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Post Acid stage questions- 1st timer
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original oil titrated 16.5 NAOH... i used 1.5ML/Liter of acid for a 100 Liter batch. Heated to 131F, added acid and 10L Methanol, mixed 30 mins and let settle in my closed reactor. 12 hours later I drained off about 2 liters and then remixed and titrated again and got 6.5ml.. letting settle another 12 hours to see if it drops more.

Question 1- When i drained oil for titration there's "movement" at the surface- 2 chemicals mixing and swirling around. Is this the acid still working?

Questions 2-? What is in the 1-2 liters i drained off the bottom? I know it's partly water, but is there still H2SO4 in there? Methanol? WVO? it seemed lighter in color and then got darker so i stopped draining. Also I'm trying to figure out what to do with this stuff to get a safe discharge for the sewer... if I collect enough of this stuff, will it settle out to layers? If not, do you mix with glycerol fro m a different bath to neutralize the remaining acid and then boil off the methanol? I don't want to dump any nasties down the drain.

thanks
 
Registered: February 06, 2008Reply With QuoteReport This Post
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Update- after more settleing I remixed and titrated again and we're down to 5ml... now I'm reheating to see if the temp got too low to continue. Still looking for answers to the other Q's for anyone who can help???

Thanks
 
Registered: February 06, 2008Reply With QuoteReport This Post
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Originally posted by ski2liv:
original oil titrated 16.5 NAOH... i used 1.5ML/Liter of acid for a 100 Liter batch. Heated to 131F, added acid and 10L Methanol, mixed 30 mins and let settle in my closed reactor. 12 hours later I drained off about 2 liters and then remixed and titrated again and got 6.5ml.. letting settle another 12 hours to see if it drops more.

Question 1- When i drained oil for titration there's "movement" at the surface- 2 chemicals mixing and swirling around. Is this the acid still working?

Questions 2-? What is in the 1-2 liters i drained off the bottom? I know it's partly water, but is there still H2SO4 in there? Methanol? WVO? it seemed lighter in color and then got darker so i stopped draining. Also I'm trying to figure out what to do with this stuff to get a safe discharge for the sewer... if I collect enough of this stuff, will it settle out to layers? If not, do you mix with glycerol fro m a different bath to neutralize the remaining acid and then boil off the methanol? I don't want to dump any nasties down the drain.

thanks


T 2.5ml NAOH would be the theoretical lowest you can go (prior to draining) based on your 1.5ml acid.
It looks like you may a bit light on either the methanol or sulfuric.
I personally would add more acid as opposed to methanol since you'll have to drain the lower phase before base processing.
Using 10% methanol, I think you would have seen a lower drop in titration if you had used 1.9ml H2SO4 per Liter of oil.
If you don't get a drop in titration after letting it sit this time, it would be great if you would mix it continuously for a few hours at 140F or so then titrate just to give us some data.

Is your processing vessel completely draining? Meaning is there any liquid left in the processor form a previous base stage?

To answer your questions though,
1- Certainly could be doin it's thing.

2- D all of the above. Mostly methanol/sulfuric/water, likely some oil/ester/FFA also. Mix with glycerine byproduct sounds good to me.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post
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OK So after the last post I re-heated to 131 and circulated and settled again.. titration dropped to 3.5. Didn't drain this time.. just added the balance of the methanol and the lye and she's cookin!

Guess we'll see how well i did tomorrow!

FYI -to answer question- reactor is a Propane Hot Water heater... I use it for drying WVO and the AE reaction, then pump to an electric heater for Methanol boil-off and soon methanol recovery. So there's probably trace amounts of couch potatoes in the bottom of the reactor from the previous batches which could certainly be screwing with things slightly. But hey- everyone seems to have their own "exact" science... so as long as I'm anal elsewhere (and I am), I should be OK here.. i hope! Smile
 
Registered: February 06, 2008Reply With QuoteReport This Post
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Originally posted by ski2liv:
OK So after the last post I re-heated to 131 and circulated and settled again.. titration dropped to 3.5. Didn't drain this time.. just added the balance of the methanol and the lye and she's cookin!

Guess we'll see how well i did tomorrow!

FYI -to answer question- reactor is a Propane Hot Water heater... I use it for drying WVO and the AE reaction, then pump to an electric heater for Methanol boil-off and soon methanol recovery. So there's probably trace amounts of couch potatoes in the bottom of the reactor from the previous batches which could certainly be screwing with things slightly. But hey- everyone seems to have their own "exact" science... so as long as I'm anal elsewhere (and I am), I should be OK here.. i hope! Smile


So it dropped after mixing again!!
Sounds like a successul AE.
Propane tanks work great at allowing complete draining.

I know there are some guys that that don't like continuous mixing, but IMO it is important to keep the reactants banging into one another. Oil and methanol don't like to mix and when the two stratify, the reactants are effectively seperated and the reaction is slowed dramatically.

Good job ski2liv.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post
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