sliding barn door suspended in air

Hey Everyone!
This is my first post! My fiance and I just bought a new 2 bed 2 bath loft. It's amazing, but has one small drawback: it has no door separating the master bedroom from the rest of the loft. To complicate things, while one side of the "doorway" is a wall, the other side is a window, which means hanging a traditional door won't work very well. To make matters worse, the "doorway" goes all the way up to the 17ft ceilings, and there's a giant HVAC tube that runs through the space. I've attached a picture of the space to help you visualize what I'm talking about.

So, we're contemplating installing a sliding barn door that will go part way up the 17ft (basically, up to the HVAC), closing off the area visually. The issue I'm having is how to do this in a structurally sound manner. The wall to the right of the doorway is exactly 3'1", and the door way is slightly under 4' wide. I don't see this as a problem though, because we'd like to have the door extend slightly over the wall when closed, so that it can be closed from either side of the room.

So, my specific questions are these:
1) Do folks think having the rail for a sliding door that extends into the air would be a possibility?
2) If the answer to #1 is yes, How should we do this in a structurally sound manner? Would mounting the rail on the 3'1" wall be sufficient to hold up a solid wood door? Should we drop a cable from the ceiling to help support the overhung section?
3) How should we stabilize the door to keep it from swinging without a bottom rail? Could we have a shorter rail on the bottom that would only be used for this purpose?

Any other thoughts or suggestions on how to close this space economically and aesthetically? We're not dead-set on the sliding door, it just sounded like a neat idea. Thanks ahead of time for all your thoughts!

Welcome to the site and congrats on the new digs.
This is the kind of thing, where you get a different answer every time you look at it.
When we divide up office space we often have walls that just stop at a window sill and I think that might be an answer here. I would look at building the wall in floor to ceiling and and leave a standard 32x81 opening for a 30" door. You could build it thicker to allow a pocket door and that would need higher rough framing. The plug on this wall wiould be another problem.
I think others will be along with more ideas

Thanks nealtw! Correct me if I'm wrong, but it sounds like you're suggesting I build the wall in around the space to enclose a traditional door. I don't think I'm interested in building a new section of wall entirely. I like having the open loft feel, and a sliding door that doesn't go all the way to the ceiling would maintain that feel. I'm hoping to build it out of reclaimed lumber to give it an old look that matches the old warehouse feel of the condo. If we can accomplish this, I'd like to show off the door, and not hide it in a pocket. You mentioned the wall outlet... Good point. I'm planning on moving that outlet regardless of how we manage the door, so I'd say disregard it.

Well then, with the step down at the door I would guess the we are looking at a bearing wall, and not steel studs. If so then you could bolt up something heavy duty like 4x6 timber or a 4x4 angle iron and hang the door off of that.
Old warehouse doors have a small wheel on each side of the door bolted to the floor which would be just infront of the old wall

Yeah! That's along the lines of what I had in mind, except the bit over the doorway isn't connected to anything. Do you think a cross beam would be necessary, or do you think that the rod that the door is suspended from would be substantial enough to hold the door up on its own? The only reason I ask is that we have limited space, and installing a 4x6 beam would either require some revisions to the wall, or would make the doorway stand out substantially. What about attaching a cable from ceiling to the free end of the rod instead of adding a cross beam for support? Do you think that has any hope structurally?

Cable would help carry the weight but would not give you anything for in and out stability. The standard hardware will not be strong enough as it is designed for bolt every so many inches. I think you should by figuring out the weight of the door and then talk to some iron works shop for help on the design of the upper support.