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** Disclaimer **
We do not recommend or support this AppleSeed Biodiesel Reactor design.

 We offer the AppleSeed plans only for academic comparative purposes.
We fully believe our BioDiesel Processor is a much better processor design than the Appleseed.
By design, the AppleSeed processor does not have provisions to wash or dry your biodiesel to meet ASTM specs.
Do not be mislead, into believing the AppleSeed is fume free because it is not.... you risk methanol exposure.
The AppleSeed must be drained while hot exposing you to hot methoxide fumes or you risk glycerol hardening inside.

Our "All in One" processor design allows full access to the inside of the processor to clean & inspect any time.
Our design is much cheaper to construct and easier to maintain.
Our processor is fire resistant, steel, very low to fume free processing and can both wash & dry to ASTM Specs.
Build a better Processor, forget the
AppleSeed & build our "All in One" Processor instead!

**We provide this Open Source AppleSeed Biodiesel Reactor Plan for Educational Purposes ONLY.
**We shall be held harmless in the event you build or create this AppleSeed Biodiesel Reactor & suffer damages of any kind.
The Apple Seed processor is feature limited and shown in our DARE TO COMPARE area.

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                The Appleseed Biodiesel Reactor

                'open-source' plans for biodiesel homebrewing equipment,

                        using off-the-shelf parts and a water heater:



an old water heater tank can be adapted to make a safe and inexpensive biodiesel homebrewing apparatus. An HDPE carboy (white jug in photo) or other tank can become a passive small-scale methanol-catalyst mixer, and an inexpensive centrifugal pump (blue motor in photo) from Harbor Freight tools mixes the two liquids to enable the biodiesel reaction to take place. After a day of settling, the glycerol byproduct can be drained out fairly well- the tanks have a wine-bottle-bottom profile, with a drain at the 'pointed' edge, so separation of two liquids can be reasonably clean. The processor costs about $150 in plumbing and electrical, and about a day or less of work. The tank can be an ancient lime-crusted one scavenged from a dump, or can be bought new for about $200 more.

After draining off glycerol, the same mixing pump can transfer the biodiesel to a 'wash tank' for a water wash to remove methanol and water-soluble impurities. There's an extremely simple 'standpipe' design which requires no welding, which makes a nice minimal tank, the  Sean Parks' Standpipe Wash Tank. The standpipe wash tank costs about $30 in plumbing to build. People have built variations which include heating, ways to use plastic barrels, and build-in mist wash heads (which only works for smaller batches).


This system has developed a huge following in the biodiesel community, and there are hundreds of homebrewers who have built or built and modified theirs.


Plans for building the Appleseed:

there are many possible plumbing variations. Here's the bare-bones original and a parts list. Please note that the original plans really should have an additional set of valves above the pump- see photo next to the plans for the most current way I like to build these:


simplest plans, please add the extra 'fluid transfer manifold' as shown in photo next to the diagram: Here's how I now build these
Below are a couple of variations: separate sight tube and extra valves on each tube (I now consider these valves unnecessary) here is the plumbing for my 'bells and whistles' variation, with the temperature gauge shown in original packaging:

I purchase the valves at Harbor Freight Tools, where they cost considerably less than Home Depot and other places. Lowes' is my preferred big box hardware for the plumbing. Local stores like Ace or True Value can be cheap or can be very expensive for plumbing, at random. Home Depot is my last choice- their plumbing section is usually very disorganized and prices are high. Avoid at all costs.

Harbor Freight runs sales on their online or retail stores every few months- so pumps may end up costing about $25 and 3/4" ball valves can be $2 when on sale. valves will bankrupt you on this project- shop around. They range from $6 at Lowes to $12 at some local stores I've patronized, and you'll need lots of them.


Here's the shopping list and general instructions for building this reactor:

(note: all plumbing 3/4 inch unless otherwise noted. All plumbing black iron threaded pipe if possible- galvanized is sometimes the only choice for some fittings but is not preferred due to zinc content):

The modifications needed to an electric water heater are:

Remove dip tube (?) from the top cold water inlet. Dip tubes are underneath any pipes or pipe nipples threaded into the heater. This is the worst part of the operation- undoing any old piping. If it is a two-heating element water heater you might also need to disable the upper element and thermostat- the upper element is usually above the level of the oil you are heating, and would burn out if heated without being covered by liquid. You will also probably also want to mount the water heater on a stand- I use two milk crates stacked together- and strap it to the wall studs for earthquake safety in earthquake country.
I usually disable the upper heating element and thermostat in a two-thermostat water heater processor- because the upper heating element will be above the level of the oil you’re heating.


A. 3” pipe nipple
B. 3/4” x 3/4” x 1/2” tee
C close nipples – you’ll need 5
D ball valves- buy 3
E cross fitting (a sort of four-way tee, available at home depot but not all hardware stores)
F. Bushing: 3/4” by 1/2”- buy 2
G. 1/2” close nipple- 3
1/2" swing CHECK VALVE between bushing F and the 1/2 inch ball valve that controls the methoxide inlet tube. Place check valve on the 'hot oil' side of the ball valve to melt any glycerol that congeals around it. Check valve will be attached with close nipples like all other components...
H 1/2” ball valve-2
I. Nylon or Brass 90degree 1/2" thread-to-barb fitting
J. Length of 1/2 vinyl tubing
K. straight or 90 degree 1/2 inch nylon or brass hose barb
L. 3/4” Hose Barb (I use plastic grey ones, they’re also available for more money in a steel version. Plastic ones might be available through US Plastics if you can’t find them locally)
M. 1 or 2 feet of vinyl tubing as a drain/filler tube
N. Union
O 1” by 3/4” bushings- 2
P. Length of BRAIDED 3/4” vinyl hose
Q 90degree elbows-2
R. length of pipe nipple (purchase correct size after assembling everything else)
S. 2” pipe nipple- 2
T Automotive mechanical temperature gauge. I prefer the heavy-duty one from Pep Boys over the other brands/stores. It should be $15.
U. Proper plumbing to attach to water heater’s pressure relief vent and direct any fumes away from you. Ask at the hardware store
V. Water heater strapping, or other earthquake strapping for attaching the processor to your wall studs. I use webbing strapping. Please don’t use plumber’s pipe strap- its not sturdy enough to support the weight of this machine in case of earthquake.
W. Pump: This is a ‘1” Clear Water Pump from Harbor Freight Tools or Northern Tool- $35. This pump allows your 3/4” hose become sight tube (so you know how high the oil level is when filling the processor). Other pumps won’t give you this feature, in which case you will need to add a tee and another tube as sight tube
X Heating elements and thermostats: I usually disable the upper heating element and thermostat in a two-thermostat water heater processor- because the upper heating element will be above the level of the oil you’re heating.

also, not shown in diagram above: fluid transfer manifold parts:
this goes on top of the pump and before the plastic tubing:
close nipple,
two ball valves and two more close nipples
an extra 3/4" hose barb
several more hose clamps.


Disconnect power from the water heater before opening it’s electrical panels! I turn 220Volt water heaters into 110 volts and add a heavy-duty 110V plug on a 12 or 10 gauge cord, because we don t usually have 220V outlets easily accessible at the sites where I work. A 220V heating element operated at 110V will put out 1/4 the power output (watts). In practice this usually means that the lower element will heat far too slowly on 110. I purchase a 110V replacement element instead. Thermostats will work at either voltage.


(c) design 2003 Maria Alovert, published in Biodiesel Homebrew Guide, Nov 2003 edition

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Last modified: 11/26/16