Essential Ingredients:
Only three ingredients are required to make biodiesel: vegetable oil, methanol, and a catalyst. Here’s some information on each one and where best to find them.
Vegetable Oil:
New, virgin vegetable oil is ideal for making biodiesel. You can also use oil left over from restaurant fryers. Waste fryer oil will yield a bit less biodiesel than fresh oil, but you can often find it for free at local restaurants, where they usually pay to dispose of it. Restaurants, food manufacturers (salad dressing companies), and food processors are good sources for finding free or cheap vegetable oil.
You can also buy it new in large quantities from restaurant food suppliers. Oil quality varies depending on how used it is. Older, more heavily cooked oil generally yields more waste in the biodiesel reaction than newer, less-used oil. Canola and soy oil are common, but you may find other types. Most cooking oils will make a suitable biodiesel. Avoid using lard or anything else you can’t pump at room temperature. Waste fryer oil often is available for free, but you may find that competition for the oil — from other biodiesel brewers like yourself — has made it a more valuable commodity.
Methanol:
Methanol (CH3OH) technically is wood alcohol but generally, is derived from fossil fuels. It is required for transesterification, the basis of converting vegetable oil to biodiesel. The amount of methanol required for a successful reaction varies a bit but typically is around 20 percent of the initial volume of oil in the recipe.
This fossil fuel is available in 55-gallon drums from chemical supply companies. You might be able to find smaller quantities at your local car racing track or from a propane gas supplier. For test batches, you can use “dry gas” gasoline additive that contains a high percentage of methanol. Do not use this type with ethanol or other alcohols.
Catalyst/Lye:
Sodium hydroxide is also known as caustic soda or lye, or chemically as NaOH. Potassium hydroxide (KOH) also may be used, but 40 percent more is required in the recipe. The catalyst is required to chemically combine the oil and methanol to form biodiesel. The amount of catalyst varies based on the acidity of the oil.
Oil that has been heated, burned, or used for cooking is more acidic than new oil and will require more catalyst (a base) to neutralize the acid and create the chemical bonds. Liquid catalyst mixes better than dry or crystallized products, Sodium hydroxide generally is more widely available than potassium hydroxide, and the recipes in this chapter are based on using dry sodium hydroxide.
Lye is available in various quantities from chemical supply companies or, for small batches, use drain cleaner that is 100-percent sodium hydroxide, found at hardware and grocery stores. Keep the lye dry in a tightly sealed container.
Equipment Needs:
To make your own biodiesel, you will need equipment for collecting, storing, pumping, mixing, and heating the oil, as well as some basic chemistry equipment, and, of course, appropriate safety gear.
Collection. If you plan to collect waste fryer oil from local restaurants, first talk to the manager and find out how they currently dispose of it. It may go into a garbage bin in 5-gallon buckets, or it may go into 55-gallon drums or 300-gallon receptacles to be picked up by a waste oil hauler. If they dispose of it in 5-gallon jugs, your job is easy. If not, you’ll need to transfer the oil from their storage vessel to a collection tank or buckets on your pickup truck. You can do this with a hand or motorized pump. If the oil normally is collected by a waste hauler, you may need to enter into a contractual agreement.
Pumping. If you’re making only small quantities of biodiesel, an inexpensive, hand-cranked barrel pump works well. For moving a lot of liquid, a 12-volt DC-powered diesel-fuel transfer pump is a good solution. Just attach the power cable to your truck battery and run hoses between the collection vessel on your truck and the restaurant’s oil storage bin. When you’re back home, use the same pump to off-load the oil from your truck into your storage barrels. The same pump can be used to:
• Fill the reactor, or mixing, tank with vegetable oil
• Pump the glycerin out of the bottom of the reactor and into a waste collection container (after mixing and settling)
• Remove wastewater mixture from the tank after washing
Tip: Draw from the Middle
Water and debris settle to the bottom of the waste oil bin. When using a transfer pump to collect waste fryer oil, adjust the length of the intake tube so that it won’t sit on the bottom of the barrel. Debris and scum water accumulate on top of the grease, so also avoid pumping off the top. Water in the oil will ruin a batch of biodiesel.
• Transfer the biodiesel from the reactor to the fuel storage or settling tank
• Pump biodiesel through a filter and into your car’s fuel tank
You can get by with a single pump, but it’s handy to have two. Diesel fuel pumps are not designed for use with water, but you should be able to avoid problems by making sure the last liquid through the pump is oil or biodiesel. This keeps the seals lubricated and prevents rust from forming inside the pump. Good sources for fuel-handling equipment include large auto supply shops and the online retailer Northern Tool and Equipment (see Resources).
