Biopowered - vegetable oil and biodiesel forum

Biodiesel => Chemistry and process => Topic started by: Chug on January 07, 2014, 05:26:27 PM

Title: Current best practice with ASM
Post by: Chug on January 07, 2014, 05:26:27 PM
I'm gonna be helping Chunder with his first batch of bio and he wants to use ASM.

So are the current figures on the wiki page what most peeps are using for calculating their amounts for 2 stage?

Ie. (batch size x 4) x 5

So for 150 litre batch = 3000ml ASM mixed into 12% methanol?

http://www.biopowered.co.uk/wiki/Processing_with_anhydrous_sodium_methylate
Title: Re: Current best practice with ASM
Post by: RichardP on January 07, 2014, 07:21:05 PM

It's a good starting point and you and Chunder shouldn't go far wrong using them. It's one of those things you can adjust according to the quality of the the oil. I started using a base of 4 and have found the best for me is 1st stage at 2.5 then2nd stage using 4.
Title: Re: Current best practice with ASM
Post by: Jamesrl on January 07, 2014, 07:59:21 PM
I use a base of 3 for both stages.

I start with the ASM 3 x 5 x 150 = 2250ml.

Then add methanol to total 15% of batch size,  so I'd put 20ltr in with the ASM.

BTW I never inject the methoxide under 64c, I like it 'ot.
Title: Re: Current best practice with ASM
Post by: Chug on January 07, 2014, 11:30:53 PM
Cheers chaps, going on this then, maybe the wiki page should be edited, what do folks think?
Title: Re: Current best practice with ASM
Post by: Julian on January 07, 2014, 11:59:01 PM
I've recently gone back to NaOH, but when I was using ASM I used a base of 3.5 -4 and never bothered to titrate.  With frequent sampling I used to add methoxide until I got a gel to form and noted a temperature rise.  At this point I assumed the bulk of the reaction was taking place following which the samples would go quite clear.

Adding a little more methoxide would start to make glycerine drop and that point I would consider my first stage complete.  Second stage would be adding just a little more methoxide until I got a clear 3/27.  It was quite time consuming, but resulted in a very low soap level which was neutralised with minimal acid before a couple of pump washes.

Worked well for me but as Chunder is just starting out, sticking to known values might be best until he has a few batches under his belt.

I thought the wiki page had been modified to suggest a base of 4 from an initial recommendation of 5.  It could perhaps be modified to suggest a slightly lower level, but I think we should err on the safe side.  Personally I wouldn't suggest too lower base without a lot more people confirming successful and consistent conversions.

Title: Re: Current best practice with ASM
Post by: Chug on January 08, 2014, 12:34:17 AM
Good point Julian, lets wait and see what Nigel and the rest of the asm converts have to say, I've just ordered a bag of NaOH meself coz I'm skint, but I'm gonna borrow a bit of asm from chundy when he gets some and when we do his first batch so I can have a play with it.
Title: Re: Current best practice with ASM
Post by: Julian on January 08, 2014, 12:40:54 AM
One of the differences you'll notice is yield.  Using NaOH I recon I'm down about 3-5 ltrs on an 80 ltr batch.

Title: Re: Current best practice with ASM
Post by: Jamesrl on January 08, 2014, 12:41:08 AM

without a lot more people confirming successful and consistent conversions.

I'd like to confirm that my conversions are consistently consistent with crystal clear 10/90 on every batch, I will accept nothing less.
Title: Re: Current best practice with ASM
Post by: Jamesrl on January 08, 2014, 01:04:52 AM
One of the differences you'll notice is yield.  Using NaOH I recon I'm down about 3-5 ltrs on an 80 ltr batch.

Thats down to the water created when mixing NaOH methanol.

You generate more soap.
Title: Re: Current best practice with ASM
Post by: willbuild on January 08, 2014, 05:58:50 PM
One of the differences you'll notice is yield.  Using NaOH I recon I'm down about 3-5 ltrs on an 80 ltr batch.

Thats down to the water created when mixing NaOH methanol.

You generate more soap.
Thats 5% roughly, Am surprised its as much as that.
Title: Re: Current best practice with ASM
Post by: Jamesrl on January 08, 2014, 06:03:32 PM

Thats 5% roughly, Am surprised its as much as that.

That's about right.
Title: Re: Current best practice with ASM
Post by: willbuild on January 09, 2014, 09:23:05 AM
I got 20kgs of Nah and 20 of potassium. anyone need any in cardiff area?
would like to try asm method.
Title: Re: Current best practice with ASM
Post by: nigelb on January 09, 2014, 06:30:50 PM
I got 20kgs of Nah and 20 of potassium. anyone need any in cardiff area?
would like to try asm method.

It's a shame you didn't shout up a few weeks back when i was running a few errands in the south Wales area.
Title: Re: Current best practice with ASM
Post by: Chug on January 09, 2014, 07:23:43 PM
c'mon nige now you finally got on the thread and all we get is smalltalk, what about the asm amounts?
Title: Re: Current best practice with ASM
Post by: Jamesrl on January 09, 2014, 08:02:33 PM
c'mon nige now you finally got on the thread and all we get is smalltalk, what about the asm amounts?

He prolly don't use it Chug, just retails the stuff.  ;D
Title: Re: Current best practice with ASM
Post by: nigelb on January 09, 2014, 09:51:06 PM
c'mon nige now you finally got on the thread and all we get is smalltalk, what about the asm amounts?

Sorry Chug...my usage is pretty similar to others on this thread. When I first started I was consuming 3.5lts of ASM for a 150lt batch. Typically 3lts for stage one and the balance for stage two.

 Using a double glycerine wash as a pre-treatment I now use 2.8 as a first stage and then about 200-300ml for stage two. It's all down to stage 1 dropout.

At 4-4.5ppl I reckon it's pretty good value.

Adjustments to the amount you use on stage 1 are best judged on the amount of dropout from your first 10/90. I think, personally you should aim for 10-20% unreacted. Anymore than that I would recommend an increase in the amount you dose.

I've had some difficulties when the calculated dropout from stage one reached 40%. This normally resulted in a 3 stage process rather than a 2 stage to acheive a clear pass on the finished raw bio. Hence the aim for that in the above paragraph.
Title: Re: Current best practice with ASM
Post by: db on January 11, 2014, 04:01:02 PM
I use a base of 3 for both stages.

I start with the ASM 3 x 5 x 150 = 2250ml.

Then add methanol to total 15% of batch size,  so I'd put 20ltr in with the ASM.

BTW I never inject the methoxide under 64c, I like it 'ot.

I use exactly the same figures / amounts.

Out of interest what % conversion do you achieve on 1st stage? I achieve only 33% and this is utilizing a glycol pre treatment too.
Title: Re: Current best practice with ASM
Post by: Jamesrl on January 11, 2014, 08:03:37 PM

I use exactly the same figures / amounts.

Out of interest what % conversion do you achieve on 1st stage? I achieve only 33% and this is utilizing a glycol pre treatment too.

I usually get well into the 90's percentage wise, last batch was 94%.

I will admit I'm a little anul when it come to drying my feedstock, it settles for as long as possible then it's dried at 70c using my diffuser THEN it gets a glyc wash.

I haven't a clue what it titrates at but it really is dark black.

I'm disappointed if the precentage drops to the low 80's.