Uses for extra science packs
If you intend to continue playing post 0.15 release, then you can just wait and use them for Infinite Research, but beware of Research Revolution.
Without the use of mods, its not possible to recycle materials of any sort. I found a Steam forum post discussing this matter. You can destroy them by placing them in a chest and then destroying the chest, but that's not really a "use."
I also found a Reddit post that discusses the same topic.
There aren't any other uses for science packs besides using them for research.