New Methods #2. The Imisides Method

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: New Methods #2. The Imisides Method

Thanks Murf,

Have you ever made biodiesel by the exact same process, except omitting the CaO as a direct comparison?

With reasonable oil, heat and at this level of KOH, this recipe should make perfectly acceptable biodiesel without CaO.

I'll have to repeat my tests at room temp to see if I can see any difference in the rate of reaction.

I've been doing more reading and it seems that CaO can absorb a maximum of 28.5% by weight of moisture and it takes several days to saturate. So if we wanted to fully dry the methoxide we would need to use about 3.5 times the weight of KOH.
Murfs method of leaving the methoxide for several days to settle would have merit to let the CaO 'soak'. Although, to maximise absorption we would need to agitate the mixture to fully expose the surface area of all the CaO particles to the methoxide.

[murf Member Find all posts View Profile Close murf]

Re: New Methods #2. The Imisides Method

Thanks Murf,

Have you ever made biodiesel by the exact same process, except omitting the CaO as a direct comparison?

With reasonable oil, heat and at this level of KOH, this recipe should make perfectly acceptable biodiesel without CaO.

I.

good question, no I haven't made BIO without the CaO

it works for me and I guess if it ain't broke don't fix it

I am no chemist or scholar just a brain challenged bloke I suffer chronic headaches and chronic neck pain so I just look for the easiest path to travel so in saying that is there an easier way? always open minded to suggestions

cheers Murf

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: New Methods #2. The Imisides Method

I just look for the easiest path to travel so in saying that is there an easier way? always open minded to suggestions

Yeah, just do what you do now, except leave out the CaO.

Save a couple of days lead time, avoids the messy sedimentation, decanting and disposal of caustic slurry.

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: New Methods #2. The Imisides Method

Just to recap the claims for this procedure,
It is foolproof (no titration required)
It proceeds at room temperature.
The process is utterly anhydrous
A complete reaction is achieved in about 10 minutes at 6 deg C
Only uses 15% methoxide.

Apparently there was no testing performed to support any of these absolutely amazing claims. A faith based procedure?

To be honest, I have a hard time believing any of the above claims other than the fact that the reaction will procede at room temperature, but certainly not to completion in 10 minutes.

I could not locate any CaO so I decided to perform a reaction using the recommended amounts of chemicals minus this magic ingredient.
In earlier experimenting when I was using NaOH, I had observed that there was a certain trade-off between the amount of Methanol and NaOH used. In other words if you increased the amount of NaOH used in the reaction you could decrease the amount of methanol and still achieve the same results as far as biodiesel quality was concerned.
The tradeoff was that increasing NaOH increased soap production and you soon produced a gelled biodiesel because of the extra NaOH soap produced.
KOH soap does not normally form a gel in biodiesel.

In my mind I thought the huge excess of KOH used in this procedure was probably more important than the CaO.
So I heated up a litre of WVO (titration probably around 1 KOH) and reacted it with 150ml methanol containing 15g KOH (A huge excess of KOH) in a 2 litre Dr Pepper bottle. After 2hours of repeated shaking I performed a 3/27 test with the biodiesel and it just passed the 3/27 test.

I am pleasantly surprised.

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: New Methods #2. The Imisides Method

Just a minor correction Tilly, it's 10 minutes at 8 deg C.

I once made a batch at 8 degrees C (in Melbourne "room temperature" can be pretty cold) and it appeared to go to completion in about ten minutes.

I tend to agree with you, the reason Mark claims its titrationless is the substantial dose of KOH, which would probably react any of the good to moderate oils that most of us encounter. 10%w/v equates to 15g/L WVO which should take care of oil titrating up to about 7ml.

I have had my small batch of 10%w/v KOH methoxide 'soaking' with CaO for two days now, so I am all set to run my side by side tests at room temperature when I get home tonight. I'll report back with my results in a day or two.

By the way Tilly, in your test why did you heat your oil? Did you ever doubt that 1ml titrating oil would fail the 3/27 test with this much KOH?

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: New Methods #2. The Imisides Method

Hi Geewizztoo,

Just a minor correction Tilly, it's 10 minutes at 8 deg C.

