GCG from Arbor Biofuels had some Thermax analyzed under an electron microscope to see what it would look like.
I took the images & animated them into a single image so you can see what the Thermax looks like the higher the magnification went.
Check out the results!
Pretty cool images!
I actually was the one who suited up for the clean room in order to get those shots
I took pictures of Amberlite BD10dry before GCG provided me with some of the T-45.
I have asked Graydon to post the Amberlite pictures as well. Once you see the difference between the surface of Amberlite BD10dry compared to Tulsion T-45 BD it is obvious which has more surface area.
The SunBreak BioStudio, LLC
OK, I just fixed the Thermax Animated graphic.
Jeff noticed the 10,000 x image didn't look like Thermax so we've pulled that one out (he's not sure what it was, probably Amberlite, but to be safe, it's gone).
Also, here's the Amberlite sequence.
You can really see the difference between Thermax (porous) and Amberlite (non-porous) at the 500x interval.
Check out how porous the Thermax is and how non-porous the Amberlite is.
Net-net, the porous stuff is going to work better.
I have over 700 lbs of spent Purolite PD206 resin that I have been testing regeneration procedures on.
So basically I have 14x48" FRP columns with a total volume of 31 gallons. In each column I have 50 lbs of Purolite PD206 with a bed height calibrated based on another column with a known amount of resin.
It takes 20 gallons of biodiesel with a tracer dye to start seeing the dye in the output. So I can assume the swelling of the resin has increased from its initial volume of 6 gallons to just over 11 gallons, indicating 183% expansion.
So to start with I needed to figure out "how much soap is in there?". For this you need to figure out the ion-exchange capacity.
So we know that Rohm & Hass advertise 400ppm soap content gets you 131 gallons of clean fuel.
So 130 gallons of fuel weighs about 7.3 lbs/gal.
So we can assume we have ~ 950 lbs of fuel capacity per pound of resin. If we are removing 400 ppm.
So we also know that we will remove a total of 950 lbs * (400 ppm / 1000000) or 0.37 lbs of soap / lb of resin.
Since soap weighs 305 grams / mol, we can determine that we have 0.37 lbs of 168 grams of soap or 0.55 mol / lb of spent resin.
This is the important as it will be used to calculate how much H2SO4 you will need to dilute into your methanol regenerant.
Since I have a bed volume of about 11-13 gallons, I will need to prepare 5 to 7 times that amount of regenerant. For me this means I'll need 91 gallons of methanol. For my experiments I typically used 2 entire barrels.
This methanol will not be wasted, you can use it again in another batch of fuel, particularly if you want to use acid/base.
Since you can react 1 mol of H2SO4 with 2 mol of soap. We know that we will need about 0.27 mol H2SO4 / lb of spent resin.
The problem is that in order to realize 40% of the original capacity it is necessary to increase the stoichiometric amount of reagent to 1.4. So instead of 0.27 mol, it is now 0.38 mol H2SO4 / lb of spent resin.
Although consistiently getting 40% capacity back is nice, it is really not that great either. The problem is that for each 20% of additional capacity you want to restore you need to pretty much double the previous quantity.
You start to get diminishing returns rather quickly when you realize how much acid you are going to use.
So in a perfect world the acid that is in the methanol would be completely neutralized into sodium sulfate by the resin. However through the course of regenerating the column the acid content in the output stream is rising and rising as the exchange capacity is restored.
You can always neutralize and precipitate the remaining acid in the methanol. However I would like to avoid this.
