No there isn't unfortunately. To add friends both would have to be on at the same time. The game won't allow the second alt to sign in as the first shows as signed in already.

I've already seen problems with this when my internet connection goes. Often I lose internet for a few minutes at a time and when the connection comes back I try to log in again to find it sees me as already logged in due the fact I didn't log out. The only solution I've found for that is to restart my computer.

So sorry it isn't going to work.