Titrated Acid water wash.

[Tony]

At this rate it'll be "Drywash corner" at the BBB with just three blokes in it 

[1958steveflying]

What made you try this jim, is it just out of curiosity or necessity?

Disbelief ! ! !

[Jamesrl]

What made you try this jim, is it just out of curiosity or necessity?

With so many going on about it I had to give it a try.

It's more time consuming, hand on wise but hopefully a quicker finished product.

It was the low volume of water that swung it for me.

I'll give it a few batches before I decide which way to continue.

[Head Womble]

Give the acetone wash a try, uses even less water and is quicker.

http://www.biopowered.co.uk/wiki/Using_acetone_to_aid_soap_removal

[julesandtash]

I do the acetone stage now.

I do the acid wash first then stop, wait for a couple of hours and drain it.
Then, for 300 litres of bio, I add 45litres of cold water with 100ml of acetone mixed into to it. It really does seem to pull out the contaminants quicker.

Two batches in a row have given a clear 50/50 shake test after just the acid wash and one acetone enriched water wash.

Not sure of the soap ppm as I need some more chemicals from Nige (which I will collect next weekend).

I am tempted to try acetone in the acid wash so what happens.

I cant see that anything nasty is likely to form. I know that Acetone and Hydrogen Peroxide in the presence of Sulphuric acid can form TATP which is explosive but then that needs concentrated chemicals and becomes explosive when dry. As there is no Hydrogen Peroxide anywhere near the process and it is only small quantities of chemicals mixed into loads of water and bio, I can't see any real problem.

[nathanrobo]

Jim

Pretty pleasing to see you giving it a go.  U gonna try the acetone next time too?

[Jamesrl]

All done, it took four 15ltr washed to get a good 50/50. I gotta get me some Acetone for the next go.

Now riddle me this, I took a sample from the last wash, let it settle and split took some of the Bio and did a 50/50, nice clear water phase.

I drained down the 15lt from the reactor and it's like milk.

??

[RichardP]

All done, it took four 15ltr washed to get a good 50/50. I gotta get me some Acetone for the next go.

Now riddle me this, I took a sample from the last wash, let it settle and split took some of the Bio and did a 50/50, nice clear water phase.

I drained down the 15lt from the reactor and it's like milk.

??

I'm so happy reading this I almost have a tear in my eye. 

It doesn't follow that if you have 'unclear' wash water then the 50/50 or soap tests are going to be poor. And remember that the crap is in the settled water and not in the bio.

[K.H]

What made you try this jim, is it just out of curiosity or necessity?

With so many going on about it I had to give it a try.

It's more time consuming, hand on wise but hopefully a quicker finished product.

It was the low volume of water that swung it for me.

I'll give it a few batches before I decide which way to continue.

No reason you cant do both is there?, washing if you need fuel in a hurry or for winter and settling at other times maybe

[nathanrobo]

All done, it took four 15ltr washed to get a good 50/50. I gotta get me some Acetone for the next go.

Now riddle me this, I took a sample from the last wash, let it settle and split took some of the Bio and did a 50/50, nice clear water phase.

I drained down the 15lt from the reactor and it's like milk.

??

Got a theory about this... well here goes!

I wonder if the meth reduces with each wash rather than in just one wash, with the subsequent washes the meth ppms or % reduces.  When it gets to a critical low level it suddenly releases the greatest concentration of soaps. 

If this is true it would explain how you can get fairly clear discharge water on one wash and then the water on the next wash seems more cloudy.  I've seen this on the odd occasion with gradual mist washing, can't recall seeing it with pump washing though, so not sure how or if it's likely to be true with pump washing.  It's only a theory, no other evidence to suggest that it's true. 

If I was making bio at the mo, I'd use my shiny new meth tester (compliments of KH) to add some numbers to the idea.

I'll sit back now and await the ridicule :-))

[julesandtash]

No ridicule at all. That is a very plausible explanation.
I guess it would be worth doing soap testing on the fuel after each wash and recording the PPM

If there is a sudden drop between, say, the third and fourth wash then that would support your theory.

[RichardP]

I would think that the soap will reduce inline with the reduction in Methanol, as it is fully water soluble, and will come out as easily as the meths when washing. I can't see the soap sticking with ever reducing amounts of methanol until a 'critical' point where soap is released - I can understand that when demeth and settling but not when water washing.

I would be interesting to see results of meth vs soap after each wash though.

[nathanrobo]

Sadly, until I get a new processor, I'll have to stand on the sidelines.  But the tests mentioned should be easy enough to replicated and demonstrate or dismiss.

[Head Womble]

I'm doing a batch tomorrow,
this is going to be split in two for a comparison test, standard pump washing V acetone washing.

To get comprehensive results I'll be doing titrated soap tests at every stage of the washing,
these results may help with your theory.

[Jamesrl]

I forgot to mention the fact that the bio had been demethed within an inch of it's life before it was Acid washed.

As no one seems to have mentioned their drying methods I went into condenser drying with the Squirrel merrily working away. At 85°C there was a small but steady flow of water, after 90mins of demething and a few litres in the cubie I transferred the bio to the settling tank and turned on the bubbler. The last time I checked it it had changed from orange juice to a nice dark bio looking liquid.