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Thread: Terminology

  1. #1
    Join Date
    Oct 2005
    Sunshine Coast, QLD

    Lightbulb Terminology


    BD: (biodiesel) common name for methyl ester fuel converted from VO vegetable oil.

    WVO:waste vegetable oil, SVO straight vegetable oil, VO vegetable oil: clean or used vegetable oil from a fish and chips shop

    Titration: the process of determining the amount of reactant NaOH or KOH needed to convert the VO into biodiesel.

    Glycerides: long chains of fatty acids found in VO (and in blood for that matter). Triglycerides is the more accurate name for these chains of fatty acids. Diglicerides have had one glyceride molecule converted into methyl ester and glycerine. Monoglycerideshave had two glyceride molecules converted into methyl ester and glycerine. So Biodiesel with Diglicerides and Monoglycerides left in it have not been fully converted and will be bad for your engine.

    Methyl ester: technical name for biodiesel

    Glycerin: byproduct formed by breaking a triglyceride molecule into a diglyceride, glycerine and a methyl ester molecules. Glycerine will sink to the bottom. Methyl ester floats hence the seperation.

    Sodium Hydroxide – NaOH – caustic agent. Commercial names, caustic soda, lye, Red Devil lye

    Potassium Hydroxide – KOH – can be used in the place of NaOH except more will be needed. 1.4 times more. Will be more expensive than NaOH but the Glycerine is more user and environmental. Commercial names, caustic potash, potash flake. 80% pure or better is recommended.

    Methanol - liquid reactant used to assist conversion of VO into BD. Boils at 65 degrees centigrade.

    Methanol Recovery - process of recovering excess methanol from Glycerine. You can expect to recover 1 litre of Methanol from 5 litres of Glycerine. Heat to around 65-70 degrees C (never use naked flames) and use a distillation process to reclaim the methanol.

    Hydrometer: scientific instrument used to measure specific gravity. Refers to density of liquid being measured. Water is 1 or 1.000, beer is 1.012-1.016, biodiesel falls between .860 - .900, car battery is between 1.100 and 1.300. Often the hydrometer or specific gravity test will need to be performed at a certain temperature. Usually around 26 degrees centigrade. (Also the test should be performed at sea level but now we are getting techonogical (and yes I know I misspelt that)).

    Sodium Methoxide or Potassium Methoxide: dangerously caustic liquid created by adding sodium hydroxide NaOH or potassium hydroxide KOH with methanol. Caustic means the Ph is higher than 7. This stuff is VERY hungry and assumes you want it to eat you if given the chance.

    Washing: necessary process of adding water, mixing it with the processed BD and allowing to separate. This allows and the water soluble methanol or glycerine to bond with the water and separate from the BD. Because the BD has a SG (specific gravity) of .9 ish and the water has a SG of 1, the water which is heavier will sink and the BD will float. This also roughly explains how cocktails can be layered if done correctly.

    Drying: water will remain suspended in the BD after washing. “…up to 1500 parts per million is allowable by international quality specifications.” Time and circulating warm air past an open container will dry BD. Some people use an air pump to pump air (duh) through the drying tank and other use a water pump or spray mister to circulate and dry the BD.

    *** This thread is for information only. Please post any questions or discussion in a new thread. ***
    Last edited by joe; 28th November 2005 at 10:30 AM.


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