After almost ten year of making world class bio I'm in a fix, after processing I have almost 375 gallons of soap, I suspect the tote of methanol I bought has a lot of water in it,
I do acid base and the titration never went down during the acid stage, it ended at 5 koh so I went with that.
Did the base stage normally and failed 3/27 badly, reprocessed with a little more meth and koh, failed again, repeat reprocess, this time it passed 3/27 beautifully.
Wait over night and drain glyc, heat to 170 and start vacuum demeth process, after pulling off most of the meth I immediately send it to a flash demeth tank where the hot bio is pumped onto a screen and it falls into a tank the remaining 170 degree meth flashes off almost immediately.
And it did, but, the product is almost 95% soap.
Is there any way I can turn this into bio? After thousands and thousands of gallons of bio this is a first for me.
Soap can be made into biodiesel. Economically it's probably better to use the soap as soap for whatever task. But to make soap into biodiesel, figure how much caustic you've put in then add a slight excess of 1/2 molar equivalent of sulfuric acid to make an inorganic salt + the free fatty acids. Remove impurities and all the water to get fairly pure, dried, free fatty acids. Take the free fatty acids add enough anhydrous methanol and a little (a catalytic amount) concentrated sulfuric acid, with mixing/stirring. While mixing heat to just under the boiling point, for a faster reaction. I think heating with stirring for six hours would be long enough. An excess of methanol should have been added to help ensure a more complete reaction. That will produce methyl biodiesel , the fatty acid methyl esters, but there is a bit of sulfuric acid in the reaction product which probably can be removed by extracting with distilled water. After extracting with water, the biodiesel should be dried. I suppose a flash evaporator like you seem to have might dry the biodiesel adequately for use as a motor fuel. Reacting free fatty acids with an anhydrous (without water) alcohol in the presence of a strong mineral acid is called the Fischer Esterification. I've done that one several times. It has a few advantages, like being able to make anhydrous isopropyl alcohol react with free fatty acids to produce isopropyl biodiesel. Isopropyl alcohol won't make biodiesel in the normal base transesterification reaction. I made isoproyl biodiesel via the Fischer Esterification. Soap can be made into biodiesel, but it's not very economical. Thanks
Thank you for the reply, you are right, that does seem a bit much. I was just considering mixing it 50/50 with raw oil and putting it through my normal heat to 180 degrees while centrifuging to dry everything out.
After it's good and dry, out it in the processor and do a titration and then do my regular acid/base process. Do you think that would work? I'm sure I would have a reduced yield but at least it would be doing some good.
I'm not sure I know what you mean. As best I know the normal acid/base process will not make soap into biodiesel. Soap is potassium, sodium or even lithium bonded to the organic acid, carboxylic acid. Vinegar is an example of a carboxylic acid, as are free fatty acids. What I've done before was make free faty acids from soap, then I used a free fatty acid to make a fatty acid methyl ester which is what normal biodiesel is. Thanks
I'd have to agree with Wesley B. It was a specific chemical process that, although unplanned and unexpected, made soap out of your WVO. It will take a specific process to reverse that result, rather than wishful "magical" thinking and holding your mouth the right way.
Sorry about that!
Hey Paul ling time no type, I'm hoping for holding my mouth right.
Looks good from here, lol
Years ago, I didn't take or keep notes, I made sodium soap from lard or vegetable oil. Later for reasons I don't recall, I put the soap in a large beaker, maybe 2 litre. I added muriatic acid (Hydrochloric Acid). At room temperature it didn't seem to do much but when I warmed it up, with stirring with a glass rod, it magically turned from solid soap to liquid, wet, free fatty acids. There were two layers, a lower layer that probably had glycerine, water, sodium chloride (table salt), and an upper layer that was mostly pure white, liquid, free fatty acids. The free fatty acids were wet. If they were to be used to make biodiesel, drying them would be necessary. In separate experiments I used stearic acid technical grade, to make stearic acid methyl ester, which is one of the components in biodiesel. Stearic acid is one of the fatty acids in vegetable oil and animal fats. I put stearic acid in a flask with an excess amount of alcohol and a little concentrated sulfuric acid (to act as catalyst) , with stirring, at a little below the boiling temperature, for maybe 6 hours, I reacted the free fatty acid, stearic acid with anhydrous alcohol. The product was the fatty acid methyl ester, some water, with residual sulfuric acid catalyst and the extra methanol I added to cause a more complete reaction to occur. Maybe you see, soap may be used to make free fatty acids, then if water is present remove it by whatever method. Then dry free fatty acids may be reacted with anhydrous alcohol to make biodiesel plus a little water is produced as a side product. There are easier ways to make biodiesel, but soap can be used to make it also. Thanks.
soap soap soap! if you acidify the soap you should be able to reclaim your fatty acid, then dry and process normally.
" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
I did the muriatic experiment yesterday, I had what looked like three distinct phases, the bottom was clear as water the next was more oil colored but still watery phase, then the thickest phase that looked just like bio.
I drew it all off with a syringe and it smelled like raw bio and it made a crystal clear 3/27.
Fab, is the 3/27 test appropriate here? If it only tests for di- and tri- gly, these would have disappeared in the soap making, hardly likely to reform if you are pushing FFA's towards FAME with methanol and acid.
Hell I don't know, I know just enough to be dangerous, to do the acid base everything needs to be bone dry, if it is you'll make really nice bio, if not you will have varying degrees of conversion.
There, that is the sum total of stuff I want in my head.
The proceedure I outlined in this thread was for 100% soap and 100% free fatty acids. With part soap part vegetable oil, being bone dry, acid/base might work well enough, if enough acid is used to salt out all the caustic that went into making the soap that's present, then plus some additional strong acid to act as catalyst.
I have a drum of sulphuric, would you have an experimental starting point in mind as far as ml per L?
If I understood what happened all the caustic you used went into making soap. For me to suggest a proceedure I need to know some things. How much, what purity and type of caustic was used. To calculate about how much acid is needed, then amount of base should be known.
I use 1ml/L of sulphuric so it was 1325ml of sulphuric to 350 gallons of oil, couldn't get it below five so I added 500 more ml of sulphuric, so 1825 total acid.
It never went below five, In the base stage I use seven grams base so it came out to 35 lbs of koh, there was quite a bit of fallout in the 3/27 so I pulled it out and it was about 3/4 of a ml.
I added eight more pounds of koh with five gallons of methanol, and added it very, very slowly.
The 3/27 then came out perfect.
I then allowed the glyc to settle and drained it off, then I vacuum demethed, pulled out close to 55 gallons of the approximately 95 gallons used, while it was still 180 degrees I flash it off into my wood chip tank, after about an hour it was clearly apparent I had a tank full of soap not bio. Thank you for your time.
In an acid/base method of making biodiesel I thought methanol is added with the sulfuric acid to make esters of the free fatty acids present prior to proceeding with the base/methanol, methoxide step. In your description of your proceedure no mention is made of adding methanol with the sulfuric acid. How did you decide 95% of your product after the flash evaporator was soap? Soap making does produce glycerine as a byproduct. I'm working on a suggestion of how to do a test batch on it to make the soapy product into biodiesel. Some potassium soap I made is semi-solid. Is your product with potassium soap in it entirely liquid? Thanks
Methanol is added with the acid my total methanol per batch is 76 gallons, I mix the acid with 38 gallons then at at the base stage I mix the amount of koh the titration calls for with the other 38 gallons.
The 95 I refered to was the total amount of methanol I used while adding more catalyst to get a complete reaction, and yes at room temperature which is 85 F here now it is semi solid, a tea colored jelly, a popscicle stick will stand up in it.
The 1825 ml of H2SO4 neutralises about 1338 grams of KOH if it's 100% pure, producing potassium sulfate salt. That would leave 18,182 grams of potassium hydroxide to act as catalyst in the base part of the reaction, if water wasn't present. But since too much water was present (probably) all or most of the potassium hydroxide went into making potassium soap. That's an amount called 324 moles of potassium hydroxide which forms soap from wet vegetable oil, with methanol present. So to remove the potassium from the soap requires about 8.6 litres of concentrated sulfuric acid, with mixing and warming the material to maybe 40 degrees centigrade. The reactions should be obvious when they occur. But since you drained off some glycerine, probably part of the unreacted caustic and some soap probably went out with that removal of liquid. So, removing some of the potassium would lessen the amount of sulfuric reaction required to produce the free acid, in the reaction where sulfate bonds with potassium to make the inorganic salt potassium sulfate. I would call it a difficult problem. Since a good analysis of the content of the glycerine layer is probably not available, my best guess is that with fast mixing if possible add the acid gradually into the soap. I don't know the best temperature to do it at, and methanol (poison) fumes would be present. That ought to be enough acid to produce the free fatty acid. Concentrated sulfuric acid also reacts with double bonds in fatty acids that have them. But I suppose the production of the inorganic salt might be faster at 40-50 degrees than the reaction of sulfuric acid with fatty acid double bonds, if strong mixing can be accomplished. 100% of your vegatable oil is not soap, there's not enough caustic to do that. After producing the free fatty acids water would have to be removed to react an anhydrous alcohol with the fatty acids in the presence of catalytic sulfuric acid. I described that Fischer Esterification above. I'm now being called by someone to help them. The Fischer Esterification not only produces the methyl ester, it also produces water.
Thank you very much for your help, my reactor is very fast mixing, should the acid be mixed with some methanol or just add the straight acid very slowly by itself?
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