Miele uses the residual heat from the dishes to evaporate the water off of them and condeses it in a side pocket cooled by room air. Thus, the heat that is contained in the steam is released into the room and can't be reused to dry dishes.
Bosch used to use a side pocket filled with water. That would cool the left side of the tank, thus the air in the tank and have a simmilar condensing effect.
However, in the US, the hot water connection ment that that was less effective and you always needed high final rinse temperatures which ment high energy usage.
The trick behind Zeolite is that that mineral is incredibly porus on a microscopic level.
This means if you blow moist air through it, the moisture condenses out of the air without a major temperature gradient present, simply due to the incredibly high surface area.
If you know some basic physics, you know that you need incredible amounts of energery to transform water into water vapour, more so then just heating it up without changing its state from liquid to steam.
Thus, if water vapour condenses, it releases huge amount of heat. You for example might now that effect if you ever got burned by steam of a pot.
So, the moist air inside the tank is blown through that mineral. The moisture condenses and releases a huge amount energy, which in turn warms up the air again.
Moist, warm air enters the Zeolite container and hot dry air exits.
The heat of the final rinse cycle is basicly recycled over and over again while the moisture is removed. Verry little energy is lost, most of it is reused to dry the dishes further.
The mineral acts like a small heater, basicly.
The regeneration of the mineral (basicly drying the mineral) is achieved
a) just by natural evaporation in the time between cycles and more importantly
b) during the wash phase of a cycle due to the heat inside the tank being transfered to the Zeolite tank.
This allows for highly efficent drying no matter how much heat an item can hold and even with verry low final rinse temperatures (as low as 35°C or in other words 95°F). Higher final rinse temperatures of course improof drying results and times even further.