Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Ian61 on August 10, 2022, 05:26:51 PM
-
Hi, new member here, thanks for letting me join the forum.
So I have just made my first batch of what I thought might be biodiesel, but my 3/27 test says otherwise as I have 3ml of oil on the bottom.
I thought the process had worked because it had split into darker glycerine below and lighter colour oil or bio on top with cloudy white water coming out when I washed it.
I think the problem might be that I used old meth that I got with the secondhand kit.
Question 1 does the "biodiesel" need to be dry before doing the 3/27 test?
Question 2 can I use a spirit making ethanol hydrometer for methanol? (I get a result of 85% which I'm guessing is too low for bio production.)
Question 3 Is it worth re-processing with 99.95% methanol or should I just ditch it and start again with unadulterated WVO and new meth?
Thanks Ian.
-
First of all Welcome.
You should find everyone on here very helpful to get you started or solve problems and queries.
Water is going to cause you problems - whether it is in the oil to start with, the methanol, or the bio.
You can use a normal alcohol hydrometer provided it covers the 0.8-1.0 sg range.
If the methanol is only 85% for processing you are likely to create a significant amount of soap due to the competing reaction of the transeterification and saponification (catalysed by water).
The 27/3 test can be performed on the bio/oil mix once the glcerol has dropped, no need to wash the bio. In fact the 27/3 test can be performed even before the glycerine has dropped if desperate.
If you used 85% methanol for the 27/3 test the results will be meaningless. The test needs nearly pure methanol and dry bio, otherwise the water present in the methanol seriously reduces the ability of the methanol to dissolve the bio.
If you used 99.95% methanol but wet bio, then you will also have a meaningless result as above.
Worth posting what quantities of things you used and what process you used to try and make the bio.
Did you dry the oil first, how?
Did you titrate the oil to find out how much FFA was present?
What catalyst did you use (NaOH, KOH, ASM)?
How pure were the reagents? (F|YI: you have already said the methanol was 85%), if using NaOH has the pack been open and absorbed water/CO2, KOH is normally only 90% pure).
How much glycerine did you produce?
From what you describe, I strongly suspect you have produced Bio, but possibly have an incomplete conversion, however the 27/3 test being suspect does not help. If that is the case, and the conversion is incomplete, you can certainly reprocess the oil/Bio. The first step will be to get a meaningful 27/3 result. This will work as a guide as to how much of the reagents you will need to complete the process.
-
Hi countrypaul thanks for your advice.
I used a spirit hydrometer for measuring % alcohol in spirits it doesn't have any sg markings on it only % and 'cartier' 10 to 44 but it was probably warmer than 20 Degrees C today so my reading will have been a bit off anyway.
But "If you used 85% methanol for the 27/3 test the results will be meaningless. The test needs nearly pure methanol and dry bio" tells me everything, I'll certainly wait until I have some fresh meth before I go any further.
So:
Did you dry the oil first, how?
I heated the oil uo to 60C and left it overnight then drained a small amount out of the bottom. I did wonder if this would be sufficient to de-water, but this is what I had read.
Did you titrate the oil to find out how much FFA was present?
Yes I got a reading of 5.5
What catalyst did you use (NaOH, KOH, ASM)?
KOH
How pure were the reagents?
I bought some fresh KOH at 90%
This was my calc for the mix
40 gallons oil (181.84 liters) (I assumed it to be imperial gals, well I kind of tested the markings on the processor by partially filling with known quantities of water first)
Titration 5.5
Base 7+5.5 =12.5g/l
90% pure 7.8 + 5.5 =13.3
13.3g x 181 Liters = 2.4kg KOH used
"How much glycerine did you produce?"
Hard to say as it is spread over several containers of unknown volume, but I guess it's ~36 liters. It's still settling in the processor I assume, how long do I leave it to settle?
Now when I open the bottom tap having removed all the black stuff I get an emulsion which settles out in a bottles to give what looks like very cloudy oil/bio over water.
