A few donation centers near where I live no longer accept books because it is costing them money to dispose of them. Outside of books that might have special interest; I had a few proofs/advanced copies I have sold and even purchased. A few first prints of some novels are valuable as well but a library or other won't know that. In the end, if you don't need the space just keep them on display. If you have lots they work great as a sound break on a wall you have noise issues with