How to Make Biodiesel

Transcription

1 How to Make Biodiesel Overview Biodiesel can me made by anyone in a simple process that is often compared to brewing beer. For this reason it is possible for nearly anyone to take control of their own energy independence by making their own fuel. It is made by a chemical reaction known as transesterification, which involves replacing the glycerol component of an oil with an alcohol in the presence of a catalyst. There are three primary ingredients needed: Ingredients The primary component for making biodiesel is an oil or fat. For home brewers this is commonly waste vegetable oil, which is usually available for free from local restaurants. Farmers in the United States often use virgin vegetable oil grown from canola or soybeans. It should be obvious that farmers can grow their own feedstock to run tractors and other equipment offering them true energy independence. Larger scale producers may use recycled cooking oil, virgin oil, as well as animal fats, algae, fish oils, trap grease and many other types of oils or fats. Indeed one of the beauties of making biodiesel is the wide variety of choices in the ingredients that can be used. The second ingredient is a type of alcohol. When using recycled vegetable oil, the most common choice is Methanol or racing fuel, which is readily available for purchase throughout the country. When using virgin vegetable oil, it is often possible to use ethanol instead, however the ethanol cannot contain water and the vegetable oil needs to be dewatered and degummed. For doing test batches "Heet" brand gas antifreeze contains nearly 100% methanol. The final ingredient is a catalyst. One option for a catalyst is Sodium Hydroxide (NAOH), which is available at local grocery and hardware stores as a drain cleaner. The most common brand is "Red Devil Lye". Another option is Potassium Hydroxide (KOH). One advantage to using potassium hydroxide as a catalyst is that the glycerin by-product from the chemical reaction will be far less toxic than when using sodium hydroxide. Many people find it is possible to compost their glycerin by-product when using KOH as a catalyst. Oil Collection While it is possible to make biodiesel out of many different types of oil, by far the most popular type of oil used by small scale producers is used cooking oil. Restaurants normally have to pay grease collection companies to have their used cooking oil hauled away. For this reason, it is normally fairly easy to make arrangements with restaurants to let you take their used oil for free. The best method is to arrange with the restaurants to pour their cooking oil back into the containers it arrived in. This way the oil is not exposed to water, dirt and other contaminants as it can be in an outdoors grease dumpster or barrel. Also, once the oil is placed in the grease collection barrel or dumpster it often times becomes the property of the grease collection company. If a restaurant does not want to put the oil back into the original containers, they will often allow you to supply your own barrel. Then you can simply pump the oil out of that barrel into another container, or switch and empty barrel for the full one.

