On most recessed ethanol fireplaces the frame is non-removable. We do have some models like Ignis Ardella and Ignis Accalia on which the frame can be removed. However, because you have to leave a gap around the fireplace when you recess it into the wall for the hot air to come out, this gap will be visible when you remove the frame. That will not look pretty.
Basically, if you are looking for a frameless ethanol fireplace your best option would be an ethanol firebox. And we have many different sizes of those here:
https://modernblaze.com/collections/ethanol-fireboxes/