In order to reduce the amount of methanol used and make the most of my acid, I have developed the following routine and it seems to be working fairly well.
a. Backwash column, this removes lots of suspended junk that has accumulated in and or on the resin bed. It also has the added benefit of redistributing the beads largest to smallest. This helps prevent fouling, resistance to flow, etc.
b. Completely drain column by pressurizing with compressed nitrogen and purging all biodiesel.
c. Fill column with methanol/acid regenerant solution. Let sit for 1-2 hours and purge column completely with compressed nitrogen into a seperate container for future using making fuel.
d. Refill column with methanol/acid regenerant solution. Let sit for 1-2 hours and purge column completely with compressed nitrogen into a seperate container. Keep this spent regenerant handy as the next time you regenerate your column you will use this as the first regenerant fill.
e. Now fill the column with straight methanol, let sit and purge the same as before. This will flush almost all of the acid from the column.
f. If used in lead/lag, always return regenerated column to the lead posistion as any residual acid will be exchanged into the lag column.
g. You can calculate how effective your regen was by titrating a sample of each acid/methanol flush and determining the total acid remaining. Basically, starting acid concentration - ending acid concentration = soap removed.
When you do the first regenerant fill the concentration of acid in the effluent is much weaker, about 25-30% of what it was.
The second regenerant fill on the other hand is much more potent around 70-80%. So it is best to keep this for reuse.
I have found this routine restores the resin to about 60-70% of it's original capacity and utilizes the minimum amount of methanol and acid, plus it reuses a portion of the regenerant for the next time.
Sorry if there are some typos, math errors, etc. I wrote this up right before heading home from work. I'll try to edit it with more detailed information later.
I'm aware that almost everywhere I said soap I meant to say sodium and my molar calculations are most certainly off. Like I said I'll fix them later from my actual notes.
BTW: Just remember ... this is not an "offical procedure", just what I have been toying with. I'm waiting for my macro-pourous column to "need" regenerating before I try it on that.
The SunBreak BioStudio, LLC
Part 2 of Our Secret and Why this T-45 BD Macro Dry Wash Resin is superior
Actually I already revealed the meat of our second secret at the end of a previous post however since I have received several request/questions regarding this info - here is the official Part 2 posting.
In Part 1 I referred to one of the differences between gel-type resins and macroporous resins as micro-channels vs. macro-channels. When the experts from Thermax performed a peer check of my material, they were quick to point out that technically this statement is inaccurate since gel resins in the business are referred to as "non-porous".
Gel resin more accurately in our particular application have a surface (as can be easily seen in the posted electron microscopic photos provided by Sun Break Biofuels) which could be described as non-porous semi-permeable since they allow methanol and water to be adsorbed but not biodiesel.
It is the methanol still in the biodiesel or in the gel-resin beads that actually allows for the internal ion exchange sites to be accessed.
In actual molecular action or movement the thin layer of unpurified biodiesel which coats the surface of the bead is called an interstitial layer and a transfer of impurities occurs between this interstitial coating and the fluid in the gel-type beads.
Therefore it is for this reason that I believe the macroporous resin is superior since the macroporous bead doesn't fully rely on this methanol agent for ion exchange since due to the macro-channels - the long chain hydrocarbons can deliver the impurities themselves to the interior portion of the bead.
Additionally as the gel bead adsorbs glycerin it displaces methanol in that area of the bead rending it unavailable for continued ion exchange where as the macroporous bead actually utilizes the adsorbed glycerin to entrap soaps transported directly by the long chain hydrocarbons.
Incidentally this is the key to why we don't use the sodium form macroporous resin sold by Lewatit (GF202) because initially it is unable to remove soaps since it has NO hydrogen (H+) ions to exchange with the soap impurities and relies totally on glycerin entrappment for soap removal. So initially these resin beds pass soaps and then by the time the resin bed has adsorbed enough glycerin to be effective at removing soap, it doesn't have much life left. This is because it only has 60% of the swelling or expansion capability of the gel-type beads.
So inconclusion the Thermax T-45 BD Macro utilizes the best characteristics of both of these resin.
1)It can operate at much lower levels of methanol content since the bead itself can be penetrated by the biodiesel molecule. This allows the producer to remove more methanol prior to the resin bed(s). This subsequently reduces the impurity concentration in the biodiesel to the levels necessary for the economic use of ion exchange for purification (dry washing).
