Biodiesel Biodiesel is a cleaner-burning, better lubricating alternative diesel fuel that has been extensively researched and used worldwide for decades. It can be mixed in any ratio with petroleum diesel or it can be used by itself without modifying your diesel engine. Mixtures are commonly referred to as BXX, where B100 refers to 100% biodiesel and B20 to 20% biodiesel and 80% petroleum diesel. If you live in a cold region, using a B50 or B20 in the winter will help prevent clouding or gelling of your. Diesel fuel additives are also compatible with biodiesel. In addition to being a renewable resource, Biodiesel offers advantages over petroleum diesel. It has a higher cetane rating and a higher flashpoint. These makes for cleaner combustion and safer handling. Biodiesel emissions are lower than petroleum diesel by 20-80% (with the exception of nitrogen oxides) and particulate matter virtually disappears. Biodiesel offers better lubrication than the currently available low sulfur diesel fuel as well. Better lubrication means more efficient and longer lasting engines. Biodiesel is commercially available for around $2.50-$4.00 per gallon. If one makes biodiesel for personal use using waste vegetable oils, the cost can be $0.60 per gallon.

Transesterification Vegetable oil consists of triglycerides. The more the oil is heated and used for cooking, the more free fatty acids form. This means, the more used the oil is, the more base (NaOH or KOH) will be needed. The sodium methoxide nucleophylicaly displaces the glycerin from each of the three fatty acids forming a fatty acid methyl ester (biodiesel) and glycerin. The excess methanol, water and impurities settle out to the bottom. If you are careful with your calculations and processing, you are left with pure biodiesel and

crude glycerin. If you use too much base you are left with a whole lot of soap, and if you don’t use enough you are left with crude biodiesel that contains too much glycerin.

Ingredients for a 20 gallon batch:

• 2 Gallons Used Vegetable Oil • 0.4 Gallons Methanol (20% of the amount of vegetable oil for the batch; 20% of 20 gallons = 4 gallons. • 1 Bottle NaOH pellets (Red Devil Lye at the grocery or hardware store) • 1 Bottle 97% Isopropyl Alcohol • Package of pH litmus paper • Chemical Scale or Balance • Graduated Eye Dropper • Graduated Test Tubes • Safety gear

V. Making Biodiesel: For our example we are making a 2.0 gallon batch, which equals 7.57 liters. Adjustments can be made depending on how big your batch is. Pour the vegetable oil into the processor through a metal sieve lined with a filter paper or pantyhose to filter out any chunks. Heat the oil to 44o C (110o F). This will melt any solid making the mixture homogeneous.

Titration Titration is important because if you don’t use enough NaOH, you won’t remove the glycerin from the biodiesel. Also, if you use too much NaOH, you will have 2.0 gallons of soap on your hands! Perform a titration of the oil to determine the pH. Repeat the analysis to ensure consistent results. The goal is to add a solution of base and methanol to bring the pH up to 8.5. If you’re using brand new oil, you will need 3.5 grams of NaOH per liter of oil. Since we are making 2.0 gallons and that equals 7.57 liters,

3.5 g base * 7.57 l oil = 26.495 grams of NaOH for unused oil. If you use used oil, you will need more base. Ideally, you want oil that is liquid at room temperature (i.e. not fully hydrogenated) hasn’t been cooked to death (high free fatty acids) and is free from food particles and water. First, make a base solution of 0.1 gram of base dissolved in 0.1 liter of distilled water. You can keep this in a sealed bottle and use it every time you make a batch since you only need a little at a time. To do the titration process, measure out 10 ml of 97% or stronger isopropyl alcohol into a small bowl or beaker, and then add 1 ml of the used vegetable oil and 1 ml of the base solution. Mix it well and then test the pH with the litmus paper. It will be somewhere around 6 to 7.5. Now, add the base solution 0.5 to 1.0 ml at a time and test with litmus paper. Bring the pH up to between 8 and 8.5. Now, including the very first 1 ml, add up the total amount of base solution that you used, in milliliters, to reach a pH of 8.5, and then add 3.5 to that number. This is the number of grams of base per liter of oil that it takes to cause the chemical reaction for that particular batch of oil. Based on those results, calculate the amount of base you will need and measure it out. Double check your math. For example, if you had reasonably clean oil and had to add 2.0 ml base solution to reach a pH of 8.5, you would add that 2.0 to 3.5 for a value of 5.5 g base per liter of oil, or 5.5*7.57 = 41.635 g of NaOH

Mixing the Methanol and Base • Pour 0.4 gallons of methanol into the plastic bucket. • Add the calculated amount of base to the bucket and mix for 1 minute. The bucket will get warm. Do not breathe in the fumes or spill the mixture • Pour the mixture into the oil.

• Mix/Stir vigorously for 1 hour. • Let the biodiesel settle for 24 hours. This will make 2.0 gallons of clear-pale yellow (or light amber) biodiesel on the top of 0.4 gallons of glycerin. Pump or bail out the biodiesel from the top, filtering it through an automotive-type oil filter or other filter to trap any particles before pouring it into your vehicle’s tank. The glycerin on the bottom of your biodiesel reactor is a byproduct and can be composted (fully biodegradable) or used as a cleaner. You can use the glycerin to make your own soap. Allowing longer standing times can make for a more pure product. Transesterification (for advanced makers): You can use KOH instead of NaOH. The advantages of KOH are: 1. you end up with potassium-rich glycerin, which can be used as fertilizer, 2. you get a liquid byproduct (sometimes base-glycerin byproduct hardens in the bottom of the barrel), 3. KOH dissolves much easier in methanol, meaning you don’t need to mix it with the drill mixer. Just agitate the container and in 5-10 minutes it will dissolve, and 4. KOH is CHEAPER, at least around here. I typically pay $4-5 per pound of base, but am getting KOH for 60 cents per pound! HOWEVER, the reaction requires 1.6 times more KOH than NaOH. Therefore, in our example above, instead of using 41.635 grams of base for the 2.0 gallon batch, you need to use 66.6 grams of KOH.

VII. For more information, search the internet and be sure to check out the following sites: Biodiesel.infopop.cc www.howstuffworks.com www.journeytoforever.org

www.veggievan.org www.biodiesel.org