100 litres of jelly.

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

I made a blue and now not sure what to do.

I did a titration test and found I needed 9.5 grams/litre of NaOH. I had 60 litres of used vegi oil in a large hot water cylinder. By mistake I added NaOH 9.5 x 12g to the methanol instead of 9.5 x 60.

After heating and adding the meth mixture, nothing much happened by the next day. I then realized my mistake, reheated and added a further 20 litres of WVO and 4 litres of meths with the balance of the NaOH I should have used in the first place to the mixture.

Now 24 hours later I have about 100 litres of jelly. Liquid at about 30 degrees but turns to jelly below that.

Any suggestions how to recover from my mess?

I am trying a wash with a sample, Ie I added 100 % water and am bubbling air through it for 4-6 hours to see what happens.

I'm not to worried about the quality of final product as it is to only run in our diesel house burner.

Thanks Wallace

[joe Moderator Find all posts View Profile Close joe]

Re: 100 litres of jelly.

this doesn't make sense. WHy ar eyou multiplying grams by grams. 9.5 grams x 12 grams?

what is your base amount 3.5 or 5 ands what what your titration amount?

multiply that x 60 litres to get your correct amount of caustic to add to the meth.

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

Re: 100 litres of jelly.

My typo it was 9.5 grams x 12 litres of methanol. It should have been 9.5 grams x 60 litres of WVO.

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

Re: 100 litres of jelly.

OK,
First, Gelling is often caused by soap production as a result of water in the oil. Was the oil tested for water content? Was it dry?

Are you confident that your additional NaOH amount was correct? Excess NaOH can cause gelling also.

Next, you need to look at the mixture in your processor.
Have you drained off any byproduct?
How much was/is there? There should be around 12L of byproduct (or more) in a good batch of 60L oil and 12L methanol.

Then, Take a number of 1L samples of the contents of the processor. Heat them to 50°C.

On the first, add 1g NaOH and 100mL methanol.
On the next 2, add 2g and 3g respectively of NaOH in 100mL methanol each and mix that with the heated sample. Mix for 10 minutes and set aside to settle.
Did the mixture change colour // viscosity during the mixing?
Allow to settle for a few hours. Is there separation occurring?
Which batch looks best?

Use this information to decide on your next course of action.
Do not decide to reprocess all of the remaining batch, just reprocess a larger sample to verify your earlier testing and the scaling of your volumes.

If happy with the larger batch, reprocess the remainder.

Let us know how you go.

regards,

Tony

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

Re: 100 litres of jelly.

A bit of a delay is getting back. Earthquakes interrupting normal service here in Christchurch. The aftershocks are incredible. We get 20 - 30 each day.

I did 5 new samples of 1 litre with, 4.5, 5.5, 6.5, 7.5, 8.5 grams.

All went a bit cloudy and then a nice into a nice thin mixture. The 4.5 took the longest.

6.5 gave more sediment than 4.5 and 5.5
The sediment in 7.5 and 8.5 were the same as 6.5 so I guess that 6.5 would be best.

Tony, you suggested 100 ml methanol with 1 litre of veg oil. Is this correct? I though it should have been 20%

10 % would be better as the methanol is the expensive part.

Back to the 100 litre is jelly. I used 9.5g/litre to make jelly. Do you think that if I add +- 30% more vegi oil to the mixture, it will revert back to what it is supposed to be ?

A suppose a small sample run would be easy enough to test.

PS I didn't check for water as the oil has been standing for 2 years and I just drew from the top.

Thanks Wallace

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

Re: 100 litres of jelly.

Hi wallace I use to live in Chch It all a bit sad to see the place demolished.
I think your 100 L batch is a write off, It probably all turned to soap which is quite hard to fix. What your done with the the mini baches sound right and is a good way to gain experience with the bio making process and confirm how much naOH you need. the standard method requires 20% methanol. your mini batches show you need 6.5 grams, of naOH. and It is a good idea to heat the oil to 55C when you make your bio as it speeds up the reaction and you get a better result, especially in winter. and you already know this but it is very important the oil must be dry before you start.
Hows that road user charge going? Last time i was there it was more than the fuel. Great country ruined by greedy politicians and their mates.

