Will 2x11-speed front derailleur work on 2x9 system? mine Shimano 105 FD-5501 broke (I stripped thread for screw which holds it on braze) and I need to buy a new one. Will 2x11 speed front derailleur work with mine 2x9 system?

Thanks for help.
The short answer is yes, it should work.  I like to refer to Sheldon Brown's site because it tends to be clear and fairly technology-neutral.  It has this to say:

Pretty much any front derailer will work with any modern chain system.
It is true that the cages have gotten slightly narrower to match the narrower chains used on systems with more rear sprockets, but this is rarely a problem in practice.