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cracking byproduct to give ffa and GLYCEROL

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October 13, 2009, 12:38 PM
cracking byproduct to give ffa and GLYCEROL
If you add acid to glyc byproduct to give FFA layer,Glycerol layer,and salt layer,has anyone done anything with the glycerol layer-for example if you check and adjust to make sure the pH is 7 and maybe add some EDTA could it be considered as automotive antifreeze?
I do not see why not-anyone any experience of this or similar?
October 14, 2009, 08:53 AM
I have split byproduct, the biggest problem is the salt(sulfate) which seems to stay in the glycerol/water. This might not be a problem as they use salts in anti-freeze as a pH buffer, I don't know which salts are okay though.

Drying the glycerol/water causes the salt to drop out but drying is difficult. If you distilled the glycerol you would get rid of the impurities, but that is also difficult. The pure product has many uses but is probably a bit to valuable to use as anti freeze.
October 14, 2009, 04:34 PM
Jon Heron
I used strait glycerin byproduct in my deep freeze water setup for my recovery condenser.
I added 4 cubies of glycerin to the 4X3' freezer that was half full of water. It gets a crust of ice on top if I let the freezer go for 2 full days without using it but the water/glycerin mix still flows well. It covers the hoses and uninsulated tee's on my condenser with about a 1/16" of frost that remains there even after running for a 3+ hour WBD recovery...
Not very scientific I know but it definitely lowers the freezing point of the water... Smile
Just dont use the glycerin from a push/pull or WBD like I did at first as it is full of soap and will foam like crazy. Smile
Good luck!


Simple schematic for a pump and heater control with a high limit
Sensor for the biodiesel/glycerin layer
October 14, 2009, 05:23 PM
Thanks for the replies-Like your method for the super cooled condenser water Jon-that would make some wine/beer chiller-a crate at a time(or more)!
I think I'm going to try and split the glyc first-from all my pre-treat stuff my glyc must be full of soap,so I can probably get some FFA to mess about with into the bargain(turbo glyc logs?).The isolated glycerol I will try and neutralize and filter the excess sodium sulphate out(assuming I use sulphuric).Then if I can dry it a bit,more sulphate may drop out-filter again-seems sodium sulphate is considered pretty inert anyway(used in some industrial process to get water out of organic liquids-interesting)Anyway let you know what occurrs.
October 16, 2009, 11:25 AM
Has anyone tried acid estrifying the FFA following splitting of the glyc byproduct layer, to make yet more bio from a waste?. When i split the byproduct i had far more ffa's than pure glyc. about 4:1 might be a bit wasteful on the H2SO4, whats the best way to work out how much is needed, i just kept adding it to my sample untill the FFA and glyc layers stopped getting deeper, not the most scintific approach but then it was just an experiment.. Also i'd imagine water production during estrification might be a problem premiturly stalling the reaction, any one found a good way to remove just the water content while etrifying? I thought i'd found a good way with electrolysis but then found it would also strip the hydrogen out of the methanol as well as the water! not so good.

VW Passat 2.0 TDI with a BKP engine 86,000 miles on B100 and not going strong. Bio-diesel broke oil pump drive shaft! ..No oil pressure, dead turbo.
October 17, 2009, 10:33 PM
Cineman I have tried making bio out of FFA, it wasn't very successful because of the water. I was getting some conversion but had to keep removing the wet meth and add fresh dry meth. It was going to consume huge amounts meth so I abandoned the idea.
Someone else on this board has suggested using glycerol as the alcohol. Because of it's high boiling point you could boil the water off. You could then process normally.
November 30, 2009, 03:06 PM
Wayne Zschech
G'day all,

Q. Does any one have a simple way of bringing the pH of the acidic glycerin back to 7?
I've been using HCl for my first 'lab' tests. Adding 10% volume of HCl (probably about 30% purity) has been the rule of thumb. The acid has been splitting the FFA and glycerin nicely. Now I want to neutralize the semi-pure glycerin.
BTW. Salt dropped out after boiling the water out of the glycerin.

