Page 3 of 5 FirstFirst 12345 LastLast
Results 21 to 30 of 41

Thread: Bio Sludge in fuel tank

  1. #21
    Join Date
    Apr 2011
    Location
    Lismore NSW
    Posts
    309

    Re: Bio Sludge in fuel tank

    Quote Originally Posted by smithw View Post
    Ive have bee thinking of adding a bit more water but never tried it
    I have added up to 10% of HOT water with no issues. But it has to be HOT and the mix has to be still hot too!!! I have a gas hot water system outside the shed and the water is at about 50 degrees Celcius. Makes the bubbling very very easy. Since I have set up my 1000l processor I can only fit 7% in which is good enough to do the job.

    You have to make sure you leave the glycerine in! Mix it for a minute and let it settle.
    If you drain the glycerine before, you get a big mess!
    Done that, been there :-)
    1990 Toyota Hilux LN106 with ATG 2 tank system (sold after running 150.000 ks on mainly WVO)
    1993 Toyota 75 Series with 1 HZ engine both 75l factory tanks and a custom 170l under tray tank.
    200.000km 80% on bio 10% on WVO 10% on dino,

    "him who never made a mistake, made no discovery either"


  2. #22
    Join Date
    Dec 2016
    Location
    York UK
    Posts
    27

    Re: Bio Sludge in fuel tank

    I think as long as our methods give us high quality biodiesel then within reason our slightly different ways of processing arn't too significant.

    Just for the record here is a brief description of my method;

    Oil is settled for at least 4 weeks but not dried (water @ 850ppm level)

    Glycerol pre-treated in a separate tank powered by an M67 (military immersion) so nearly free heat. Water after this process @ 350ppm

    Transferred to a conical feed tank that feeds the processor, settled for another 3 weeks.

    !st reaction uses 12.5% methanol and is done at ambient temp in Summer reaching @ 30degs. I use a mixture of K and Na and ASM in warmer weather which produces far less water in the methoxide.

    Left overnight so most of the glycerol can be removed.

    Dropout with a 10/90 test after S1 is between 0.3 and 1.0 mls

    S2 uses 15% methanol and a process temp of 40degs for 1 hour.

    5 litres of water added after 1 hour and mixed for 10 mins, then bubbled overnight, settled at least a few hours.

    Transferred to wash tank, washed @ 5 times at 30 degs with 8 litres of water per wash. Left overnight.

    Dried with an IMB Turbo dryer (dries the incoming air with silica gel) Water content<300ppm after just 1 hour drying at 60 degs. (I have left the dryer on as an expt once for 13 hours and got a result of 50ppm water ) it is hard to get bio down to this level and totally inefficient but it was just to see.

    When the bio cools then centrifuge and filter.

  3. #23
    Join Date
    Mar 2013
    Location
    Sydney, NSW
    Posts
    175

    Re: Bio Sludge in fuel tank

    Evening all,

    I've been experimenting on the 'tarry stuff' (TS). I had to decant my latest batch into cubies tonight and had several that were just too contaminated with TS to fill, so I tried some different solvents on it. Here's what I found:

    • Nylon bottle brush - works a treat at dislodging the TS. The first cubie I did it worked very well - stuck to the brush and left the cubie clean. Second one not so well. I think the nylon got coated with bio and even after cleaning it would dislodge the TS, but it would fall off and re-stick to the cubie. The TS noticeably clumps together when disturbed.
    • Repco degreaser from an aerosol can - little or no passive impact on TS.
    • Repco brake cleaner in an aerosol can - little or no passive impact on TS.
    • Kerosene - little or no passive impact on TS.
    • Acetone - seemingly little impact, but I compromised the experiment by using the second drum I scrubbed with he brush. I don't think the acetone did much though as it wouldn't dissolve or shift the clumps of TS left behind.
    • Mineral turpentine - success! Dissolved TS really well.
    • Methanol - success again! Maybe even better than turps, which is good because it is cheaper and we have plenty of it at our disposal.
    • Methylated spirits - TBA. I will try this on one of the other drums that failed on other solvents.


    So a good result with the methanol I think.

