Pump wash gone wrong.

[julesandtash]

I have been using the titrated acid wash process since August/September 2012 when Paul originally asked myself and KH to trial it.
I have used no other process in all that time, all my fuel for both the heating and road vehicles has been made that way.
After the acid wash, I do one water wash for the heating fuel and two for the road fuel.

I have not seen any problems with either the boiler fuel pump or the vehicle pumps so I think it is safe to assume that the finished dry fuel is pretty safe and free from any acidity.

[Manfred]

When you do a titrated acid wash you measure how Much acid to add to stabilise the addition of water. When it turns yellow you know that it's on the acidic side of the table so safe to proceed. When all water washes are done if you do a test and it turns yellow instantly you know that you have no soaps present. So it's good to use, but how far is it into the acidic side as green is a neutral reading. Or am I understanding this wrong.

[Julian]

I've heard back from Paul as follows ...

Hi Julian
Sorry about the delay things are really up in the air at the mo.

In answer to your question bio cannot become acidic if it is completely reacted and well dried.

By doing a 50/50 water test then testing the water is by far the most straight forward and easiest way to test for acidity.  If you can get your hands on a reagent called BTB in ethanol this is a good indicator for pH as the neutral is quite a small window.  A quick test I just draw some in a pipette then down into settled water no mess.

With regards to Steve's samples I tested ,I remember doing the tests and  the results but can't remember any definite conclusion so not really sure.

One thing to remember though is strong acid in too high a dosage  can make the methanol disassociate from the fatty acid (not a problem for titrated acid wash or going at it slowly but does mean that in theory you could turn the whole batch to Ffa then wash the methanol out .

Will try and pop into biopowerd soon just got lots going on.

Hope this helps a bit.

Cheers,
Paul

So it looks like Paul agrees with my PhD mate, that if completely reacted, washed and dried, bio cannot be acidic.


He then sent what looks to be a useful snippet, but it leaves me wondering why do a titration titration to arrive at the volume of acid?  I guess doing a titration and making a comparison will help explain things.

Hi Julian
No problem with cut and paste my reply to the forum.
Also a quick calc that may be helpful for people using conc sulphuric acid is to X the base amount used of sodium by 0.12 for amount of acid required .
Example
2L ASM /5=400g base X ,0.12 =48ml conc sulphuric acid .
This can then be adjusted for any concentration of sulphuric acid.

Be back soon
Cheers
Paul

[Julian]

When you do a titrated acid wash you measure how Much acid to add to stabilise the addition of water. When it turns yellow you know that it's on the acidic side of the table so safe to proceed. When all water washes are done if you do a test and it turns yellow instantly you know that you have no soaps present. So it's good to use, but how far is it into the acidic side as green is a neutral reading. Or am I understanding this wrong.

When I acid wash I titrate to establish the quantity of acid required to neutralise the soaps.  That gets added to around 7% water and a pump wash carried out.  After that, I've only tested the wash water with litmus paper, never done another titration.

See also Paul's replies above.

[Manfred]

Good news that as it means  we can add the acid as needed and no worries so long as we dry it afterwards.
 What he says matches what I found with the rough litmus test on the settled out 50/50 test.

[Julian]

Good news that as it means  we can add the acid as needed and no worries so long as we dry it afterwards.
 What he says matches what I found with the rough litmus test on the settled out 50/50 test.

Just to be on the safe side, I'd do at least two or three water washes afterwards ... won't do any harm and we've proved that water washing reduces HMPEs and improves cold weather performance,  unlike some commercial producers!

[Julian]

Hi Julian
No problem with cut and paste my reply to the forum.
Also a quick calc that may be helpful for people using conc sulphuric acid is to X the base amount used of sodium by 0.12 for amount of acid required .
Example
2L ASM /5=400g base X ,0.12 =48ml conc sulphuric acid .
This can then be adjusted for any concentration of sulphuric acid.

Be back soon
Cheers
Paul

Tried this on a batch yesterday, correcting for 40% acid and it seems to work well.  Subsequent wash water tested at pH 5.  So I think I'll use this method in future, saves a lot of messing around with titration.  I'll give it another couple of goes and put up up on the wiki ... thanks, Paul.

[Manfred]

This sounds easier and faster to use,  I suppose for those of us that don't use ASM we could work backwards from a tritated sample to see if it calculates out for subsequent batches. Looking forward to the wiki.

[Julian]

In the example above the 400 g is the NaOH quantity.  The bit before that converts ASM to NaOH equivalent.