Many people, when getting into the production of biodiesel, do so for ecological reasons, as well as economic reasons.
For many, the use of methanol is a little disconcerting as it is derived from fosil fuels,(although some is also derived from wood) however it is still the simplest alcohol to use for the biodiesel production process. As a means of reducing the ecological impact of methanol use some have opted to recover a portion of it via the use of a condenser and simply distill it from the glycerine by-product left over after the reaction has completed.
There are many ingenious ways of building a condenser; some are attached to the reactor/processor while yet others are free-standing units, not unlike the old pot stills used in the moonshine days. Actually a pot still would make an excellent methanol recovery unit, for those with the knowledge and materials to build one.
For common people, like us, we have chosen a simpler route. A very basic, water-cooled condenser with steam entering one end and liquid coming out at the other. Our condenser can be made by anyone who has access to a hardware store where plumbing supplies are sold.
We have used a piece of black two inch water pipe as the body and a coil of 1/4" soft copper as the condensing unit.
In the above photo you can see all the materials needed,(*note: we have made some modifications since this photo was taken) other than what you attach it to, to build a no-nonsense
methanol recovery unit.
A .91m (3ft) piece of 5.08cm (2in) water drain pipe with two 7.6cm (3 inch) nipples cut from the ends. Then the nipples are fitted into end caps
and T's with a 5.08cm (2") female thread in the side port. Into these threaded side ports we screw in poly bungs from poly
drums with a center thread of 1.9cm (3/4in) already installed in the knock-out plug. Into these openings we screw in 1.9cm (3/4in)
male to hose barb fittings. Standard teflon pipe tape is used for the fittings. Be sure to use the proper type of pipe cement when
glueing the parts together. Ask the people where you get the drain pipe from which is best for your application.
Were it not for the soft copper coil we would be done, but then it wouldn't work, so on to the coil.
Seeing as we are using soft copper and it already comes pre-measured, we decided on a 3.04m (10ft) piece. You may think that that
is way too long to fit inside that short piece of drain pipe, but think again. We took a 3.8cm (1 1/2in) diameter pipe and, leaving enough
for end lengths, started slowly coiling the soft copper around the pipe until we got the result seen in the photo. Now all that has to be
done is fit it inside the drain pipe and close it all up.
The end caps have to have holes poked through to let the ends of the copper coil
stick out through a compression fitting that is afixed to the cap. Make the holes just barely big enough for this purpose.
Aftre having passed the compression fitting tightly through the cap, attach it to the inside with a locking ring, the type used in electrical joints.
Remember the 2 male to hose barb fittings ? To these we attach lengths of the hose of your choice. We prefer clear hose so we can see what is happening (or not happening). The bottom one is for filling the condenser with water, so a garden hose attachment may be handy. The top one is where the water comes out, so have it eiter return to the bucket from where you are filling it from or somewhere else you want to have water, like a garden, flower box, or in our case, to the water tank that we draw from for washing the biodiesel with. It essentially serves four purposes; one, it cools he condenser, two, it preheats the wash water,three, it washes the biodiesel and four it then, being full of lye and methanol residue, kills weeds like the poison ivy that we have.
The completed unit, is then attached to a still. In our case it is a pail from a chemical wharehouse made for handling dangerous chemicals, with a special heavy resistant gasket. In the lid of the pail we have made a couple of holes, one for the fill pipe (1/2" nipple)
to be afixed to it, again using Goop as a sealer, and a funnel on top of a ball valve. The second is again just big enough to let the steam through and is mounted on a 1/2" floor flange. From the flange, which is heavily sealed using the Goop prior to tightening it all down,
we have a short nipple and a T fitting into which there is a thermometer screwed in. This is the same thermometer we use for the main reactor. The top of the T leads to a 1/2 by 1/4 compression
fitting through which the copper tube passes on it's way to the condenser's main body. Another hole was made in the side of the pail to be used as a pour drain for the hot glycerine once the methanol is all removed. First open the inlet (funnel on top) and then the outlet drain. From this point we make bar soap (see soap section).
The electrical power is derived from a water heater element. A short 1500W 115V element is attached via conversion flange (used to convert square elements to round ones) into the side of the pail (all properly Goop-ed) and bolted down.
The equipment you will need:
- a piece of 5.08cm (2in) water drain pipe .91m (3ft) long.
- 2 T's with female threaded 5.08cm (2in) side ports.
- 2 x 5.08cm (2in) poly drum bungs.
- 2 x 5.08cm (2in) threaded caps
- 2 x 1.9cm (3/4in) male to hose barb fittings (PVC is fine)
- 2 hose clamps
- 2 lengths of hose.
- 1 3.04m (10ft) coil of 1/4" soft copper tubing.
- 1 piece of pipe 3.8cm (1 1/2in) in diameter.
- 1 garden hose adapter (optional)
- 1 tube of Goop adhesive. (Bulldog Cement MAY work ok too)
- 3 x 1/2 to 1/4 compression fittings
- 2 x 3" 1/2 NPT nipples
- 1 x 1" 1/2 NPT nipple
- water heater element coversion flange
- 1 x 1/2" floor flange
- 1 x 1/2" T
- 1 x 1/2 to 1/4 bushing (for the funnel, optional if you have a larger funnel)
- a chemical resistant pail with heavy gasket lid.
- 1 x short 1500W 115V heating element.
- some vinyl or braided clear hose
- 10GA electrical wire (or extension cord used for a car block heater unit, snip the end off.)
For copyright please see top paragraph: B100-WH