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Using heat, pressure and slow Aggitation ????
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Does anyone here do AE using pressure and heat? We have unlimited heat and up to 30 PSI available. We have a small 1000 ML PARR reactor with a mixer motor we have been running on slow speed and we are not getting the results we should be. Our oil titrates at a 6 and after several hours it only drops to about 5.8. Does anyone have a recipe that will work well with lets say 195 F and 30 PSI? We also have a 1800 gallon reactor we want to duplicate the process in.


Todd Smith
Green Horizons Inc.
 
Location: OC CA | Registered: September 07, 2010Reply With QuoteReport This Post
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what is your starting water?
What recipe are you currently trying?
What oil type do you have?

I ran into problems when mxing with AE when I was using an oil that had not been degummed. My theory is that the acid was reacting with the gums and I was getting what appeared to be black flakes or sand in the reactor. I fixed this by not mixing at all other than when initially adding chemicals. I haven't had a chance to retest this with another gummed oil so maybe there is another explanation but since gums are removed with acid and the solid catalysts all react badly with gums it's what I went with.

Also the lower water the better, above about .2% water things REALLY go downhill and the reaction almost stopped.

For such low acid # oil what I used that had good results was 25% by mass of acid and 20:1 methanol. If you calculate that you have 100g of FFA I would add 25g of acid (modified for concentration of course). Methanol I used a 20:1 molar ratio of methanol to FFA. So if you have 1mol of FFA in the oil you would add 20mol of methanol. Note that this is for FREE fatty acids not total fatty acids which has confused some people.

General results... if I kept my oil at 60C and then drained off the glycerin/water/crud layer at the bottom the next day I would expect acid # to drop to about 1.2. Repeated this with both process and lab experiments with similar results. With such high pressures you could run hotter and definitely have results faster I would imagine.

There are a few other people that have good results with much lower chemical usages but I have never managed it myself. You might have better luck with your system though if you can pressurize.
 
Registered: February 25, 2010Reply With QuoteReport This Post
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Todd
-Naoh or KOH titrarion?
-at .2% water AE will not work, try .02% (200 ppm) but not more than .05% (500ppm)water is the main AE killer!!!!
-at that temperature AE should be compete in less than 4 hours.
-when you mix for the full AE process, as is required for hight temp AE to keep the methanol mixed in, you should let the batch settle for several hours, over night is better and then drain some junk water acid and other crud from the bottom of the tank prior to remixing and titrating.
-not enough info to offer any other suggestions.


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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how much acid are you using?
how much methanol?

-dkenny


'84 bluebird school bus, DD8.2L turbo( 4/2011, the bus tranny has died..Frown 8.23.11 bus driven to scrap yard Frown )
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Location: RTP, North Carolina | Registered: December 15, 2004Reply With QuoteReport This Post
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