First Batch: Need help with incomplete batch process...

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Hi everyone, I'm new to this forum and to making biodiesel with the exception of several small batches in a 2L bottle. All of which have been successful. Last night I ran my first batch thru my newly constructed Appleseed and this morning found a partially reacted batch. The glycerine layer was very thin and looked like cola and the bio layer was fluid but looked like peanut butter. Here are the specifics:

95L of waste oil, strained the crud and fluid at room temp
21L of methanol
867g of NaOh

I titrated the oil two times and each suggested an additional 4.25g of lye +5g lye (base formula). I preheated to 125F and evacuated the processor to 29 in of vacuum to boil all of the water out. In the absense of the boiling sound I started to mix my methoxide. I introduced the methoxied at approx 100F to 104F and circulated for 2hrs. (Not sure if the lower temp effected the process.)

I've been fooling around all day trying to crack the crud out of the bio without much success. The best result so far was when I heated a 1L sample of the oil in a frydaddy to 250F. A film of foamys floated to the top leaving an amber colored bio in the middle and a layer of silt on the bottom (looked like remnants of a fish fry). In the heating process it did bubble but I'm thinking this was due to the methanol boiling off. Didn't see any water on bottom.

I searched this forum for answers and found this thread:

http://www.biofuelsforum.com/making_...h_probelm.html

It sounded similar to my problems so I considered reprocessing my batch a second time. I performed a tritation on 1ml of the now "peanut butter" looking oil. During tritation I added 10ml of isopropanol, 5 drops of phenol red and stared to add 1ml of the oil. To my surprise just before adding the last bit of the ml of oil the solution turned purple. I'm guessing that this would suggest that there is already enough lye in the oil to balance the solution. So where did I go wrong?

Very thin and runny glycerine layer on bottom.
Thicker "peanut butter" bio layer on top with suspended crud.

This is my first large batch and I am determined to save it and learn in the process. Any ideas are much appreciated.

[joe Moderator Find all posts View Profile Close joe]

Re: First Batch: Need help with incomplete batch process...

In the absense of another solid reason I always assume water contamination.

Also pardon my ignorance but what does creating a vacuum do. Do it allow the water to boil out at a lower temp?

Have you successfully converted a 1 litre batch of the same oil. Also have you tried a hot pan test to see if the water starts to boil and spit at 100c (220).

Try heat and seperation to remove the water

Cheers

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Re: First Batch: Need help with incomplete batch process...

Correct. The vacuum lowers the boiling point of water and allows you to remove water with a lot less energy. It's the same concept that HVAC techs use to evacuate a system. Here's a good link for more info on vacuum processing. Although it's from another forum it may be useful to others:

pressure dewatering - Page 2 - Forums

I did not do the HPT prior to processing. I relied on the sound of the absense of boiling in the processor. When you say "heat and separation to remove water" I'm assuming you mean prior to the introduction of Methoxide. Oddly enough the amber colored pic on the above post was when I heated to 250F after the unsuccessful reation. I'm going to try to wash and dry a sample to see if it clears. I wonder if heating after the fact would allow separation to occur? Any idea why a sample ML of the oil would turn purple when mixed with isopropanol and 5 drops of phenol red??? I'm just wondering if this could be a clue of some sort? Thanks.

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: First Batch: Need help with incomplete batch process...

Hello Hilton, welcome to the forum!

You are aware this is predominatly an Australian Forum?

Have you performed a Warnqvest test.
If not, I recommend you do one to see whether you have an incomplete reaction.
Sometimes things are not as they look.

[whoflungdung Member Find all posts View Profile Close whoflungdung]

Re: First Batch: Need help with incomplete batch process...

Sounds like one of two problems (or both):

1. Your oil was water contaminated before you added your methoxide. There are various ways of drying your oil before processing. Personally - my sure fire method is to heat the oil to 55 degrees and pump cycle for a few hours. Also have a look through the forum on ways to check for water in your oil. The pan test is a good one.

2. Another problem may be that your mix cooled too quickly. I pump mix my reactions at 55 degrees for two hours.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: First Batch: Need help with incomplete batch process...

While vacuum distillation is good technique to remove water from oil, the fact that it was boiling indicates to me that there was way too much water there when you started.
The absence of boiling does not indicate that the water is all gone.
You should try a hot pan test to verify that the oil is dry.

