I do not know your alchemy, but I would posit that the energy used to open the portal was ultimately captured by the Barge and or the Admiral, and thus could be reapplied to you upon your death. Energy cannot be created or destroyed, after all. Merely moved around. And from all evidence, the Barge is something of a closed system most of the time.

[ Someone's been reading a lot of science books donated by people while he's down in Zero. ]