Mixing tank. A suitable mixing tank for the home brewer can be made from a 50- to 200-gallon plastic barrel with a conical bottom, which facilitates pumping out the glycerin after processing. Such tanks are available from specialty agricultural supply stores, such as PolyDome. or industrial plastic manufacturers, such as U. S. Plastic Corporation.
Heat. You will need to devise a way to heat the vegetable oil to 120°F for mixing. This can be done in an old water heater, in a barrel with a submersible electric heater, or using another heat source and heat exchanger of your own design. Good places to find heaters suitable for this task include farm stores; agriculture supply outlets; auto parts stores; and online resources, such as Diesel-Therm and Jeffers Pet
Mixing motor. If you’re making only a few gallons of biodiesel, you can get by with a portable drill and a paint mixing attachment. A 3∕8" drill will do fine for starter batches, but you may soon find yourself upgrading to a 1/2" drill with a larger motor. For mixing larger quantities, you’ll want to use a 1/2-horsepower (hp), 1800-rpm motor and a good mixing blade attachment to provide vigorous
agitation. Remember that methanol is flammable. Sparks from motor brushes can ignite methanol vapors, causing an explosion. Use only Class 1-rated “explosion-proof” motors around flammable vapors. A Class 1 motor is constructed to contain an explosion within itself without rupturing. A suitable motor-mixer combination, designed for use with drums and barrels, is available from Neptune Chemical Pump Company (model F-3.1; see Resources). These are costly but will pay for themselves the first time they prevent an emergency-room visit.
Lab ware. Some basic lab equipment is required for measuring and weighing the ingredients and determining the proper amount of lye to use for the biodiesel reaction. The more often and longer the grease was heated for cooking, the greater amount of lye is needed for a complete reaction. The process for determining this is called titration
For lab ware, Frey Scientific is a good source (see Resources). Order extra; glass breaks. A basic lab kit to get started converting waste vegetable oil to biodiesel includes:
• Electronic scale for weighing quantities of lye up to 2 kilograms (kg), with a minimum resolution of 1 gram (g)
• Calibrated, 1.5-milliliter (mL) pipettes for measuring small quantities of oil and alcohol for titration when waste vegetable oil is used
• Hydrometer to measure the specific gravity of the biodiesel
• Two 10-mL graduated cylinders
• Glass beaker or wide-mouth jar
• 2-liter (L) beaker to measure your lye
• 1-L bottle to store your 1-percent solution of sodium hydroxide
• pH paper
• Funnels for pouring various wet and dry ingredients
• Scoop for measuring out lye
• Stirring rods
Filtering. Biodiesel must be filtered before it goes into your fuel tank. You can use a “sock”-type filter (a filter bag that looks like a big sock) or standard automotive fuel filters in line with the fuel pump to filter out particles greater than 10 microns.
Storage. Biodiesel can be stored for over a year in a clean, dark, dry environment. Use only containers suitable for liquid storage, made from black mild steel, stainless steel, fluorinated polyethylene, or fluorinated polypropylene. Keeping the biodiesel cool helps it last, but longer-term storage may result in fungal growth within the biodiesel (especially if any water is introduced into the fuel), requiring treatment with a chemical biocide. Keep in mind that there may be state or local regulations governing storage of large quantities of fuel or vegetable oil, so check with your city or local health department for more information.
Safety:
Biodiesel is flammable , but much less so than diesel fuel. It has a minimum flash point (the temperature at which vapors will ignite when exposed to a spark or flame) of 266°F, compared to about 165°F for diesel fuel. Biodiesel is relatively safe and less toxic than fossil fuels, and it’s not difficult to make and use, but it does require close attention to detail and respect for the materials and equipment you will be working with. Don’t get lazy with safety. It is extremely important to use personal safety equipment when working with methanol and lye. Obtain, read, and understand the material safety data sheet (MSDS) from the supplier of any chemicals you use. Handle biodiesel as you would any other fuel, and always take steps to prevent personal and environmental contamination. Biodiesel must be made outdoors or in a very well ventilated area, using great care to protect yourself from hazardous materials and conditions. At a minimum, you will need:
• Chemical-resistant goggles
• Organic vapor respirator
• Nitrile gloves
• Chemical-resistant apron
• Clothing that completely covers all of your skin
• Ground-fault circuit interrupter (GFCI) — use this type of electrical outlet (receptacle or extension cord) for plugging in any electrical devices used in your processing operation
• Vinegar and water to neutralize spills of the corrosive lye and sodium methoxide
Only three ingredients are required to make biodiesel: vegetable oil, methanol, and a catalyst. Here’s some information on each one and where best to find them.
