I went to the shop earlier today, to pass a Tote of crude bio thru our woodchip set, then 10 micron bag and finally thru ion exchnage resin.
Usually bio comes out the woodchips at 200pppm and after resin it comes around 40ppm (KOH)
For fueling, We pass the biodiesel thru a 2 micron BioTek Hydroglass and finally a biodiesel compatible Golden Rod water block.
I was going to fuel the truck and find some nasty stuff in the golden Rod canister.
I dont think that is soap (we do soap titrations after reaction, after woodchips and after resin) i also dont think is resin from the wood chips (i drain the resin from the woodchip barrels, before filtering bio thru it).
Temperature at night has been around 62-64F so i dont know if thats the issue, because the bio on the Tote before woodchips and the bio thats in the Tote after resin treatment its not gelling at all.
I dont usually drain the golden Rod after using.
I leave a picture, whats your opinion?
image.jpg (17 Kb, 29 downloads)
By the way, fuel comes out crystal clear.
Ive runned at least 15,000 miles on B50 with my Nissan YD2.5L TDI even tho it has a dpf Filter.
What could be the issue?
image.jpg (14 Kb, 19 downloads)
That's the temperature for HMPEs to drop out of biodiesel. I see it start to show in the cold filter settling barrels at that temperature. I settle BD at ambient temperature then cold filter through 5µ into the vehicle tank.
As the temperature drops below freezing, I add 50% kerosene+petrol into the mix and continue pumping from the clear layer.
Thanks for the advice john!
So i dont have to worry, its gelling fuel...
My head was spinning all day!
You only have to be concerned with the HMPEs that settle out in the vehicle tank clogging the intake screen and causing the engine to stop. It usually happens at inconvenient times and places.
Sorry but i dont know what HPMEs stand for.
My English is not that complete.
High Melt Point Esters. They can start to precipitate out at <15C in my experience.
You need to chill your winter fuel to get them to drop out before you put the fuel in your tank. Otherwise your asking for trouble, even when blending as they will still drop out of blended fuel.
I'm sure I that this stuff has been in my fuel for the last 7 years, but I only realised it about 4 years ago.
I used to centrifuge my fuel after drying and then dispense it via a filtertechnik polishing / final drying pot to ensure moisture levels weren't too high. The fuel looked great with no real problems, but then one winter I centrifuged a drum of bio that had settled at a temp of around -6 deg C. and got a full cake of waxy stuff.
After this I was certain that these 'waxes' formed at sub-zero temps, until this summer when I made my last few batches prior to giving in (I have a two year contract that will keep me too busy to make fuel). I left this fuel to settle as I had been buying derv - too busy to even polish and dispense bio. Then a few weeks ago whilst temps were still >10 C I centrifuged a couple of hundred litres. Prior to fuging the fuel had a nice colour and clarity - really bright, but still I pulled out about 500 grams of wax.
a couple of winters ago I scrapped some of this wax into a jar and put it on the wood burner with a thermometer in it - It took 50 C to melt the stuff and it went solid again at around 43 C? Can anything be concluded from this. For example is there a chemical definition for HMPE's, is this stuff definitely HMPE's? I did a 10 / 90 test with some after melting it and it dropped out. Although this doesn't prove that it's not meth ester, as the temperature of the meth probably had an influence.
Some have concluded that WBD influences the production of HMPE's many I know get them including me and have never Whole Batch Demethed.
Although I'm no longer making bio, I still have an interest as a mate of my has taken over my WVO collections and is giving me a drum of bio from time to time which I will polish prior to use.
Ok Thanks john.
Temp usually gets 16-18C at night (for about 5 hours).
Usually we are about 28-32C, my question is.
If they are already in the tank, Will the dissolve at the middle of the day when temp is above 28C?
Will it dissolve also in the shop?
I wonder, how do you precipitate them and then drain it?
Can i use some additive to prevent this to happen?
The melting point depends on which ester it actually is.
Methyl palmitate melts around 28C while Methyl stearate melts around 35C.
Yes, like Tilly said, some of the HMPE's seem to take quite a bit more warming to become liquid again than others. Best way to see whats in you tank is take a sample out of it and put it in the fridge overnight.
I use an upflow chip drum in a keg fridge at -3C to filter them out, it works perfect for my needs.
As far as I know there is no known additive that will change HMPE's to LMPE's. The best additive to keep your fuel from clouding and/or gelling is pump diesel or kerosene, this does not keep the HMPE's from plugging your filter though it does help...
Nathan, I read through the threads on the other forum your referring to quite some time ago. That discussion did not convince me that WBD had any effect on HMPE's. The testing done was inconsistent and inconclusive as far as I can recall.
