Centrifuges and soaps / jelly batches?

[julianf]

Ive been doing some experiments with jelly recently, involving recovering them with nothing more than heat (ill write it up better when im sure)

Anyhow, following on from this id like to know how a centrifuge would perform on a jelly batch, as it cooled.

Ie. If a known jelly batch was centrifuged all the time, as it cooled from hot.

My hypothesis (not having ever used a centrifuge!) is that the jelly forming substances would be taken out by the fuge, before they managed to 'lock up the methyelsters in the jelly matrix.


I suspect noone has tried this?  The key point is that the job would be run on cooling from hot, keeping the rate of cooling fairly slow.

[Julian]

Julian, how are you making the gel/soap in the first place?

[julianf]

Ive only *ever* done it twice -

first time was before 2 stage no-titration.  large bio migration from gyc wash upset the numbers, resulting in an overdose.

second time was last week.  rotten 2yr old kebab fat.  but some of the resultant jelly from that batch has found its way into my current brew also (solid jelly clinging to the reactor walls, with a flowing core through the center to disguise the fact that it was even there!)

...so, i have this current situation to deal with, however, its a pretty uncommon occurance here.  Ive been experimenting with it, as the one time i put water in the reactor, it all ended badly, hence my desire to find a solution that does not involve water.

My jam-jar tests have resulted in a good recovery rate.  Im going to scale up in the comming week, and then ill report back, however, i think a fuge may also be a simple sollution, if one was to hand.

[photoman290]

if you are talking about the oil pressure type 'fuges like nathan sells they have quite small orifices for the oil to go though. 200 micro i think is the largest size particle you can put though them. would think for it to work you would have to filter down to 200 micro before the 'fuge or it will block up very quickly.

[nathanrobo]

The jets are are sensitive to viscosity.  I've been fuging feedstock and it requires about 45 deg c to be happy :-)

[Julian]

If you have half a jam jar of spare gel, can you try heating to around 65°C (temp not  critical) and add about 50ml methanol and 5ml ASM (if you're using it) if not I'd guess about 6 or 7 grams Na OH and shake like buggery.

This cures Wombles jelly/soap and has cured some of mine.

I keep banging on about it but I think there's a stage of the reaction that is a jelly state, before full conversion.  If the reaction is stalled by water more catalyst seems to push it through the jelly stage.

Other than that,  await further details on your method.

[julianf]

The jets are are sensitive to viscosity.  I've been fuging feedstock and it requires about 45 deg c to be happy :-)

My thoughts are that, when hot, the jelly is fully fluid, but, as it cools, if it is *somthing* that holds the bio in a matrix, that somthing starts to solidify.

I was thinking that, if it could be removed, as soon as it appears, then it may not have time to lock up the bio.

If the above is the case, then the viscosity would be the same as the bio - the only way it would be thicker than that would be if the jelly was starting to form properly, and, if that were happening, my above ideas would be proved wrong anyhow.

[julianf]

I keep banging on about it but I think there's a stage of the reaction that is a jelly state, before full conversion.  If the reaction is stalled by water more catalyst seems to push it through the jelly stage.

This stuff has been through another reaction, and still, it seems, remains.  Ie the jelly (which showed full convertion on the 90/10 test) was reheated (unintentionally) and re-processed, along with a load more fresh oil (from a different source).

A sample seemed to be some jelly, some clear, with no further manipulation - almost like the jelly had carried through the reaction unchanged (which i dont really believe, but its like that happened!)

[Julian]

Surely it's a little inaccurate to make observations based on a mixture of feed stock.  The original gel may have converted but then later oil converted to gel.

I think the method I suggested may be worth a try ... just start with one batch of jelly and see if it will convert.

[julianf]

Sure, ill try out your method - it's (unfortunately) not as if im short of the stuff right at the moment!


I have (or had) three different fluids now -

a) half of last weeks batch that the glyc would not split on, which was demethed, and the venturi / pump combination caused a gulf of mexico incident
b) the other half of last weeks batch that i split off just before putting the above on to demeth.  this is now a clear liquid (ie the glyc has fallen out) and the remaining methanol is keeping it liquid.
c) yesterdays brew, which had a significant quantity of (a) in it, that remained against the reactor walls.  Glyc split from this as expected.

My tests so far have been -

Heat sample from of (a) to ensure it was demethed - result was jelly still formed on cooling.
Mix above sample with same amount again of good bio - result double the amount of jelly.
Heat above sample, without agitation, and cool - result was mainly jelly, but with a small clear layer on top.
Repeated the heating a number of times - result was eventually a thin hard layer on the bottom, with clear all the way up.  Ie. looking good : )

I ran the same procedure with a sample of (b) using good WVO (from our own kitchen) but the best ive got is a a 1/2 and 1/2 mix of clear on top of jelly.  Ie. not looking good.
I need to try the same with bio, as two things have changed above - the removal of the glyc and the change from bio to wvo.  Id assumed the result would be the same as the first tests, hence being lax at changing one thing at a time.

