Aerosol - A dispersion of a liquid or solid in a gas.

Acid esterification - A common approach for removing free fatty acids from the feedstock is via acid catalyzed esterification in the presence of methanol. This converts the free fatty acids to methyl esters (e.g., biodiesel). Acid esterification equipment requires the use of stainless steel equipment due to the corrosive nature of the process.

Anhydrous- "Without water" - transesterification of biodiesel must be an anhydrous process or funny things hapen. 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, containing methyl or ethyl esters made from fresh or waste vegetable oils (triglycerides).

Biodiesel Recipe - Like a recipe for making a cake, a biodiesel recipe specifies the ingredients required, and the steps for combining and processing them to make biodiesel fuel. The most common recipe uses waste vegetable oil (WVO), methanol (wood alcohol), and sodium hydroxide (caustic soda) to produce biodiesel and glycerine. The most common steps are: (1) cleaning/heating WVO, (2) titration of WVO sample, (3) combining methanol and sodium hydroxide in exact amounts, (4) combining (3) with (1) and mixing at 50c, (5) waiting for separation, (6) separating the biodiesel from the wastes, (7) washing and drying the biodiesel, (8) disposing of the wastes.

Bubble Wash - A method of final washing of biodiesel through air agitiation. Biodiesel floats above a quantity of water. Bubbles from an aquarium air pump and air stone are injected 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 soluable 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.

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.

Canola - a trademarked hybrid of rape initially bred in Canada. Rape Seed Oil was produced in the 19th century as a source of a lubricant for steam engines, and the oil has a bitter taste due to high levels of acids. Canola has been bred to reduce the amount of acid, yielding a palatable oil. Canola = CANadian Oil Low Acid. (unverified)

Colloidal size - .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.

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 - to form an emulsion...as in mixing oil and vinegar in a blender. voila: salad dressing.

Emulsion - a usually unstable dispersion of two liquids which do not normally mix (they are immiscible). Emulsions can be formed either by mechanical aggitation, or by chemical processes. Unstable emulstions will separate over time or temperature, stable emulsions will not separate.

Esters - a product of the reaction of acids (usually organic) and alcohols. ch3cooch3 - methyl acetate is the simplest ester. one of the oxygens has a double bond. you can replace the 'ch3' part on the right with more ch2 chunks, and you get other methyl esters, including biodiesel's methyl stearate. many of the esters smell good.

Ethanol - ethyl alcohol - c2h5oh - ch3-ch2-oh = the intoxicating stuff in beer, and a good solvent. "beer is proof that god loves us and wants us to be happy" :: ben franklin.

Foam - A dispersion of a gas in a liquid or solid.

Glycerine - A 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.

Kerosene - A thin oil distilled from petroleum or shale oil, used as a fuel for heating and cooking, in lamps, and as a denaturant for alcohol, diesel or WVO.

KOH - Potassium Hydroxide. used to make biodiesel from ethanol. a metallic base.

Lye - a quaint american term for NaOH - Sodium Hydroxide

Methanol - methyl alcohol - ch3oh - the stuff they burn in top fuel eliminator dragsters and toy airplane engines. a good solvent and a component of gasahol. lethal if consumed. In biodiesel production, methanol is used to make methoxide. Methanol absorbs water from the air, so keep the container closed tightly, and purchase methanol which is known to be dry (anhydrous) or is 99.9% pure. solvent or paint grade methanol may not be anhydrous, and you will run the risk of making soap.

Methoxide - a.k.a. sodium methoxide a.k.a. 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. rinse with water, seek medical attention immediately. also highly explosive. making sodium methoxide is the most dangerous step you deal with when making biodiesel. for this reason, you should carefully consider the safety of the design of your equipment and workspace before using, and you should wear protective clothing and a respirator when handling. you should also make only what you intend to use immediately.

NaOH - Lye, Sodium Hydroxide, Caustic Soda, a.k.a. 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. For biodiesel, this is one of the main reactants. Make sure you are purchasing "anhydrous sodium hydroxide." Anhydrous means it's dry, and water turns biodiesel into soap. Store this product in an airtight container to prevent NaOH from absorbing water and CO2 from the air. Store separately.

Optimal PH for Biodiesel - 7 (seven)...neutral, same as distilled water (and most tap water).

pH - (mirriam - webster) a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution; also : the condition represented by a pH number.

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.

Rape - Rape Seed - Rape Seed Oil - a.k.a. Cole seed. A member of the Mustard family. Any of a number of crops grown for oil from the seeds. Canola is a member of this family. Another early term for this oil is Colza. Makes good biodiesel.

