Great work everybody on this testing. I have a couple of thoughts and question though which are purely theoretical as I have never tried this idea yet.
If the idea is to dry the methoxide is it not possible to measure the water content of the methoxide before reacting the oil? Rather that testing the oil which introduces other variables, dissolved water in the oil and in fine food particles.
The 3/27 test or the 10/90 test. Very small quantities so the possibility of measuring errors are greater.
I use a 270/30 test, a local coke bottle has a moulding mark at 270ml so measurement is easy. Just mark the bottom of the bottle with 3ml mark and 5ml and 10ml mark for quick check. Otherwise a syringe body glued to the cap with a hole through the cap will give an accurate drop out measurement. All the drop out is at the bottom of the bottle just pour off the top methanol and use again, the bottom bit use in the next batch and the mono & dies get another chance to convert.
the trick is to keep the methanol on closed containers with little air space so as not to absorb water. I have kept my test running sometimes for a couple of days, where there is 100%pass initially there is never any additional drop out. IME (in my experience)
Hi Tilly and thank you for your comments.
The testing so far demonstrates that something is affected in the main reaction by the addition of quicklime to methoxide. I don't think we know exactly what.
So the method is not nonsense. I am still thinking about it and I wonder, as I mentioned above, if it would be useful to those who don't have access to good quality methanol. Even the stuff that is sold as virgin can contain a lot of water.
Also, the wvo experiment I conducted was carried out using wvo that was perhaps much drier than that used by the average backyard brewer. It was a simple task for me to heat up 3 litres of oil on the stove and dry it thoroughly. I did think that I had done a pretty good job drying the 200 litre batch in my processor, but when I started heating up 3 litres of it in a pan it popped and crackled like crazy. Imisides's sole test of whether the oil is dry enough is a visual check of clarity. Even clear oil can be pretty wet. I'm wondering if the methoxide that has been treated with quicklime encourages a better reaction with wet wvo than untreated methoxide.
I'm not sure I want to undertake too much more testing, though it has been an interesting exercise so far.
Thank you for your kind comments.
I think that we must conclude that some chemical change, or the transfer of something to the wvo as a result of glyc washing caused that problem in our large batches over Christmas.
Like you, I also perceived a reduction in the byproduct layer in the 200 litre batch, but it was difficult to put a figure on it due to the conversion that took place as a result of the enhanced glyc wash. I remember that I got a good bit more glycerol out after the enhanced prewash than I had put in, so a fair bit of oil had converted and resultant byproduct dropped before starting the stage 1 reaction.
Hi David. Regarding dry oil, most of the moisture in the oil is in food particles, I filter my oil through a big blue string wound cartridge filter at 100Mu. the oil comes out clear. Fortunately I have a loose pump and hoses for this and am not dependant on the processor pump. I built a separate heater/dryer out of 210 litre steel drums with gas burners underneath, a turbo dryer with silica jell to dry the air and spray nozzle to fan the oil on top of the drum. The oil is circulated the whole time through the pump sucked from the bottom and through the spray nozzle on top, by the time the oil is at 60DegC I assume it is really dry. Then transfer to processor . Bit off topic but if dry oil is a prerequisite than maybe its important to dry the oil.
Yes, I have been thinking for some time that I ought to make a purpose built drying rig using a 210 litre drum. Sounds like you have a fantastic set-up there. I use the immersion heaters in my processor to heat up the 200 litre batch and then continually bubble it with the turbo dryer before reheating and so on. Even after three days my oil still isn't dry, and I'm going to have to continue the heating and bubbling a bit longer.
Making a drying drum is just one of a long list of things on my 'to do' list!
Thank you for your input
Firstly these soaps were insoluble in water.
A flame colour test gave a brick red colour, the sign of calcium or calcium salts.
How did you determine it was soap?
What burned brick red colour?
Once again I thank you for performing these tests.
I can not recall saying the procedure was nonsense.
However, considering the claims made such as Fooloproof, no titration required, the reaction finished in 10 minutes at room temperature while using a HUGE excess of KOH and not enough Methanol...
The results are as expected.
I didn't say anything about being burnt.
Some of the soap precipitate that I recovered from the centrifuge was put onto a nichrome wire and subjected to a flame, it showed a brick red colour, indicating the presence of calcium.
A flame test is an inexpensive test that produces significant information in analysing a sample.You can do it with a paper clip that's bent with a small circle on one end and a natural gas bunsen burner. A flame test is taught in first year college chemistry here in Texas. I have done the flame test. You get a chart giving the colour produced when to dip the 1/2 centimeter circle of the paper clip into a solution of the material being tested. In this case the results are consistent with calcium being present due to the observed fact of the brick red colour produced when the flame test was done. Also analysis/identification of a material sometimes may be done by observing physical properties of a material being consistent with knowing what the starting material was what was present when the material formed in this case calcium oxide, vegetable oil, caustic, methanol and some water produced by the formation of methoxide. So we know that soap scum that forms when a person takes a bath using hard water (ring around the tub) is soap that forms from a reaction of elements on the left side of the periodic chart with a valence of two (they form two bonds) those types of soaps have two fatty acids bonded to a central calcium or magnesium atom. The end of the fatty acid with the carboxilic acid group bonds to one of the two oxygen at the acid end of the fatty acid leaving the two long non-polar tails extending outwards. So calcium soap is insoluble in water. It was observed that a product of the imisides cold esterification of vegetable oil produced a product with properties consistent with those that calcium soap have, therefore the insoluble material probably is calcium soap. Possibly you might suggest what else it might be? Thanks
Excellent explanation Wesley, thank you.This message has been edited. Last edited by: Dgs,
Thank you for your very thorough explanation.
I knew Minder was wrong
Not being a person who worries about soap, I did ask how it was determined to be soap but did not receive an answer.
What properties did this substance have that would make someone think of soap?
According to a chart I just looked at "brick Red" also indicates cadmium.
There are other chemicals that also show red in the flame test so I guess you would need to be quite experienced to be able to differentiate between Brick red and the other types of red.
Always a pleasure
Is it really likely to be anything else but calcium when CaO was used to dry the methoxide.
Do you fancy mixing up some cadmium methoxide to try a flame test?
Do you think if the methanol quantity were upped, say to 20%, the reactions would complete in a single stage?
Back to my original question, how did you determine it was soap?
Many people do make biodiesel that passes the 3/27 test using a single stage reaction and 20% methanol.
It is very unlikely that a single stage procedure will pass the 3/27 test using the very limited amount of methanol that is present in this procedure.
The other concern is the limited amount of time the reaction is run considering the temperature.
This procedure as written was never intended to produce biodiesel that passes the 3/27 test. All that was required was separation.
This is exactly what I have been saying for the last year.
When you do a "glycerine prewash" or whatever else you might want to call it that contains an unknown amount of chemicals, it is impossible to do any meaningful tests.
I do a glycerine prewash, and then titrate after I have drained the glycerine. It lowers the titration value a couple of grams.
There can be many advantages to doing this.
One disadvantage however of glycerol pre-treating is that a suprising amount of soap can be transferred from the glyc into the oil. Have you ever tested your treated oil for soap, it could confuse your FFA titration.
I do not recall ever hearing of this before.
Please explain how soap from a glycerine prewash can confuse the FFA titration.
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