Correction noted

I have had my small batch of 10%w/v KOH methoxide 'soaking' with CaO for two days now, so I am all set to run my side by side tests at room temperature when I get home tonight. I'll report back with my results in a day or two.

I wait to see your results

By the way Tilly, in your test why did you heat your oil? Did you ever doubt that 1ml titrating oil would fail the 3/27 test with this much KOH?

I have never really done any in-depth experimentation with KOH. By the time I started using KOH I was finished with all the testing I wanted to do (until now)
I know that using this much excess NaOH would be a disaster. I really have no experience using very limited methanol with a huge excess of caustic. I was pleasently surprised with the results.

The reason I heated the oil was because I do not believe in magic. From past experience I know that if I had performed the reaction at room temperature I would have been shaking the Dr Pepper bottle for at least 10 hours. Probably more like 12 hours.
There is a rule of thumb in chemical reactions (which seems to apply pretty well to the biodiesel reaction) that for every 10deg C the temperature is reduced reaction time is doubled.

So if the reaction takes 1.5 hour at 50deg C then it takes 3 hours at 40deg C, 6 hours at 30 deg c and 12 hours at 20deg C.
And then you add on more mixing time "Just in case"

My Thoughts
Most of my oil titrates around 1 KOH. The oil I used in this reaction was from a particurlarly lightly used batch that I got from a private school. It was probably used about once.

I will have to do some further testing. I may well change my production technique. I will call it "The World famous Dr Pepper KOH Hammer Technique (Pat Pend)"

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: New Methods #2. The Imisides Method

I've completed my experiment and I've written up my findings.

The long version can be found in the attachment below

In my experiment, two identical 1L batches of WVO were reacted simultaneously (at room temp) with a standard undried methanol/KOH solution compared with a similar strength solution that had been dried for 2 days in the presence of Calcium Oxide powder (CaO).



In summary, as far as the biodiesel reaction went, I could not observe any difference in behaviour between the two methanol/KOH mixtures. Both reacted the oil at room temperature in about an hour. During mixing, the viscosity change was the same, the temperature increase was about the same and the quantity of by-product was the same. The only difference was a marginal fail of the 3/27 test by the control sample, with the CaO sample clearly passing.



I have spent the last three weekends experimenting with CaO and I cannot replicate the spectacular benefits Dr Mark is claiming. I feel I have been as thorough as possible bearing in mind the lack of specific details supplied on this thread. Whether the extra cost in time, money and effort of the CaO method, plus the added complexity and mess is worth the end result is up the individual to decide. But for me, I cannot find any compelling reason to pursue this any further.

I have posted more photos in my public album here:

geewizztoo's Album: CaO desiccant Experiment

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: New Methods #2. The Imisides Method

I have spent the last three weekends experimenting with CaO and I cannot replicate the spectacular benefits Dr Mark is claiming. I feel I have been as thorough as possible bearing in mind the lack of specific details supplied on this thread. Whether the extra cost in time, money and effort of the CaO method, plus the added complexity and mess is worth the end result is up the individual to decide. But for me, I cannot find any compelling reason to pursue this any further.

Why not. What happened? Please describe what you did step by step in detail, and I'll try to work out what's gone wrong.

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: New Methods #2. The Imisides Method

I can't write it in any more step by step detail than I already have. Did you read the attached document and look at all the photos in my album?

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: New Methods #2. The Imisides Method

Well, its been a week and no reply Dr Mark? I was hoping for some feedback on my test results and compare them to yours.



So just summarise,

Your claims were:

This method has two advantages over the conventional base-catalysed transesterification process:
1. It is foolproof (no titration required)
2. It proceeds at room temperature.

My findings were:

1. No it isn't (Titration 14 oil didn't react)
2. Yes it does, but so does the standard method at exactly the same rate, with almost the same result.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: New Methods #2. The Imisides Method

I can't write it in any more step by step detail than I already have. Did you read the attached document and look at all the photos in my album?

