Hello Doug
Hello group,
I am a beginner in the conversion of WVO to BD and I have been
having trouble with my titration process. On JTF there are 2
reference documents on titration which I have been using as my guide.
There's more than that there about titration.
However, I don't seem to get consistent results. For example, One
time I will get 1.55ml and the second time I get 3.22 ml using WVO
from the same batch and drawing from the same solution of NaOH and
water.
First is that kind of variability to be expected?
No.
Second I noticed in reviewing the tritration documents again, that
isopropyl alcohol is specifed.
But how could you not have noticed that the first time round?
Everywhere is says so.
I have been using the same methanol that I use in the conversion
process. Prefacing this with "I ain't no chemist", Is that the
source of my problem? If that is the case can someone explain why
the titration is done with one type of alcohol when the process is
run with a different one?
I also ain't no chemist, very few of us are chemists, but we can
learn, and do. I can't give you a technical comparison of the effects
of different alcohols, but why depart from established practice when
you're just starting? It doesn't make a lot of sense anyway,
titration and processing have different purposes, with titration
you're only finding out how much acid will have to be neutralised,
not processing the WVO. The result of the titration is applied to the
subsequent processing in the form of the amount of lye required, not
the kind of alcohol to use. If you assume that the two different
processes should use the same alcohol then why don't you also assume
that they should use it in the same proportions? - ie 10 litres of
99%+ isopropyl alcohol per one litre of WVO to be processed?
Anyway, it is possible to use isopropyl alcohol to make biodiesel,
called branched-alkyl esters, which have the advantage of much
improved cold-weather properties. There's discussion of this in the
list archives, using either isopropyl alcohol or butanol. But it's
not for homebrewers, though many have tried - it's laboratory-level
stuff, patented but not used, nobody is using these techniques yet
AFAIK.
Also I seem to be having difficulty keeping the WVO and alcohol
mixed during the titration process, which would be what I would
attribute to the variation in the results.
I don't think so.
I have been carrying out the titration in a test tube and shaking
it after each drop, but the oil still seems to settle out.
Stirring is better. Did you warm the mixture first (and the 0.1% NaOH
solution)? Use something wider than a test tube that you can stir.
And even when they are mixed it is a cloudy white solution, not
clear as the JTF documents indicate.
They do not indicate that. What they say is that it should be clear
(thoroughly mixed) BEFORE you start adding the 0.1% NaOH solution.
"Warm the beaker gently by standing it in some hot water, stir until
all the oil dissolves in the alcohol and turns clear. Add 2 drops of
phenolphthalein solution. Using a graduated syringe, add 0.1% lye
solution drop by drop to the oil-alcohol-phenolphthalein solution,
stirring all the time, until the solution starts to turn pink and
stays that way for 10 seconds." ...
Biodiesel from waste oil
http://journeytoforever.org/biodiesel_make.html#biodwvo
"Dissolve 1 gram of lye in 1 liter of distilled or de-ionized water
(0.1% w/v lye solution). In a smaller beaker, dissolve 1 ml of
dewatered WVO oil in 10 ml of pure isopropyl alcohol. Warm the beaker
gently by standing it in some hot water, stir until all the oil
dissolves in the alcohol and the mixture turns clear. Add 2 drops of
phenolphthalein solution. Using a graduated syringe, add the 0.1% lye
solution drop by drop to the oil-alcohol-phenolphthalein solution,
stirring all the time, until the solution stays pink (actually
magenta) for 10 seconds." ...
Basic titration
http://journeytoforever.org/biodiesel_make2.html#titrate
"Instead of the usual 1 ml of oil and 10 ml of isopropyl alcohol, mix
4 ml of oil in 40 ml of isopropyl alcohol in a glass beaker. Warm the
mixture gently by standing the beaker in hot water, stir until all
the oil disperses and it becomes a clear mixture. Then titrate as
usual, measuring milliliters of stock solution used." ...
Better titration
http://journeytoforever.org/biodiesel_make2.html#bettertitrate
"Mix 10 milliliters of isopropyl alcohol in a small container with a
1 milliliter sample of WVO -- make sure it's exactly 1 milliliter.
Take the WVO titration sample from the reaction vessel (Figure 5 #1)
after it's been warmed up and stirred. Add to this solution 2 drops
of phenolphthalein, an acid-base indicator that's colorless in acid
and red in base. Using a graduated eye dropper (with increments
marked in tenths of milliliters) or some other calibrated instrument
(from medical supply outlets), while carefully keeping track of the
amounts, drop measured amounts of the lye/water solution a couple of
tenths of milliliters at a time into the
WVO/isopropyl/phenolphthalein solution. Follow each drop with
vigorous stirring of the solution. In cold weather the WVO might
congeal and not work so you might need to do the titration in a
heated room. If conditions are right eventually the solution turns
pink (magenta), and stays pink for 10 seconds." ...
Mike Pelly's biodiesel method > Titration
http://journeytoforever.org/biodiesel_mike.html#titration
Any help would be appreciated.
There's more info there about titration. You don't tell us just what
you did - did you use phenolphthalein or a pH meter? Spell it out,
step by step.
Meanwhile I think you should give everything on these two pages a
thorough read:
Make your own biodiesel
http://journeytoforever.org/biodiesel_make.html
Three choices
1. Mixing it
2. Straight vegetable oil
3. Biodiesel
Biodiesel
Where do I start?
What's next?
The process
Our first biodiesel
Biodiesel from new oil
Biodiesel from waste oil
Removing the water
Washing
Using biodiesel
Safety
How much methanol?
Ethyl esters -- making ethanol biodiesel
Reclaiming excess methanol
More about lye
How much lye to use?
Basic titration
Better titration
Accurate measurements
pH meters
Phenolphthalein
pH meters vs phenolphthalein
High FFA levels
Deacidifying WVO
No titration?
The basic lye quantity -- 3.5 grams?
Mixing the methoxide
Test batches
Stock methoxide solution
Poor man's titration
How much glycerine? Why isn't it solid?
PET bottle mixers
Viscosity testing
How the process works
What are Free Fatty Acids?
Iodine Values
-- High Iodine Values
-- Talking about the weather
Which method to use?
Why can't I start with the Foolproof method?
Quality
Quality testing
Cetane Numbers
National standards for biodiesel
-- standards and the homebrewer
-- standard testing
Biodiesel in gasoline engines
Home heating
Lamps and stoves
Other uses
Identifying plastics
Best wishes
Keith
Thanks
Doug Memering
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