I'm assuming I need to drain all this off until the bio comes out? I've drained off 10 liters of this and there is more still in the processor.
So I started off with 40 galls WVO added 8 galls meth and now I've got 30 galls left of bio or oil. My guess is it's mostly oil as I think it's too viscous for bio, but, for sure a valid conversion test result would take out the guesswork.
I read that it's better to only use 80% of the methoxide, run that, then let it settle and drain, then run again with the left over 20% which is what I did.
I can't wait to get some fresh meth to test it properly and also make a new batch.
Any comments on my calculations or process would be much appreciated.
-
Just heating to 60C then allowing to settle and draining a few litres off will not ensure the oil is dry. Even oil that looks cler can have several % water present.
The simplest and easiest (imho) is to add the glycerine from the previous batch to the oil mix and allow to settle, this has several benefits:
1) Removes most of the water, I'm sure Dave (dgs) can give you ppm figures if interested.
2) The caustic present in the glycerol will help neutralise any FFA present producing soap and water which the glycerine can remove.
3) Can start the transesterificaion process due to the methanol and caustic present in the glycerol.
4) Saves on caustic as the FFA neutralised by the caustic in the glycerine will result in a (hopefully) much lower titration figure.
Unfortunately, unless you were given some glycerine with the processor, you can't easily do that.
Nearly everyone on here will use Litres rather than gallons (imperial of US) so it might avoid possible confusion by staying with Litres.
Beware that spirit hydrometers are not always calibrated at the same temperature, some are at 15C, some at 20C and some at 25C there may be others, these also tend to measure ABV rather than W/W I believe.
Since you use KOH the glycerine will remain liquid so no gret hurry to drain. Wait until you get some virgin methanol, carry out the 27/3 test, or 10/90 and see if there is any dropout or cloudiness - either indicates urther processing should be considered. Post the results on here and someone will advise how best to proceed.
-
Ian61,
Up on the Yorks/Lancs border . Probably not all that far from me.
I am a bit surprised that you are going straight for a 40 Gallon batch for your first try. I would strongly suggest trying a few small test batches first. Just until you are sure the method you are using works. Dr Pepper is the way to go.
Dave
-
DavidA
That's right, Keighley is just over the hill from me.
Did you see my post a couple of minutes ago about sharing an IBC of meth?
Anyway yes I was going to do a test batch first to see how it would turn out.
But I decided as I have heaps of WVO at hand due to the fact that my "new" car won't run on WVO with twin tank system like my previous 6 cars did. Also I got 3 barrels of meth with the secondhand processor, so I thought I would jump right in and do a fullish batch.
Now I know that was a mistake due to using old meth, but it allowed me to test my plumbing and pump on the processor.
-
Ian61, why would your methanol be so wet, if in sealed containers it lasts for years. Forget that 80/20 ratio on the 2 stage process, its a load of rubbish. After a glyc wash use 15% methanol and 9 or 10 gms.litre KOH.
Use 8 gms and 15% of the unreacted portion for the 2nd stage. If your conversion was 95% on the 1sr stage then thats good, so more like a 95/5 conversion. I actually go for a 97/3 as making the last stage as small as possible lets you 'fine tune' the reaction end point much better. (Absolutely essential if you are going to water wash)
I've sent you a PM.
-
I had a visit from Ian61 today. amongst other things he brought me a sample of his possible 'wet' methanol. I did 2x 10/90 tests with his bio and my good methanol and his possible wet methanol. the results amazed me.
with my 'virgin' methanol dropout was 1ml.
with the wet methanol dropout was 8mls.
so i don't know how much water is in his methanol but obviously a lot!
Ian may be along later to mention some of the other things discussed.
-
I had a visit from Ian61 today. amongst other things he brought me a sample of his possible 'wet' methanol. I did 2x 10/90 tests with his bio and my good methanol and his possible wet methanol. the results amazed me.
with my 'virgin' methanol dropout was 1ml.
with the wet methanol dropout was 8mls.
so i don't know how much water is in his methanol but obviously a lot!