Hot Pan Test :

Smear some oil on a frypan.
Heat the frypan until the oil smokes
Add 1 teaspoon of oil.

If the oil spatters it is Very WET!
If it sizzles a little, it is Wet
If it shows some small bubbles it is almost dry and
If it does not show bubbles but has the heat waves visible, it is DRY!

Almost dry oil can be used to make biodiesel successfully.
WET oil is likely to promote the production of soaps.
The creamy colour of the batch has me thinking that the contents are mainly soap.

The process can react in 15 minutes or less at 50°C if the batch is homogeneous.
A couple of factors which affect the reaction time are:

• reaction temperature (40 - 60°C is recommended) 10°C increase will halve reaction time.
• effectiveness of the mixing method - a small pump on a large reactor will need more reaction time (pumping time) to effectively mix the batch, than a large pump on that reactor.

I hope this helps,
Tony

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Re: First Batch: Need help with incomplete batch process...

Wow! Thanks for all of the replies. I was not aware this forum was predominatly Austrailian. I was a little suspicious when I seen all of the temps in degrees C. The good news is that we all share a common interest and williness to help eachother. I will certainly contribute when I can.

After further testing I think there may have been a combination of a low temperature conversion coupled with water in the oil. I did the 3/27 test and had some trouble even getting the oil to dissolve in the methanol. In a matter of seconds nearly all of the oil had dropped to the bottom of the beaker.

So what now? Can the batch be salvaged? There seems to be a lot of viable looking veg oil there. Definately not glop. I tried to tritate for a 2L batch of this poor conversion oil and the phenol solution turned purple right as I was at the end of adding the 1ml oil sample to the 10ml of isopropanol. What would this indicate? Too much or too little lye? Maybe just right? Can a person safely reprocess a failed batch and heat the oil/methanol solution to drive off the water? No doubt you would boil the methanol off but could it flash ignite at a certain temperature? How exactly should this be done?

For the low heat problem I'm going to replace my 1500w 110v element for a 220v element and run it at 110v. This should give me the lower heat density needed to preserve the element. I think my element was gunking up and losing its heating ability. I should have suspected this after burning a 110v element up on my initial heating of the oil. My understanding is that the reaction is not dependent upon external heat but it shortens the amount of reation time.

P.S. Sorry for the loaded questions. Seems like I'm stuck in info mode.

***So others can learn from this I wanted to bring up the "peanut butter" looking oil produced from this failed batch. I typed in peanut butter on the forum search and came up with nothing yesterday. Maybe in the future someone will see this. I think the "peanut butter" looking oil was largely in part to the suspended solids (fryer batter silt that made it past my screen filter) not dropping into the glycerine layer since this batch did not convert. This with the lye,water and oil produced a product that closely resembles peanut butter and a very runny glycerine which may be just methanol and a small amount of lye. This glycerine was liquid at room temp and reaked of methanol. Look like cola. Hope this helps.

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: First Batch: Need help with incomplete batch process...

Hello Hilton

Can the batch be salvaged?

Yes, the batch can be saved.

I tried to tritate for a 2L batch of this poor conversion oil and the phenol solution turned purple right as I was at the end of adding the 1ml oil sample to the 10ml of isopropanol. What would this indicate? Too much or too little lye?

Titrating a batch of biodiesel will not tell you what you want to know. The titration only detects acids in the oil it does not tell you how far the conversion has gone.
There is no simple backyard test to tell you how much NaOH to use in the re-process.

Can a person safely reprocess a failed batch and heat the oil/methanol solution to drive off the water?

The batch can be reprocessed. The water is mostly in the glycerine layer. As long as everything remains liquid you do not need to re-heat.

No doubt you would boil the methanol off but could it flash ignite at a certain temperature? How exactly should this be done?

You do not want to get rid of the methanol in the biodiesel, it will add to the reprocess.

You will need to do some test reprocesses to o find out how much NaOH is required in the reprocess.
Remove the glycerine .
I would do two 1 litre re-processes.
The first litre I would reprocess with 1g NaOH mixed into 35ml methanol.
The second litre I would reprocess with 2g NaOH mixed into 35 ml methanol
If you are doing it at "Room Temperature" you will need to mix longer, maybe 4- 5 hours.
After you have finished mixing do a Warnqvest test and see what happens.

