I was told you can revitalize the dry wash media by simply baking it in the oven to the temp of 450 degrees F.

Is that true????

Is that temp too hot? Purolite advertises max working temp for their media is 300F. Does that mean the media will be harmed by going over 300?

Well I was hoping there was a fairly simple answer to this question.

The directions state to just heat it to 450F. I have read up on other dry wash resins. Not many really talk about rejuvinating the resin.

So I am going to wash the resin with Methanol (which I will reutilize in my next few batches)

Then I am going to use a forced air vented oven to warm the resin to 130F for 30 minutes. After which I will bring the temp to 450 for a a brief second.

Well my dry wash media is finished. I dont think I got to bed until 2am last night.

I give the media 2 rinses with methanol. The first time it come out nasty brown/black with sludge on the bottom of the bucket.

The second time the methanol looked more like watered down milk.

Well drying the media at 130F in the vented oven went well. However once we set the oven at 500F and the media reached them temp of 326F all kinds of grease smoke started pouring out of the oven. We had to vent the shop by opening up both bay doors and the side door.

The smoke darkened the media. I am not sure how effective it was to roast my media. I was talking with my friend about it and I think next time I will do 4-5 rinses with the methanol and only bring the media to a meager 230F (hardly no smoke) to make sure there is no residual water in the media and dry off the excess methanol.

Please provide more information about your operation.

Which resin are you using: amberlite; lewatit; dowex; or, other?

You referred to "instructions" in a one of your post. Were these instructions supplied with the resin? What is to be achieved by following the instructions?

What aspect of the ion exchange resin performance is to be regenerated: glycerol/soap adherence; or true ion exchange of the soap molecule?

Methanol washing/rinsing the resin will regenerate the glycerol/soap adherence capacity of the media, but methanol rinsing will do nothing to regenerate the ion exchange capacity.

Heat will not regenerate the ion exchange capacity.

The ion exchange resins that I have personal knowledge of are made of very small, plastic spheres. It seams to me that exposing the plastic beads to regeneration(?) temperature of 450 deg either C or F will melt the plastic.

What am I missing?

Great questions.

I do not exactly know which type of drywash I have. The guy I bought the unit from didnt tell me, just handed me instructions he typed up with the information to cook them to 450F.

Problem I experienced with my processor is I didnt make sure all the glycerin was off the batch before I started sending it through the drywash tank. Luckily the filter clogged and showed my ignorance 5 minutes into the wash cycle. Well this was enough to coat the media and not allow the cycle to finish.

So I just want to pull the free glyercin/soap out of solution of the fuel before pumping it into my truck.

When I was at my friends house we compared this media with some molecular sieve balls he bought 5 years ago. They look identical and feel identical. They both appear to be clay based, as both are fairly easy to crush.

I am going to attempt to call the person I bought the unit from and find out exactly what the name of the dry wash media is so atleast I know......

Ok. I contacted my processor guy. He said the dry wash media is Silporite (a molecular sieve). With that said, I looked it up and yes you are supposed to dry at high temps to remove any water. So maybe I will dry at 450F but I will have to make sure all the dang biodiesel is off it first and use a dang oven outside...

Choke choke. That gave off alot of smoke last night.


So what are the advantages/disadvantages of using a molecular sieve vice ion exchange resin?

I am somewhat familiar with ion exchange resins and how they work when used to purify biodiesel. I am very ignorant about molecular sieves.

With that in mind, I don't think you have any ion exchange capability with the unit you have purchased.

A molecular sieve works like a filter. For instance a molecular sieve can be used to filter the large (relatively speaking) water molecules out of small (relatively speaking) ethanol molecules to produce dry ethanol. The molecular sieve is sized to allow the ethanol molecules to pass through the sieve while trapping the water molecules on the surface.

Ion exchange resin converts soap to a Free Fatty Acid (FFA) by chemically exchanging the sodium (or potassium) ion of a soap molecule for a hydrogen ion. The hydrogen ion is donated from a reservoir of ions bound inside the ion exchange resin beads. The beads contain a finite supply of hydrogen ions. There is no way for a home brewer to chemically regenerate the hydrogen ions once the resin is "spent".

Both the ion exchange resins and the molecular sieve material will physically trap some of the glycerol that is delivered to them. Glycerol is a "sticky" type material. This sticky property causes the glycerol to stick to the resin or sieve material. Washing/rinsing with methanol will "regenerate" the glycerol-only removal capability of the materials.

Well graded beach sand will perform the same function. But, probably, none of the three are very efficient at removing glycerol.

If your supplier advertised the unit as an ion exchange unit to remove soap from biodiesel, then we need to know more about its design to help you figure how to make it work, or you need to go get your money back.

My supplier did not advertise it as an ion exchange unit. Simply advertised it as a biodiesel processor with a dry wash system built into it.

Being that I am fairly ignorant with this entire process anyway, please explain to me why it is important to get rid of the soap?

