Provided is a method for energy recuperation in the expansion of processed natural gas before the delivery of the latter to an acetylene production plant (H). The method includes delivery of heated processed natural gas to an expansion device and expansion of the processed natural gas in the expansion device to a pressure of 2 bar to 8 bar. The expansion device is a piston expansion machine which is operated by the expansion of the processed natural gas and which generates energy. Also provided is a plant for energy recuperation in the expansion of processed natural gas.