Ian may be along later to mention some of the other things discussed.
Dave,
It takes very little water in methanol to completely ruin the 10/90 test. I can't remember for certain but think I found <1% id sufficient to render the test next to useless. If you have some spare methanol and bio/oil...
-
I had a visit from Ian61 today. amongst other things he brought me a sample of his possible 'wet' methanol. I did 2x 10/90 tests with his bio and my good methanol and his possible wet methanol. the results amazed me.
with my 'virgin' methanol dropout was 1ml.
with the wet methanol dropout was 8mls.
so i don't know how much water is in his methanol but obviously a lot!
Ian may be along later to mention some of the other things discussed.
It was great to visit you the other day and get some fresh methanol to work with. Thanks for the time you took to explain the chemistry and process involved in making good bio. It seems like most of the Youtube content I've watched is now out of date because you and others on here have learned through years of experience how to do it easier and more efficiently. I read somewhere that anyone can make biodiesel, but not everyone can make good biodiesel.
So now I know that my first attempt I got roughly 90% bio and as my soap test kit hasn't arrived yet, what I'm going to do is dump this batch in my central heating tank to mix with the kero and get on with making a fresh batch. First though (after seeing Dave's setup) I'll be making mods to my processor. I'm hoping, but more confident now that my second batch will be 'car grade'
-
How are you getting on with the 'dry' methanol, Ian.
-
Success! My second batch reacted fully with 100% conversion. No dropout at all using dry methanol and 300g less KOH.
So I thought I'd try dry washing this time instead of water washing.
I cleaned out the old sawdust (not a as bad a job as I thought it would be) and started packing the tower with some mixed hardwood shavings.
Do I pack it tight pushing it down or do I leave room for expansion?
It's a stainless tower so I doubt it would blow apart if the sawdust expands.
I also took the tops off what I thought was a centrifuge but it looks like a twin filter setup to me.
I've just put the tops back on for now as I don't know where I might get new filters like this.
Anybody seen filters like this? and where to buy?
Or should I just bypass them into a 10" cartridge filter?
Also I didn't de meth the first time as I was water washing, but now I have to de meth.
How do I know when all the methanol has evaporated? Can biodiesel be easily tested for methanol?
-
Well Done re the conversion. If you are bubbling with an aquarium bubbler I would leave it 48 hours and then up to 1 week to settle. There is no easy way to tell if your bio is methanol free but after 48hrs bubbling and extended settling your soap should be <250ppm which is fine before the wood filter column.
don't pack the column too tight.
Those filters are 'hippo pots' Filtertechnik used to sell the replacement filters. If available they are expensive. When I use my woodchip column I just filter through a 1 micron bag filter as the bio drips out of the 30 litre container with the woodchips, its a lot simpler and just as effective.
Btw its claimed those filters also dry the bio (or at least reduce water) Don't believe this, I've tested them.
-
http://biopowered.co.uk/forum/index.php?topic=3283.msg40122#msg40122
-
Thanks for the link to that post neisel.
Dave, in the post you mention 'blue workshop roll' is that the paper stuff like kitchen roll but a bigger roll? Or is it cloth?
So I finally got my dry wash tower packed with shavings and after ditching the Filtertechnik and changing the pipe to go through a 10" 1 micron, I pumped the lot through.
After doing a soap test I got ~568 ppm nearly 10 times the acceptable level.
What to do now?
Could I reduce the soap level by pumping through the wood shavings again?
I would of course wrap the cartridge in blue roll first.
Get some ion exchange resin and try out my ion exchange resin tower?
Or should I just go ahead and water wash?
My first batch that was 10% unreacted that I was going put in my central heating... I put it in my car tank The thing is, the tank is now less than 1/4 full and as I don't want to buy dino again, I really desperate to get this last batch finished off asap.
So what is the quickest way to significantly reduce the soap content?
