DIY industrial chemistry

[dave]

I have seen examples online of water heaters used to make biodiesel. Does anyone know of other examples of making useful chemicals using water heaters, or other setups of similar scale?

[Shotgun]

Potassium nitrate
Collect urine and dung in barrels that have a bung on the bottom edge. Cover and let sit for several months. Filter through stainless screen and then through charcoal or ashes into plastic lined trays. Let evaporate in the sun for potassium nitrate crystals.

[Billy]

With some ingenuity, some scrounging and the book "A Text-Book of Electro-Chemistry" (ISBN-13: 978-1444624342), you could probably cobble together a DC powered rig and, using precursor chemicals, make some interesting things...

Most I've done is electro-chemically clean steel using washing soda as an electrolyte, chopped up 1/2" rebar as a cathode and anode (using soft iron wire to connect everything together) and a battery charger as a DC power source... but you could use the same tech to create some interesting things...