I have a stand alone range, between two doors, not on an outside wall. My question is, can I send the vent up to a 90 degree elbow above a drop ceiling and straight 7 feet to an outside wall?

Is the range designed to be vented?

I want it going out because we want to eliminate all the cooking odors in the home.

Then install a range hood and follow the install instructions. A range hood properly installed will give you enough square inches of capture area and they are also powered so you can use a longer vent pipe to terminate it outside.