I tried the same thermal cycling of a sample of (c) today with poor results.  (c) was demethed over night last night, so it may have further reacted.

I thought i was on to something with the thermal cycling, and i may still be, but, possibly, the glyc needs to be present.  Which may further support your own ideas, as, whilst im certain the first test with (a) was fully demethed, there may have been residual caustic etc. in the glyc.


I know none of the above is complete - like i say, i was not planning on writing it up just yet, as i wanted a conclusive positive, which i dont yet have!

[Julian]

I've tried two methods ... the one described above which I've extended to a whole batch with good results.  So if the overdosed test works just heat the gel and add little bits of methanol and catalyst until you notice a colour and viscosity change.

The other method was to do a glycerine wash with a large quantity of glycerine.  Once drained it yielded a nice clear "something" that wasn't bio as the 3/27 test simply didn't work, but would process normally into bio.

The gel in both batches was solid at ambient.

[julianf]

I wonder if we are talking about the same stuff?

You mention colour change -

The stuff i still have has undergone the colour change.  In my list above, (a) was still dark (ie no colour change), (b) has now split, and is lighter, and (c) is light, having had the glycerol split.

I have none of (a) left.
I have 200 ltrs of (b) - which, again, is still fluid, having not been demethed.
I have 300 ltrs of (c) - which i dont currently know the status of, as the sample i took and manually demethed was prior to running overnight on standard (slow) demeth.  Im, of course, hopefull, although not confident, that *somthing else* might have happened in this time.  I dont yet know its status, as the settling drums are still warm to the touch.


The consistency of the jelly that ive encountered -

The stuff years ago was a gelatinous lump lurking under the surface of my bio. Its somewhat unpleasent to describe it as such, but, when you have a cold, and hack up a lump of clear, but jelly like stuff, that sits proud of any fluid saliva (im sorry, but that's what its like!)

When i encountered this years back, i wondered if i smashed it all up, if it would yield more bio, so i stirred it up in the drum, then pumped it using my Leo pump to break it up further.  It did not really work - from memory, i then just got a haze layer, only very slightly below the level of the original jelly layer (eg a tiny amount was liberated, but not worth the bother)


The sample (a) was harder - hard enough that a significant portion managed to cling to the reactor walls, and cause further issues.

Sample (b) behaves like the affore mentioned flem when demethed.
Sample (c) likewise.



In short - all my samples, except for (a), look and behave about the same, and all, apart from (a) have lost the glycerol component, and undergone the colour change.
All, apart from (a), are the viscosity of bio when hot / demethed.  For example, when draining off the glyc, i saw both the colour change, and the sudden increase in flow thats familiar.


Anyhow, as i say, you mentioned colour change, so im just checking that we're both reading from the same starting page?

[Julian]

Hmm, not sure that we are.

The gel/soap I'm talking about occurs during processing.  There's not discernable bio or glycerine produced and it's a yellow ochre colour, pretty much solid at ambient, but liquefies with heat.


I have had soap like this in bio ...




but that's not what I'm talking about here.

[nathanrobo]

The jets are are sensitive to viscosity.  I've been fuging feedstock and it requires about 45 deg c to be happy :-)

My thoughts are that, when hot, the jelly is fully fluid, but, as it cools, if it is *somthing* that holds the bio in a matrix, that somthing starts to solidify.

I was thinking that, if it could be removed, as soon as it appears, then it may not have time to lock up the bio.

If the above is the case, then the viscosity would be the same as the bio - the only way it would be thicker than that would be if the jelly was starting to form properly, and, if that were happening, my above ideas would be proved wrong anyhow.

Mate  you'd be welcomed to a fuge kit on loan for your experiments - perhaps the x country svc to get it to you.

[photoman290]

The jets are are sensitive to viscosity.  I've been fuging feedstock and it requires about 45 deg c to be happy :-)

My thoughts are that, when hot, the jelly is fully fluid, but, as it cools, if it is *somthing* that holds the bio in a matrix, that somthing starts to solidify.

I was thinking that, if it could be removed, as soon as it appears, then it may not have time to lock up the bio.

If the above is the case, then the viscosity would be the same as the bio - the only way it would be thicker than that would be if the jelly was starting to form properly, and, if that were happening, my above ideas would be proved wrong anyhow.

Mate  you'd be welcomed to a fuge kit on loan for your experiments - perhaps the x country svc to get it to you.

i could drop into yours in a couple of weeks when i am going from cambridge to brackley, then on to cornwall. could arrange to meet julian somewhere along the A30 if that would help. usually stop for an hour near oakhampton.