i have had some history with thermodynamics. According to Boyle's Law one can augment extraction of mechanical power from compressed air by adding heat as in "waste heat" from and internal combustion engine. So let's say you could have a drive train using compressed air (not gears and turning shaft drive line); It seems like this would allow one to add the engine's waste heat before it got to the "mechanical power out" phase of the power flow.
This would be making a new power technology, out of something we have conceived or have known about for quite a long time already. It would be something like extracting most of the exhaust heat and changing it into mechanical before it get out to the "outside air" and is lost for further direct use.
When you add heat to a pneumatic tank you would want to make sure the heat does not effect the structural integrity of the tank, but when heat is added to the compressed air through the wall of the tank or other heat transfer means. It does not simply make the internal air hotter, it adds total potenial energy or total usable power that can come out. Or with a finite amount of air, you can still get augmented power-out or total energy out. Seems like the trick would be to add as much heat energy as possible from the internal combustion stage of the engine.
We have all these new higher tech material that can be used. We have carbon fiber tanks. We might be able to use super-heated water to transfer exhaust heat, or there is the very promising crystalized carbon or industrial diamond shapes to transfer heat. (It is not common information, but industrial diamonds have 5 times more the ability to conduct heat energy than any other substance). i don't have a conceptual atomic model for that, but whatever... electrons become super efficient at moving heat energy in the diamond crystal lattice.
The initial proof or experiment would be similar to whatever experiment Boyle used in determining Boyle's law. You heat and enclosed container and watch how the pressure changes.
Since the energy storage in the tank will be designed to save instead of quit heat, whatever heat energy is lost will be "accidental" and/or through mechanical output. It seems like it could be done to create an energy capturing engine using pneumatic storage instead of battery storage.
i don't have the wherewithall to work this concept. The idea might be to create an engine that would have a far better "total energy use through air compression and then use that same compressed air to capture the heat from the internal combustion engine and turn it into heat enhance power before it reached the point of mechanical power-out.
i think there is a great deal of promise in the power technology of using compressed air to capture heat energy and turn it into electric or mechanical power. It's like a giant spring that can be augmented with heat.
Heat capture tech is something we tend to ignore because it is either too "complex or dangerous" but they have pneumatic cars in France, but apparently just in a " charge and drive" kind of way. Seems hybridizable to me.
While there's not a great deal to know about the physical gas laws that allow for this the materials, methods, and process to achieve this might be effortful. Knowing what we know, it seems like it could be done. Pneumatic energy storage would be more ideal than batteries for local energy storage from wind or solar capture for home use.
The point is there are different options that are available, but pushed out of the way because wasting or throwing away energy is the way we do it now.