Saponification - The reaction of an ester with a metallic base and water. The making of soap. This happens sometimes when you use too much lye in a biodiesel reaction... No worries - you can re-react the resulting top layer of unreacted liquid, and if you wish you can turn the semi-solid bottom layer into soap by adding more lye (make sure you know how much to add...).

Soy - Soy Oil, a vegetable oil pressed from soy beans.

Soy Diesel - a media term for biodiesel which accentuates the renewable nature of biodiesel. Popular in soy producing regions.

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 petro diesel or biodiesel is often used during starting and stopping engine, and an electric valve allows transfer to the SVO tank.

Titration - as 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. by knowing how much base neutralizes an amount of WVO, we discern how much base to add to the entire batch.

Transesterfication - Process of creating esters from vegetable oil (a triglyceride), and sodium methoxide. Products are Glycerine, Methyl Stearate, Methyl Oleate, Methyl Linoleate. (assuming soy veg oil)

Viscosity - the "thickness" or "thinness" of a fluid. methanol is "thin", having a low viscosity, while vegetatable oil is "thick" having a high viscosity. (mirriam - webster) the ratio of the tangential frictional force per unit area to the velocity gradient perpendicular to the direction of flow of a liquid.

WVO - Waste Vegetable Oil - WVO is the usual starting product for the making of biodiesel.


                                
How much methanol should you use?

Oils and fats	Total molecular weight	Density	Density @ 50ºC	Volume oil (ml)	Volume methanol (ml)	Stoich. ratio methanol : oil %
Tallow	858.54	0.895	0.88	981.18	121.52	12.4
Lard	863.73	0.92*	0.9*	959.7*	121.52	12.7
Butter	797.64	0.91	0.89	896.73	121.52	13.6
Coconut	674.51	0.926	0.91	744.57	121.52	16.3
Palm kernel	704	0.912	0.89	789.33	121.52	15.4
Palm	847.28	0.923	0.9	938.29	121.52	13
Safflower	879.1	0.927	0.91	966.44	121.52	12.6
Peanut	885.02	0.919	0.9	984.45	121.52	12.3
Cottonseed	867.38	0.918	0.9	963.76	121.52	12.6
Maize	872.81	0.923	0.9	966.57	121.52	12.6
Olive	870.65	0.923	0.9	964.17	121.52	12.6
Sunflower	877.22	0.925	0.91	969.3	121.52	12.5
Soy	882.82	0.925	0.91	975.5	121.52	12.5
Rapeseed/Canola	959.04	0.914	0.89	1072.75	121.52	11.3
Mustard	925.43	0.916	0.9	1032.85	121.52	11.8
Cod liver oil	908.81	0.929	0.91	1000.34	121.52	12.1
Linseed	872.4	0.934	0.91	954.48	121.52	12.7
Tung	873.68	0.944	0.92	945.54	121.52	12.9
* Approximate

Excess

Further arguments rage over how much excess is needed, with figures quoted claiming that this much will achieve 98% conversion but that much only 95% or less.

Good process completion depends on several different factors, not just the excess methanol: the type of oil, its condition, the catalyst, the type, size and shape of the processor, the type and duration of agitation, the temperature of the process -- and the arguments don't make much sense anyway if the stoichiometric ratio is wrong in the first place.

However, excess is usually between 60% and 100% of the stoichiometric amount. So if the stoichiometric ratio of the oil you're using is 12.5%, that is 125 ml of methanol per litre of oil, the excess would range between 75 ml and 125 ml, for a total amount of methanol of 200-250 ml per litre of oil.

Oils with higher stoichiometric ratios seem to need higher excesses of methanol. So, for fresh (new, uncooked) soy or canola, you can try 60%, though 67% or more would be better. For palm kernel or coconut, try higher excesses.

For used oil, WVO -- waste vegetable oil, as it's called, though it often contains animal fats from the cooking, use 60% minimum excess. For heavily used oils with high titration levels, use higher excesses, up to 100%.

If you don't know what kind of oil your WVO is and you're having difficulties with it, try using 25% methanol -- 250 ml methanol to 1 litre of oil. If you've taken care with the titration, used accurate measurements and followed the instructions carefully, you should get a good, clean "split", with esters on top and the glycerine and free fatty acids cleanly separated at the bottom. If you have trouble washing it, with a lot of frothing, that could be because the process didn't go far enough and unconverted material is forming emulsions -- try using more methanol next time. If everything works well, try using less methanol. You'll soon figure out what's best for you.

Most people use 20% or 22% methanol by volume, 200-220 ml methanol to 1 litre of oil. This usually gives good results. Difficulties with washing and the quality checks are more often due to errors with titration and inaccurate measurements or to poor processing than to not enough methanol.

In Bioforce system only small amount of excess methanol is required in general it is only about 2%-5% excess.