2)Initially it removes soap through a true ion exchange process and then later as adsorbed glycerin loads the resin bed, soap contamination continues to be removed by entrapment or engulfment.
3)Since more methanol can be removed reducing initial concentrations of soap, this limits the formation of FFA's from soap molecules created by the ion exchange process. This helps ensure ASTM acid numbers are met.
Hey thanks for all the interest and just so everyone knows we will be performing several on the spot demonstrations in booth 445 (Thermax-USA booth) so please come by take a lo0k and say hi!
We will have a miniature lead lag column set up thanks to Chad utilizing a really cool clear head metering pump so everyone can see the biodiesel coming in and going out.
These demonstrations will include pre and post testing.
Some of the test being performed for sure are Soap ppm, Total Acid Number and our New Biodiesel Percent methanol test.
And we need some help because we would also like to do a total Glycerin/glycerides test so if some one has a line on a GC or some other method please please please let us know.
A Demonstration Schedule will be posted later.
So the 2009 National Biodiesel Conference is over and in the history books - not a huge turn out this year apparently maybe 1/3 of past participation...
However the highlights were the Biodiesel Sustainability Summit just prior to the NBB Conf., The San Francisco premier of the Josh Tickell's biodiesel documentary "FUEL" (spectacular!!!)
Arbor Biofuels Company plans to sponser this film and bring it to Ann Arbor, Michigan later this Spring - we should get as many people there as possible - its very personal and inspirational...
We had our miniature lead lag system there and thanks to Raften, about 10 gallons of unwashed biodiesel to run a few demonstrations on Sunday.
The cool thing was one of the leading FTIR analysis companies Cognis QTA’s performed about $500 worth of biodiesel purification analysis for FREE on the demonstration samples.
There unit in 2 minutes can accurately test for 15 of the ASTM test.
Anyway the test results were perfect and I will post photo copies later. The technician working the QTA booth initially tested the raw crude biodiesel and his first comment was; "oh this biodiesel isn't going to pass spec." He said that because the total glycerin count was off scale high for their tester and the only parameters of the ASTM test to pass were Ester conversion, Acid Number or Acid Value and viscosity.
However the post lead lag system containing Thermax Tulsion T45 BD resins passed every test except for the Acid Value which is due to the overnight soak time of the initial biodiesel...
Chad and I use to recommend soaking the biodiesel overnight since that is the practice used to initiall expand the gel type resins however with the macroporous resin we simply suggest backfilling to remove air and then start pumping. Not even worrying about the gel resin in the lag bed since initially it isn't doing the work anyway and it will expand over time...
Here is a great link that list a series of papers with data provided by Idaho State University under the auspice of Dr. Jon Van Gerpen which cover the basic points of biodiesel purification using ion exchange resin and other drywash media:
7 PDF files on dry washing biodiesel information
Thanks for the great info GCG.
I have a few questions.
You mention that due to the fact that T-45 does not rely on the methanol to work, that the bio can be de-methed first, which in turn allows a greater quantity of the impurities to also drop from the bio.
In our arrangement, our bio goes through BD10Dry first, then on to an inline continuous flash evaporator to demeth/dehydrate.
I am a little concerned about running the bio through the flash dryer BEFORE purification in that I fear build up of soaps and impurities in the dryer itself. Are there any practical methods of avoiding this issue with such an arrangement? I should also point out we use 5%prewash so our typical soap levels are under 400ppm before hitting the resin or the dryer unit.
Otherwise T-45 sounds like a great post-dryer final polishing step.
Assuming a direct replacement of BD10Dry with T-45 (before demeth stage), how does performance and capacity of T-45 compare to BD10Dry?
The gel resins like BD10 Dry, actually require methanol for them to operate well since they are essentially non-porous.
If you are doing a 5% prewash then you are already knocking down the methanol content by appox. 50% and as you have seen the glycerin and soap levels have also been greatly reduced. Using the ion exchange columns to remove soap levels of 400 ppm suggest that you're operating in a nearly ideal state.
