On Tue, 10 Apr 2018 18:02:44 +0100
Peter Parry wrote:

The proposed solution is a long vertical metal pipe
so the temperature drop and condensation of oils and fats will be far
worse. The mesh grease filters will stop some oil and grease but by
no means all. In a long vertical pipe what remains will condense out
and eventually trickle back down.

That sounds like a job for some sort of catalytic converter.