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Re: First Batch: Need help with incomplete batch process...

Thanks for the input Tilly. Yesterday after I got home from work I set out to reprocess two 1L batches as you suggested. As I went to scoop the "peanut butter" looking oil into my bottles I noticed that what lied on top of the drum appeared to be a clearer amber looking colored oil. Several inches in fact. Is it possible that this oil was still reacting 24hrs later????

I did a series of 3/27 tests each of which miserably failed. So I continued to reprocess the test batches. I did not have a way to mix the solution for 4hrs as suggested so I shook the tar out of the them and let them settle, off and on for 2-3 hrs. Here are my results after settling for 1/2 day. From left to right in the pic below: 1g NaOH + 35ml methanol has a small bit of crystal looking clouds forming below a foam layer on top very small amount of white dropout in bottom (lye??), then 2g NaOH + 35ml with more noticeable cystal clouds below a larger foam top, no noticeable droupout on bottom, then 3g NaOH + 35ml which now has a lighter colored oil with a severe case of suspended cystals, no foam on top no dropout.

So what does this test tell me? I have no idea what the crystal looking clouds are. Maybe partially reacted oil with glycerine suspended in the solution??? I'm also guessing that white dropout and foam on top is NaOH that didn't react???? Any ideas what I should do next??? Should I stick with 1g NaOH solution or step it up past 4g? How would one go about this on a larger scale for the other 90L of oil? Is it reasonable to continue the 35ml methanol per liter of unreacted oil or is there a rule of thumb for methanol to unreacted oil?

By the way, I sure do appreciate all of the responses. I find great value in everyones input.

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Re: First Batch: Need help with incomplete batch process...

Curiosity got the best of me! I made one more 1L batch with 5g NaOh and 45ml of methanol. (Could not dissolve 5g in 35ml) 5 Minutes later and Hello Glop! Or should I say Hello Gel. I guess this answers my question about going to the higher end of NaOH dosage. Now I really don't know what to do. The 1g/35ml dose left the oil relatively unchanged with the exception of foam on top and some white soapies on the bottom. All of the other 1L batches showed signs of starting to gel or crystallize. To top it off this oil still fails the 3/27 test. Any ideas???

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Re: First Batch: Need help with incomplete batch process...

Ok, so I've been racking various forums trying to find some answers. I know, i need to work on patience. Heres the conclusions I've drawn about my first process.

Although I strained the large food chunks out of the oil it still had quite a bit of fryer silt (finer particles). This may have contributed to the peanut butter looking oil after my initial processing.

The runny cola type glycerine must have been any excess water + methanol leftover from the reaction. After settleling for two days in a barrel BD separated from all of the junk and turned an amber color instead of a peanut butter color. I'm still mythed as to why it took so long to separate???

On my 1L reprocessing tests the 1G NaOH solution did drop some glycerine to the bottom. At 2G there was a suspended cloudy formation forming in the solution indicating full conversion at that point and the rest of the NaOH went to soap formation (cloudy crystals). The 5G solution formed an immediate soap gel. Here is some more info on the reprocess test that I have drawn my conclusions from. I found this on accident while trying to figure out why I made gel from BD.

World Famous Dr Pepper ASTM Reprocess Technique (Pat Pend) Revised

World Famous Dr Pepper ASTM Conversion Reprocess test (Pat Pend) Revised - Topic Powered by eve community

My next step is to re-reprocess the 1G NaOH solution again with 1G NaOh to see if a gel forms. If so this should indicate that a full conversion would be possible if I reprocessed the entire 90L batch with 1G NaOh and 50ml of methanol. Then I'll let the remaining glycerine settle out and wash and dry. This should produce a high conversion fuel.

I would like to note that the 1L test batches I performed were not washed or dryed which may be why it required less methanol to reprocess and it may explain the white bubbly foam on top of the BD being soap?

I still don't know why it took so long for my BD and fryer silt + glycerine to separate??? Any ideas????

I wonder why a person should wash inbetween reprocesses when performing this test?????

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: First Batch: Need help with incomplete batch process...

