Glossary of terms
Anhydrous
- "Without water" - transesterification of Biodiesel must be an anhydrous
process or funny things happen. Water in the vegetable oil causes either no
reaction or cloudy Biodiesel, and water in lye or methanol renders it less
useful or even useless, depending on how much water is present. Either let
your vegetable oil settle for 2-3 days before using and drain the water off
the bottom, or heat the oil and boil off the water. Store lye and methanol
in separate, air-tight containers.
Biodiesel - An environmentally safe, low polluting fuel for
most diesel internal combustion and turbine engines. Can be mixed with
petroleum diesel fuel and stored anywhere petroleum is. Made from fresh or waste
vegetable oils (triglycerides) that are a renewable energy source. Both
commercially and privately made around the world. Relatively safe and easy
to process when conscientiously approached. Benefits are substantially
reduced engine emissions, even with as small a blend as 20% Biodiesel with 80%petroleum
diesel.
Blending vegetable oils
with petro diesel -
A number of methods exist
to blend vegetable oil with petro diesel and create a low viscosity fuel oil
with similar properties to diesel. One such method results in a product
called
AGTANE and
this is the result of mixing recycled Yellow Grease with hydrogen in the
presence of steam, later blended with heavy diesel oil.
Bubble Wash
- A method of final washing of Biodiesel through air agitation. Biodiesel
floats above a quantity of water. Bubbles from an aquarium air pump and air
stone can be sued to injected air into the water causing the bubbles to rise. At the water/Biodiesel
interface, the air bubbles carry water up through the Biodiesel by surface
tension. Simple diffusion causes water soluble impurities in the Biodiesel
to be extracted into the water. As the bubble reaches the surface and
breaks, the water is freed and percolates back down through the Biodiesel
again.
Cetane Number
- Measure of fuel
ignition characteristics. Like the octane number used for gasoline, the
higher the value, the better the fuel performance. A higher cetane number
correlates with improved combustion, improved cold starting, reduced noise,
white smoke, HC, CO and particulate emissions particularly during early
warm-up phase. The EPA uses this parameter as a measure of aromatic content
in fuel. Typical Cetane numbers around the world are as follows: Europe: 43
- 57, average 50 U.S. lower, minimum 40, average 43.
Cloud point
- The temperature at which the first wax crystals appear and a standardized
ASTM test protocol is used to determine this temperature.
Colloid
-
A stable system of small particles dispersed in something else. A
multi-phase system in which one dimension of a dispersed phase is of
colloidal size. Colloids are the liquid and solid forms of aerosols, foams,
emulsions, and suspensions within the colloidal size class. Milk and smoke
are both colloids. Colloidal size is typically .001 micron to 1 micron in
any dimension. Dispersions where the particle size is in this range are
referred to as colloidal aerosols, colloidal emulsions, colloidal foams, or
colloidal suspensions.
Dispersion
- A stable or unstable system of fine particles, larger than colloidal size,
evenly distributed in a medium.
Emulsification
- to emulsify or to form an emulsion.
Emulsion
- A suspension of small drops of 1 liquid in a 2nd with which the 1st will
not mix. Emulsions can be formed either by mechanical agitation, or by
chemical processes. Unstable emulsions will separate with time or
temperature. Stable emulsions will not separate.
Esters
-
Any of a large group of organic compounds formed when an acid and alcohol is
mixed. CH3COOCH3 (Methyl acetate) is the simplest ester. Biodiesel contains
methyl stearate.
Ethanol -
Ethyl alcohol - C2H5OH - CH3-CH2-OH. A good solvent and the trade name of an
alcohol based gasoline replacement.
Glycerin
- The major byproduct of Biodiesel production.
CH2-OH--CH-OH--CH2-OH - Each of the
"OH" sites is one of the three places where an ester is broken off of the triglyeride molecule (veg. oil).
Gum Number - The measure of the tendency of a fuel to form gums via oxidation.
Iodine #
- Standard natural oil assay to measure the degree of unsaturation (or the
number of double bonds present) in vegetable oils and fats.
KOH
-
Potassium Hydroxide, which is used to make Biodiesel from ethanol, a metalic
base (acid)
Methanol
- Methyl Alcohol - CH3OH - Good solvent and a component of gasohol. Burned
in top fuel eliminator dragsters and toy airplane engines. Lethal if
consumed. Used to make methoxide in Biodiesel production. Methanol absorbs
water from the air and only methanol which is known to be dry (anhydrous) or is 99.9% pure
should be used in Biodiesel production.
