Everything is possible, the question is "is it worth one's while".
When fitting a front derailleur to a bicycle the following aspects need to be considered:
- affixing the derailleur to the front tube - is there a hanger already or one needs to be put, or a clamp-on derailleur will fit
- is routing the cables possible - are there the suitable eyelets
- can the shifter be easily added or perhaps a brifter needs to be installed
For the first one - putting any clamp on a steel frame with round tubes is easy as pie. Even brazing a hanger (if you plan on painting the frame afterwards). For oddly-shaped tubes you are facing a challenge, and remember not to overtorque the clamps on carbon tubing.
The second one on steel and aluminium frames can be solved by attaching some routing guides with pop rivets (or brazing those on for a better visual effect if you plan on painting the frame afterwards). Carbon is not that easy to customise. You can install an electrically activated derailleur (e.g. Di2 from Shimano, EPS from Campagnolo or eTap from SRAM) and simply attach the wires with tie-wraps or electrical tape.
The third issue is the easiest to solve but depends on your current setup. And remember not to overtorque the clamp if having a carbon steering bar.
Thus, it is possible. But if you are looking for more speed range I suggest you watch this RJ The Bike Guy video where he converts a 2x7 to 1x10 and explains how the current speed range is kept in the new setup (see the chart from 13'54").