Spenz looking at the pictures that you posted I think I would guess you still had some soap but that stuff off of your filter I would say looks like glycerin. Anyway soaps in my biodiesel on my 6.9 gives me surges but usually only near highway speeds. I have used failed 3/27 biodiesel without problem just need to make sure it's dry and soap free. Or just blend it up after with some diesel or biodiesel.

quote:

Originally posted by Jon Heron:
Ditto on the soap testing and settling.

quote:

Yeh a kit, or just buy a pH meter for $30. That way u never need to buy indicator again.

Can you elaborate on that? I dont understand how the PH meter can be used in determining soap PPM.
Spenc, pour yourself a tall glass of your favourite bevvy and read all about Chug's WBD method HERE, its well worth the read!
Jon

You titrate with your 0.01M HCL until the pH meter reads 4.5. You then multiply the mL of titrant* 304 for NaOH or 320 for KOH and that will give u ur soap ppm.

quote:

Originally posted by paulb3:
Anyway soaps in my biodiesel on my 6.9 gives me surges but usually only near highway speeds.

And that is exactly where the surging would occur, when I put the spurs to the engine and fuel demand increases.

quote:

Originally posted by Jon Heron:
Ditto on the soap testing and settling.

quote:

Yeh a kit, or just buy a pH meter for $30. That way u never need to buy indicator again.

Can you elaborate on that? I dont understand how the PH meter can be used in determining soap PPM.
Spenc, pour yourself a tall glass of your favourite bevvy and read all about Chug's WBD method HERE, its well worth the read!
Jon

Thanks for the link! I'll check it out this evening when I get home from checking on the latest batch settling out.

quote:

You titrate with your 0.01M HCL until the pH meter reads 4.5. You then multiply the mL of titrant* 304 for NaOH or 320 for KOH and that will give u ur soap ppm.

OK I see, instead of using the bromo blue you use a PH meter to determine when its neutralized.
Thanks for the explanation, its nice to know there are options!
Jon

Ok, been reading through Chug's posts about demething an entire batch. One thing concerns me though, Chug uses NaOH I use KOH, is that going to change the results?

Also is equation for figuring how much methanol is recovered down to the stoichiometric limit is in metric, does it also apply to US measurement?

For the WBD I just did a 25% batch; I recovered a little less than 6 gallons.

% of Methanol used - 12 to 13% required for reaction = amount of excess methanol
(25%-13%) = 12% x 45gal batch = 5.4gal

Spence,

WBD works with NaOH or KOH, and yes I did my calcs in international units, but as long as you do the math for 12.5% stiochiometric amount and only recover the excess over and above this it doesn't matter which units you use.

Thanks Chug,

I'm going to give your method a run here this weekend. It will have been a week of settling in the tank this Saturday before I do a WBD on this most recent batch.

Should one do WBD right after the 1 to 2 hours for initial mixing or is there a time limit on when WBD has to occur?

spence, let me know if the whole batch demeth stops the formation of that guiness like foam when doing demething..

Reece,

Will do, but it won't be until Saturday when I have the time to get to it.

Spenc, you can do the WBD as soon as you pass the 3/27. Keep your pot temp below 75C and dont exceed the stoich amount of methanol and you should be fine.
Reece, I typically experience allot of the "Guinness type foam" when I am bubbling my bio after doing just a demeth of the biodiesel. When I do a push/pull (WBD only acid is added to neutralize any remaining caustic) there is very little if any foaming during bubbling. The glycerin seems to take the vast majority of the soap out with it when using these methods...
Jon

Jon,

That may be bit of a problem as I do not have a sample taking port on the reactor to see if I'm getting to 3/27 without draining most of the contents of the reactor.

I've already calculated the limit for methanol recovery and am looking forward to trying this method. It will 'kill two birds with one stone' as it were, doing methanol recovery on the biodiesel and glycerin at the same time without having two add two separate steps.

And the recovered glycerin can be immediately turned into soap for sale through my soap business.

Would keeping ur pot temp at 75C remove enough methanol from the glycerine to make it safe for making soap?

Ive heard some people saying you need to bring glycerine above 100C (212F) at least to ensure all the methanol is driven off.. Im not sure..

If you go to or above 212 then you risk getting water in your recovered methanol. 75-80C is plenty hot to drive off the methanol until you reach the stoichimetric limit.

I've done 55 gallon glycerol recovery batches and held the inlet temp at or around 75C with great results. The glycerin gained was perfect for soap and has been getting great feedback from my test audience and first customers as to its effectiveness as a cleaner. I have a video up on youtube documenting its use on a concrete shop floor.

I understand if you go hotter you will get water contamination, Im not talking about recovery.. what Im saying is that for the glycerine at 75 deg C there will still be methanol in there.

Is it worth when demething the glycerine to keep it at 75 deg C, then change containers to not contaminate ur recovered methanol and then turn the heat up further to ensure no methanol in the glycerine before making in to soap?

I just run the process at 75-80C until the methanol stops running out of the condenser. I change containers when the methanol level gets to 5 gallons in each methanol carboy.

The reason for keeping the temp at or below 75C is to try to mitigate the back reaction witch is accelerated by heat. GL recommends keeping the temp below 70C but I have better results capping it at around 75C.
The glycerin must be taken up to 260F and held there until the methanol stops dripping. This is to meet the HazMat requirement of the glycerin having a flash point of 140F or less to be unclassified, if I remember correctly. 75C is no where near hot enough unless you want your soap classified as a hazmat material...
See farmers research HERE on the topic...
Jon

I think you might have misread my earlier post, a temp of 75C is shown at the intake of my methanol recovery condenser. I haven't any idea as for now how high the pot temperature is. I have the thermostat bypassed and I babysit the processor to make sure nothing gets out of hand.

Thanks for that Jon, Ive often wondered about that.