2 Oil Quality The cleaner and newer the cooking oil, the easier it is to make quality biodiesel. Generally the lighter the color and the clearer the oil, the better. Be careful of oil that is very dark or oil that looks like it has a lot of extra particulate immersed in the oil. Watch out for oil that smells bad. The oil should smell like cooking oil and not have a spoiled, bacteria type of smell. If you are unsure if the oil is good, the best bet is to take a half gallon sample. Run a titration on the oil and make a small test batch. Then if you get good fuel, you can be more confident in collecting larger amounts of oil and making full size batches of fuel with it. Titration When making biodiesel out of used oil or grease, it is important to determine the free fatty acid content. This is because the amount of catalyst used in the biodiesel reaction is determined by the amount of free fatty acids present in the oil or grease. The way to determine this is through a process known as titration. The procedure is straightforward: 1. Dissolve 1 gram of catalyst (either Lye or Potassium Hydroxide) in one liter of distilled water. 2. Measure out 10ml of isopropyl alcohol (90% or better) into a small container. 3. Mix in 1ml of the oil to be tested with the alcohol. Make sure it mixes thoroughly. 4. Mix in 2-3 drops of PH indicator solution (phenolphthalein or phenol red). 5. Start adding water/catalyst solution to mixture while stirring. Measure how much solution is required to bring the solution to a stable violet or pink color (approximately PH 8.5). Keep track of how many milliliters were used. That's it! If the oil required less than 3ml of solution, it is probably very good oil. If it required 3-6 ml it is most likely adequate oil for making biodiesel. Anything over 6ml is not very good oil, but it may still be possible to use this oil to make high quality fuel. Regardless of your titration results, it is highly recommended to make a 1 liter test batch of fuel before proceeding to the full size batches. Test Batches It's always a good idea to make small test batches of biodiesel before making a full batch. It's especially important to make test batches when dealing with any new sources of oil, questionable oil, or if you're not absolutely sure of your titration results. This way, any problems are limited to a quart or a liter as opposed to 20 or 40 gallons. Luckily it's quite easy to make a 1 liter test batch of biodiesel. Start by heating up 1 liter of oil to 120F. In a separate leak proof container, mix together 220 ml of methanol with the amount of potassium hydroxide or sodium hydroxide determined by your titration. If using Potassium Hydroxide: New Oil - 7 grams, Used Oil - 7 grams + 1 gram for every milliliter of catalyst/water solution needed in titration. For example if your titration used 3.5 ml, then you would use = 10.5 grams of potassium hydroxide. If using Sodium Hydroxide: New Oil - 5 grams, Used Oil - 5 grams + 1 gram for every milliliter of catalyst used in titration. For example if your titration took 4 ml, then you would use = 9 grams of sodium hydroxide. Mix Methoxide until all catalyst is dissolved, then carefully pour into oil. Make sure container is completely leak proof, then mix together for minutes. Allow to settle for 1-8 hours. Success: Clear separation between the biodiesel and the glycerol, two distinct layers. At least 10% glycerol by volume. Problems: 1. Less than 10% glycerol - Most likely did not use enough catalyst. Try again adding more catalyst. 2. Significant layer of soap between biodiesel and glycerol - Indicates too much catalyst was used. Try again with less catalyst. 3. Glop - Could indicate bad oil or incorrect titration. Redo test batch, if you get glop again, consider not using that oil source.

3 Caution: Methanol, Methoxide (Methanol mixed with catalyst), Lye and Potassium Hydroxide are all dangerous chemicals. Read MSDS sheets before using. Work in well ventilated area and always wear protective clothing, goggles and gloves when dealing with these chemicals. Full Size Batches This B-60 Home Biodiesel Kit system is capable of making batches of biodiesel up to 45 gallons at a time. The system is designed to be as automated and simple as possible. Anyone can learn to make their own biodiesel with a B-60. Note: This is meant as an overview, please read your B-60 manually carefully and be sure you understand the whole procedure before attempting to make your own fuel. Filter 40 gallons of oil to about 200 microns. Perform titration to determine amount of catalyst needed. If this is a new oil source or you have any doubts about the oil or your titration results, make a 1 liter test batch of fuel. Caution: Methanol, Methoxide (Methanol mixed with catalyst), Lye and Potassium Hydroxide are all dangerous chemicals. Read MSDS sheets before using. Work in well ventilated area and always wear protective clothing, goggles eyeware and gloves when dealing with these chemicals. Washing Washing biodiesel is very important to to remove contaminants, which could otherwise damage engines or fuel injector pumps. Washing removes soap, excess methanol, particulates and any other water soluble particulates in our fuel. The B-60 comes with a dry wash system.