Any assistance would be appreciated.

December 01, 2009, 06:03 AM
Sodium carbonate/bicarbonate, which should give you sodium chloride and CO2.
December 01, 2009, 08:55 AM
Wayne, what are you going to do with the FFA's?
December 01, 2009, 03:14 PM
Wayne Zschech
Re:Sodium bicarbonate. Any idea how much? I'll need a simple titration set up. I'll see if I can find some locally.

Re: What to do with FFA. I'm was originally going to use them as liquid fuel for my furnace. But I'm open to other options. Ukraine is a very interesting place to live. Highly industrialized but with massive shadow economy and over zealous tax officials. e.g. methanol is not available to individuals or most companies. Mention that it's alcohol and you could be up for genecide!

A local chemist recently said that there might be buyers for it even in relatively small quantities. I currently remove most of the methanol from crude glycerin. But if the ffa has traces of methanol in it I may have to extra hard to remove it. To sell it. Same with methanol from glycerin.

BTW. Ukraine basically doesn't have a biodiesel industry. All rapeseed is exported. Only small operations exist really. Recently a small R&D crew took some biodiesel to see if it could be used as an ingredient for their product used in the drilling industry.

I'd also really like to have a better idea of what the ffa is made up of. I'm told 1/3 ffa and 2/3 biodiesel. Nothing more concrete.

Again any suggested uses for the ffa?

December 01, 2009, 06:50 PM
I believe you could add the FFA's to your WVO and perform an acid esterification on the combined product prior to transesterifying with lye. That way you won't need to neutralize until after the transesterification.
December 01, 2009, 06:52 PM
If you are burning it in a furnace, I doubt you need to neutralize it. I could be wrong on that.
December 02, 2009, 01:58 PM
Originally posted by Cineman:
When i split the byproduct i had far more ffa's than pure glyc. about 4:1 might be a bit wasteful on the H2SO4.

Is there really that much FFA's on average in the glycerine byproduct? Thats a bunch, and worth recovering for AE/HTAE if it is the case.
December 03, 2009, 08:02 AM

That does sound like a high ratio, but even if it is 2:1, wouldn't it be worth trying? I did some experiments about a year ago, but never got motivated enough to continue. The problem was getting the salt water layer out of the glycerine. Maybe the AE team could take on this project. Especially since you have a handle on the water problem.
December 03, 2009, 08:54 AM
I copied this from a previous post. Notice the fat content.

We had a de-methed glycerin sample tested by a lab. The results are interesting. Not sure what everything means.

Moisture, Karl-Fischr........... 5.70 %
Dry Matter...................... 94.30 %
Protein, Crude...........Less than 0.1 %
Fiber, Crude.............Less than 0.2 %
Fat By Acid-Hydrolysis........... 32.7 %
Ash.............................. 5.34 %
TSI-Total Sugars as Invert........ 2.9 %
Methanol......................... 0.89 %
December 03, 2009, 09:19 AM
I guess the fat is what we would be looking for. Only 1/3. Seems low.

Fuelfarmer, Are you doing an AE process first?
December 03, 2009, 09:47 AM
Fuelfarmer, Are you doing an AE process first?

No, using new farm pressed crude veggie oil.
December 03, 2009, 10:53 AM
Doh! That makes sense.
December 03, 2009, 10:59 PM
A lot of acid is needed to neutralize the lye in the by product.
You can reduce the amount of acid needed by using gypsum to neutralize the lye.
December 05, 2009, 05:44 AM
We had a de-methed glycerin sample tested by a lab.

I assume the sample went to a feed lab like Cumberland or some such? Perhaps the Fat figure is a "nutritional" figure, and not a chemistry figure...if that makes any sense. I would assume that the Ash is primarily catalyst?

Or I could shut up and stop thinking out loud....

"Don't complain about farmers with your mouth full."
"Arguing with a government inspector is like wrestling with the pig. You both get dirty but after a while you realize the pig enjoys it".