Unconfigured Ad Widget

Collapse

Announcement

Collapse
No announcement yet.

bio diesel wash

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • bio diesel wash

    I'm new to the forum so let me know if there is something you don't like. I have been making bio fuel for the company I work for in 35 gallon batches for about a year. In the early stages I had 2 large batches go bad. My question is if I have water washed fuel that has soap in it and it does not separate what can I do to recover the fuel. It partially separated but remains cloudy at room temp. PH is a little low. Any help would be appreciated.

  • #2
    Re: bio diesel wash

    Sounds like you agitated it too much when washing. If you have the space just put it in some drums and leave it to settle, it may take months but it will settle. Then decant the good fuel off the top.
    Johnnojack
    4WD Isuzu Jackaroo 3.1 200000km on WVO,(2020) 2 tank home built system 6 solenoids FPHE, heated filter fuel line and tank pickup for thicker oil. Mk. 9 version now and no changes planned as trouble free.
    Mercedes W201 190D 1986 model: 2 tank system, bigger fuel line from tank, no heat exchanger, electric pump for diesel 22000km so far sigpic

    Comment


    • #3
      Re: bio diesel wash

      If you have the facility to do so, leave the drums in a warm place to assist the separation if the fuel and water.
      Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

      Current Vehicles in stable:
      '06 Musso Sports 4X4 Manual Crew Cab tray back.
      '04 Rexton 4X4 Automatic SUV
      '2014 Toyota Prius (on ULP) - Wife's car

      Previous Vehicles:
      '90 Mazda Capella. (2000 - 2003) My first Fatmobile. Converted to fun on veggie oil with a 2 tank setup.
      '80 Mercedes 300D. 2 tank conversion [Sold]
      '84 Mercedes 300D. 1 tank, no conversion. Replaced engine with rebuilt OM617A turbodiesel engine. Finally had good power. Engine donor for W123 coupe. (body parted out and carcass sold for scrap.)
      '85 Mercedes Benz W123 300CD Turbodiesel
      '99 Mercedes W202 C250 Turbodiesel (my darling Wife's car)[sold]
      '98 Mercedes W202 C250 Turbodiesel (my car)[sold]
      '06 Musso Sports Crew Cab well body. [Head gasket blew!]
      '04 Rexton SUV 2.9L Turbodiesel same as Musso - Our Family car.
      '06 Musso sports Crew Cab Trayback - My hack (no air cond, no heater).

      Searching the Biofuels Forum using Google
      Adding images and/or documents to your posts

      Comment


      • #4
        Re: bio diesel wash

        If your fuel does not separate adequately, you can make the soap into free fatty acids and sodium or potassium acetate dissolved in water. Then the part of the liquid containing free fatty acids and methyl fatty acid esters (biodiesel) should float on the water with sodium acetate dissolved in it, when the two liquids can be separated. But the biodiesel will have some free fatty acids dissolved in it. Then magnesium silicate treatment with some heat, about 60 degrees centigrasde, will adsorb or absorb the free fatty acids onto the magnesium silicate (solid) that may be filtered out with about a 20 micrometer porus paper filter, after settling out the magnesium silicate that will settle out. I did an experiment with potassium or sodium soap. I put vinegar into a small beaker, added a little homemade sodium or potassium soap. The metal (sodium or potassium) switched its bond upon heating , to acetic acid (vinegar) and free fatty acids were released, floated up to the surface of the vinegar. So, sodium acetate or potassium acetate (water soluble) was formed producing the free fatty acids from the soap. This happened because acetic acid is a stronger acid than free fatty acids are. That is so because of molecular orbital is longer, bigger, with more electrons in the longer carbon chain. The oxygen on the carboxylic acid group have a high electronegativity forcefully pulling some electron density towards the oxygen, but the longer carbon chain allows the negative charge on the acid ion (the acid with the hydrogen detached) to be stabilized by electrons bonded to the hydrocarbon chain connected to the two oxygen bonded to one carbon , the longer carbon-hydrocarbon chain allows the electron density to spread out in the molecular orbital.. Formic acid with one carbon, two oxygen, two hydrogen is the strongest. Two carbon chain, acetic acid is next strongest. Acetic acid (vinegar) pulls the metal potassium, lithium, or sodium to it more forcefully than octadecane , a free fatty acid with an eighteen carbon chain length. The longer carbon chain makes a weaker acid, so the acetic acid ends up with the sodium or potassium metal, which will dissolve in water. Magnesium silicate (magnesol) made in Dallas , Texas, will remove the free fatty acids from the biodiesel. Magnesium silicate treatment was done by me to purify biodiesel. I heated the biodiesel to about 60 degrees centigrade after demething the biodiesel, then added magnesium silicate, stirred for maybe 30 minutes, allowed magnesium silicate to settle out, then vacuum filtered the biodiesel with an about 20 micron porus paper filter. You might separate your fuel that way. You could use salt sodium chloride also, but if you put salt into your wet biodiesel, you need to get it all out before using the biodiesel in an engine. You do not want salt in your combustion chambers.
        WesleyB
        Donating Member
        Last edited by WesleyB; 22 February 2017, 09:50 AM. Reason: didn't write it quite right

