Alternative fuel source, a lot of old paper, what to do??

workie job has about 400-500 banker boxes full of "unclassified" documents that need properly disposed of. It would be Very cool if I could use them to heat stuff without smoking out the neighborhood. Has anybody converted stacks of copy paper and file folders to heat things or recycle without doing the Shred/paper mill toxic chemical bath then mix/blend into pulp thing??

I want a more permie style use of this resource that can destroy the sensitive/controlled words on the paper yet not kill the environment. I'm open to any & all suggestions.
90% of said stuff falls outside of Department of Defense or Department Energy jurisdiction but sorting them requires time, so complete burn or decompose is optimal to eliminate regulatory concerns.

Well, I don't know if it would work for you or if it would work with this kind of paper but you could try the paper log maker.  It works well with newspaper and such.

https://www.amazon.com/QWORK-Newspaper-Briquette-Fireplace-Cost-Saving/dp/B0D8FG6CP6