I ordered these distillation cups about 2 weeks ago on AliExpress, and they just arrived! These collect the distilled/condensed liquids as they flow downwards, and allow you collected different grades of fuels based on molecular weight. These are designed for the home-brewing market, for distilling things like moonshine and tinctures, but they should work for any kind of distillation. I'm still waiting on three 18" condenser tubes that go with these collection cups. That should allow me to run water and/or coolant through the condensers, which will hopefully allow me to precisely control the temperature at each stage, and thus control which grades of fuel distill out. We'll see!