New to BioDiesel

[Tom D]

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

[Phydeaux88]

what do you need?

[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.

[Tom D]

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.

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

[Tom D]

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

I have been in contact with Delevan Corp to purchase a nozzle to flash my BD in the chamber. I have a 6"x24" steel chamber. Their catalog can be found @ www.Delavaninc.com/PDF/WDxNozzles.pdf Could you please take a look and see what you think? I don't know what kind of nozzle Fabman has. All I know is he has a 1/16" hole which would equate to .625. Their closest nozzle is .070" which would be 31.4 gal @ 100 PSIG. I don't know whether I need a brass or SS adapter.and what degree pattern would be best. Will the methanol react badly with the brass? Hopefully Fabman will notice this post and put in his 2 cents. I have been unable to contact him. Thanks a lot. Tom

[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.

[Tom D]

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.

Thanks. Appreciate the info. Do you think the pattern makes any difference? I notice you are from the South Texas Coast. My wife's family are all from Galveston, Freeport, Lake Jackson area. Maybe some time when we are visiting, we can stop by and shake your hand.

[kennedyford]

The pattern will not make a diff, you will need a specific material to keep from blasting though the container. Please email me again so we can talk. Troy