I have never used a centrifuge but the way I understand it they heat up the fuel as it passes through due to friction, this would be the opposite condition you would want to get rid of HMPE's.
If you could run your feed pipe through a chiller, bucket of ice water or whatever, you would be able to fuge out the HMPE's as they precipitate out from the cold. Of course if the bowl in the fuge gets warm it would likely just remelt the HMPE's back into the output of your fuge.
Thanks for the replies and support.
I never use more than B50, and no power loss for filter clogging st all so far.
John, looks good.
My woodchip drums (55gal) are also upflow so crappy stuff drops to the bottom.
Then thru a 10 micron Filter bag.
But i do it at room temp.
What temprature do you recommend to pass the bio thru the chips?
Wont the bio gel at low temps?
The HPMEs stay in the chips?
What to do with the bio after that? Send it thru my filter bag?
Because after this i do polish with ion exchange resin.
I took a sample that was soaking in chips for two weeks and i was amazed!!
I did a soap titration and it was around 42-48ppm (KOH)
I leave you guys a picture you can see the extinguisher instructions thru the stored bio, even tho the sample is in a plastic container.
In a glass container i crystal clear gold fuel. And it hasnt even passed thru the resin.
image.jpg (47 Kb, 11 downloads)
I store the BD at outside temperature which settles the HMPEs when it's cold. Then I pump from the clear layer above the HMPEs to cold filter through 5µ as it goes into the vehicle tank. That way the HMPEs 'automatically' drop out in cold temperatures then melt back into solution when it's warmer.
I never have this issues because i live in the caribbean in Yucatan, México.
So in any season but winter, temp is always around 30-40celsius (90-100F).
On winter lower temps are 14-18 celsius (57-60F) and only for about 3 hours during the day.
Then temps are around 25-30 Celsius (77-86F)
I have an upper TOTE (demethed biodiesel settling) at about 10ft height, from that tote i send the bio thru my woodchip drum (upflow) then it goes to a TOTE at ground level (TOTE has a 10 micron bag for filtering any sawdust).
Then i polish with resin.
For fueling i send it thru a Biotek and finally a 10 micron Golden Rod.
What can i do (cheap) to be able to cold filter the bio or cooling my woodchip drum to get the HPMEs to drop?
Sorry to ask the same questions, its only that i never even heard about HPMEs, and even tho im not having any important drop out, i want to avoid it.
At what temp do you think HPMEs should drop out?
Any ideas on how can i do it, since town isnt that cold?
I dont want to add much electrical cost to this (freezer idea is great but i want something more simple.
It's so hot where you are compared with Canada, so I can see how someone there wouldn't have a lot of experience with HMPE problems. For those of us who live where it snows, it happens often enough that we got tired calling them "High Melt Point Esters". It's biodiesel made from animal fat, palm oil, and hydrogenated vegetable oils.
Most of the troublesome HMPEs start to settle out in the mid 60s °F, <15°C. I suspect that the ground temperature there is lower than that. If it is, then place the BD in a barrel buried 80% in the ground, and cover it to keep the sun off, and I suspect the BD in drum will get cold enough to settle the HMPEs to the bottom. Then you can pump the clear BD from the top. Free and easy cold settling. If it works well it could easily be made into a buried 'cold upflow' system for continuous processing. Where I live it's almost always cold enough outdoors in my unheated fuel shed, that almost all HMPEs and water settle out in the bottom of the cold upflow barrel.
Your English is way better than my Espanol.
I studied the language since i was a kid. Now its a must.
The burrying its a good idea.
The problem is that we operate in a warehouse and have concrete floor.
I want to chill my poly wood chip drum maybe with a coil and cold water.
The question is;
If im gravity feeding (upflow) the drum;
A) At what temprature (higher temp possible, to save money) would the HPME should drop, if lower temps in the year are around 12C (54F), why should i go lower?
B) What flow rate do you recommend?
C) Is biodiesel gonna be able to pass thru the 10 micron bags (at room temp 25-27C, 80F, after passing thru the drums.
HI Yuka, you might try a different approach. Your supply of waste oil must contain high melting point oils and fats to produce high melting point esters. These come from animal fats, palm oils and hydrogenated oils. If you store your waste oil for a few weeks in a barrel or tote in a cool shady spot the heavier high melting point fats will settle to the bottom. Use only the top liquid layer for biodiesel in the winter and use the bottom layer for bio in the summer months. Your summer temperatures should be high enough that you wont be bothered by HMPEs .
|Powered by Social Strata|