<Derogatory comments removed by moderator. >

Please reread my original post and follow is step by careful step. If somehow you are still unable to get it to work, I suggest you go back to the Dr Pepper method.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: New Methods #2. The Imisides Method

Yeah, just do what you do now, except leave out the CaO.

It won't proceed at RT without the CaO - There isn't enough methoxide - and you'll finish up with a heap of soap in your raw product. . This has been explained several times over now - you are really struggling to understand anything at all about this method, aren't you? Is this why you can't get it to work?

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: New Methods #2. The Imisides Method

Final comments.

I don't have time to read every post and answer every question asked. Most of you aren't chemists, so I'm wasting my time anyway, and don't have time to give free online chemistry tutorials. But for those of you that are (WesleyB?) there is plenty of information to understand the principles involved. As it happens I have written the method in as simple a form as possible, so that you don't need to be a chemist to make it work.

Comparison with Dr Pepper Method:

Advantages:

1. Almost foolproof (nothing is completely foolproof of course). No titrations required. (Almost) anyone can make it work.

2. Proceeds at room temperature.

3. Anyhdrous. Air washing is all that is required for clarification

Disadvantages

1. Cost. Extra chemical required (CaO), although this may be offset by reduced heating costs.

2. More intractable waste. The glycerol is water soluble, but the hydrated lime cane be a problem. Murf spreads his around his propery - I just dumped mine in the Sulo bin but it's pretty messy stuff, and highly caustic.

One other thing - there is a lot of talk on this site about the 3/27 test, as though it's important.

It's not.

Making biodiesel is all about one thing - reducing viscocity. It doesn't matter if you have unconverted triglycerides in your fuel.

Which method is more likely to get the higher conversion? Consider the reaction:

triglyc + MeO- = methyl ester + gly.

This is itself an equilibrium, so with a higher MeO conc (my method) the equilibrium lies further to the right - higher conversion but lower yield.

And here we have a conundrum - the ideal method - if it were possible - would be to convert each triglyceride molecule to two methyl ester molecules and one monoglyceride. This would produce a lower viscosity brew, with no glycerol (high yield low conversion). I doubt such a process is possible, but there you have it.

But it is likely that the Dr Pepper is a higher yield, lower conversion method than mine. Hence the obsession with the 3/27 test. The only test that is really necessary is a viscosity test (and maybe gel point test), although if your motor starts OK when cold, that's a good enough test.

One other trhing - a rule of thumb test as to whether you have enough CaO for dehydration is whether it gets hot when you wash it out as waste afterwards - if it does then you had enough in there for dehydration (as it means that there was left over unreacted CaO).

Finally, I have my own radio show now. Tune in to 6PR at 6:30am on wednesday mornings to hear "Dr Chemical" answer viewer questions.

[WesleyB Donating Member Find all posts View Profile Close WesleyB]

Re: New Methods #2. The Imisides Method

Dr. Mark; I've been working on getting some CaO here for about at least 58 american dollars for 500 grams. The government is tight on chemicals here. It is not easy like walking to the grocery store. Fats and oils have three fatty acid chains bound to glycerin . Making biodiesel actually takes one triglyceride fatty acid ester and produces three methyl esters and one free glycerin molecule. We don't want to make any monoglycerides if possible. I know that CaO dries the alcohol, but does it pull all the water away from the KOH molecule in alcohol solution? CaO only produces 199 proof ethanol, it is not 100% anhydrous, but it still might work better than what I've been doing. I intend to try your method with ethanol, not methanol. I expect when monoglycerides burn in an engine that they produce more soot than methyl fatty acid esters. Have a good day Thanks

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: New Methods #2. The Imisides Method

Yes I understand the stoichiometry and rxn mechanism. i was just suggesting that if you made one monoglyceride and 2 ME per trigly molecule you'd get more fuel, as it'd all be fuel with no gly. But you're probably right about the soot it makes, and anyway I doubt that it'd be chemically possible - the monogly is probably more susceptible to nucleophilic subst than the trigly anyway. Yes, of course strictly speaking it's not 100% anhydrous - but I'm happy to call 99.5% efficiency anhydrous.

Yikes - the lime sure is exy! Have you tried cement factories?