Hello all!

I am having some trouble drying a 60gal batch. My set up is a 105 gal conical tank with an air compressor line that ports through the base. On top of the tank is a HVAC fan that pulls air out of the tank. My most recent Sandy Brae turned up at 1350ppm. The previous was 1250ppm. This batch took about 6 separate 10gal washes but has gone through nearly 4 rounds of 4 hour drying with the compressor. The overhead fan has also been running constantly and is strong enough to agitate the surface of the fuel by itself.

I am wondering why after this much time the water content appears to be increasing. Could it be my Sandy BRae kit? I recently had to replace the pressure gauge and while I bought one that is the same Wika brand and scale, it ended up being a 4.25" diameter (quite a novelty looking item). Could humidity in the air have anything to do with it?

If this goes into my purolite tanks and the assumed water content is true, will they take care of the rest of the water?

I appreciate any help.

Hi Justin,
Pretty sure your trying to dry it with damp air,what is the RH
where you are?
Also compressors produce a lot of condensation.

Go to the thread "drying biodiesel in a damp climate" and look
at IMB's turbo dryer, they work really well,just tested a friends bio,dried with one of these (with my sandy Brae)
was 75ppm!

Re your S/Brae ,I had the same problem,was getting high results
Turned out that the results were correct,the instrument is very
accurate.It was just the bio that was wet!

DO NOT put your wet bio thro the resin it will not dry it and will not do it any good.

Dgs thank you! Humidity is at 60% right now. Would adding a water filter to the compressor line help enough?

Justin,It would help but not very much.
The air that bubbles thro the bio needs to be dry.

When i had this problem(before i built the turbo dryer) i did an experiment to prove it was the wet air I was introducing that was keeping it from drying.
I put the input to the compressor inside a cardboard box. At the opposite side of the box I cut a hole and had a fan heater blowing into the box. I left it for 2 to 3 hours with the bio at 60degsC.

Tested it with S/B was 450ppm,instead of my usual 8 to 900ppm!

With the dryer , any air that is in the headspace above the bio is dried through silica gel,as is the air that is bubbled up through
the bio.They are cheap to build and are very economical on
electricity.

Thank you! I will look through that thread and start planning the build!

Hi Justin, here is a link to the thread that Dgs mentioned.
http://biodiesel.infopop.cc/ev...7078823/m/5697001243
Just briefly looking at your setup I think you would need a larger air pump than is normally used in the turbo dryer for 150 - 300 litre processors. Something around 4 - 500 litre per hour would be good. Silica gel will reduce the humidity of your 60% air down to about 15% and will dry very effectively ( we have to use 95 - 99% air for half of the year.) You dont need such a powerful fan, a 6 inch computer fan is good enough.
If you dont want to wade through the entire thread start at pg 9.

Thanks IMB, only just learning how to do this link thing.

Justin, just tested a batch I dried today with my turbo dryer,
was 158ppm as tested with Sandy Brae. Temp was hot today
for UK-26degs C and R H was low,obviously this helps.

If you are having problems with drying due to either the fuel being damp or high humidity giving you trouble then I suggest heating the biodiesel as you dry it. Stick a heating element in the dying tank and get it up to around 140F/60C then blow lots of air over it and it will dry pronto.

Of course if you were to not use water at all then the demething process will give the dampness something to hang onto and drop of of solution with the soaps/ glycerine as these are more hygroscopic than biodiesel/FAME. And what very little the demething doesn't get the chips and/or resin will.

Thank you everyone. I just picked a dual computer fan out of a E-recycling facility and will add that the the dryer I am building. Also had to replace a silica filter the other day so once I regenerate the beads I should be good to go.

Legal Eagle, we thought of adding a heating element to the mix but decided to steer away from using that much energy. The silica regeneration may be of equal energy demand though. Will have to crunch the numbers to see.

Honestly the amount of energy that a compressor running for hours to dry the fuel is going to be greater than the energy to heat it up for a short time. I use the 6000W inline heater in my processor to dry the fuel, 1 hour x 6Kw = 6kwhr or about 60 cents in my part of the world. I run the pump to spray the fuel against the side of the processor tank for several hours after to utilize the residual heat in driving off the remainder of the water. When the temp drops to 120 it is dry as a bone. Don't make the solution more complex than it needs to be. Regards Dan

Hello bigblockchev,
Sorry to ask,but how do you know it is as dry as a bone,it's just that we've heard that so many times.