I thought that with water present the glycerin/water/KOH turns to soap. So if the molecular sieves are trapping the water within then wouldn't it in effect do the same thing as converting the soap to FFAs? I know its not truly the same but isnt it the same effect by removing the soap from the diesel?

When i start the wash, my diesel is fairly cloudy. I associate this with the soap/excess water being in the stock oil. After I run it thru the dry wash portion it is crystal clear.

If your processor produces biodiesel that is "crystal clear", then you probably have very good biodiesel. There are three tests that you can do to analyze certain qualities of the biodiesel.

The first is a water "shake-em-up" test. Mix equal parts of biodiesel and water in a small container. Mix gently and then let settle. The biodiesel will float to the surface and the water will sink to the bottom after a short settling time. If the biodiesel is relatively soap free, then, both will still be very clear. Caution, don't shake too hard or settling will take much longer.

The second is the "3/27" test. Mix 3 parts of finished biodiesel with 27 parts of methanol. Shake vigorously for about 5 seconds, let settle. After about 10 minutes see if anything has settled to the bottom of the container. Any settlement at this point is an indication that the fuel is not fully converted. No settlement is a pretty good indication your biodiesel may actually meet the ASTM glycerol standards.

The third is a form a water test. Place a small sample of biodiesel in a clear container and place it in your refrigerator for a few hours. Is the biodiesel still clear after cooling? If so, then it is relatively water free. However, if it appears hazy after cooling and then clears again when it warms, then this is an indication of water still dissolved in your biodiesel.

Soap in biodiesel causes some slight deposits to build up on the injectors and cylinder walls. I am not sure if this is problem in older engines as many on this forum report running unwashed (still contains soap) biodiesel for many years with no engine problems.

Soap also may causes problems in the catalytic exhaust systems of newer (2007 and up) diesels in the United States. If your vehicle does not have a catalytic muffler, then soap in the biodiesel will not be an issue in the converter.

I have done the 27/3 test on the unwashed and it had next to no settling.

I did inadvertantly do the last test as well. This was more to see if the biodiesel would start to gel at refrigerator temperatures though.

The first water test I have not done, however I did do a post titration of the fuel to ensure I was not way under/over PH wise.

I will try the first test tonight.

I appreciate the info. I am running a 1995 F250 with the 7.3 turbo.

Would it be considered excessive if there was both the molecular sieve and ion exchange resin hooked into the same unit?

Have the ion exchange after the molecular sieve and then run it thru the filter?

I dont suppose i want to pay for the ion exchange portion anytime soon though. Just food for thought.

If your processor produces good fuel now, then why add anything else?

Granted, you may know for sure whether your unit has a molecular sieve or whatever. But, who cares? As long as it produces the biodiesel of good quality, then adding another treatment step will increase your cost and complicate your operation? What will you gain?

We would like to know more about your molecular sieve, but our understanding the system doesn't mean it is not making good biodiesel.

My setup utilizes a 10 gallon fiberglass tank. It looks similar to a tank O2 bottle. Just fiberglass. Of course it has a drain tube running down the middle of it with a basic strainer on the end to keep the sieves in the tank. There is approx 22 lbs of media in the tank. This equates to about 2/3 5 gallon pail of media.

I dont really know how much more info I can provide about the molecular sieve, however I wanted to post the process I used to rejuvinate it last night as it didn't seem as though there was any advice about this here. So maybe thru my trial and errors others can learn if someday they maybe interested in utilizing the molecular sieve...

So here are things I learned from last night diong this the first time. I dumped Methanol in the 5 gallon pail which was already full of the sieves. Once it had about 1 inch over the sieves I used an old broom stick to stir them. Then I dumped the sieves on a standard house screen over a another 5 gallon pail. I repeated this process one more time.

Next time I do this I will cut the lid of the 5 gallon pail around the outer perimeter of where the lid latches onto the pail. Then I will melt/glue the screen material over the hole in the lid. I will snap this down and just dump it all at once and allow it to drain.

Also I will rinse with the methanol until the methanol comes out clear. I stopped after the second time and it still looked like watered down milk.

I friend has nice commercial ovens used for cooking polyurethane parts. That is what we used to cook the media. Also next time I think I will buy a crappy standard house hold oven and use that. Place it in the driveway and let it smoke like crazy!!!!

D.

Take a look at this photobucket site to see the procedure for flushing an ion exchange column (dry wash tower) - several bed volumes of methanol flushing with final clarity and soap testing videos...

http://s88.photobucket.com/albums/k196/chads454/

GCG

You may find this interesting, http://www.purolite.com/Library/Products/Resources/rid_341.pdf
This is for the purolite product.

Quick note about the last test Producer mentioned. I do the test as the last thing done before the bd goes to storage or use. I use a fairly flat sided glass bottle so the light does not bend much and I leave it in the refrigator overnight. There will always be condensation on the outside when you take it out of the box to look so you need to wipe it down but if it stays clear and passes 3/27 I figure I have the best bd I can make.

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...

GCG

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

GCG

GCG thanks for posting that link, its a great source of info - well worth downloading for reference.