M.F.
I would just not let him have the books in bed. I had the same problem with my kids so I would only make accessible the books they couldn't rip apart like board books and cloth books. I would save the "good" books for when I or someone else was reading to them. When they would ask if they could have them I would politelely say no and explain that these books are for reading not tearing. Now I have all of their books in one place and there are no problems.
For some reason it's fascinating to kids to hear and see paper rip. I would also make them clean up the pieces if they got a hold of something and tore it apart. This works with other things too like food on the floor...if they are the ones left to clean up the mess they discover that it's no longer fun.
Good Luck...