I process at around 150F so it doesn't take long to get up to my maximum 165~170F pot temp for recovery. Thats why I increase the vacuum slowly over the course of a few hours, if I jack the vacuum to anything over about 8Hg for the first 45 minutes or so I will overload the condenser and get methanol fumes coming out of the pump as well as the bio will start to foam from the rapid boiling and the foam ends up in the condenser... I also pack the top of my collection carboy with ice and wrap it all in a wool blanket to keep the methanol from boiling in the collection carboy. This keeps all the fumes out of my vac pump.
For my next setup I intend to either refrigerate the collection container or use a simple copper pipe wrap around it to circulate my super cold condenser water through. I think a condenser on the output of the collection vessel to the vac pump is also a good idea.

Doug It sounds like you have a failing vacuum pump. If you had a leak I doubt it would hold 15Hg for a few hours. Pressurize your rig to around 30PSI and use soapy water on all the joints, look for bubbles to check your plumbing.
Jon

Jon
-the brown foam is from the byproduct, When the methanol boils out of the byproduct rapidly, it creates the brown soapy foam. If this gets into your recovered methanol you can let it settle and decant the methanol from the top and dump the rest into the next byproduct.
-Why do you process at such a high temp? are you not afraid of setting up a reverse reaction. The info I sent you shows the commercial producer processes at 50C or 122F. Jim the chemist from the plant, says aviod temps above 55C 130f at all cost! during the transesterfication and wash processes.
-I emailed Jim last night about the WBD, haven't heard back yet, he's probably still shaking his head Tom

tom did he mention a reason he doesnt process above 50 deg C?

To do with soap formation or polymerization of your BD?

Tom,
I process at around 150F because it takes less time to process. Also I have never heard of any issues processing up to as high as 170F other then from your contact in Greece. I also have a hard time understanding how a back reaction could be going on at the same time the esterification reaction is happening. Is it possible for the reaction to be going in opposite directions at the same time?
The way I understand it there can be no back reaction until the solvent is removed.
I can see the high temp being an issue during the wash stage because the methanol is being removed.
Of course I am just an electrician and my chemistry knowledge could be written on the head of a pin!
To my knowledge I have never had any issues processing at this temperature. I have never had any GC testing done but I do check my finished fuel with the phlip test and I have yet to fail one. I cracked open my shop furnace fuel drum last weekend and it has been sitting 1/4 full all year and the fuel still looks and smells as good as it did last year so I dont think I am having any stability issues either?
Time for some of you chemistry pros to chime in...
Jon

Jon,

could you 2 things.

1) If you are doing soap tests, test demethed bio before you water wash.

2) Do a shak'em test, on the same sample of demethed unwashed bio as well.

Take pics or report back results.

Thanks

Doug,
I have never water washed, only settled after demething and then filtered to 5 micron ala GL's process.
I can give you my soap titration results from earlier this year on fuel fresh out of the processor after demething if you like but I doubt they will be of much use? Let me know as I will have to search out my notes... no small task!
I have done a shak'em up test on freshly demethed bio with definite failures if that helps any? I find about 3 weeks of settling is necessary before I can pass the shak'em up test but I also have very soft water... My finished fuel (settled for a minimum of 3 weeks)soap tested at around 150PPM if I remember correctly. This testing was done on push/pull batches as thats my standard procedure now...
Are you neutralizing with acid?
Once I get a wood chip setup going I am expecting to settle for a week and then send through the chips into my fuelling station as finished fuel, only time will tell if that is going to work out!
Jon

No acid, just WBD. Forget your notes for now, lets just keep compiling data. I am going to run a batch next week with KOH and measure the heck out of every step and report back here. It would be great if you did something similar then we could eliminate other errors in calculations. Samples I am going to take:

1. Right after pass 27/3
a) Fresh Bio taken from the middle (push/pull benefit)
b) fresh glyc
c) Sample with both glyc/bio and let settle.

2.) Demeth at low temp (130 max at the bottom and measure the vacuum)
a) Take a sample of Bio every hour for 4 hours.

3) Let cool overnight
a) sample of pure bio
b) Sample of pure glyc

4) From 1a or 1c, I am going to bubble out with no heat the meth and then measure soap PPM from that as well.


Keep track of your failed Shake'em test and see if they emulsify badly (entire stuff turns creamy for at least 20 minutes) or you get separation pretty quickly with bio/thin white layer/cloudy water. My calculations are showing NaOH causes bad emulsification above 1000ppm or so and will allow separation below that.

I will keep samples of all of this in case I find a couple hundred dollars to test for Free and total glycerine tests.

