CBA process.

[Julian]

It's worked for three batches now and can only be a tribute to the way I usually manage to cock things up.

I've been two staging for many years.  Since acquiring ASM, I've tried the non titration method a couple of times with reasonable success.

Three batches ago I must have been away with the fairies because I mixed ASM and methanol using 3.5 as the base amount and did an 80% stage.  Realising a little later that I should have put the whole lot in and then done a 3/27, I thought blow it, (or words to that effect) and just carried on doing a two stage process.  A 3/27 test after the first batch looked promising, so I drained the first stage glycerol and ran the 20% balance at the end of which I got a good 3/27 pass.

Thinking this was a little jammy I ran the next batch the same way, but with reduced catalyst.  I ran the same process but used a base of 3 and got the same result.  Today's batch I used a base of 2.75 and still got a great 3/27 pass.  None of this accounts for any titration values ... next batch I'll do a titration.


This is the 3/27 after the first stage today ...





And this after the second stage (both stages were processed for and hour) ...



What's the least amount of ASM people have used to date?

[Jamesrl]

Would it be right in assuming CBA stands for "Can't be Arsed"?

[Julian]

Spot testicle on!

[Head Womble]

Nice to see you've finally posted this method (we spoke about it when I was fly tipping a small amount of soap at Julian's place).

How are those bungs holding up to bio/meths ? They look OK in the photos.

[Julian]

How are those bungs holding up to bio/meths ? They look OK in the photos.

Just fine but this was the first time I've used them!  They fit both my small measuring cylinders too.

The puzzling thing about this method is the reduction of ASM.  I'll keep reducing it until I don't get a 3/27 pass.

Next time I think I'll try a base of 2.25g which should give me 900 ml for 80 ltrs of oil.  I'm still using 15% methanol PLUS what's in the ASM, so not scrimping on that, but it's recoverable.  Got about 7 ltrs out of this batch.

[db]

I've been using a base of( 3 x oil ) x 5 for a while. The last batch I used 3 on 1st stage, then 2 on 2nd stage and still passed 3/27.
Bearing in mind everyone's oil will be of differing quality (and some people dry their oil more than others) I don't suppose this will work for everyone, There are so many variables.

Dawson

[Julian]

Do you mean + oil or x oil?

[db]

Do you mean + oil or x oil?

Yes, x oil. Typo!!

[Julian]

Do you mean + oil or x oil?

Yes, x oil. Typo!!

OK, no probs, but you are doing a "complete" single stage and then a second stage to account for unreacted oil (all be it a reduced qty as per the no titration method)

I'm using 80% of one stage and then the 20% balance as per the old two stage process and therefore must be using less catalyst.  I still recon further reductions could be possible.

Said it before ... the more bio I make the more I don't understand.

[nigelb]

I had a go at this CBA method today with somewhat disappointing results. Following the steps laid out by Julian at the start of this thread I got a 30% under-reaction from the first step and a 15% under-reaction from the addition of the balance from stage one. The disappointing aspect for me was the time taken to get to this stage. It took another 2 stages to get somewhere near a reaction I was happy with.

I ended up using pretty much what I normally do with regard to the amount of ASM used.

It was an interesting experiment that I'm unlikely to try again.

Glad it works for you though Julian.

[Julian]

Sorry it didn't work for you, Nige!

I'm still playing with it though.  Toady's batch was interesting ...

I tried a base of 2.5 and it would appear that that's not quite enough (when using very clean, well settled and dried oil titrating at 2, Na OH).  The batch reached a yellow ochre, jelly stage after the introduction of the first stage and went no further.  Upholds my thoughts that soap/gel can be caused by too little catalyst.  I added 25 ml ASM ... no change, 30 ml ... no change and then 50ml at which point the colour of the batch changed to dark brown and the viscosity reduced considerably.  As with the last batch there was a two degree temperature rise which held stable  for nearly an hour in a very in a poorly lagged processor.

Samples taken shortly after the temperature rise were most unusual, very nearly completely clear, but with no glycerine drop out when human centrifuged.  A 3/27 test gave a massive drop out of about 50%.

Two further additions of 50ml sent the samples cloudy, they quite readily dropped glycerine and gave only a small drop out in a 3/27 test.

There's still the second stage to run for this batch, but I think I've reached the limit of ASM reduction.  Next batch I'll go back to a base of between 2.75 and 3.


Don't know what use all of the above is but the very marked difference betwen the gel and clear phase was fascinating in a sad anorak type of way!

[Julian]

Forgot to post the pic I took of the mid batch clear sample.  Bear in mind this is straight out of the processor during the first stage ...

[Julian]

Completed this batch today by only using ½ the remaining ASM/methanol from the second stage.  That makes a tad over 1000 ml for 80 ltrs of oil.

If you take the figures on the wiki page as gospel you come out with a figure of 2800 ml.  Dawson is obviously using far less catalyst and I know many others are.  I think we should revise the wiki page so the base of 5 is replaced by 3.5 or even 3 if the titration value is accounted for.

Do others agree?  Jim, do you have any comments as I think they were your figures in the first place?
 

[Jamesrl]

Do others agree?  Jim, do you have any comments as I think they were your figures in the first place?

I wasn't aware I ever advocated a base of 5, I started with 4 and now down to 3.

The 5 is the multiplier use to adjust g/ltr NaOH to ml ASM.

[Jamesrl]

Completed this batch today by only using ½ the remaining ASM/methanol from the second stage.  That makes a tad over 1000 ml for 80 ltrs of oil.

Julian, where on earth did you get the 2800ml of ASM from? If I were doing an 80ltr batch stage one would be 15% methoxide, including the methylate, using a base of 3 giving 960ml of ASM.

No wonder you've made so much soap in the past.