Week 30/2019

Going green with dry ice

CO2 dry ice pellets just a few millimeters in size remove dirt in engines
CO2 dry ice pellets just a few millimeters in size remove dirt in engines
During every flight, the engines of an aircraft suck in insects and dust from the air that accumulate in the engine. If the machines are cleaned regularly, they consume up to one percent less kerosene for the same output. A clean engine thus saves up to 80 tons of CO2 emissions per year. Lufthansa Technik in Hamburg has now developed a globally unique process that cleans engines even faster and with less residue – and can even be used in winter at sub-zero temperatures.

The new process is called Cyclean dry ice. A mobile cleaning system is backed up to the engine – no matter where the aircraft is standing – and sprays pellets of CO2 dry ice a few millimeters in size at high pressure into the turbine. On impact, the -78,5 (-109.3 °F) cold pellets release kinetic energy, removing impurities.

Faster cleaning, less resource consumption

The new cleaning process has enormous advantages. Since the cleaning system does not have to be attached to the engine as in previous processes, the cleaning time is halved to just 30 minutes. The consumption of resources is also reduced, as water no longer has to be used. The CO2 applied is a byproduct of the fertilizer industry and does not have to be generated for this purpose. And the pellets vaporize after cleaning, so there are no residues.

The process is a further development of the Cyclean® cleaning process, which Lufthansa Technik has been using worldwide since 2007. Since it works with water, however, it cannot be used at temperatures below 5 °C (41 °F). There would then be a risk of cleaning water accumulating and freezing in the core engine. Cyclean dry ice, on the other hand, can be used at sub-zero temperatures. This means that engines can be cleaned anywhere in the world 365 days a year – even in permafrost regions.

The effect on the environment is also enormous: a clean engine saves up to 80 tons of CO2 emissions per year. In total, clean engines reduce CO2 emissions in civil aviation by several hundred thousand tons per year.

Lufthansa Technik developed the new process together with Darmstadt University of Applied Sciences. The development tests are currently in the final phase, and several patents have been filed. The new process is expected to be applied in addition to the water-based Cyclean engine washing from 2020 – and will make a significant contribution to "green MRO" in aviation.