BIODIESEL & SVO DISCUSSION FORUMS





Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Other uses for Glycerine by-product    Neutralizing Glycerine
Page 1 2 

Moderators: Shaun, The Trouts
Go
New
Find
Notify
Tools
Reply
  
Neutralizing Glycerine
 Login/Join
 
Member
posted
This may have been posted before although I couldn't find anything when I searched.

Something that I have discovered is that Gypsum(Calcium Sulfate) is soluble in glycerol/water/NaOH solution and reacts creating Calcium oxide and Sodium sulfate.

Calcium Oxide(lime) is insoluble and precipitates out.

Sodium sulfate is pH neutral and is easy to remove from the glycerol by cooling.

Gypsum is a very cheap way of neutralizing the glycerol.
 
Location: Nimbin Australia | Registered: December 04, 2007Reply With QuoteReport This Post
Member
posted Hide Post
Well Iam newbee making soap and just like to know how you remove this from the cold glycerol..
I have a problem with my Ph value... I can cook long time or Cold Process and adjust my KOH ( I make liquied soap) and more water and so on... but I can`t get my ph under 9 Ph... maybe this is the solution
for me Sodium Sulfate ...

Gert.
 
Registered: July 22, 2009Reply With QuoteReport This Post
member
posted Hide Post
Gert,
a pH of 9 - 10 is normal for liquid soap. If you try to lower the pH you could be turning soaps back to fatty acids.

If you really want to drop the pH you should use citric acid or lemon juice.


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post
Member
posted Hide Post
Hello Rick.....

Thanks for info... I will try to use juice to start with... I was trying to bring ph down
with some vinegar but the hole batch turn to a cremy substance ... and it was not soap at all so
this was not working... but I will try the juice...

Yes I have read your book and that`s a nice one Smile... Lots of work to come so far... but wash hands in Ph 9-10 goes a couple of times but then it might start to burn your skin.. Well the soap is excellent.. nice and smooth really great ( made some from your book ) but in the end it might be too hard for skin because of the Ph value soo I will try to lover the Ph.

Thanks... Gert. Wink
 
Registered: July 22, 2009Reply With QuoteReport This Post
member
posted Hide Post
Gert, Thanks for the complements on the book.

When you used the vinegar what happened is you probably converted some of the soap back into fatty acids.

Soap naturally has a pH around 9. That should be safe for almost anyone's skin. In fact it is a better pH for our skin because the oils in our skin are slightly acidic. If you try to drop the soap much lower than pH 9 you end up with fatty acids in your soap.

You might do okay with citric acid (lemon juice). Citric acid is the common acid used to adjust pH in the soap industry.

But honestly... A pH of 9 - 10 is normal for soap. Detergents like SLS (sodium lauryl sulfate) that is in most liquid soaps my have a pH lower than 9...


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post
member
posted Hide Post
Sinbad,

When you say neutralize the glycerin, are you referring to if there is extra caustic in the glycerin?

How are you removing the sodium sulfate?

I hardly see glycerin with excess caustic. I've recently seen my first batch when working with Tim's glycerin to help him work out a nice bar soap.

I'm in the process of modifying my SAP calculation to account for glycerin that has excess caustic. Actually having a -SAP value. In Tim's case it was about -5% SAP.


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post



member
posted Hide Post
gert,
If you use the borax solution you can lower the pH while increasing the viscosity of the soap. Borax is great it neutralizes and thickens!


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post
member

posted Hide Post
Gert;
The methods outlined by Rick here are spot on, however YOU DO NOT NEED TO LOWER THE PH of soap that comes in between 9-10.5, that is where it SHOULD be. It will not burn the skin unless you have not cured it (cold process) long enough for all the caustic to neutralise.

My soaps are consistently around the 10Ph area. FYI the PH cale for our purpose goes from 1 to 14 with 7 neutral. Below 7 and it begins to acidify, and above 7 it begins to become alkaline.It is preferable to have soap slightly alkaline than acid, and at 9-10.5v that is precisely what you have.

Enjoy it, you have good soap.



** Biodiesel Glycerine Soap - The Guide
- on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


 
Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
member
posted Hide Post
Couldn't have put it better.

The pH of natural soap liquid and bar falls between 9 and 10.5.

A quick an easy test is the "battery" or "Zap" test. Touch the soap to your tongue. If it bites like a 9volt battery then the pH of the soap is too high and the soap is caustic hot.

If you do not get zapped then the pH is between 9 and 10.5 and is safe for use.


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post
Member
posted Hide Post
quote:
When you say neutralize the glycerin, are you referring to if there is extra caustic in the glycerin?

How are you removing the sodium sulfate?


I am not sure I put this in the right thread but I couldn't work out which one was right.

I don't make soap but was trying to remove the caustic and other impurities from the glycerin which usually means an acid, the gypsum is a safe neutralizing agent for NaOH.


Sodium sulfate is very soluble when warm but practically insoluble at low temperatures. I put some in the freezer and it just fell out of solution if left to cool slowly it makes some nice crystals.
 
Location: Nimbin Australia | Registered: December 04, 2007Reply With QuoteReport This Post
member
posted Hide Post
This is the right area.
The soap discussion sort of hijacked your thread...

So what you are saying is you have glycerin that is high in NaOH after you have made biodiesel.

You want to neutralize the NaOH. And you are using gypsum to do so. And both the Calcium oxide and Sodium sulfate fall out after the glycerin cools.


