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whatarascal

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Hi all

I make biodiesel and from the glycerol have been making soap.

I use Potasium Hydroxide and methanol for the reaction and Potasium Hydroxide for the soapmaking the soap I get is pretty thick but by no means solid.

The soap works very well but is very dark in colour and smells a little of fish and chips a bit like the feedstock used to make the biodiesel.

I would like to know how to make liquid soap from rapseed oil using koh .

At the moment I would like to make the soap without any essential oils or fragrances.

Can anyone help thanks :?:
 
you need sodium hydroxide to make solid bars. as far as i know potassium hydroxide makes liquid soap.
 
I pound of KOH (453 grams) per gallon of oil will give you a good cleaning oil. Use a lye discount for something more moisturizing.

Adding coffee grounds will nuetralize the food odor but will also darken the color.
 
Thanks donniej

I pound of KOH (453 grams) per gallon of oil.I have a supply of distilled water.

So please tell me what I do with them.

IE:how hot the oil how much water and how long to stir.


I have spent the last year trying to avoid soap in my biodiesel reactions so this soapmaking is unatural to me
 
I got into soap because I was producing 5 gallons of glycerol with every batch of biodiesel. I didn't know what else to do so I made soap and gave it to my friends. It's a lot of fun, especially if you get into bar soap.

Heat your oil to 120*F or hotter. The hotter it is, the faster it will saponify.

In a second bucket mix your KOH and water. The amount of water you use is not critical... 50% of the quantity of oil is a good starting place for liquid. Let the KOH/water cool to approx the same temp as your oil and then mix the two. Slowly add them together. Mix until they stay in solution, you may notice it slightly thickens or depending on the color of your oil the color may change a little as it saponifies.

It will take a day or two to finish saponifying, but depends entirely on what temp you're working at. It's ready to use when you can touch a tiny bit to your tounge and it doesn't zap like a 9v battery.

To use your glycerol you need less alkali becuase most of the catalyst you used to make BioDiesel is still in the glycerol. 5.5 ounces KOH per gallon of glycerol is a good starting point but you may need more.
 
Hi Donniej

Were those instructions for liquid soap or biodeisel? I got a little confused at the end. :shock:

And are you saying that this is biodiesel too? At what point does it become soap?

Val
 
Hi Val,
That was all soap talk, geared towards someone who knows BioDiesel but not soap.

The main difference between making soap and BioDiesel is to make BioDiesel you use methyl alcohol instead of water. Otherwise it's very similar. BioDiesel also uses a lot less lye. They are so similar that if you have water in your oil and you don't process it out, you will make soap instead of BioDiesel. This happened to me with one of my first batches many years ago... I ended up with 5 gallons of stinky soap full of methyl alcohol :oops:

PS. Making BioDiesel usually uses 20% methyl alcohol and a small amount of lye, <1 ounce per pound of oil. You mix the alcohol and lye then mix the alcohol/lye with warmed oil (120 - 150*F). Mix for a while the let sit over night and the next day the BioDiesel sits on top and the glycerin sinks to the bottom.
 
Very Interesting!

I made a Smacks Booster for my Tahoe. Haven't installed it yet .. really need to do that :wink:

So do I understand this right .. making liquid soap ... do you remove the glycerol and use that for other soap or leave it in.

Val
 
Liquid soap is the same as bar soap, just liquid. The glycerin stays in. The glycerin is only separated out of the oil if you make BioDiesel.

This is because oil is made of 3 fatty acid molecules and one glycerin molecule. Making BioDiesel plucks the fatty acids off of the glycerin and reattaches them to molecules of methyl alcohol. The glycerin which is now separated from everything else sinks to the bottom of the container.

It can also be described as...
Triglyceride + methanol = Fatty-Acid-Methyl-Esters + glycerin.
The lye is a catalyst, which means it is not consumed in the process. After processing it sinks to the bottom with the glycerin.
 
Ok so is this part of your post for making glycerin soap from the glycerol that is left over from making biodesiel?
I may can get some of this free LOL

Val

donniej said:
Heat your oil to 120*F or hotter. The hotter it is, the faster it will saponify.

In a second bucket mix your KOH and water. The amount of water you use is not critical... 50% of the quantity of oil is a good starting place for liquid. Let the KOH/water cool to approx the same temp as your oil and then mix the two. Slowly add them together. Mix until they stay in solution, you may notice it slightly thickens or depending on the color of your oil the color may change a little as it saponifies.

It will take a day or two to finish saponifying, but depends entirely on what temp you're working at. It's ready to use when you can touch a tiny bit to your tounge and it doesn't zap like a 9v battery.

To use your glycerol you need less alkali becuase most of the catalyst you used to make BioDiesel is still in the glycerol. 5.5 ounces KOH per gallon of glycerol is a good starting point but you may need more.
 
Thanks for the info donniej I will give it a try and post my results.

Back to bio just to confuse the issue,after demething the biodiesel I get about 200 or so ml of soap,glycerol dropout have you used this for making soap or do you dispose of it?
 
The black glycerol layer will contain; glycerol, free fatty acids, soap and most of your catalyst. All of which are fine for soap making. I've made many, many batches of soap using this.

There's actually a section of the infopop BioDiesel forum dedicated to uses for glycerol, soap is the most common. A fellow there named "Legal Eagle" who sells a guide on how to make soap from BioDiesel glycerol. I bought a copy, it's just a pamphlet but it's worth the few dollars it cost.
 
well I tried a small batch 1 pint and all I have is a tray of hard small lumps resembling sawdust mixed with oil.I used 2ozs koh and 1 pint of oil 1/2 pint water.
Seemed like a lot of koh though.

So I went back to what I know,put 200ml methanol in 1 liter rapeseed oil then 10grams koh mixed and heated to 45c shook every 5mins for an hour then left to split,poured of the bio then warmed glycerol to get rid of methanol.
Then mixed 1/2liter water with a further 5grams koh mixed it with the glycerol and warmed untill it traced.

I found that easy why cant I make soap the easy way?
 
What you described happens with NaOH but I've never seen that happen with KOH.

If you mix your oil soap with a whisk, blender, etc... can you smooth out the bumps?
 
I have drained off what I thought was the excess oil "perhaps it wasnt excess"and now the lumpy stuff is acting like soap when used to wash hands.
Tasted it and no burning on tounge.Perhaps I should now have a go at whisking blending it although it is rather hard
 
It sounds like an incomplete reaction. I'd try another batch, heat the oil to 200*F and add the KOH/water. Shake it like he11 every 5 minutes and it should be fine.
 

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