    Tony - do you recall someone from a Sydney university posting on the forum some years ago? I thought he was doing a PhD on biofuels for something? I'd like to get hold of him and take a sample of TS to look at under a microscope to confirm whether it is biological or other.
    3DB
    1995 Isuzu Rodeo 2.8TD 4X4 - 45,000km & 3.5 years on B100
    1976 Mercedes 300D Turbo 'The Coal Grenade' - 3,000 km on B100, 280,000 Km on the clock, but probably more like 1,280,000
    (@thirddegreeburns on Instagram)

  4. #24
    Join Date
    Sep 2005
    Location
    WA
    Posts
    4,012

    Re: Bio Sludge in fuel tank

    3DB, I cannot recall any details but have a similar recollection. Perhaps you could search for "Sydney Uni" to narrow the field.
    I will try some methanol in my washed biodiesel to try it out. I don't know if my biodiesel has this issue (I do get some drop out in my 20L HDPE drums, but I have not examined it. My wife's car suffered from my settled biodiesel having gunked up her IP. They didn't find anything that shifted it, so needed to manually remove it from the IP workings.
    Should I try 200mL MeOH per 20L of bio. (ie. 1% solution).
    Perhaps, if I have an existing build up, I should shock it with a 10% solution for one tank of fuel before reverting to the 1% solution
    As you say, it is cheap and available.

    Thanks for your testing.
    Tony
    Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

    Current Vehicles on oil based fuels:
    '85 Mercedes Benz W123 300CD Turbodiesel
    '98 Mercedes W202 C250 Turbodiesel (my car)
    '99 Mercedes W202 C250 Turbodiesel (my darling Wife's car) [sold]


    Searching the Biofuels Forum using Google

    Adding images and/or documents to your posts


  5. #25
    Join Date
    Dec 2016
    Location
    York UK
    Posts
    27

    Re: Bio Sludge in fuel tank

    I'm wondering if 'gum' in the oil could be anything to do with this. This takes a bit of reading but may explain a little more.

    In the case studied in this paper, a small scale (1 million gallon per year capacity) soybean, sunflower, and canola crushing facility wanted to improve the quality of their finished product through degumming. Their product market was mainly to biodiesel producers which helped define an acceptable level of gums and metals removal, and their desired capital investment was relatively small. After testing a variety of methods with crude soybean oil which could be applied to their scale, the most cost effective method for achieving oils for the biodiesel market was determined to be simple water degumming. Crude Canola, however, may require more testing to ensure that water degumming achieves low enough levels of metals for the biodiesel industry.

    Background
    Gums in vegetable oils refer to a variety of compounds which are generally removed during the refining process, including hydratable and non-hydratable phosphatides, lecithin, and other impurities. Gums vary significantly between oil types, and some oils will naturally drop gums out of solution after pressing. However, significant amounts of gums can remain, specifically the non-hydratable type which are soluble in the oily layer

    1. This material is removed during the chemical refining process which usually includes an acid addition step (phosphoric, oxalic, or citric acids) and an alkali addition step (typically NaOH).

    2. For biodiesel producers, gums are a concern for two reasons: metals contamination in the final product (P and Ca specifically) and yield loss. Previous work by Van Gerpen and Dvorak indicates 50ppm phosphorous is the upper limit before yield loss is noticeable in soybean oil

    3. This work also showed that phosphorous contamination in the finished fuel was not an issue, probably because alkali was used during the transesterification step. However, little previous work has evaluated degumming methods which achieve less than 50ppm phosphorous for various oilseeds using mechanical pressing. While a multitude of information exists on the chemical refining process for RBD quality oils (edible oils), very little exists describing the minimum degumming required to create a high quality biodiesel feedstock. Identification of this minimum level of refining required and further defining of “biodiesel quality” crude oil will help biodiesel plants understand the product, and give refiners the knowledge of what the industry specifications are for crude oils.

    Materials and Methods
    Three 2.5 gallon samples of soy, Canola, and sunflower oil were taken from the crushing facility from side ports out of the finished product storage tanks. The sample did settle out visible gums during storage in the lab, and were shaken vigorously before use during testing. There were 3 sections of the testing: degumming trials, transesterification trials, and final yield trials. Degumming and transesterification trials effectively screened the methods under various conditions using crude soy only, while the final yield trial was used to obtain more accurate yield data on the best performing method for crude soy, crude Canola and crude sunflower.

    Degumming Trials
    All glassware (100ml graduated cylinder, 100ml mixing container, and centrifuge tubes) was heated to 85C to help maintain the oil temperature once removed from the water bath. The oil to be tested was heated in a hot water bath. Then, the oil was measured to 98 ml in a 100ml graduated cylinder and transferred to the capped 100ml containers. The appropriate amount of acid or water was added to the container and shaken vigorously for 1 minute. After this stage, the method for each samples varies according to the descriptions in Table 2. Crude oil metals levels for phosphorous and calcium are stated in Table 1.