Vegetable Oil:
New, virgin vegetable oil is ideal for making biodiesel. You can also use oil left over from restaurant fryers. Waste fryer oil will yield a bit less biodiesel than fresh oil, but you can often find it for free at local restaurants, where they usually pay to dispose of it. Restaurants, food manufacturers (salad dressing companies), and food processors are good sources for finding free or cheap vegetable oil.
You can also buy it new in large quantities from restaurant food suppliers. Oil quality varies depending on how used it is. Older, more heavily cooked oil generally yields more waste in the biodiesel reaction than newer, less-used oil. Canola and soy oil are common, but you may find other types. Most cooking oils will make a suitable biodiesel. Avoid using lard or anything else you can’t pump at room temperature. Waste fryer oil often is available for free, but you may find that competition for the oil — from other biodiesel brewers like yourself — has made it a more valuable commodity.
Methanol:
Methanol (CH3OH) technically is wood alcohol but generally, is derived from fossil fuels. It is required for transesterification, the basis of converting vegetable oil to biodiesel. The amount of methanol required for a successful reaction varies a bit but typically is around 20 percent of the initial volume of oil in the recipe.
This fossil fuel is available in 55-gallon drums from chemical supply companies. You might be able to find smaller quantities at your local car racing track or from a propane gas supplier. For test batches, you can use “dry gas” gasoline additive that contains a high percentage of methanol. Do not use this type with ethanol or other alcohols.
Catalyst/Lye:
Sodium hydroxide is also known as caustic soda or lye, or chemically as NaOH. Potassium hydroxide (KOH) also may be used, but 40 percent more is required in the recipe. The catalyst is required to chemically combine the oil and methanol to form biodiesel. The amount of catalyst varies based on the acidity of the oil.
Oil that has been heated, burned, or used for cooking is more acidic than new oil and will require more catalyst (a base) to neutralize the acid and create the chemical bonds. Liquid catalyst mixes better than dry or crystallized products, Sodium hydroxide generally is more widely available than potassium hydroxide, and the recipes in this chapter are based on using dry sodium hydroxide.
Lye is available in various quantities from chemical supply companies or, for small batches, use drain cleaner that is 100-percent sodium hydroxide, found at hardware and grocery stores. Keep the lye dry in a tightly sealed container.
Equipment Needs:
To make your own biodiesel, you will need equipment for collecting, storing, pumping, mixing, and heating the oil, as well as some basic chemistry equipment, and, of course, appropriate safety gear.
Collection. If you plan to collect waste fryer oil from local restaurants, first talk to the manager and find out how they currently dispose of it. It may go into a garbage bin in 5-gallon buckets, or it may go into 55-gallon drums or 300-gallon receptacles to be picked up by a waste oil hauler. If they dispose of it in 5-gallon jugs, your job is easy. If not, you’ll need to transfer the oil from their storage vessel to a collection tank or buckets on your pickup truck. You can do this with a hand or motorized pump. If the oil normally is collected by a waste hauler, you may need to enter into a contractual agreement.
Pumping. If you’re making only small quantities of biodiesel, an inexpensive, hand-cranked barrel pump works well. For moving a lot of liquid, a 12-volt DC-powered diesel-fuel transfer pump is a good solution. Just attach the power cable to your truck battery and run hoses between the collection vessel on your truck and the restaurant’s oil storage bin. When you’re back home, use the same pump to off-load the oil from your truck into your storage barrels. The same pump can be used to:
• Fill the reactor, or mixing, tank with vegetable oil
• Pump the glycerin out of the bottom of the reactor and into a waste collection container (after mixing and settling)
• Remove wastewater mixture from the tank after washing
Tip: Draw from the Middle
Water and debris settle to the bottom of the waste oil bin. When using a transfer pump to collect waste fryer oil, adjust the length of the intake tube so that it won’t sit on the bottom of the barrel. Debris and scum water accumulate on top of the grease, so also avoid pumping off the top. Water in the oil will ruin a batch of biodiesel.
• Transfer the biodiesel from the reactor to the fuel storage or settling tank
• Pump biodiesel through a filter and into your car’s fuel tank
You can get by with a single pump, but it’s handy to have two. Diesel fuel pumps are not designed for use with water, but you should be able to avoid problems by making sure the last liquid through the pump is oil or biodiesel. This keeps the seals lubricated and prevents rust from forming inside the pump. Good sources for fuel-handling equipment include large auto supply shops and the online retailer Northern Tool and Equipment (see Resources).