4 The B-60 unit dry wash system is delivered with 2 pound of Purolite. Purolite is a dry polishing media specifically formulated to remove byproducts remaining from the transesterification process to produce methyl ester or B100. High capacity. 1 lb of PUROLITE PD 206 treats lbs biodiesel -Used for final B-100 purification -Removes residual glycerin, water and trace methanol -Neutralizes catalyst and removes soap -Filters waxes and fine particulate -Effective at ambient and elevated temperatures -Simple final polishing step -Easy to install and remove -Lowers waste volumes Purolite can be disposed of as a non-hazardous material, as long as methanol is removed. Consult with your local waste disposal supplier for specific requirements. Quality Control One of the most important aspects of brewing biodiesel is making sure you have quality fuel before running it in your diesel engine. Bad quality fuel can damage key engine components and cause breakdowns. Luckily it's fairly easy to make sure you are making good quality biodiesel. The most important part of quality control is making sure your reaction went properly in the first place. Try to start with the best quality oil you can find, do careful and accurate titrations and monitor your reaction. Make sure you get 2 distinct layers, one of glycerin and one of biodiesel. Make sure you drained at least 10% glycerin off the bottom of your fuel. Wash your fuel thoroughly with Purolite. Once you are sure all of these steps were followed, it is time to test your fuel for quality. Test #1 - Clarity Take an approximately 500ml sample of your fuel in a clear container. You should be able to read newsprint through it. If you cannot see through the fuel it's an indication there may still be water, glycerin, monoglycerides or diglycerides in your fuel. You don't want any of these in your finished fuel. Test #2 Miscibility Using your 500ml sample, mix in about 1 cup of water. Shake until water mixes with the fuel. Let it for a few minutes. The fuel should separate from the water and there should be no layer of soap between the two layers. If soap is created, it's an indication further washing is needed. If the fuel does not separate easily, it's an indication of poor quality fuel. Test #3 Odor Smell the fuel, it should have a faint odor of vegetable oil with no alcohol type smell. Other Tests If your reaction went according to plan, and the biodiesel passed the three tests shown above, you can be confident you have good fuel. However it is possible to run other tests to be sure. You can test the PH of the fuel exactly the way you titrated your original oil. Good biodiesel should have a PH of around 7. You can test the specific gravity of the fuel with a hydrometer, or you can even send the fuel out to a lab and have it tested to see if it meets ASTM D6751 specifications. Generally these tests cost approximately $100. Emulsion Issues Emulsions occur when water becomes mixed with the fuel during a water wash and will not separate. The result looks like a coffee

5 milkshake. Biodiesel emulsions occur most commonly when fuel with a lot of soap in it is water washed too vigorously. This is one of the reasons we recommend you use only a dry wash system, we do not recommend water washing biodiesel. The best policy is to avoid emulsions by carefully washing your fuel and always doing accurate titrations to avoid excess soap in you fuel. However if you do get an emulsion there are ways to deal with it. Emulsion Breaking It is a good idea to save some glycerin you have previously drained off biodiesel batches for breaking emulsions. Add 10% by volume glycerin into the emulsified biodiesel and mix. See if emulsion starts to break. If not add 10% more and mix. Repeat until emulsion breaks. When it does, glycerin will separate from biodiesel just like in a normal reaction. Drain off glycerin and wash as normal. Ingredients & Supplies Catalyst Potassium Hydroxide Sodium Hydroxide Methanol Methanol is a very common chemical and quite easy to come by. It comes in 3 grades - industrial grade, racing grade and chemical grade. The chemical grade and racing grade contain less water, which makes them preferable for producing biodiesel, but the industrial grade will work. From a price and quality perspective, racing grade methanol is the preferred grade to use. It is racing fuel and as such can be found at race tracks and high performance automotive stores. If you cannot find race grade methanol, look for "Oil Companies" in the yellow pages and you will usually be able to find places that carry industrial grade methanol quite easily in most locations. Here are some methanol distributors: United States Sunoco Race Fuels (many locations) Web: Turbo Blue Racing Gasoline s (many locations) Web: VP Racing Fuels, Inc. (many locations) Web: Bi-Products There are two bi-products associated with making biodiesel, glycerol and soap. Glycerol - The glycerol bi-product will contain the catalyst and about half the excess methanol from the reaction There are several options of dealing with this glycerol bi-product. When using Potassium Hydroxide (KOH) as a catalyst it is possible to use the glycerol to make fertilizer or to simply compost it. When using Lye, which is Sodium Hydroxide (NAOH), it is possible to evaporate or boil off the methanol (be careful of the methanol fumes) and to quite easily turn the glycerol into soap. Most people do not go to this much trouble, because small amounts of methanol and soap in the sewer are not generally thought to be a major problem and they simply dispose of the water as you would other soapy water. Consult your local EPA for guidelines. B-60 Dry Wash Unit B-60 has the capacity to produce 45-gallon batches of Biodiesel every 5 hours. This is a complete At Home Biodiesel processing system that produces Biodiesel for your personal vehicles. Order your own unit today!