Not a perpetual motion machine. There is energy input to get the carbon from the CO2
The Diagram shows the source for the Carbon is CO2, but the engine itself does not produce the carbon. The carbon is “Refined†from the atmosphere and put in the “Fuel Tank†as carbon dust.
BTW-A lot of energy is used to refine Oil. When you take in account all the energy used to find it, pump it, transport it, and refine it, a lot of energy is wasted compared to what we get out of it when we drive our vehicles. But we are willing to waste this Energy so we can have it in a form that allows us to drive our cars.