Below is a link to a video I edited together from footage sent to me from Chad & GCG of Arbor Biofuels Company that details how to properly flush a Biodiesel Ion Exchange Resin Tower.

The video shows flushing the tower with 5 flushes of Methanol and then shows how to test the methanol to ensure that the Resin is completely clean & ready to use again.

Here's the link to the video:
http://www.youtube.com/watch?v=6nMsqTujGWI

If you have questions, feel free to post them & I'm sure Chad or GCG will be happy to answer them.

I really like their example of the proper way to do a soap test on the fuel. It's really well laid out.

Enjoy the video!
-Graydon

This message has been edited. Last edited by: Graydon Blair,

Good job on the video. Very cohesive and to the point.

Thanks...
I had a lot of fun editing it together.

There's going to be more on the way too...
Just takes some time to get them put together but glad to hear you enjoyed it.

-Graydon

What is restored by a methanol flush? Not basic ion exchange capacity is it?

Ant,

Yes it restores the basic capacity. The Thermax product is unique in that it soaks up the soaps instead of breaking the metal ions off of them. I'm sure the arbor biofuels guys can give an in depth technical explanation.

Ant,

Rick is referring more to the GF202 Macroporous resin from Lewatit. It is a Sodium Form resin and doesn't actually do ion exchange for the replacement of the Sodium (Na+) or Potassium (K+) ion which are the typical metals that combine with Free Fatty Acid molecules to form soap in the biodiesel reaction during base catalyzed transesterification (as you know).

Anyway since the resin molecules in a Sodium Form resin already have been completed or bond with Sodium - they will not take on (or load) anymore Sodium or Potassium ions into its matrix.

The GF202 relies on its ability to trap soap in the glycerin it has adsorbed in the macroporous structure of the resin beads.

However here lies the problem with GF202 - if it hasn't sufficiently loaded with glycerin, then it can't trap soap, and if it is sufficiently loaded with glycerin to entrap soap, then it doesn't have much life left to remove glycerin.

It should be call GF22 (as in "Catch 22") since it can't do one with out the other and it can't do the other if the beads capacity for glycerin is already exhausted. (A little resin humor there).

That is why we stayed away from GF202 ultimately. And eventually found Thermax's Hydrogen Form, Dry, Macroporous resin. The T45 BD Macro initially removes soap by true ion exchange however as the resin loads with glycerin it starts to take advantage of the entrapment properties of the glycerins to also remove soap this way.

This make the resin self adjusting/regulating because as resin adsorbs glycerin this effectively reduces the bead surface area available for ion exchange however this area is now used to entrap soaps rather than exchange them. So at the same time the macroporous channels not filled with glycerin are still removing soaps through ion exchange -- as you loose ion exchange sites due to glycerin adsorbtion you gain entrapment.

Interestingly enough this provides the additional benefit of producing less FFA in the final biodiesel, since as more glycerin is adsorbed less Soap is being removed by ion exchange which releases FFA and increases the over all Acid Number of your biodiesel.

GCG

Hmm. ok I understand what you are saying but am still puzzled. I thought our glycerine was already saturated with soap? Most of the glyc is settled off with most of the soap after the reaction. What is left is in solution with the meth. But there seems to be a lot more soap than glycerine still in the bio at this stage. How can the glycerine left remove all that soap?

Ant,

Your exactly correct - the small dissolved quantities of glycerin still left in the biodiesel are not large enough to remove much soap that is why a hydrogen form ion exchange resin is still required to produce ASTM fuel.

The thing to note though is; as the entire bed volume of resin begins to load with glycerin (which it is taking out of the solution) - this glycerin itself starts to entrap soaps and this saves on the number of FFA molecules created from the removal of the Sodium or Potassium ions from the Soap Molecules that occurs during an ion exchange vs. the simple entrapment.

GCG

Please note that in the above reply I use the word "solution" loosely since colloidal mixtures/solutions are technically differentiated.

For (what I thought was) interesting reading see a very clear explanation here:

http://en.wikipedia.org/wiki/Colloid

Hmmm still leaves woodchips looking like the front contender for cheap bulk soap removal to me.

"Hmmm still leaves woodchips looking like the front contender for cheap bulk soap removal to me."

It works for me.

We like the wood chips and the Eco2Pure for gross soap removal especially right after methanol removal however we haven't really got into yet...

Eurocab - are you using this method presently?

The one thing we have heard and when we look at our supply of Eco2Pure we see this stuff rocking up pretty solid after it has absorbed these gross soaps and glycerins.

What kind of vessel are you guys using to contain the wood chips - I always thought a trough would work best???

GCG

PS remember the resins are reusable though - this is a big advantage!

It seems possible the woodcips are also reusable with a methanol flush which can then be recovered from the soaps later.

I think I'm missing something?......is this procedure for a specific Ion exchange?
I use purolite, will this work on purolite as well?

Yes. The video will work for Purolite as well.
They just happened to have Thermax in the tank that day.

-Graydon

quote:

Posted 29 November 2008 05:20 PM Hide Post
We like the wood chips and the Eco2Pure for gross soap removal especially right after methanol removal however we haven't really got into yet...

Eurocab - are you using this method presently?

The one thing we have heard and when we look at our supply of Eco2Pure we see this stuff rocking up pretty solid after it has absorbed these gross soaps and glycerins.

What kind of vessel are you guys using to contain the wood chips - I always thought a trough would work best???

I am sorry it took so long to respond. I have been extremely busy trying to keep my business alive.

I use a 4" PVC column for the wood chips and then I run the BD through my macroporous resin columns. For me it increases the life of my resin bed. You have to change out the wood chips a lot, but it makes a good fire in the wood stove.

My target is near zero waste and a cheap filtration system. Maybe not in that order. :-)

Graydon is right on it...

See this link for the PD206 Purolite page for their exact flushing procedure.

Purolite's Ion Exchange Resin flushing procedure

GCG