Warning -- LONG POST
First -- my setup.
Processor is an re-sealable 55 gallon barrel. I've got a "manifold" that comes in the center of the lid, through a T, and out each side. All 1" iron pipe. I drilled holes in the pipe so that as it's being processed, I get a really good mix on everything.
There is a connection built into the bottom of the barrel that goes to the pump. I used a 120V 1500W water heater element in the side of the barrel about 1/3 the way up. Try to keep as much of the plumbing pipe as you can. I used a lot of clear tubing, and I've got to replace it all -- doesn't really hold up well.
Wash tank is a clear poly 55 gallon drum with a concrete bottom (I did this to make a semi-conical bottom to drain better). It's upside-down with a spigot in the smaller bung.
How I process
1. Fill processor up with oil. I do 40 gallons, which is just about all the processor can handle by the time you get everything done.
2. Start heater and pump. If you don't pump while you heat, it's more likely that you'll burn the heater element out.
3. As it's warming up, I do my titration. I take 20 ml of rubbing alcohol, add some turmeric (from grocery store) for color. Mix well. Take two syringes, fill one up with titrating fluid. Drop by drop, add titrating fluid to the alcohol until it makes the color change to pink, then back to yellow. It should do this on the first one, or two. Add two ml of oil, mix well. Then, add titrating fluid drop at a time until color goes to dark red and stays there. This could take anywhere from .5ml up to 7. Mine usually ranges 2-4. The better the oil is, the lower the number.
4. Fill a vessel with methanol, I use 23% of the volume of oil. You have to use at least 20%, but you can use up to 25%. The more you have, the less problems you'll run into, but the more it costs.
5. Measure lye (amount varies according to titration) and mix slowly with the methanol. Most of the time, it takes me 30 minutes or so to get the lye to dissolve. I'm not stirring it the whole time, just stir for a while, let it sit, come back and do it again.
6. When oil reaches 120 - 130 degrees, TURN HEATER OFF. Then, introduce methanol mixture BEFORE the pump. My batches take 5 - 7 minutes to fully incorporate the methanol. While adding this, you'll need to vent the processor (I have a spigot in the small bung of this attached to a hose fed outside). After the methanol is added, close vent.
7. Let mix for at least 1.5 hours. 2 is better. I don't think you can go too long.
8. Add 5% water to the processor, mix for 15 minutes. This is one of the best things I learned...
9. Allow to settle. Depending on a lot of things, it could take 3 hours or longer. I usually let it sit overnight.
10. Drain off glycerin from the bottom of the barrel.
11. Pump biodiesel from processor to wash tank.
12. Add water SLOWLY via a mister (Use a MistPro from utahbiodieselsupply.com) I usually add 10 gallons or so each wash cycle.
13. Start air bubbler (from an aquarium -- find a wooden "stone" -- also at utahbiodiesel) The plastic ones will just melt after a batch or two.
14. Let bubbler run for 6-12 hours.
15. Let settle for 12-24 hours.
16. Drain water from wash tank. Stop when emulsion (looks like mayonnaise) comes out.
Repeat steps 12 - 16 as many times as you need until the water comes out CLEAR and there is no emulsion left. Doing the pre-wash (5% water into processor), I usually only have to wash twice.
17. Dry -- I just turn on the bubbler -- no water, until I can shine a light through the biodiesel and it's perfectly clear. Not cloudy at all.
18. Move to storage container. I've got a 275 gallon tote that has another pump with a filter and fuel handle on it. I use a goldenrod.
19. Fill up the truck. It gets filtered on the way.
If you've got any questions -- ask away!