        Comment


        • #5
          Re: bio diesel wash

          When I have this happen I chuck a litre or 2 of vinegar in the mix and that soon sorts things out

          Comment


          • #6
            Re: bio diesel wash

            The disadvantage with using acid is that it converts the soap into FFA's. If the starting soap level is unknown then so are the levels of FFA's that are formed. The use of acid also 'splits' any monoglyceride emulsion formed when water washing agressively, leaving the mono's in the biodiesel. This increases the temperature at which the bio will mist/gel (a problem here with cold UK Winters)

            The use of acid also leaves the biodiesel slightly darker in colour. I try to avoid using it whenever possible.

            Comment


            • #7
              Re: bio diesel wash

              Oh no we have a new member with the user name smithy thats going to cause some confusion
              smithw

              Comment


              • #8
                Re: bio diesel wash

                lol, I hope not.

                Comment


                • #9
                  Re: bio diesel wash

                  Someone wrote , using acid. A distinction ought to be made, strong (mineral) or weak (caroxylic, organic, vinegar or acetic). When the free fatty acids are produced when vinegar and a little heat, with stirring, the weak acid, free fatty acids have a polar end on the long chain molecule. These weak acids, free fatty acids in biodiesel stick to, adhere to, absorb or adsorb onto magnesium silicate (Magnesol?) , so the ffa's can be removed by treating the liquid with the solid magnesium silicate, then filtering out the magnesium silicate solid with ffa's stuck to its surfaces. The issue of monoglycerides was mentioned. Monoglycerides are an ester of glycerine, that's three carbons single bonded to each other with a hydroxide group bonded to each of the three carbon atoms in the molecule, but one of the hydroxide groups was previously reacted with an organic, carboxylic acid group minus one water molecule. That leaves three of the glycerine carbons bonded to a fatty acid through an oxygen atom (an ester), but the other two carbon atoms on the three carbon chain glycerol back bone have hydroxide functional groups bonded to them that are polar, being polar they will stick to , adhere to , absorb onto ,or adsorb onto the surfaces of magnesium silicate and then filter out the solid magnesium silicate solid that has the impurity stuck to it, leaving a purer biodiesel product. Using magnesium silicate treatment I've got my potassium soap content in biodiesel down below 20 parts per million. The stuff works. In the past a company in Dallas Texas manufactured Magnesol (brand name) which was used to clean up fry grease (vegetable oil) in restaurants by removing break down products from the frying oil.

                  Comment


                  • #10
                    Re: bio diesel wash

                    Thanks for the info Wesley. I have used Magnesol in the past with generally excellent results. After reading your post I'm wondering if the slightly darker colour left in the bio after an acid wash is simply due to the mono's being left in the mix.( the reason I say this is that after emulsifying the mono's during water washing , then removing this layer and splitting with acid the monoglycerides are much darker than the resultant biodiesel) If the magnesol really does remove them, could this be one of the reasons that the use of magnesol slightly lightens the colour of the bio.

                    The reason I stopped using Magnesol was the worry that a small amount could be left suspended in the bio even after filtering through a 1 micron filter, in fact after doing a 50/50 shake up with my finished bio (zero soap by titration) I got a milky water layer and I am still convinced that this was due to some suspended magnesol.

                    I now centrifuge my finished bio, so may give the Magnesol another go and see if the centrifuge removes anything.
                    smithy
                    Senior Member
                    Last edited by smithy; 26 February 2017, 09:13 PM.

                    Comment


                    • #11
                      Re: bio diesel wash

                      Hi smithy,

                      Originally posted by smithy View Post
                      The use of acid also leaves the biodiesel slightly darker in colour...After reading your post I'm wondering if the slightly darker colour left in the bio after an acid wash is simply due to the mono's being left in the mix.
                      After reading your first post, I did some testing this weekend.
                      One part of the testing was to compare the color of biodiesel that was Acid washed with biodiesel that was not acid washed.
                      I do not know what acid you are using, but the acid mentioned in this thread was vinegar.