-
Water washing?
-
Thanks for the link to that post neisel.
Dave, in the post you mention 'blue workshop roll' is that the paper stuff like kitchen roll but a bigger roll? Or is it cloth?
So I finally got my dry wash tower packed with shavings and after ditching the Filtertechnik and changing the pipe to go through a 10" 1 micron, I pumped the lot through.
After doing a soap test I got ~568 ppm nearly 10 times the acceptable level.
What to do now?
Could I reduce the soap level by pumping through the wood shavings again?
I would of course wrap the cartridge in blue roll first.
Get some ion exchange resin and try out my ion exchange resin tower?
Or should I just go ahead and water wash?
My first batch that was 10% unreacted that I was going put in my central heating... I put it in my car tank The thing is, the tank is now less than 1/4 full and as I don't want to buy dino again, I really desperate to get this last batch finished off asap.
So what is the quickest way to significantly reduce the soap content?
yes the blue roll is just the blue paper stuff, but it won't remove soap.
Its strange that even after the wood chips the soap is so high, i've never come across that before. The wood method is highly efficient at removing soap, so much so that i remember reducing some soapy bio from around 3000ppm to virtually zero in one pass. don't use any ion exchange, its a waste of money. Try the wood again. Is it hardwood and how much volume are you passing the bio through.
-
Ok, so I was just getting set up to wash by misting in my wash tank. I pumped it from the two smaller tanks (apart from the bottom 5 litres in each tank) back through the wood chip and 1 micron cartridge.
Looking into the tanks the bio looked cloudy. Is this the 568 ppm soap in it making it cloudy? It can't be water as I haven't water washed it.
However, before I connected the hosepipe I did another soap test.
Result!
Down from 568 ppm to 169 ppm!
Maybe after the first pass through the wood, the wood hadn't expanded and settled down.
Do I now pump it through the woodchip again to see if it comes down further?
Dave, interesting you say that blue roll won't remove soap, could you elaborate on this. I thought it was about particle size and the finer the filter, the better filtration. I'd heard also that if there was too much soap in the biodiesel it would block the fuel filters on the car. Is there another reason why the soap content must be low, for example it doesn't combust too good?
Yes it is mostly hardwood ~90%, mixed tropical hardwoods and some English hardwoods, so I was told.
As for the volume, the tower is about 3 foot high and 8" in diameter.
It takes very little time and effort to pump through the wood chip tower, I'll do it tomorrow and post the result.
-
Hi Ian, ok so anything dissolved in the bio cannot be removed by filtering through something like blue roll or even a centrifuge. Filtering it through woodchips is different however. The apertures in the wood are about the correct size for a soap molecule to fit in ( from memory something like 50 angstroms, so 50x 0.0000000001 metre) We are talking atom/molecule sizes here, much different to microns.
Soap will form an ash on the valves which is really difficult to remove. I don't know where the spec of 66ppm came from but using bio at several times this spec (imo) would take years to have any adverse effects on an engine.
High soap in your bio won't be causing the cloudyness. Do a hot pan test for water.
-
Another go at pumping through the wood chips has brought the soap down to between 83 and 118 ppm. Looking in the top of the tank I pumped it into, I can now seen the bottom of the tank as it's no longer cloudy.
I pumped it from the top leaving about 75 liters in the conical and I can't see the bottom of this tank.
Does the wood chip dry wash also remove water in the bio?
The spec of 66ppm came from a Utah biodiesel supply Youtube video I watched.
https://www.youtube.com/watch?v=Z6On5gB6VwA (https://www.youtube.com/watch?v=Z6On5gB6VwA)
He says it's the ASTM standard for soap. Maybe we have different names and standards for levels this side of the Atlantic.
-
The soap spec is the same here, our regs are en14214.
Your wooschips won't remove water, but everyone as far as I know doesn't dry if they don't water wash. Does the cloudyness go if heated slightly. In any case I think the bio and fuel pump problems are unrelated.