Flashing the methanol out ahead of time will cause the soap and glycerin to fall out and coagulate - we use a cone bottom tank to drop out this settled soap and glycerin prior to running it through the resin columns.
Additionally we have been experimenting with Eco2Pure; using it as a pre-filtering material so we don't have to wait for the soap and glycerin to drop out. We want a continuous process and Eco2Pure has worked as a gross knock down filter media...
Finally you could easily use the T45 BD macro as a final polishing media if you wanted to.
Yes, I am aware of the reduction results of our 5% prewash.
Again, my fear of hitting the dryer unit before resin is the chance of resulting dropout accumulating in the (very hard to access) parts of our flash dryer unit.
I guess what I was getting at is, would there be any advantage to consider using T-45 instead of DB10Dry if demething before resin is not an option?
I agree that from what I can tell, T-45 may make a great final fail-safe/polishing step, but that BD10 may make more sense if we can not demeth first.
Do you have any idea how much methanol you have present after the 5% prewash and after the initial glycerin separation?
Typical numbers are around 1% - even at these lower levels the Macroporous resin is likely to out perform the gel-type resins since they actually work best at 4% methanol content.
Also do you have any idea how much dissolved glycerin or what your Total Glycerin numbers are in the biodiesel prior to the ion exchange resin bed? It is this glycerin number which really matters...
Your not going to believe this but irony is an amazing phenomenon ...
Just tonight we had our demethylation unit get plugged up by soap fall-out -- can you believe it!!!
We have the tank plumbed with an air fitting so generally speaking we never have problems; if it is a little slow coming out when making transfers, we just put some air pressure to it and any plugs have been easily dealt with -- that is until you brought it up!!!
Oh well that's how it goes in the Biodiesel Game...
Im tossing up between using the Thermax and Purolite.
If you use the 5% prewash method first to reduce your methanol, which resin do you think could absorp the most amount of water?
I know gel resins are best for wet biodiesel and purolite is just that..What about thermax tho does that exhibit some of these good water absorption properties?
The gel resin will out perform the macroporous resin for water removal however its fundamentally a bad idea to use either of the resins for water removal (or methanol removal) since these two things would then become the resins most limiting factor.
Having said this if you have a water concern then other producers have had better success with the gel resins.
The beauty however of the 5% pre-wash is that it leaves very little residual water in your fuel (at least that's what I've heard - I should have the real numbers in the coming weeks since a friend who is just starting to use one of our ion exchange dry wash towers is going to do the testing on some very real world used cooking oil!!!)
After I get his numbers - this should tell us exactly which way to go...
Have you used Thermax? Share your thoughts.
Did you like it? Hate it? Has it worked better/worse than other ion exchange media?
thanks for asking...
"upgraded" waterwash to thermax system few month ago. This is my first drywash system and this may be reason for my results...
After moving to thermax I've had problems with oilpump of my burner. It seems to be corroded by the bio I use. There is light alloy part that has severe corrosion. I assume this is because there is methanol present. I also assume that FFA's generated by thermax are accelerating this process. Also found copper film on steel part of the pump (probably from copper pipes of oil piping) . I guess this points to the FFA's also.
So I emptied my oil tank. Found brown layer that does not dissolve in bio but dissoves in water, methanol, isopropanol and does not show up in soap test. I assume this to be glycerin. I wonder how it could sneak through thermax at flow rates I'm using - app. 1BV/h.
So I'm waterwashing again untill I can figure out these issues.
Hey, what kind of biodiesel production process do you use? Do you do a prewash?
Do you do any kind of methanol recovery prior to using your Drywash tower?
How much biodiesel have you processed through your drywash tower?
Do you have a post filteration system with a site glass? If you do and if glycerin is getting through your ion exchange media then you should observe fall out in the site glass?
Let me know and I'll try to help you resolve the issue.