In many combustion-based systems, the flue gases are not released in the atmosphere at ambient temperature. The heat they carry is then wasted and the global efficiency of the system is penalized. In this context, the PAC group investigates whether thermo-acoustic engines could offer a competitive solution. A 20-W thermo-acoustic cryo-cooler for carbon removal by solidification at 80 K is currently under construction. This project is supported by a CCRC CCF grant.