Methoxide
- Sodium Methoxide - Sodium Methylate - (CH3-O+ Na-). An organic salt, in
pure form a white powder. In biodiesel production, "methoxide" is a product
of mixing methanol and sodium hydroxide, yielding a solution of sodium
methoxide in methanol, and a significant amount of heat. Sodium Methoxide in
methanol is a liquid that kills nerve cells before you can feel the pain.
If you ever come into contact with it, rinse with water and seek medical attention immediately,
it is also highly
explosive and making the sodium methoxide mix is the most dangerous step when making
Biodiesel.
Micro Emulsion
- Arthur Schwab and Everett
Pryde filed a patent # 4,451,267 in 1984 that outlined quite a promising
vegetable oil refining method. This method claimed a Biodiesel like fuel
could be made from refining vegetable oil with micro-emulsions. The fuel is
a micro-emulsion in which water and alcohol are dispersed in the oil by
means of a trialkylamine in either a detergent or detergent-less surfactant
system.
NaOH
- Sodium Hydroxide, lye, caustic soda (Red Devil Drain
Cleaner). A metallic base. Strongly alkaline and extremely corrosive. Mixing
with fluids usually causes heat, and can create enough heat to ignite
flammables (such as methanol), so add slowly. "anhydrous sodium hydroxide"
is one of the main reactants in the manufacturing process. Anhydrous means
it's dry, and water turns biodiesel into soap, so this product needs to be
stored in an
airtight container to prevent NaOH from absorbing water and CO2 from the
air.
Pyrolysis -
The Pyrolysis cracking
vegetable oil method uses heat and pressure to change the nature of vegetable oil. The Pyrolysis refining process does produce reduced viscosity oil and an
acceptable diesel fuel replacement.
Pour point
- The temperature at which the fuel is no longer pumpable.
pH
- A
measure of acidity and alkalinity of a solution on a scale with 7
representing neutrality. Lower numbers indicate increasing acidity, and
higher numbers increasing alkalinity. Each unit of change represents a
tenfold change in acidity or alkalinity. pH is mathematically found by
taking the negative logarithm of the effective hydrogen-ion concentration or
hydrogen-ion activity. The units are gram equivalents per liter of the
solution. The optimal pH for BioDiesel is 7 or neutral as distilled
water and most tap water.
Rape Seed
- Rape Seed Oil - Food grade oil produced from rape seed is called Canola
in North America. Canola is a name taken from "Canada oil" due to the fact that much of
the development of the oil was performed in Canada. Another early term for
this oil is Colza and is a good feedstock for Biodiesel.
Saponification
- The reaction of an ester with a metallic base and water,
i.e. the making of soap.
Soy
- Soy
Oil, a vegetable oil pressed from soy beans.
Soy Diesel
- A marketing term for Biodiesel made from Soy Beans,
and is used to highlight the renewable nature of Biodiesel.
SVO -
Straight Vegetable Oil. Burns well in many diesels, but does not start
engine, and will coke in the injectors as a hot engine cools. A separate
tank of petroleum diesel or Biodiesel is often used during starting and
stopping engine, and an electric valve allows transfer to the SVO tank.
Thermal depolymerization
- A company called
Changing the
World has come up with a process called Thermal depolymerization to
convert carbon based feed stocks into oil and other useful materials. This
process super-hydrates material, so temperatures and pressures need only be
modest, because water helps to convey heat into the feedstock.
Titration
- Applied to BioDiesel, titration is the act of determining the acidity of a
sample of WVO by the dropwise addition of a known base to the sample while
testing with pH paper for the desired neutral pH=7 reading. The amount of
base needed to neutralize an amount of WVO determines how much base to add
to the entire batch.
Transesterfication
- Process of creating esters from vegetable oil (a triglyceride), and sodium
methoxide. Products are Glycerin, Methyl Stearate, Methyl Oleate, Methyl
Linoleate (assuming soy oil is used).
Viscosity
- Is a measure of how a liquid is resistant to flow; "thickness" or
"thinness". Methanol has a low viscosity, while vegetable oil has a high
viscosity.
WVO
-
Waste Vegetable Oil.
