Bio-Diesel is made from
vegetable oil. In my case, the oil is
used fryer oil from restaurants. This
keeps the oil from going into a landfill, and as a bonus, restaurateurs don’t
have to pay to have their used oil removed from the premises. I show up, offer to take it away and everyone
is happy-the shop keepers for saving money and me for getting the main
ingredient of my fuel for free.
This was my mixer for four and a half years until the weekend
of
It’s just a 55 gallon poly drum with a ¼ horse
electric motor turning a shaft and propellers.
The hose, whose end is out of site, has a screen mesh to avoid picking
up French fries and chicken bones. The
pump on the left of the mixer is used to fill the drum and it is attached to a
standard under sink filter that is used as a simple gravity filter. From there the oil runs into the mixing tank.
After a little re-arranging this is the new mixer:
It uses the same motor and mixing shaft combination
and timer switch as before. The main
difference is instead of a hacked out 55 gallon poly-drum I now have a 115
gallon chemical mixer. Not only does it
look a lot nicer, but I can make twice as much fuel at a time now (or half as
often) and emptying/cleanup is greatly simplified. The Wile E. Coyote figure is courtesy of my
dad – he thought it was perfect when he found out what I was doing in my
garage.
Once I have the oil up to the required amount, I pour
in the catalyst and turn on the mixer’s timer switch and walk away. Several hours later (or sometimes the next
day) I drain off the glycerin, which is the only by-product of this process and
run it through my still to get back the excess methanol.
This is a 5.5 gallon pressure cooker attached to an
oil cooler style radiator in a water bath for the condenser. As the methanol boils off in the cooker it
goes through the hose to the condenser where it, you guessed it, condenses, and
runs down to the 1 gallon collection bottle that sits on the floor. I have since changed to a 5 gallon bucket for
collection as I usually get 2 to 2.5 gallons of methanol back per 5 gallon of
glycerin. The next step is to create a
larger distillery to accommodate the large amount of glycerin coming out of the
larger mixer. The plan is a 30 gallon
water heater and a large automotive radiator with its DC fan(s) still attached
– obviously, even larger collection containers than 5 gallons will be required.
The hot water heater has several advantages over the
current setup. First of all, unlike the
pressure cooker, it is a sealed vessel – meaning once the inlet valve is closed
the only place for methanol vapor to escape is the outflow to the condenser (aka the radiator) and there won’t be any nasty smelling (or
explosive fumes) in the air. Secondly,
it already has thermostats, so I can just set the thermostats to just above the
boiling point for methanol (60C) and I needn’t worry about getting water (B.P.
100C) into the recovered methanol. This
whole setup can be put in the garage, adjacent to the mixer, where it will free
up the stove, serve as a space heater in colder months, and speed up the
process with it’s proximity to the mixer.
The water heater is also insulated minimizing the heat required to
vaporize the methanol. Lastly, water
heaters have a drain valve on the bottom of the tank. This will be perfect for draining off the
distilled glycerin so it can be made into proper soap.
On the left is the new still with the element and
thermostat covers still off. They will
be put back once I have the proper temperature set. The lead form the breaker box is evident as
are the valves, one of which is the input side with an adapter that fits the
large mouth funnel I use to fill the still perfectly. The other valve leads to the condenser via
the clear poly hose. This allows me to
see if glycerine is getting through and the still needs to be turned off. Once the thermostats have been set properly
this should be a walk away process, but it isn’t yet. The hose goes to the ceiling, so that the
vapor can expend some of its energy on the way to the condenser pictured on the
right. It enters at the top of the
radiator and as it flows down it is condensed back to liquid by the air forced
through the radiator/condenser by the box fan sitting behind it (white outline
on either side). Finally, liquid
methanol accumulates in the bottom of the condenser causing a mild back
pressure and then it pours out of the down spout into an awaiting bucket. Once the process is fully automated (i.e.
there is no chance of water or glycerine contamination) it will pour straight
into the methanol storage drums. As you
can see, this is simply a larger version of what is shown above.
This is what the finished product looks like. The two main changes from above are the
fittings on the drain valve at the bottom and the pressure relief valve near
the upper thermostat cover (blue plates).
Being plastic, the original drain valve would not transfer enough heat
to re-liquefy the glycerine so that it could flow out of the small opening in
the valve. In addition to the new valve
being metal all the way from the vessel, I have used a straight-through ball
valve. If there is ever a blockage it
will be a simple matter to spin off the elbow at the end and clear the problem.
The other change is the tube on the pressure relief
valve leading to a collection bucket (old oil container). Now, if this ever actuates, instead of
getting brown soap sprayed all over my still and garage floor it will be neatly
deposited in the container at the end of the hose. This is important while setting temperatures
and leaving at the wrong moment. You can
see in the above picture that it happened once already.