OIL REFINERY GLOSSARY

Antioxidant 
A substance that slows or interferes with the reaction of a fat or oil with oxygen.
The addition of antioxidants to fats or foods containing them retard rancidity and increases stability and shelf life.

Bleaching 
The purification process to remove color bodies and residual impurities from oils and fats during refining, generally through the use of an adsorbent clay material.

Biotechnology 
The use of living organisms or other biological systems to develop food, drugs 
and other products.

Catalyst 
A material which accelerates a chemical reaction without becoming part of the reaction products.

Cholesterol 
A fat-soluble sterol found primarily in animal cells important in physiological processes.

Chlorophyll 
A natural, green coloring agent vital to a plant’s photosynthesis process which is removed from vegetable oils through bleaching and refining processes.

Cis 
The term applied to a geometric isomer of an unsaturated fatty acid where the hydrogen atoms attached to the carbon atoms comprising the double bond are on the same side of the carbon chain.

Cold Press 
Extraction process whereby oil bearing materials are mechanically pressed without any heat treatment.

Confectionery fat 
A broad range of fats with steep melting profiles used in the formulation of sweet goods such as candy bars, bakery product coatings, cream centers, and granola bars.

Conjugated fatty acids 
Polyunsaturated fatty acids exhibiting two or more of unsaturated carbons atoms not separated by a saturated carbon atom.

Crude oil 
The oil product obtained from the initial extraction, either mechanical and/or solvent based, of an animal or vegetable source.

Degumming 
The process that removes phosphatide compounds from crude oils prior to refining.

Deodorization 
The process of subjecting oil to high temperatures in the presence of a vacuum to remove trace volatile components that may affect flavor, odor and color. It is generally the last step in the refining process.

Dewax 
Removal of natural waxes from edible oils

Diglyceride The glycerol ester containing two fatty acids.

Emulsifier Compounds having the ability to reduce surface tension at the interface.

Emulsifiers are often used to disperse immiscible liquids such as water and oil or fats in products such as mayonnaise, ice cream and salad dressings.

Ester 
The condensation reaction product of an alcohol and an acid.

Esterification 
The reaction of chemically combining an alcohol and an acid resulting in the formation of an ester.

Expeller pressed 
Mechanically separated oil from oilseed meal.

Fat 
Esters of fatty acids and glycerol which are normally solid at room temperature.

Fatty Acid 
A long chain carboxylic acid, which generally contains an unbranched chain with even number of carbons.

Fully refined oil 
The term used to describe an oil which has been subjected to extensive processing methods to remove: (1) free fatty acids and other impurities (refining), (2) naturally occurring color bodies such as chlorophyll (bleaching), and (3) volatile trace components which may affect color, flavor and odor (deodorizing).

Fire point 
The temperature at which an oil sample, when heated under prescribed conditions, will ignite for a period of at least five seconds (spontaneous combustion).

Flash point 
The temperature at which an oil sample, when heated under prescribed conditions, will flash when a flame is passed over the surface of the oil but not maintain ignition.

Fractionation 
The process of separating fats and oils by differences in melt points, solubility or volatility.

Free fatty acids 
The fatty acids in a fat which are not chemically bound to glycerol molecules.

Fully hydrogenated 
The term describing a fat which has been hydrogenated to the completion or near completion of saturation, which results in significant chemical and physical changes. Changes include, transformation of liquids to solids at room temperature, and increase in melt point, solid content, saturation, and stability. As conversion to saturation is complete, trans isomers are not formed. Products containing hydrogenated fats include “heavy duty” frying fats for restaurant use, solid shortenings, confectionary coatings, peanut butter stabilizer, and solid margarines.

Geometric isomer 
A type of isomer distinguished because of its structural location of certain elements.

Glycerol 
A three-carbon chain alcohol molecule with chemical formula, C3H803. Also known as glycerin. When combined with one, two, or three fatty acids forms a mono, di, or triglyceride, respectively.

Hydrogenated 
A required term identified in the Food & Drug Administration’s labeling regulations (21 CFR 101.4(b) 14) relating to hydrogenated fats and oils. The term indicates a fat or oil is completely hydrogenated. See “fully hydrogenated.”

Hydrogenation 
The reaction of adding hydrogen atoms to the carbon-to-carbon double bonds in unsaturated fatty acids. This process results in increased melt points, higher solid fat content, and longer shelf life without rancidity in fat-containing products.

Hydrolysis 
The splitting reaction of fat with water to form glycerol and free fatty acids.

Interesterification 
The reaction of rearranging the fatty acids in triglyceride molecules. It is used principally in confectionery fats, table spreads, shortenings, and margarines to maintain solid fat content at ambient temperatures while lowering the melting point.