                      Part of my testing was to do two "Shake-em-up tests" using two Dr Pepper bottles, each containing one litre of low conversion biodiesel that had not been water washed and had sit for 2 years in a sealed drum. I added about 500ml Rain water for the test.
                      After performing the "shake-em-up" test, I added a good "glug" of vinegar to one of the batches, again shook it hard, and have allowed them to both sit over the weekend.
                      I just had a look at both of the test batches. There was no discernible difference in color.

                      It is "common knowledge" that biodiesel produced using the two stage A/E procedure that passes the 3/27 test is significantly darker than biodiesel that passes the 3/27 test using a base only procedure. This assumes that both batches of biodiesel are made from identical WVO.

                      "Conc sulphuric acid burns organic compounds." was Neutral's explanation for the darker colour when using acid.

                      Comment


                      • #12
                        Re: bio diesel wash

                        Hi Tilly,
                        Thank you for your reply. It doesn't suprise me that when you did your test that you found no colour change. Even though your biodiesel isn't initially water washed, I doubt that after being settled for that amount of time that there is little or no soap present for the acid to convert to ffa's. As to the prescence of mono's, without GC analysis it's anyones guess.

                        I do indeed use acetic acid.

                        I did a test a while ago where I 'split' a 200 litre batch 50/50 One half was water washed with no acid and the other half washed with acid water, very diluted. I took some photo's of the finished bio in cubies and the difference is there to see.

                        I posted a thread on our Biopowered Forum which I will link on here with photo's when the biopowered forum is running again (it is down at the moment)
                        smithy
                        Senior Member
                        Last edited by smithy; 28 February 2017, 04:06 AM.

                        Comment


                        • #13
                          Re: bio diesel wash

                          Hi Smithy,
                          In your previous post you had speculated that the change in colour was "simply due to the mono's being left in the mix." I must admit that I was scratching my head over that one because as far as I know Acid and water have no affect on the monoglycerides remaining in the biodiesel after it is water washed.

                          Now you seem to be suggesting the change in colour is due to converting soap back into FFA's.
                          I wonder what colour FFA's are?

                          Comment


                          • #14
                            Re: bio diesel wash

                            The reason I mention mono's is that when I have used acid I sometimes have soap tested between each wash and haven't added acid water (probably 15mls glacial acetic 1n 10 litres of tap water) until the soap level is less than 100ppm and still the bio ends up slightly darker.

                            Comment


                            • #15
                              Re: bio diesel wash

                              The brown color resulting from concentrated sulfuric acid contacting biodiesel in the Fischer Esterification is due to the organic chemistry reaction called electrophilic addition. Electrophile means electron loving. Sulfuric acid is two hydrogens bonded to four oxygens plus a sulfur central atom. The hydrogens have I believe single bonds to a single oxygen atom. The molecule turns into a charged ion easily. The hydrogen one or both of them detach, break their bond with oxygen, so a plus charged proton an ion without an electron on it approaches the phi bond, the second bond of a double bond between carbon atoms in the fatty acid chain. Since the positive charge proton has no electron with it, it goes to the electrons of the second bond between carbon atoms. The positive proton can bond with two of the electrons that make the phi bond between a double bond in the fatty acid chain. So the proton forms a single bond with one of the two carbon atoms that had the double bond between two carbon atoms. I've forgotten which carbon the positive charge is set up on when this occurs, which side of the carbon atom that just formed a bond with the proton making a new hydrogen attached to one of the carbons that had a double bond. You might look it up on the internet if you care to understand why it happens. So , a positive charge forms on a carbon adjacent to the carbon that just had a proton add to it forming a single bond. One of the two carbon atoms in the double bond is deficient in electrons, giving it a positive charge, so when a sulfuric acid molecule loses a hydrogen, ionizes, it has a negative charge. The negatively charged sulfuric acid, one hydrogen, four oxygen, and one sulfur atom , attacks the positively charged carbon atom in the fatty acid chain and forms a bond with the carbon chain of the fatty acid. So you get sulfuric acid bonded to the fatty acid carbon chain. Sulfur involved in being bonded to carbon can produce a brown colored material that smells bad, it stinks. The brown material is very polar, a big charge difference , a big variance in electron density from one spot in the molecule when compared to another spot in the molecule, so I expect Magnesol, magnesium silicate would adhere to the brown crud (brown stuff) and then filter the Magnesol out. If I'm right about this issue then Magnesol would lower sulfur content of biodiesel made in part with the Fischer Esterification using strong concentrated sulfuric acid (minberal acid).
                              WesleyB
                              Donating Member
                              Last edited by WesleyB; 1 March 2017, 05:19 AM. Reason: left a word out

                              Comment

                              Working...
                              X