Recycle your old used vegetable oil for using in china diesel heater or similar.

I don't think material you print parts from matters too much, but i used ABS as it has excelent resistance towards vegetable oils.

BOM:

• all 3 parts printed
• IKEA365+ 3.3L jar and lid (192.777.67)
• M4 screws and nuts
• Piece of strong fabric (like denim from old jeans)

Assembly:

• Place bottom part underside the lid and mark hole positions.
• Drill 4mm holes through the mounting holes and 32mm hole for the center.
• Attach funnel and bottom parts on the opposite sides of the lid with M4 screws.
• Cut piece of fabric that is big enough to cover the funnel, press it down some and then place holder ring on top and attach with M4 screws. (you might need to make holes to the fabric, or you can sharpen ends of those screws)

Usage:

• Connect vacuum cleaner (preferably shopvac, some oil might get up to the vacuum) to the side.
• Place sacrificial fabric on top of the denim (makes cleaning so much easier and you can use cheaper fabric)
• Turn on the vacuum and slowly pour oil on the fabric. Oil should make it through the filter and collect at the bottom of the jar.
• Filter batch multiple times if there are still particulates.
• Mix filtered oil with diesel 50:50 and burn it in the heater.

So far i've done one batch of 4 litres and burning it through. No smoke and heat generated is like with diesel alone.