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wood chip questions
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so i'm almost done building my dry wash columns, they are 6" dia x 70" tall. they are made of .25" wall steel pipe with removable flanged caps on top and bottom. i'm planing on running two in series if thats not enough i can make more.

out of the processor to a settling tank with a standpipe, after settling for a day or two i'll drain any remaining glycerine then start pumping the bio in to the columns then to a whole house water filter at 5 micron then to the fule tank. i'm going to use a blue pump with a bypass line back to the settling tank to regulate the gpm.

can i use aspen shavings? if not what's best and where can i get them?
do i need to demeth before dry washing, whats the best process if its needed?
should i pack the shaving in the colums or leave them loose?
does temp matter?
speed... GPM?
any questions, comments, or concerns?
thanks
jonathan
 
Location: southern IL | Registered: October 11, 2008Reply With QuoteReport This Post
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can i use aspen shavings? if not what's best and where can i get them?
  • Yes the most important thing is that the chips are dry (not still full of tree sap) and the smaller the shavings the better to create more surface area.

    do i need to demeth before dry washing, whats the best process if its needed?
  • You can, you will get slightly better results if you demeth first in my experience. Especially with sodium catalyst rather than potassium. Presumably this is because all the soaps that drop out after demething are filtered as well as absorbed

    should i pack the shaving in the colums or leave them loose?
  • I prefer packing quite tightly as the whole column then acts as a depth filter for the dropped out soap (see above) but it might not matter, especially if you are flowing top to bottom. Packed quite tightly and using sodium catalysts you can expect to have quite high pressures as they start to clog though so if you can't handle those pressures don't pack.

    does temp matter?
  • Not really, but if you have at least partially demethed the colder the bio is the more soaps will drop out. It will also be slightly harder to pump as well.

    speed... GPM?
  • http://www.utahbiodieselsupply.com/arborpure.php see the flowrates they list there. Column diameter and chip/shaving size are going to be the biggest controller of speed. Also the rates they list are approximately correct from experience, but the slower you go the better results you are going to get and the larger your shavings the slower you will have to go to get the same results as well.

    any questions, comments, or concerns?
  • Wood shavings will only remove soap they won't remove an appreciable amount of glycerin. You will require an extra step to remove glycerin.
    thanks
  •  
    Registered: February 25, 2010Reply With QuoteReport This Post
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    so how do i remove the glycerine?
     
    Location: southern IL | Registered: October 11, 2008Reply With QuoteReport This Post
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    You are settling in a standpipe equipped tank so most of the glycerin will drop below the SP's outlet port, or should unless there is too much and then all you have to do is open the floor drain and lower the level to where all that is coming out is biodiesel.

    Any residual suspended soaps ect will drop out after demething; I recommend this step to help achieve a high quality fuel. There is a settling period required after demething; I leave it anywhere from 48 to 72 hours, and then run the biodiesel, via the SP's outlet in the demething tank, through a drum of hard wood chips followed by lead/lag Puroilite PD206 resin and then followed by a 2 micron CAT fuel filter.

    My results doing it this way are ZERO ppm soaps, and even though some containers have frozen and thawed several times over a winter no drop out was noticed. It ain't broke, so I'm not planning on fixing it.

    HTH



    ** Biodiesel Glycerine Soap - The Guide
    - on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


     
    Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
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    How much time do we think is necessary to settle out the glycerin? When we are finished with a batch we typically drain off a sample and see good separation in 5 minutes. Is settling 24 hours sufficient when using a drywash to make sure that any glycerin that does not settle will be removed by the woodchip wash?



     
    Registered: April 28, 2008Reply With QuoteReport This Post
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    24 hours should be plenty of time; however then comes the demething process and subsequent re settling to allow any residual soaps ect to drop out of solution. At least another 24 hours IMO is minimal, and the longer the better if for nothing else but to elongate the life of the chips and or resin.

    Where hard wood chips are in abundance and you don't mind preparing batch after batch of them you can get away with demething and allowing just enough time for the solution to cool and run the fuel through the chips twice and you should be good to go after that. This will of course deplete the usage of the chips much quicker, but as said, if you got plenty and don't mind prepping them ...



    ** Biodiesel Glycerine Soap - The Guide
    - on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


     
    Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post



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    not to sound like an idiot but... i thought the drywash removed the methanol, soap, and glycerin. i think i need to back up and ask what the process is. exactly what do i need to accomplish the correct process, with the least equipment, time, cost, etc. i'm running acid, koh, koh. approx 143L per batch varing qty per week (1-3).
    thanks
    Jonathan
     
    Location: southern IL | Registered: October 11, 2008Reply With QuoteReport This Post
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    will methanol in the fuel hurt the truck? after all you can buy water/methanol injection kits to increase mpg, decrease egt's, increase hp... the list goes on. if its safe then all we need to concentrate on is removing soap and glycerine, correct? or does the methanol interfear with the drywash process?
     