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post
member
posted Hide Post
Sinbad,
That is a great Idea. No hazard materials to handle!
I beleive what your creating though is, Sodium sulfate and Calcium Hydroxide.
2NaOH + CaSO4 -> Na2SO4 + Ca(OH)2
Keep us posted on the process.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post



Member
posted Hide Post
... hey Rick ang Legal... well might be I just have to wait for the curing period.. but I have HP all my soap and it ended up Ph 9-10 and it`S a great soap.. The only thing I was wondering about was that normal soap you buy have a Ph of 7 and mine 9-10 so that`s why I was worried about my skin.

But I will let my soap cure for some weeks and see what`s happening with Ph.
I have washed hands every day and have not burned my hands but they were dry at the last.. but that would happen to ordinary soap too I think so... but I will works a little with borax I think and lemon juice..

Thanks... Gert Smile
 
Registered: July 22, 2009Reply With QuoteReport This Post
member
posted Hide Post
the difference between your soap and "ordinary" soap is that ordinary soap, in most cases is a detergent. Detergents will have a pH around 7. Natural soap, Like ours, has a pH of 9 - 10.5.

You pH falls right were it needs to be without neutralizing.

In fact if you are going to use borax to thicken your liquid you should make the pH 10.9 - 11 on purpose and allow the borax to lower the pH to between 9 and 10.5.

Basically you are already there, and it sounds like you have some great soap!

Congradulations!!! Smile


-Rick

http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.

Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!

"Closing the loop on biodiesel production one bar at a time!"

Beware of the Dunning–Kruger effect.
 
Location: S.E. Michigan | Registered: April 15, 2007Reply With QuoteReport This Post
Member
posted Hide Post
Sinbad, Does the FFA split out from the Glyc in the same way it does if you add acid? or is this just a method to shift the PH back towards 7


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.
 
Location: Calne, Wiltshire, England | Registered: October 22, 2008Reply With QuoteReport This Post
Member
posted Hide Post
Hi Cineman short answer is no.

Gypsum is pH neutral so it doesn't split soap but it does convert the residual lye into sodium/potassium sulfate which reduces the amount of acid you need to use to split the soap. You would need to let the lime created drop out and separate before the acid is added or the acid will react with the lime.
 
Location: Nimbin Australia | Registered: December 04, 2007Reply With QuoteReport This Post
Member
posted Hide Post
so this is more of an ion exchange then a neutralization..just a small clarification. if I'm off base here..speak up?? hey I know I've been wrong before..

when I read neutralization..I think acid and bases meeting..H2S04 and KOH, for example..

KOH or NaOH meeting CaSO4.2H20...hum..I rethinking my chemistry..time to go back to the books..I'm afraid..Frown

ok..what is the glycerin is KOH based? instead of NaoH based


NaOH we'd get..per double D..
2NaOH + CaSO4 -> Na2SO4 + Ca(OH)2

KOH
2KOH + CaSO4 -> K2SO4 + Ca(OH)2 -> I don't know about this..

but gypusm
is CaSO4 · 2 H2O - per wiki.. so where does the di water go double D? I know I don't know.
some day over a beer or two I'll share about my HS chem final..yes I passed with an 'A'..but as usual the devil is the details..Smile


hey..I'm just looking for ways to use/sell/burn my glycerin..even more so since I can get H2S04 for $3/gallon..make other options available besides burning..we don't have that long of a heating season. I think we need around 1-1.5 cord/year for heating. compare this it fabricator or murphy..

-dkenny


'84 bluebird school bus, DD8.2L turbo( 4/2011, the bus tranny has died..Frown 8.23.11 bus driven to scrap yard Frown )
2006 Jeep Liberty CRD Smile - the wife's
99 dodge 2500 5.9l 24v..-mine Smile
everything run B100 when its warm enough Smile
 
Location: RTP, North Carolina | Registered: December 15, 2004Reply With QuoteReport This Post
member
posted Hide Post
dkenny,
I didn't notice the dihydrate part for gypsum. I was focusing on the CaSO4.
I came up with Na2SO4 + Ca(OH)2 from working up an electron dot configuration to balance the reactants and products.

Even with the dihydrate disolved into the glycerol, I think the water could be taken out of some of the reaction since you would have the Ca++ and SO4-- and 2H+ 2OH- and Na+ OH-. I think the Na+ OH- would be able to form Ca(OH)2 and Na2SO4. There could/ would also be the formation of other stuffs in the process though considering everything that is floating aroung in the mix.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post



Member
posted Hide Post
Hello Sinbad,

Was wondering if you could elaborate on your procedure. What are the ratios between gypsum glycerol water and sodium hydroxide. How can you be sure that the precipitate you see is Cao and not CaSO4?
Thanks
 
Location: Vancouver, Canada | Registered: April 09, 2010Reply With QuoteReport This Post
Member
posted Hide Post
Hi Joe.

You need about 3.5 kilo's of gypsum to every kilo of NaOH you want to convert but some will be tied up as soap so you probably don't need that much.

I just roughly mix the gypsum in bubble air through for a day and leave it for a couple of weeks to settle. If it is to thick to settle I add some water till it's a bit sloppy. Dry is better because soap is soluble in methanol and the gypsum should break some dissolved soap. As the NaOH is converted to sodium sulfate it drops out of solution because it isn't as soluble as the lye so the glycerol thins a bit over the course of the reaction.

I can only tell the difference between the gypsum and the lime by feel, the lime particles created are very fine when compared to the gypsum.

The reaction never really goes to completion in one step, a bit like bio there is always the potential for the reaction to reverse and a point of equilibrium is reached.

If you reduce the gypsum and mix well you shouldn't get any get any gypsum dropping out because gypsum is soluble in NaOH solutions?
 
Location: Nimbin Australia | Registered: December 04, 2007Reply With QuoteReport This Post
  Powered by Social Strata Page 1 2  
 

Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Other uses for Glycerine by-product    Neutralizing Glycerine

© Maui Green Energy 2000 - 2014