Thanks
Doug

Doug,

Depending on how you do the shakemup test, different results can occur. If you just wrist flip a couple of times, maybe you can pass at 500ppm; but if you shake the he11 out of it, you will probably fail at 200ppm. Once you master the soap test and perform shake tests, you may be able to use the soap test less frequently. The shakemuptest is not science -- it is an art.

I think the WBD and WBD with acid neutralization are both valid tests and I will pony up $25 for that cause.

Thanks Eurocab. However, in my tests, Shake'em up hard, doesn't 'fail' (create a complete emulsion) with NaOH under 1000ppm. It will separate under 10 minutes - at least compared to over 1000ppm which stays thick for at least 30-60 minutes. I will be taking pictures and videos to demonstrate it later.

Doug,
I doubt I will get another batch done this year, I am way busy and am 4 drums of fuel ahead of the game right now. But if I do I will keep track of things and send you the results.
I agree with Eurocab that the shakemup tests arent too accurate at all. It depends on the water type allot too.
Soap titrations are the way to go in my opinion.
Its easy enough to do the shake test though if you insist!
Cheers,
Jon

Ok,

Is it possible

1) That bio that passed 27/3 but has had a back reaction will fool the soap test? Meaning that the MG and DG will read as soap in the soap test? Meaning that it will take more .01M acid?

2) That the emulsion I am seeing during my vigorous shake'em test is not a result of soap but of MG and DG?

My unspoken assumption was that NaOH soap was causing the horrible emulsion I am seeing in the vigorous shake'em test, but after more and more reading, I seem to have learned/remembered that its the MG and MG that cause them. Right after passing 27/3, bubble out the meth, and do a shake'em test.

Doug
-the soap test as I read it checks for soap, not monoglycerides if you are passing the soap test and still making a sustainable emulsion then it must be monos. When we talk monos, we are just speculating since we have no way of checking for then. monos are one fatty acid attached to a glyceryn backbone, as I understand it, and I could be wrong! by product which contains the stripped glycerine molicules, can cause a bit-ch of an emulsion. So I would imagine that any monos would react in the same manner. One thing I have found with the water wash and emulsions, is that if the water quantity is low enough the emulsion will not occur. I have been water washing using 5% water by volume with very good results,no emulsions, Try taking a sample and using only 2-5% water then do the shake test and see if there is any differance Tom

quote:

Originally posted by Doug Weiner:
Ok,

Is it possible

1) That bio that passed 27/3 but has had a back reaction will fool the soap test? Meaning that the MG and DG will read as soap in the soap test? Meaning that it will take more .01M acid?

2) That the emulsion I am seeing during my vigorous shake'em test is not a result of soap but of MG and DG?

My unspoken assumption was that NaOH soap was causing the horrible emulsion I am seeing in the vigorous shake'em test, but after more and more reading, I seem to have learned/remembered that its the MG and MG that cause them. Right after passing 27/3, bubble out the meth, and do a shake'em test.

That is correct, if you are doing the WBD and pass the 3/27, and your soap titration is very low, and you have an emulsion in a vigorous shake test (the only way to do it IMHO) you likely have had some back reaction and MGs and DGs are causing the emulsion.

fabricator, the only problem is that my soap tests are high as well!

Doug
-you have to get rid of that soap! try a small bath, say 1 ltr and shake wash using 5% warm water, this should settle and be ready for the next wash within 1 hr. don't be too agressive at first. You could soap test after each wash to see how much progress you have made. As I said in the previous post, if you control the water amount you will also control the emulsions. Tom

BioTom,

that is a great plan and one I was hoping to implement today.

What pumps are people using. I know Jon Heron has some big pump as does fabricator. Are any of you using Blue HF pump or something small. Perhaps something as simple as my mixing is not good enough and that is the cause of my woes.

Doug

Doug
-I use the blue pump for washing, have you ever pump washed before? this is a very thourough wash process, but it needs to be done with care, you can overwash!!! start out with a small amount of water and start the wash cycle at 2 minutes. after the second wash you can bump the time up to 5 minutes. (this is for the 160ltr batch that I wash) then repeat once every hour until the soap test show the soap is gone, or as I do until the ph of the wash water at the end of the wash is the same as the starting water, this is way faster that bubble washing, and not as tabo as some make it out to be as long as you keep the water quantity low. Tom

BioTom,

Sounds like a good idea.

1) What is overwash?

2) Do you just pour the water in the top of the drum, then turn the pump on? Or is there some other way to add the water.


Thanks
Doug

Doug
-you can pour the water in from the top, os in my case I have an entry port at the pump intake. Use warm water not hot!
-Pump from the bottom and and back in the top. no spraying, I have the top flow split into two flows by a simple T and a couple steet elbows just like this.



and this is the wash tank on the right side.

Will water washing remove the MG and DG I think I have?