New to BioDiesel
#1
New to BioDiesel
Hey Guys. I posted a thread 10/18 titled "Reflux for Methanol" and got NO replies. I was hoping one of you (Fabman,KennedyFord, etc) that have already built a successful processor similar to Fabman's would help me with some of the finishing touches. I have followed Fabman's instructions as closely as possible but I still am unsure about a few things and certainly don't want to tear it all apart because I screwed it up. I like to build RIGHT the first time. I tried to bend Fabman's ear, but he is working LONG hours planting so I am appealing to you guys. How about it, will you help me out with the final steps? I just have a few more questions. Tom
#3
OK found your other post.
I doubt that there is any real benefit to using a reflux condenser when recovering Methanol. The boiling points of the ingredients in either the Biodiesel or glycerol layers, post reaction, are far enough apart that straight fractional distillation with a conventional condenser should get pretty pure MeOH.
MeOH boils at 64 degrees C (approx 150 F)
Biodiesel is a mixture of of molecules with chain lengths in the 10 to 15 carbon range, typically molecules of this size boil at 200 C and up (approx 390 F)
Glycerol boils at 290 C (approx 550 F)
These boiling temps are at 1 atm pressure.
If you chose to effect boiling by the vacuum method, as I believe Fab does, you will lower all boiling temps proportionally thus there will still be a large seperation in boiling point and MeOH will all be boiled off long before the other components begin to boil.
You won't eliminate all contamination but your product will be quite high purety and if it isn't good enough run it thru a second distillation cycle.
There is also going to be some spill over (contamination) in reflux tube condensation.
As to how to tell where Biodiesel starts and Glycerol stops there is a noticable color change if you have allowed sufficient time for the layers to seperate.
I doubt that there is any real benefit to using a reflux condenser when recovering Methanol. The boiling points of the ingredients in either the Biodiesel or glycerol layers, post reaction, are far enough apart that straight fractional distillation with a conventional condenser should get pretty pure MeOH.
MeOH boils at 64 degrees C (approx 150 F)
Biodiesel is a mixture of of molecules with chain lengths in the 10 to 15 carbon range, typically molecules of this size boil at 200 C and up (approx 390 F)
Glycerol boils at 290 C (approx 550 F)
These boiling temps are at 1 atm pressure.
If you chose to effect boiling by the vacuum method, as I believe Fab does, you will lower all boiling temps proportionally thus there will still be a large seperation in boiling point and MeOH will all be boiled off long before the other components begin to boil.
You won't eliminate all contamination but your product will be quite high purety and if it isn't good enough run it thru a second distillation cycle.
There is also going to be some spill over (contamination) in reflux tube condensation.
As to how to tell where Biodiesel starts and Glycerol stops there is a noticable color change if you have allowed sufficient time for the layers to seperate.
Last edited by Phydeaux88; 10-22-2007 at 03:01 PM.
#4
Originally Posted by Phydeaux88
OK found your other post.
I doubt that there is any real benefit to using a reflux condenser when recovering Methanol. The boiling points of the ingredients in either the Biodiesel or glycerol layers, post reaction, are far enough apart that straight fractional distillation with a conventional condenser should get pretty pure MeOH.
MeOH boils at 64 degrees C (approx 150 F)
Biodiesel is a mixture of of molecules with chain lengths in the 10 to 15 carbon range, typically molecules of this size boil at 200 C and up (approx 390 F)
Glycerol boils at 290 C (approx 550 F)
These boiling temps are at 1 atm pressure.
If you chose to effect boiling by the vacuum method, as I believe Fab does, you will lower all boiling temps proportionally thus there will still be a large seperation in boiling point and MeOH will all be boiled off long before the other components begin to boil.
You won't eliminate all contamination but your product will be quite high purety and if it isn't good enough run it thru a second distillation cycle.
There is also going to be some spill over (contamination) in reflux tube condensation.
As to how to tell where Biodiesel starts and Glycerol stops there is a noticable color change if you have allowed sufficient time for the layers to seperate.
I doubt that there is any real benefit to using a reflux condenser when recovering Methanol. The boiling points of the ingredients in either the Biodiesel or glycerol layers, post reaction, are far enough apart that straight fractional distillation with a conventional condenser should get pretty pure MeOH.
MeOH boils at 64 degrees C (approx 150 F)
Biodiesel is a mixture of of molecules with chain lengths in the 10 to 15 carbon range, typically molecules of this size boil at 200 C and up (approx 390 F)
Glycerol boils at 290 C (approx 550 F)
These boiling temps are at 1 atm pressure.
If you chose to effect boiling by the vacuum method, as I believe Fab does, you will lower all boiling temps proportionally thus there will still be a large seperation in boiling point and MeOH will all be boiled off long before the other components begin to boil.
You won't eliminate all contamination but your product will be quite high purety and if it isn't good enough run it thru a second distillation cycle.
There is also going to be some spill over (contamination) in reflux tube condensation.
As to how to tell where Biodiesel starts and Glycerol stops there is a noticable color change if you have allowed sufficient time for the layers to seperate.
#5
Originally Posted by Tom D
Thankyou for the reply. I plan to use a "flash chamber" per Fabman instructions and heat the BD or Glycerol to 100F prior to flashing it. The gear pump wil have approx 100PSI and a nozzle to spray (flash) .Any comments or suggestions you have will be GREATLY appreciated. Thanks again. Tom
#6
#7
Originally Posted by Phydeaux88
A couple of points.
1) The 31GPH flow of that .07 orfice nozzle is based on water, since BD and especially glycerol are considerabley more viscous and will flow at a lower rate.
2) I suspect brass will be your best choice
3) Fab is really busy at this time.
1) The 31GPH flow of that .07 orfice nozzle is based on water, since BD and especially glycerol are considerabley more viscous and will flow at a lower rate.
2) I suspect brass will be your best choice
3) Fab is really busy at this time.
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