Iodine value 
An expression of the degree of unsaturation of a fat. It is determined by measuring the amount of iodine which reacts with a natural or processed fat under prescribed conditions.

Isomer 
Compounds containing the same elements in the same proportions which can exist in more than one structural form; e.g. geometric, positional or cyclic.

Lauric oils 
Oils containing 40-50% lauric acid (C-12) in combination with other relatively low molecular weight fatty acids. Coconut and palm kernel oils are principal examples.

Lecithin 
A mixture of naturally occurring phosphatides which has emulsifying, wetting and antioxidant properties, a principal source of which is crude soybean oil.

Lipid 
A broad spectrum of fat and fat-like compounds including mono-, di- and triglycerides, sterols, phosphatides and fatty acids.

Lipoprotein 
Any of the class of proteins that contain a lipid combined with a simple protein. Medium chain triglyceride (MCT)

Triglycerides 
containing fatty acid chains of 6-10 carbon atoms.

Mixed triglyceride 
A triglyceride containing two or three kinds of fatty acids.

Monoglyceride 
The glycerol ester containing only one esterified fatty acid.

Monounsaturated fatty acid
A fatty acid containing only one carbon – carbon double bond.

Non-conjugated fatty acids
Polyunsaturated fatty acids exhibiting two or more double bonds separated by at least one saturated carbon atom. Oil Esters of fatty acids and glycerol which normally are liquid at room temperature.

Oleate 
An ester or salt of oleic acid.

Olein 
The liquid fraction when an oil or fat is fractionated.

Olestra 
A sucrose fatty acid polyester used as a substitute for dietary fat which is not digested or absorbed by the body.

Oxidation 
The reaction of oxygen with a fat or oil resulting in the development of rancidity. Partially hydrogenated A required term identified in the Food & Drug Administration’s labeling regulations (21 CFR 101.4(b) 14) relating to hydrogenated fats and oils. Partially hydrogenated oils are limited in degree of hydrogenation, as compared to completely hydrogenated oils. Light to moderate hydrogenation results in limited increases in melting properties, while improving stability.

Peroxides 
The primary compounds formed from the oxidation of unsaturated fatty acids, which may react further to form the compounds that can cause rancidity.

Phosphatide 
The chemical combination of an alcohol (typically glycerol) with phosphoric acid and a nitrogen compound; synonymous with phospholipid.

Plasticize 
The process of creating a solid crystal structure in a fat or oil product resulting in a smooth appearance and firm consistency.

Polymerize 
The bonding of similar molecules into long chains or branched structures.

Polymorphism 
The property of a fat molecule to exist in multiple crystalline structures; mainly identified as alpha, beta and beta prime.

Polyunsaturated fatty acid 
A fatty acid containing more than one carbon-carbon double bonds.

Positional isomer 
An isomer distinguished by the location of a double bond.

Refining 
The process of removing impurities from crude oil by way of treatment with alkali solution (chemical) or steam stripping (physical).

Saponification 
The chemical reaction between a fat or oil and an alkaline compound creating glycerol and soap.

Saturated fatty acid 
A fatty acid containing no carbon-carbon double bonds.

Shortening 
A fat product that incorporates tenderness in the food (e.g., bakery products) in which it is used. It may carry other additives such as flavorings, colors, emulsifiers and preservatives.

Simple triglyceride 
A triglyceride comprised of three identical fatty acids.

Soap 
The salt of fatty acids.

Soap stock 
The aqueous byproduct from the chemical refining process that is comprised of soap, hydrated gums, water, oil and other impurities.

Smoke Point 
The temperature at which an oil sample, when heated under prescribed conditions, will form a thin continuous stream of smoke.

Stearine 
The solid product when an oil or fat is fractionated.

Stearic acid 
A saturated 18-carbon free fatty acid.

Sterol 
A compound made up of the sterol nucleus, an 8-10-carbon side chain and an alcohol group.

Tocopherol 
A naturally occurring antioxidant found in many vegetable oils.

Trans 
The term used to describe a geometric isomer of an unsaturated fatty acid where hydrogens attached to the carbons comprising the double bond are on opposite sides of the carbon chain.

Triglyceride 
The chemical combination product of glycerol and three fatty acids. Alternately known as triacylglycerol.

Unsaturated fatty acid 
A fatty acid containing one or more carbon-carbon double bonds.

Wax 
Hydrophobic material made of hydrocarbon, long chain fatty acids, long chain alcohols, or wax ester (ester of a long chain alcohol and fatty acid).

Winterize The process of separating the solid fraction (stearine) from the liquid fraction (olein) of an oil by cooling and filtering.