    Yield Trials
    Once the preferred method was determined to be simple water degumming, a larger sample of crude soy was prepared and run through the entire process to acquire more precise yield data (degumming, transesterification, purification). Oil was degummed 100ml at a time (the 100ml centrifuge tube limited the size of each degumming batch) until 500ml of degumming soy was obtained. That 500ml was then transesterified with 2 step addition of methoxide (60% in the first stage for 30 minutes, 40% in the second stage for 1 hour). 24% methanol by volume oil was used, along with .79% KOH by weight oil. The reaction took place at 130F. Once reacted, the biodiesel was drained after settling the sample overnight. The entire sample was then washed 6 times with 200ml of water and dried, then treated with .5% magnesol (magnesium silicate) by weight biodiesel.

    Results and Discussion

    Degumming Trials
    The best performing samples from this trial have minimal loss of triglycerides as approximated by the volume of the gums layer, while also having an acceptable reduction in phosphorous and other metals for biodiesel producers (note – many metals were tested along with calcium and phosphorous. However, these two metals were chosen because they showed greatest variation, and the most difficulty to remove. The other metals did not present a significant removal problem). Finally, a simple and inexpensive method is preferred over a more complicated and expensive one. As evidenced in Table 1, there is variation in gums volume and metals among the samples. Sample 13 had the smallest amount of gums but was also the most complicated process, requiring phosphoric acid addition and water wash, 20 minute slow stir after the reaction, and cooling and reheating. Other good performers in terms of gums volume were the water only samples, numbers 1 and 2. In terms of metals removal, most samples performed adequately for the biodiesel industry. The KOH which is used in the biodiesel industry as a catalyst also helps remove metals, so some amount of phosphorous and calcium remaining in the oil is acceptable. All samples removed sufficient amounts of phosphorous after transesterification to pass the ASTM specification. Calcium was also mostly removed, though some samples, like number 11, fared more poorly in this category.

    The method used for sample 1 was selected as the best performer according to the previously stated criterion of minimal loss, acceptable metals removal, minimal capital cost, and ease of use. The 500ml minibatch results are described in Table 3, along with 100ml degumming trial results using Canola and sunflower. Overall yields from the water degumming was not excellent, at only 87.8%. This may be due to loss of temperature during centrifugation, as the unit was unheated. However, transesterification yields were quite good, at 96.81% from the degummed oil. The final product passed the above critical specifications except cold soak filtration. Cold filtration of the oil may improve this, or further magnesol treatment. The results of the crude Canola and sunflower trials using the best performing method resulted in somewhat surprising results. The Canola, which typically has lower starting levels of phosphorous, resulted in higher metals levels after degumming at 47ppm phosphorous and 46ppm calcium. This is probably due to a higher number of non-hydratable phosphatides which cannot be removed by water only. Sunflower performed on par with the soy sample, at 13ppm phosphorous and 10ppm calcium. Both had a similar sized gums layer, indicating a similar yield to the crude soy.

    Conclusion and Future Work
    After screening a variety of degumming methods, it was determined that a simple water degumming of soybean oil was sufficient to reduce phosphorous, calcium, and other metals low enough for biodiesel producers to use the degummed oil as a feedstock. In addition, biodiesel producers should see high yields at 96.81% using this water degummed oil. While the degumming yield was relatively low at 87%, this could have been as a result of non-heated centrifugation. For Canola, though a full transesterification was not performed, the remaining phosphorous levels after water degumming were sufficiently high to require further testing to determine if metals levels are acceptable for biodiesel producers. Future work should use a heated centrifuge for the degumming step to reevaluate the water degumming yields. In addition, work should be done to determine if the remaining levels of calcium and phosphorous in the degummed Canola are acceptable for ASTM quality biodiesel. Finally, trying a wider range of water addition levels during the degumming step will help optimize the process.

  6. #26
    Join Date
    Mar 2013
    Location
    Sydney, NSW
    Posts
    175

    Re: Bio Sludge in fuel tank

    Smithy - that article is interesting, but a lot to digest. I will work on that.

    Tony - what are the risks of going for a very concentrated solution of either methanol or turps to clean your pump? I have been thinking about the same using my Facet pump to cycle a solution through the IP while the engine is off.

    Aside from the fact that it is highly flammable and toxic to humans, what are the other risks using methanol in this manner? Is it likely to damage hoses or nitrile or Viton seals in the pump in concentrated form? Assuming you flushed it afterwards with biodiesel to ensure no significant quantities of methanol make it into the combustion chamber, would it be ok?

    What about turps? Better or worse?

    And what about a residual maintenance dose added to the fuel on an ongoing basis to keep the TS dissolved. Similar to a 10% addition of ULP? What would be a safe % of methanol to try?