Mixing tank. A suitable mixing tank for the home brewer can be made from a 50- to 200-gallon plastic barrel with a conical bottom, which facilitates pumping out the glycerin after processing. Such tanks are available from specialty agricultural supply stores, such as PolyDome. or industrial plastic manufacturers, such as U. S. Plastic Corporation.
Heat. You will need to devise a way to heat the vegetable oil to 120°F for mixing. This can be done in an old water heater, in a barrel with a submersible electric heater, or using another heat source and heat exchanger of your own design. Good places to find heaters suitable for this task include farm stores; agriculture supply outlets; auto parts stores; and online resources, such as Diesel-Therm and Jeffers Pet
Mixing motor. If you’re making only a few gallons of biodiesel, you can get by with a portable drill and a paint mixing attachment. A 3∕8" drill will do fine for starter batches, but you may soon find yourself upgrading to a 1/2" drill with a larger motor. For mixing larger quantities, you’ll want to use a 1/2-horsepower (hp), 1800-rpm motor and a good mixing blade attachment to provide vigorous
agitation. Remember that methanol is flammable. Sparks from motor brushes can ignite methanol vapors, causing an explosion. Use only Class 1-rated “explosion-proof” motors around flammable vapors. A Class 1 motor is constructed to contain an explosion within itself without rupturing. A suitable motor-mixer combination, designed for use with drums and barrels, is available from Neptune Chemical Pump Company (model F-3.1; see Resources). These are costly but will pay for themselves the first time they prevent an emergency-room visit.
Lab ware. Some basic lab equipment is required for measuring and weighing the ingredients and determining the proper amount of lye to use for the biodiesel reaction. The more often and longer the grease was heated for cooking, the greater amount of lye is needed for a complete reaction. The process for determining this is called titration
For lab ware, Frey Scientific is a good source (see Resources). Order extra; glass breaks. A basic lab kit to get started converting waste vegetable oil to biodiesel includes:
• Electronic scale for weighing quantities of lye up to 2 kilograms (kg), with a minimum resolution of 1 gram (g)
• Calibrated, 1.5-milliliter (mL) pipettes for measuring small quantities of oil and alcohol for titration when waste vegetable oil is used
• Hydrometer to measure the specific gravity of the biodiesel
• Two 10-mL graduated cylinders
• Glass beaker or wide-mouth jar
• 2-liter (L) beaker to measure your lye
• 1-L bottle to store your 1-percent solution of sodium hydroxide
• pH paper
• Funnels for pouring various wet and dry ingredients
• Scoop for measuring out lye
• Stirring rods
Filtering. Biodiesel must be filtered before it goes into your fuel tank. You can use a “sock”-type filter (a filter bag that looks like a big sock) or standard automotive fuel filters in line with the fuel pump to filter out particles greater than 10 microns.
Storage. Biodiesel can be stored for over a year in a clean, dark, dry environment. Use only containers suitable for liquid storage, made from black mild steel, stainless steel, fluorinated polyethylene, or fluorinated polypropylene. Keeping the biodiesel cool helps it last, but longer-term storage may result in fungal growth within the biodiesel (especially if any water is introduced into the fuel), requiring treatment with a chemical biocide. Keep in mind that there may be state or local regulations governing storage of large quantities of fuel or vegetable oil, so check with your city or local health department for more information.
Safety:
Biodiesel is flammable , but much less so than diesel fuel. It has a minimum flash point (the temperature at which vapors will ignite when exposed to a spark or flame) of 266°F, compared to about 165°F for diesel fuel. Biodiesel is relatively safe and less toxic than fossil fuels, and it’s not difficult to make and use, but it does require close attention to detail and respect for the materials and equipment you will be working with. Don’t get lazy with safety. It is extremely important to use personal safety equipment when working with methanol and lye. Obtain, read, and understand the material safety data sheet (MSDS) from the supplier of any chemicals you use. Handle biodiesel as you would any other fuel, and always take steps to prevent personal and environmental contamination. Biodiesel must be made outdoors or in a very well ventilated area, using great care to protect yourself from hazardous materials and conditions. At a minimum, you will need:
• Chemical-resistant goggles
• Organic vapor respirator
• Nitrile gloves
• Chemical-resistant apron
• Clothing that completely covers all of your skin
• Ground-fault circuit interrupter (GFCI) — use this type of electrical outlet (receptacle or extension cord) for plugging in any electrical devices used in your processing operation
• Vinegar and water to neutralize spills of the corrosive lye and sodium methoxide
