustion product flow, and driving a turbine with the combustion product flow. The turbine is configured to drive machinery of a liquefaction system. The liquefaction fluid includes at least one of a pre-cooling fluid, a refrigerant, and a liquefied product of the liquefaction system.