cold reactions or Drying Potassium methoxide.

[countrypaul]

If you add 50g of KOH then that is equivalent to adding 50*18/56g of water, which to 400ml of methanol (assume density of 0. gives a total mass of 450g with 16g of water, or 3.57% or 35700ppm.

To absorb the water from 50g of KOH you would need 50g of CaO (coincidence since MW of CaO is also 56). In practice to ensure the methanol/methoxide is dry you would want an excess.

My guess is that calcium methoxide is largely insoluble in methanol, but I can't actualy find and solubility information about it easily.

[Glycer-rides]

Good work dgs, keep it up!

[dgs]

I mixed up my first lot of methoxide today, ready for the process. 2 cubbies, 15 litres methanol in each + 1kg KOH, followed by 1.5kgs CaO. Shook both up every 10 mins for the first hour whilst still warm.

The 1kg in 15 litres is a little stronger than normal, so if I have to add a little more methanol it's not a problem. The no no is to add more KOH so that more water is produced.

If this works I have an oid green fuels 60 litre methoxide mixing tank with the hand stirrer which I will set up to mix the methoxide chemicals in. What a messy job it is using the quicklime.

[Chug]

yeah the mess was a lot of the reason I gave up.

[dgs]

last night I mixed two teaspoons full of quicklime into a jam jar with finished bio in it. The water in this bio had been checked at 240ppm. I left the mix overnight for the lime to settle and this morning checked the top bio layer for water. It was zero. Maybe it's a little ambitious to say zero but there was no reading on the s/b. The pressure gauge was still on the zero after 4 hours.

[Julian]

last night I mixed two teaspoons full of quicklime into a jam jar with finished bio in it. The water in this bio had been checked at 240ppm. I left the mix overnight for the lime to settle and this morning checked the top bio layer for water. It was zero. Maybe it's a little ambitious to say zero but there was no reading on the s/b. The pressure gauge was still on the zero after 4 hours.

Sounds promising, but seem to use quite a lot of lime.

Do you think it would work with less and did the bio clear OK?

[dgs]

I'm sure it would work with a lot less, the top bio layer that I tested still had a lot of lime in it.

If we say that finished bio which was very slightly dried had (let's say) 900 ppm water, so from the figures that Paul gave something like 4gms would be sufficient to dry 1 litre to zero, providing it was well mixed. I will repeat the test after Christmas with far less CaO and see if the bio will clear and test for water.

the test jar and indeed cubies of mixed methoxide and lime now have clear methoxide layers, although it has taken 5 days to clear. As (I assume) the sg of bio is higher than mixed methoxide the lime would take much longer to settle in bio.

I've been wondering how to quantify the results when I do the 1st process with the dried methoxide. Soap testing may tell us something but of course every batch is different. So giving it some thought maybe yield and glycerol volume would be a good indication.

Julian, I'm finally ready to do some sensor water tests and will get on with these after Christmas.

[countrypaul]

Might be worth comparing it to some bio made with commercial ASM from the same batch of oil. The differences shouldbe similar to that you get when using KOH rather than NaOH, but any thing else might be related to for example lime left in the mix. Calcium soaps are generally very insoluble and so should drop out quite readily if there is an lime present.

[dgs]

I have now done my first reaction using the dried methoxide. The results are encouraging.

I intended to post this yesterday but our internet has been down for the last 24 hours due to the flooding in York.

As this reaction was with poor oil for the central heating the comparison to a 'normal' process is difficult, however the overall result is a lot better than I usually get with this oil.
After glyc pre-treating (no enhancement) with glycerol that had been used once (and some twice) before I suspect the oil still had a small titration.

I used 7.5gms KOH/litre and a total of 13.5% methanol over 2 reactions (200 litre batch 10/90 was 0.2mls dropout, OK for c/h)

So 28 litres of methoxide added, 21 litres of glycerol extracted without de-mething. Volume in processor 210 litres. Soap, 20 hours after last reaction 1700ppm (on my process this is usually  around the 3000ppm level.

I will repeat the process with dried methoxide when I do the next batch for road fuel.

[Chug]

Good stuff Dave,

Was the lime still in the methoxide, or did you manage to remove it?

and 28L in 200 is 14%

[dgs]

Hi Chug,
There was some lime in it but not much, I decanted the methoxide into another cubbie and left most of the lime behind.
There was 27 litres of methanol and 1500gms of KOH in total, which made the methoxide volume closer to 28 litres.

I don't normally take too much notice of how much KOH I use for the reactions for the c/heating bio and as long as the reaction is 90% or over it's OK, but I'm pretty sure it usually takes more that 7.5gms.

Do you think that leaving some lime in the methoxide has reduced the KOH amount, or it was less because of the reduced water.

I hope to mix the methoxide/lime for the next road fuel reaction tomorrow (in the old 60 litre green fuels methoxide mixer if I can get all the years of crud off it)

[Chug]

I guess the only way to tell if residual lime is affecting it,  or less water, is to compare it with a batch with lime removed.
You seem to be getting better results than I did when I tried it I seem to remember a few messy weeks with not much benefit, although with the quicklime I used there was question on how fresh it was, it'll be good if you get a handle on it.
Keep us posted.

BTW is it powdered quicklime you are using?

[dgs]

It is powdered Chug, really fine stuff, gets everywhere.

[Chug]

Be really careful geez, it can burn the fine hairs in your lungs if breathed in.

[dgs]

Thanks Chug,
will do, I have a full face mask with filter that I will use and preferably do it outside. Was cleaning the 60 litre tank outside until a few mins ago, now rained off!! bugga.