How to recycle olive oil manufacturing wastes?
The components of the 80% waste material could definitely be recycled using common procedures ( eg distillation, solvent extraction ) and could be used for many purposes like you mentioned or by converting the waste material to a more useful product. 

I'm not sure what they make from the waste from olive oil production exactly but a good example of similar biotechnology is the use of waste cooking oils to synthesize biodiesel.