Hypothesis:
-1. we provide a source perfect gas, compressed, cold temperature sorsi (150k)
-2.surce warm environment (300k).

In a thermodynamic process, compressed gas abide by the following transformations:
-12. heating isobar;

-23.isothermal relaxation;
-34.adiabatic relaxation.
In this process, all heat received from hot source is converted in mechanical work.
As the source is warm environment, resulting from friction heat can not be transferred outside.
Now the whole issue is all just to bring gas from 34.in position 12.

This is my secret theory would imagine it's possible to achieve without energy consumption.
It is a complicated job with a simple resolution.