    Location: southern IL | Registered: October 11, 2008Reply With QuoteReport This Post
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    Well I have no experience actually running fuel so I cannot answer any questions regarding acceptable limits for methanol and glycerin in your vehicle.

    http://www.make-biodiesel.org/Waterless-Washing/

    Is a good website for your basic dry washing media questions.

    What many people do with dry washing using wood chips is to place a tower of ion exchange resin like purolite/amberlite/thermax etc behind the sawdust towers (see Legals response above). This just removes that last traces of soaps and also sucks up the remaining glycerin. Basically the main purpose of the sawdust is to remove soaps while the entrapped glycerin will be removed by the ion exchange beads.

    For settling purposes, if you haven't demethed the bio I would expect it to take weeks of settling before the glycerin is at ASTM levels as glycerin dissolves in methanol so any remaining methanol will trap glycerin in your bio as well. This means that your glycerin will never drop out until the bio starts to demeth on it's own by evaporation. Basically % methanol can also be used to determine levels of glycerin in most cases. 24 hours will not get all your glycerin out without a really good demething as a previous step. This is for ASTM glycerin limits though, for 'acceptable' limits for your own vehicles usage you will have to ask someone familiar with the vehicle.
     
    Registered: February 25, 2010Reply With QuoteReport This Post
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    so whats the best, fastest, safest way to demeth? i'm using a modified appleseed processor, and can build pretty much what ever is needed
     
    Location: southern IL | Registered: October 11, 2008Reply With QuoteReport This Post
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    quote:
    so whats the best, fastest, safest way to demeth? i'm using a modified appleseed processor, and can build pretty much what ever is needed


    Taking the question verbatim at face value here goes; water washing using HOT water that is not super softened will get the job done considerably quicker than most other methods. A separate drying set up will also be needed.

    When I water washed I was able to completely wash an 80L batch in one afternoon and then dry it the next morning having it ready for use in the afternoon of the second day consistently. I used well water a the time.
    My former water wash set up may help give you some ideas.

    When the pump broke and super softened city water replaced it I made the move to dry wash as it became more efficient for me. Dry wash also allows me to process in the winter as I have no access to water when the freezing temps start. It depends on your need and you ability as well as available time as to what will serve you best. You also have to be able to responsibly dispose of the wash water.

    HTH



    ** Biodiesel Glycerine Soap - The Guide
    - on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


     
    Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
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    water disposal is a problem, i'm on septic and don't really have access to put in to my septic system. the next problem is water washing was a nightmare, emulsions out the @$$, time consuming, you name it, it happened. i made 1000+ gallons and never got the kinks worked out. the fuel i was washing was good quality, always passed 3/27, 6/27. i'd have to use acid to break the emusions regularly. if it aint broke dont fix it.... its broke, so i'm looking for something a little more reliable.
     
    Location: southern IL | Registered: October 11, 2008Reply With QuoteReport This Post



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    What you need to look at firstly is WHY you are getting emulsions. There are a few reasons this happens and a couple are: wet oil going into the process and then the most common is getting glycerin by-product in the wash cycle. The by-product is essentially a concentrated soap, although not quite finished soap if that makes sense to you, but soap nevertheless.

    You say that the biodiesel passes the 3/27 test, and I am going to assume it is done taking into consideration this test's mandatory parameters of being done at 68F. It is then unlikely that you have an incomplete reaction and that would rule out the wet oil, which then leaves glycerin in the cycle or ??

    Even if you wash using HOT water, if glycerin is present you will get soap ... beaucoup soap, so IMO that is probably where the problem is.

    Just settling in the same tank that you react in will not allow complete draining of the glycerin even if you do get to the inter-phase level. The glycerin HAS to settle out below the drain port you will be drawing from to send to either the wash tank or demething tank. If all you have is one water heater as a reactor then it is best to flip it upside down and create what is called an "apple turnover"(you can search that term here) thereby taking advantage of the additional ports to create a "standpipe" of sorts using one of the eccentric ports and leaving the floor drain for draining the glycerin AFTER.(the glyc drain can also be used to lower the glycerin level to where it is no longer coming out the transfer/standpipe port).

    The most efficient method is of course dedicated tanks for each phase of the process; preheat, reactor, settling, wash/demeth, drying/dry media, final filter.

    HTH



    ** Biodiesel Glycerine Soap - The Guide
    - on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


     
    Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
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