Hello Hilton

When I looked at the first picture in your first post, the left hand jar looks like biodiesel sitting on top of glycerin.
The middle bottle looks like biodiesel sitting on top of wash water.

The bottle on the left of the second picture is a question mark to me. Is this the peanut butter you refer to?
The third picture looks like a bucket containing glycerine and so does the fourth picture.

If this glycerine was on the bottom this is a good indication that you did get conversion because if it were methanol it would float on the top.

Your latest photo's today the left and middle bottles look like biodiesel on top of glycerine andthe one on the far right is gelled from too much NaOH.

I would try this quick test.
Put an Ice cube in a sample of the "biodiesel".
If it is biodiesel the ice cube will sink and if it is still unreacted oil the ice cube will float. .

[hiltonspc Biofuels Forum Newbie Find all posts View Profile Close hiltonspc]

Re: First Batch: Need help with incomplete batch process...

Hi Tilly, thanks for continuing to monitor this thread. Most would give up on someone with so many questions.

To answer about the jars: The "left hand jar" is actually a sample of the raw wvo after sitting for a couple of days. The middle jar is the "peanut butter" BD sitting on top of wash water. The bottle in the second picture is a full bottle of the wvo after processing. This is the peanut butter bottle and was taken as a sample of the BD after 12hrs of settling. This is the same exact BD that was used in my 1L test batches that look amber in the latest pics. All of the peanut butter BD that I thought had not reacted actually didn't separate until 48hrs after the processing. It's clear to me now that the reaction had to have occured but I don't understand why it took so long to separate??? Have you seen this happen before or have any idea why???

Also the 3rd and 4th pics up top are of the glycerine. This glycerine was very dark and still remains extremely liquid in my glycerine barrel. I thought glycerine was suppost to become a semi-solid waxy kinda substance. Mine is just like cola. Do you have any idea why???

Is your World Famous Dr Pepper ASTM Reprocess Technique (Pat Pend) Revised still a valid test for conversion quality??? I wasn't sure since I've seen you reference the Varnqvest 3/27Test recently and your reprocess test was written up in 2005. Besides I can't ever get the 3/27 to work even on the clearest 1L I've ever made.

Is there a reason why you need to wash in between reprocesses as your test calls for?

***Side Note: I'd also like for you to know that you are the sole reason I got into BD. If I ever make a million I'll send you some. I would have never even attempted to make BD if it wasn't for you writting the World Famous Dr. Pepper Technique. This instilled the confidence for me to go forward and continue on the path to learning. Hats off to you Tilly your're doing a good thing.

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: First Batch: Need help with incomplete batch process...

Hello Hilton,

I am glad you have found some of my work helpful.
No, I have never seen glycerine take anything like 48 hours to settle.
That is a concern.

Depending on the temperature and the amount of Methanol used, glycerine from a reaction using the amount of NaOH you used will frequently solidify over nioght.

Yes, the World Famous reprocess test is still valid. The Warnqvest test is much quicker and once it became clear that it was a valid test too, almost no one uses the reprocess test any more
I do not remember if there is a reason for washing between re-processes or not.

At this point I would do a "Float the ice cube" test and see if you really did get seperation.

[scvawser Junior Member Find all posts View Profile Close scvawser]

Re: First Batch: Need help with incomplete batch process...

Well...This has been interesting reading indeed!
I have been through the very same process over the past 3 weeks.
We put in 100L of UCO and we knew something was up when it titrated at 7.3! But we pushed on. One hint that should have been a clue to me was that I ducked inside to heat a sample for 10 seconds in the microwave. I do this often, but have never had so much snap crackle and pop as I did that night - lots of water!
Anyway, the reaction had little separation and lots of peanut butter, it made me think of peanut butter even more so after I took a sample into a PB jar!
The oil also went cold before adding meth, not good either.

I played with it, tried to rescue it using all sorts of advice from this forum. In the end I have about 30L of usable bioD. I guess I could have worked harder and decanted more but I had so much watery stuff coming out and then so much cloudy goldy stuff, that might have been dirty bio diesel and might have been crap - I gave up being happy with my 70% loss.

I got some new oil, tested it today at 1, put through another 100L and it separated perfect - I am happy again...with many drums of peanut butter looking soap!