I think I have it all down, but I have a question. I know that I heat the oil to 140F, then add methanol/acid. Do I maintain the temperature the entire time it's circulating, or do I cut off the heat and just let the pump run for a few hours?

sparky
-heat, mix for 20 min, let stand with heat on until target T is reached. be sure your wvo is dry! Good Luck Tom

My heater is inline, I can't run the heater without circulating.

sparky
-then of course you have to run it, but that will have an affect on how fast ae takes place.

Gotcha.... so maintain the 130F temp until the titration level stops falling. Form what I read, that can be anywhere from 1-8 hours. Gives me somewhere to start, thanks Tom!

sarky
- 8hrs or more, until you get no drop in a two hr period. what is your starting T koh or naoh

Wow... never ran my heater that long. Should be fine though. My oil is 14T KOH. I've been very successful single stage, but i'm hoping this will increase yield.

First batch is under way. I just injected the methanol acid mixture. I do have a question, in the bottom of the tank that I used to mix the acid/methanol, there is a foam residue left in the bottom of the tank. From 4.8 gallons methanol, i'd guess there's 2 cups of it. Is this foam, or has some other reaction occurred in the mixing tank?

Whatever it was, it dissipated on it's own.

I add the acid and methanol seperately. First add about 150 ml acid (for a 40 gallon batch) and then add 3.8 gallons methanol.

quote:

Originally posted by Biotom:
sparky
-heat, mix for 20 min, let stand with heat on until target T is reached. be sure your wvo is dry! Good Luck Tom

Tom--

Can you explain the non mixing allowing the AE to work better, or am I misunderstanding the procedure? I was always under the impression that you wanted to pump / stir to keep the acid/methanol/WVO crashing into each other. Also do you stir before taking a sample for titration to keep from getting a false T due to layering?

Thanks

Norman

Norman
-for ae, it works better in it is allowed to stand rather than mix continuously. I don't know why, but ending T is always lower for me, and tests that buckeye did for the acid thread, back this up. having said that, if you do the high temp ae HTAE at 70C, then you will have to use continuous mixing to keep the methanol mixed in. This process can reduce ae treatment to 1 - 3 hrs, allowing you to base process on the same day!
-Mixing is required to get an accurate T reading, then when calculating the caustic requirement, use the the total volume in the processor,(thats what T is based on) and not just the volume of the wvo you started with. Tom

how the acid and the methanol are added doesn't seem to make a difference..that is if I'm remembering correctly. I have done both ways..for me it just depends on the setup. while I haven't done many batches where I added the methanol first. something else to work on in the other thread

I cannot comment about limited mixing and just letting it sit..I have to run the pumps to run heating..but this is setup dependent..CAN YOU HEAT SAFELY WITHOUT A PUMP RUNNING? I know I cannot!

please keep in mind biodiesel making can be dangerous! using AE in my mind is more dangerous because of longer processing times, heating while processing, and using a STRONG ACID! enough soap box just be safe..

-dkenny

My processor has an inline heater, so it must be circulating to heat. I put the oil/meth/acid mix on a timer, and set the thermostat to 130F. The timer was on for an hour, off for an hour. It ran like this for 7 hours total, and then was left to stand for about 12 hours.

I'm now titrating at 4KOH, which sounds pretty good to me, considered I started at 14. I'm heating back up now for the base stage. Is it normal for the oil to be this cloudier color? It has almost a coffee with cream look.

sparky5693,

you might have created a layer that you could have drained??
sometimes this is normal?

if you ran longer you might have gotten lower, but how much lower? homw much longer?
these are much harder questions to answer. example 1..I had a batch that started at T8 ended at T4..had another batch started at T42, after 2 acid stages, ended at T4..

either way run with it..let us know what happens..

-dkenny

What is the advantage of draining? I figured the less methanol lost the better.

Got the batch almost finished, but the biodiesel I have is a shade or two darker than it is normally (I understand this is normal), but it's also cloudier than i'm used to, and it's not clearing with heat like i'm used to (i'm assuming it's water). Is there any reason other than water that would make the biodiesel cloudy?