Just recalled something that might be used to power this lift. Baking soda and water. When I was a youngster I remember seeing this mixture power a submarine both up & down longitudinally - no emissions And would also power frog man up to the surface without any effort.

Here are the by products of combining these two.
Baking soda added to water raises the temperature slightly.
Chemical reactions are either endothermic or exothermic.... Baking soda is NaHCO3 and water is H2O. Added together you get NaOH and H2CO3 which are sodium hydroxide and carbonic acid. Carbonic acid is the fizz in soda.

And all this happened right in my bath tub while taking my Saturday night bath getting ready to go to church the next morning. Think I had to send 50 cents & a cereal box top to get the submarine and the same for the frog man. Oh did my imagination go wild with those toys.