    Is there a risk of dislodging a heap of TS that has been accumulating in the fuel tank over the years and sending a big plug of it towards the IP? Hopefully the sediment trap and filter would catch it?
    3DB
    1995 Isuzu Rodeo 2.8TD 4X4 - 45,000km & 3.5 years on B100
    1976 Mercedes 300D Turbo 'The Coal Grenade' - 3,000 km on B100, 280,000 Km on the clock, but probably more like 1,280,000
    (@thirddegreeburns on Instagram)

  7. #27
    Join Date
    Dec 2007
    Location
    South Australia
    Posts
    1,115

    Re: Bio Sludge in fuel tank

    Seems everyone has come to the conclusion that 'the tarry stuff' comes from biodiesel. Here's another observation that doesn't fit with that theory. I recently drained the diesel tank of a vehicle I am wrecking. About 50 litres of diesel had sat in the tank for more than 3 years. The diesel seems fine and I have in fact used some. However at the bottom of the tank
    there was about 1- 2 litres of brown sticky stuff with the consistency of treackle. It is impervious to water, diesel sits on top of it and I have yet to find a way to clean the tray I caught it in ( will try some turps). The thing is this vehicle never had biodiesel used in it. A Toyota truck I own also had a similar substance in the tank, which I cleaned with caustic now I recall. Don't recommend that for an IP.
    DB I think you are on the wrong track thinking you can add something to the fuel to prevent your tarry stuff by dissolving it. Pumping turps through an IP would be safer than using methanol if you wanted to try it.
    Johnnojack
    4WD Isuzu Jackaroo 3.1 170,000km on WVO,(2017) 2 tank home built system 6 solenoids. Mk. 9 version. Improvements under investigation

  8. #28
    Join Date
    Dec 2007
    Location
    South Australia
    Posts
    1,115

    Re: Bio Sludge in fuel tank

    Wanted to go back a page and check something but knew I would loose what I'd typed so posted anyway.
    So seems that if it's brown and mixes with water it is glycerine. Yes I wash my bio but still get a little of it in my vehicle water trap. If it's brown or black and doesn't mix with water it's algae.?
    Then we have polymerised oil which can build up in the fuel lines, around the fuel filler and in the IP. In my experience nothing you add to the fuel can remove this, it needs physical removal after the IP is disassembled, toothbrush and petrol.
    Prevent it by flushing before shutting down, keep oil in airtight vessels, remove water from collected oil asap. Don't bubble dry excessively, choose if possible oils less prone to drying, ie cottonseed rather than soy. Easier said than done I know.
    Johnnojack
    4WD Isuzu Jackaroo 3.1 170,000km on WVO,(2017) 2 tank home built system 6 solenoids. Mk. 9 version. Improvements under investigation

  9. #29
    Join Date
    Mar 2013
    Location
    Sydney, NSW
    Posts
    175

    Re: Bio Sludge in fuel tank

    Maybe it is algae then? I have a sample and just need a microscope to have a look. I have a mate that studies Antarctic moss for a living - maybe I'll send it to him.
    3DB
    1995 Isuzu Rodeo 2.8TD 4X4 - 45,000km & 3.5 years on B100
    1976 Mercedes 300D Turbo 'The Coal Grenade' - 3,000 km on B100, 280,000 Km on the clock, but probably more like 1,280,000
    (@thirddegreeburns on Instagram)

  10. #30
    Join Date
    Sep 2009
    Location
    Brisbane (North Side)
    Posts
    664

    Re: Bio Sludge in fuel tank

    Quote Originally Posted by 3DB View Post
    Maybe it is algae then? I have a sample and just need a microscope to have a look. I have a mate that studies Antarctic moss for a living - maybe I'll send it to him.
    Food for thought - my cruiser - a 2001 model - suffered from blocked filters for the first few months of bio big time. Had 93,000 on clock at start of bio. Now my bio was aged and crystal clear. Like a bright beer. My car was a big investment for me so I needed the fuel as good as I could make it. I was changing filters every fortnight. That's why I changed to the plastic inline filters so I wasn't spending $40 every time. Filters were blocked with a dark gooey substance. Looking back I think it was crap from the diesel it had run for 4 years or so.

    Didnt have and any issues on my Mazda ute. 2005 model and 150,000km on clock.
    Regards,

    Cade.

    2001 100 series Landcruiser
    190,000 Km and counting on B100, 280,000km total on car.
    Naturally aspirated, Walbro Pusher pump just upstream of tank switch valves, Cav filter with reversed fuel flow direction.
    At 160,000 km Rebuilt pump, Reconditioned head and manifolds, glow plugs. Injectors all good after 160,000 km on B100.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •