Test-batch mini-processor

5-gallon processor

Test-batch mini-processor

5-gallon processor

For one or two litres

Cheap, simple, safe and effective

For one or two litres

Cheap, simple, safe and effective

Materials

Materials

Adding the methoxide

Send mail to ghazi@wavepowerplant.com with questions or comments about this web site. Copyright © 2006 Wave Power Plant Inc. Last modified: 04/08/06

Send mail to ghazi@wavepowerplant.com with questions or comments about this web site.
Copyright © 2006 Wave Power Plant Inc.
Last modified: 04/08/06

Eco Sustainable Village

Home Made

Fuel Processing Reactors

This mini-processor is easy to make from not very much, mostly kichen stuff and a couple of tools. It's effective and safe, closed and virtually air-tight, with no splashing or leaking of hot fumes. It will make one- or two-litre batches for test-batch or demonstration purposes, suitable for single-stage or two-stage processes, with full agitation and temperature control. And you can take it anywhere.

There's no need to follow this prescription exactly -- use what's to hand, improvise. For instance, if you don't have a plastic drill-grip that will fit a plug spanner to use for the drill-stand as described below, we made a second stand using a piece of angle iron and a strip of 3/32" steel half an inch wide bent to fit round the drill and clamped in place with bolts. If you don't have a welder or can't make a steel stand, make a stand out of bits of wood bolted together and grip the drill in a portable vice clamped to the vertical. Or something. A crock-pot might do instead of a spaghetti cooker and a portable gas ring. Our gas ring died so now we use a hot-plate instead. You might find a way of using a sealed bearing in the lid rather than a wooden bush. And so on. Let us know!

· Three-litre HDPE container with two lids;

· Spaghetti-cooker -- the bottom and sides of the inner pot are full of holes like a collander;

· Electric drill;

· Plastic grip for drill;

· Stand for the drill;

· Sparkplug spanner;

· Stirrer;

· Portable gas cooker (canned gas) or electric hot-plate;

· Two half-litre PET bottles.

Cost -- in our case, zero: this was all discarded junk, including the drill, and all in perfect working order.

The drill stand is rigged from scrap angle iron and welded together, but it could just as easily be bolted. The bit that holds the drill consists of the tough plastic grip that came with the drill, a plug spanner, which conveniently fits inside the grip, held in place by two bolts (extra holes mean you can move the drill in and out from the stand), and the plug spanner is welded to an extra bit of angle iron bolted inside the vertical section, again with extra holes above and below for adjustment.


	The stirrer is a length of 6mm steel rod with a slot cut in the end and a piece of flat steel brazed into the slot, cut to size so it fits through the larger of the two HDPE container lids.


			The lid is fitted with a wooden bush cut from hardwood with a 6mm hole drilled through it to take the stirrer shaft. Make it a tight-fitting hole, then heat a piece of the same steel rod as the stirrer and push it carefully through the hole -- not too hot, just enough to scorch the surface of the wood inside the hole, not char it. Add a few drops of biodiesel for lubrication.

Cut a square hole in the lid the exact size and shape of the bush; cut another hole in the lid insert. Saw two shallow grooves on all four side of the bush, immediately above and below where it will fit the lid. Push the bush into the hole in the lid; push the insert into the lid around the bush. Secure with epoxy resin -- push the resin firmly into the grooves to hold the bush in position. Some silicon round the seams helps.

Heat up the oil in a saucepan on the gas cooker and pour it into the mini-processor.

Slide the business end of the stirrer inside the processor and slide the bush in the lid over the other end; screw the lid on firmly. Fill the two half-litre PET bottles with water at or above the processing temperature. Put the processor into the spaghetti cooker; wedge in position with a PET bottle on either side. Add hot water to the cooker to just below the height of the oil -- as much water as it will take before the processor begins to float. Use the gas flame to adjust the water temperature to the processing temperature, then turn off the gas.

Attach the drill to the stand, tighten the stirrer in the chuck, switch on and start stirring.


	Monitor the temperature with a thermometer, turning on the heat when necessary -- this is quite safe, even with gas, as is running the drill motor, as no methanol fumes escape during processing. The temperature only needs adjustment twice in an hour at normal room temperature.		The HDPE container is translucent rather than fully transparent but it's clear enough to see the reaction going on inside, and the changing colour and viscosity of the oil.

When the process is finished, disconnect the drill, remove the container and stand it on its side to settle, small lid down; later, to drain off the by-product, simply tip it up, hold it over a container and loosen the small lid, tightening again when you hit the yellow bio diesel.

Use it once a week and this 5-gallon (20-litre) processor will make you 200 gallons of quality biodiesel a year. We made hundreds of gallons with it before scaling up to bigger batches, and we still use it for small batches and demonstrations. Like our test-batch processor, it's easy to make from not very much, mostly scrap and junk.

The big oil companies do have their uses... but we prefer their nice oil cans when they're empty. And free.

It's effective and safe, closed and air-tight, with no splashing or leaking of hot fumes. It's suitable for single-stage or two-stage processes. And you can take it anywhere.

The only thing we bought was the immersion heater, which we already had. This one is 1.5 kw, more than enough -- probably a 500-watt unit would do. You could fit a thermostat or a rheostat (better) to maintain constant heat, but we didn't bother -- we found you only need to switch it on for a couple of minutes once or at most twice during the process, easy enough.

There's no need to follow this prescription exactly -- use what's to hand, improvise. For instance, if you don't have a welder or can't make a steel stand, make a stand out of bits of wood bolted together and grip the drill in a portable vice clamped to the vertical. Steel can also be drilled and bolted together. You could also use a small pump instead of the drill. And so on.

Materials

	· 5-gallon (20-litre) oil drum, with a clamp-on steel "cinch ring" rim to secure the top Immersion heater
	· electric drill (this one was discarded junk, it works perfectly)
	· drill stand -- welded together from scrap 1-1/4" (3cm) angle iron (or similar) -- or a proper drill stand, if you're lucky enough to have one
	· temperature gauge (this one also came from a junk yard)
	· paint stirrer to fit the drill
	· female threaded fitting for the immersion heater
	· Teflon plumbing tape (to seal the immersion heater fitting)
	· 3/4" hardwood -- just a small piece, for the stirrer bush
	· two 1-gallon (4-litre) oil cans
	· 2- or 3-gallon container made of tough HDPE with two lids, for the methoxide
	· aquarium air pump (this one was also junk -- Japanese junk is wonderful/appalling!)
	· length of braided 1/2" vinyl hose
	· length of 1/4 plastic tubing for the aquarium pump
	· short length of 1/8" (4mm) copper piping
	· tough epoxy resin
	· silicon

Cost -- little or nothing, depending on what you can salvage, scavenge or scrounge, but even if you buy everything you'll soon get your money back in saved fuel costs.

The drill stand
The drill stand is rigged from scrap 1-1/4" (3cm) angle iron and welded together, but it could just as easily be bolted (add 45-degree struts for strength). We made two of them. The one in action with the processor uses the tough plastic grip that came with the drill (see below). We used a plug spanner to hold it in place, but any steel piping that fits snugly into the handle will do. Secure with two bolts, extra holes in the plug spanner/piping mean you can move the drill in and out from the stand. The plug spanner is welded to a 5" (13cm) piece of angle iron that's bolted to the inside of the stand upright -- one bolt on one side at the top, another on the other side at the bottom. Drill extra holes in the stand upright so the height of the drill can be adjusted.

Right: Instead of a drill grip, this stand uses a double section of thin metal strip bent to shape and bolted to a horizontal length of angle iron welded to the vertical section. Note the extra holes in the stand upright for adjusting the height of the drill.

Above and above right: Plastic drill grip adapted to the drill stand -- it's bolted to a length of steel piping (a plug spanner) that's welded to a short length of angle iron bolted to the stand's upright.

A clamp-on steel "cinch ring" rim secures the top. Replace the silicon seal inside the rim of the lid with fresh silicon if needed. Apply the silicon and leave overnight until it's dry but still soft. Place the lid in position on top of the processor and clamp the cinch ring in place: under pressure the silicon will take the right shape and form a perfect seal. Leave for a day.

The cinch ring

Stirrer bush

The clip-on cap in the top of the processor is fitted with a wooden bush cut from hardwood with a 6mm hole drilled through it to take the stirrer shaft. Make it a tight-fitting hole, then heat a piece of the same steel rod as the stirrer and push it carefully through the hole -- not too hot, just enough to scorch the surface of the wood inside the hole, not char it. Add a few drops of biodiesel for lubrication.

