The merlin engine uses TEA-TEB which causes the green flame seen on Falcon 9. The raptor uses electric spark ignition, which is harder but doesn't require any a

The merlin engine uses TEA-TEB which causes the green flame seen on Falcon 9. The raptor uses electric spark ignition, which is harder but doesn't require any awfully poisonous chemicals and you can't run out. https://en.wikipedia.org/wiki/SpaceX_Raptor https://en.wikipedia.org/wiki/SpaceX_Raptor