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

Re: 100 litres of jelly.

Thanks for the reply.

What uses is the soap. It does not wash off in water ??

What do you do with the sediment from your normal batches ?

Thanks Wallace.

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

Re: 100 litres of jelly.

A bit of a delay is getting back. Earthquakes interrupting normal service here in Christchurch. The aftershocks are incredible. We get 20 - 30 each day.

We were all shocked to see the images of Christchurch and gladdened to hear that there were no fatalities. I wish you and your friends and family are remaining in good health. Everything else can be replaced.

I did 5 new samples of 1 litre with, 4.5, 5.5, 6.5, 7.5, 8.5 grams.

All went a bit cloudy and then a nice into a nice thin mixture. The 4.5 took the longest.

6.5 gave more sediment than 4.5 and 5.5
The sediment in 7.5 and 8.5 were the same as 6.5 so I guess that 6.5 would be best.

Tony, you suggested 100 ml methanol with 1 litre of veg oil. Is this correct? I though it should have been 20%

I was assuming that the jelly would not have lost too much of the methanol from the process (no circulation in a jelly, therefore much less methanol evaporation).

10 % would be better as the methanol is the expensive part.

Back to the 100 litre is jelly. I used 9.5g/litre to make jelly. Do you think that if I add +- 30% more vegi oil to the mixture, it will revert back to what it is supposed to be ?

No, the Jelly is the result of insufficient caustic, not too little oil, as shown by the mini batch results.

A suppose a small sample run would be easy enough to test.

PS I didn't check for water as the oil has been standing for 2 years and I just drew from the top.

it would be prudent to perform a HPT on any oil you plan to use to make biodiesel from.

100 Litres of jelly is a pretty good incentive

.

Thanks Wallace

Congratulations, you have just proven that the test batches have recovered some of your batch of jelly.

Now, to identify the best caustic amount to use, I would like you to take 10 mL of each batch 5.5 to 8.5 and in separate containers, add to each, 90mL of methanol and shake up the mixture.

Allow to settle and see if any of the samples now has droplets on the bottom.
Any droplets are unprocessed oil. Use the lowest numbered sample which has the minimum amount of unprocessed oil. Use this sample to calculate the caustic and methanol for a 20L reprocessing batch, using 10mL per litre Methanol. Use only the caustic amount for the batch chosen, times 20 litres of jelly.

Note: the methanol used in the test above is not wasted, it can be used in the reprocessing of the jelly, as all you have done is to dissolve some biodiesel into it.

Heat the jelly to 50°C and mix the methanol/caustic solution through thoroughly and allow to settle.
If this works well, reprocess the remaining jelly using the same proportions.



Best wishes,

Tony

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

Re: 100 litres of jelly.

Tony can you check if your figures are correct here?

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

Re: 100 litres of jelly.

The batches I made were from virgin WVO. It showed that I need 6.5 g/l of caustic / litre of WVO.



When I add more WVO to the jelly, it gets warm and just makes more jelly. It is not water soluble.

Just bought more methanol. $4.60 per kg in 20 litre lots or $1.70 per kg if in 220 litres. So now I have a lot of methanol (and jelly) to use.

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

Re: 100 litres of jelly.

JJ,
While others recommend 3:27mL Biodiesel:Methanol for the Varnquist (sp) test, I recommend 10:90mL, which gives a more accurate test and one in which the % unreacted oil is easily calculated. (1mL oil in bottom of the container represents 10% unreacted oil.) In 4 tests, the total methanol used is only 360mL. This amount of methanol used is not significant, considering the fact it can be used in subsequent batches of biodiesel.


When comparing reprocessed batches, you need the greatest accuracy available.

Regards,
Tony