These clip-on oil can caps fit well, they're strong and air-tight. Cut a square hole in the cap the same size as the wooden bush. Saw two shallow grooves on all four side of the bush, immediately above and below where it will fit the cap. Plug the bush into the square hole. Secure on both sides with strong epoxy resin. Push the resin firmly into the grooves. When dry cover the resin with silicon. Cut a hole in the inside plastic seal so that it fits snugly around the bush. In action, the bush is immediately lubricated by splash oil, and the fit is tight enough to prevent fumes escaping from the processor. The bush should last quite a long time, when it starts to get worn it is easily replaced.

Extra lids
The 5-gallon oil can top comes with a single lid. We added two more. Cut the lids from the two 1-gallon (4-litre) oil cans, leaving about half an inch of metal all around the lid. Cut two holes in the 5-gallon oil can top, slightly bigger than the lids. Fasten the new lids in place in the top with pop rivets or self-threading screws: fit the new lids from the underside; sandwich a thin layer of epoxy resin between the upper surface of the metal around the lid and the under surface of the top around the hole; seal both sides with silicon.

Fitting the heater
The heater is not only more powerful than necessary, it's also too long to fit across the 5-gallon can. So we put it in at an angle -- it starts at about two-thirds the height of the can and angles down towards the bottom of the opposite side, fitting nicely. This meant making an angled hole for the fitting -- save yourself the trouble, get a heater that fits! The fitting is silver-soldered in place and sealed with epoxy putty. It's strong and it doesn't leak.

The immersion heater element must always be completely immersed -- any uncovered portion could overheat and cause a fire.

The temperature gauge is fitted to a clip-on oil can cap in similar fashion to the stirrer bush.

Adding the methoxide
See Methoxide the easy way. You can use the easy method with HDPE carboys or similar containers with screw-on caps (preferably with bungs as well). First add the methanol, then gradually add the lye. Swirl it about from side to side rather than shaking it up and down. Don't use it until all the lye is thoroughly dissolved. If you use a white translucent HDPE container you can see any undissolved lye at the bottom of the container.

For the 5-gallon processor we use a 3-gallon HDPE container with two screw-on caps and an aquarium air-pump to transfer the mixed methoxide to the reactor vessel via a hose, with no exposure at all. Clean, safe and simple. We transfer the methanol to the HDPE container the same way.

The braided 1/2" vinyl hose goes through a tight-fitting hole in the larger cap, sealed with epoxy resin on both sides, and down to the bottom of the container. The other end fits through a hole in a clip-on oilcan cap, also sealed both sides with epoxy resin. This fits the third lid in the processor top.

The smaller cap on the HDPE container has a 1-1/2" (4cm) length of 1/8" (4mm) copper piping set into it to fit the other end of 1/4 plastic tubing from the aquarium pump.

When the pump is switched on (with the processor running) air fills the HDPE container, forcing the methoxide up the 1/2" hose and down into the processor. Once it starts flowing a syphon action takes over and the pump doesn't have to do much. It takes about two minutes.

Using the processor
Use about 15 litres (4 US gallons) of WVO -- this leaves enough room for the methanol with some space on top. If electricity is expensive for you, pre-heat the WVO in a separate container with a propane burner (we use a 20-litre stainless steel soup pot) and just use the electric element to maintain the heat. Insulating the whole processor with several layers of bubble-wrap keeps the heat in and saves on heating costs.

If you do use the immersion heater to heat the oil, Biofuel mailing list member Matt Pozzi advises: "Make a rough estimate of the element's area of contact with the oil -- length x (pi x radius squared) -- and make sure the output will be around or less than 3W/sq cm. This will ensure no burning of the oil whilst heating. Elsewise you will need to stir while heating."

The 5-gallon processor doesn't have a bottom drain, and doesn't really need one -- 4-5 gallons isn't heavy, instead of draining the settled glycerine by-product and then the biodiesel from the bottom, it's easy enough to pour the biodiesel off from the top into another container (another 5-gallon oil can). It might also be better -- the biodiesel doesn't take in any residual by-product still sticking to the sides, which it might do if bottom-draining. Also, the "girth rib" about an inch from the top makes top draining quite precise -- pour slowly as you get down towards the by-product, the first bit of by-product gathers in the rib and the remaining biodiesel flows over it. You can get nearly all the biodiesel out this way without any by-product coming with it.

There's no exposure to methanol fumes doing it this way unless the weather's really hot. At normal room temperature the excess methanol doesn't fume, vapour isn't a problem. If you're worried about it, make another clip-on lid assembly, like the one shown for transferring the methoxide, with only a short stub of piping inside the lid, just enough to secure it tightly; use translucent hose and pour the biodiesel out via the hose. The other end of the hose can be fixed to another clip-on cap fitted to whatever you're pouring it into. You'll see the dark glycerine by-product starting to enter the pipe and be able to stop pouring in time. Pour the rest -- glycerine by-product and some residual biodiesel -- into a by-product holding tank with a bottom drain and a tight lid. When it's nearly full drain off the glycerine and add the biodiesel floating on top to the next wash.

Methanol condenser
This simple condenser is used for reclaiming the excess methanol from the raw glycerine by-product, where most of it collects. The methanol can then be re-used in making the next batch of biodiesel. See Reclaiming excess methanol.

Don't do it this way if you're planning to separate the glycerine by-product into its components of glycerine, FFAs and catalyst, as the by-product probably won't separate without the methanol. After separation the excess methanol can be recovered from the separated glycerine layer. See Separating glycerine/FFAs.

The condenser is made from 32" of 2" plastic water pipe with end-caps and 58" of 3/8" copper piping, held together with plastic piping glue, epoxy resin and silicon. A cheap submersible aquarium water pump pumps cold water from a bucket through a 3/4" plastic hose into the bottom of the condenser and out again at the top and back to the bucket via another hose.

We did make a coil of 1/4" piping, but decided that it wasn't necessary. A straight length of 3/8" pipe is sufficient.

The copper piping is not coiled: it goes in the top end-cap and straight through the plastic pipe, out of the bottom end-cap and into the methanol collecting container. The top end of the copper pipe is curved round and down, the end sealed into a snap-on cap that fits one of the lids in the 5-gallon processor. The condenser is held in place by two brackets adapted to fit the 5-gallon steel bucket.

The curved section of the copper pipe is insulated, to help the methanol vapour up and round the bend before condensing at the beginning of the process when everything is still cool.

And that's all there is to it. It should recover about 3 litres of methanol from a 15-litre batch of raw by-product. The recovered methanol can be used in making the next batch of biodiesel.

How it works
Put 15 litres of by-product in the processor, fit the stirrer in position, secure the lid tightly with the cinch clamp. The snap-on cap at the top end of the condenser snaps into place, the brackets support the condenser away from the processor body.

Switch on the water pump, cold water circulates through the condenser and back into the bucket.

Switch on the immersion heater, and the stirrer. The stirrer isn't essential, but the 1.5kw heater is a bit strong and the stirrer keeps the heat distributed.

Monitor the rising temperature on the temperature gauge in the lid.

Methanol starts to condense somewhere between 65 and 70 deg C (149-158 deg F), or perhaps a little higher. As the proportion of methanol in the by-product mixture decreases, the boiling point of the mixture increases, so keep the heat on to keep it boiling.

The process ends up at just over 100 deg C (212 deg F), with 3 litres or more of clear, reusable methanol in the collecting tank.

The top bracket clamps round the plastic water pipe and grips the rim of the steel bucket lid.

The second bracket holds the condenser away from the side of the steel bucket.

The water in the bucket gets warm as the process continues and should be replaced with cold water.

The condensed methanol drips steadily into the container, ready for re-use.

[ Home ]

Adding the methoxide

See Methoxide the easy way.

We mix methoxide for test batches in HDPE chemical bottles, which have a strong lid and a bung. Drill two holes in a lid and fit two short sections of plastic or 1/8" (4mm) copper piping, fix on both sides with strong epoxy resin. To one, on the inside, fix a length of rigid 1/4 (6mm) plastic tubing that will reach almost to the bottom of the bottle. To the other, on the outside, fit a length of flexible 1/4 plastic tubing. Fit a third section of copper piping to the small lid of the processor.

To add the methoxide, remove the lid and bung from the bottle of pre-mixed (cool) methoxide and screw on the transfer lid tightly.

Fit the other end of the length of flexible 1/4 plastic tubing to the inlet pipe in the small lid of the processor. Now, carefully, lift the methoxide bottle above the processor and turn it upside down. Air goes into the open pipe to the bottom (now the top) of the bottle, methoxide drains out of the second pipe through the processor lid into the oil to be mixed.

When all the methoxide has drained, turn the bottle right way up and put it down on the table beside the processor. Any stray methanol fumes that don't condense inside the processor will vent into the methoxide bottle and condense there.