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HOW TO: Brew your own biodiesel
If anyone still needed proof that world oil resources are diminishing, staggering gas prices have now confirmed it. Now, even as our wallets grow skinnier and SUV sales drop, I can’t help but wonder how deeply this new reality is penetrating the American psyche.
Proponents of alternative fuel are fervently pursuing a viable, abundant source of fuel that will maintain our mobility without harming the earth. At present, biodiesel is the most available, affordable and easy-to-use alternative to gasoline. It is made out of either used cooking grease or virgin vegetable oil (corn and soy being the most common). The process of refining oil into biodiesel is quite simple, and the resulting fuel can be used in any diesel engine with no modification to the vehicle itself.
Below is a how-to recipe for brewing your own biodiesel. I have compiled it from several sources over the last few years and have followed it myself many times with great success. Read on to learn how you can have a healthier, cheaper, more environmentally-friendly ride.
A DIY GUIDE TO MAKING YOUR OWN BIODIESEL – By Sarah Rich
I bought a 1983 Mercedes 300 Turbo Diesel in 2003 and began running it on biodiesel immediately. The mileage is equivilent to (and sometimes better than) that of regular diesel, the fuel is non-flammable, making travel safer, and I breathe easier in every way knowing that there are no greenhouse gases sprewing out of my tailpipe. On top of the practical benefits, it’s been a thrilling couple of years watching biodiesel move from the fringe to the mainstream, gaining validation from government officials and business trendspotters, and street cred from farmers and truckers.
You don’t have to make biodiesel yourself to use it. I belong to the San Francisco Biofuels Cooperative, a member owned consumer co-op that buys biodiesel in bulk from distributors around California. Biofuel Oasis, a women-owned biodiesel gas station in Berkeley, is also a crucial fueling site and biodiesel resource center for the Bay Area community. There are co-ops, producers and distributors around the nation who sell high-quality biodiesel for anywhere from $2.50-$3.90 per gallon. You can also perform a modification to your car that will allow you to put waste vegetable oil straight into your tank without turning it into biodiesel, making your fuel absolutely free forever. But that is a “how-to” for another day…
While mixing up biodiesel is not much more complicated than baking a cake, it does use methanol and sodium hydroxide or lye, all of which are dangerous substances in their pure form. Wearing safety goggles and rubber gloves is highly recommended, and preparing your first batch under the supervision of someone with experience might be wise. Finally, just as eating badly made cake will cause trouble in your belly, a sub-par batch of biodiesel can do damage to your car. So be sure you’ve got it right before you pour!
The Goal: Chemically speaking, vegetable oil is a tri-glyceride, comprised of a chain of three vegetable molecules and one glycerin molecule. Through the process of making biodiesel, the glycerin is replaced with an alcohol molecule, in this case utilizing methanol. This reaction is called transesterification. If you are exceptionally industrious, you can use the resulting pure glycerin by-product to make soap.
Preparation: To get started, you will need either waste or new vegetable oil. If you want to use waste oil, which supports the reuse aspect of biodiesel production and keeps the process local, you will need to go talk to someone at a nearby restaurant. Generally, restaurant owners are delighted to have you haul away a few gallons or more of their grease, because otherwise they pay a removal service to get rid of it. Some will even pour it into containers you provide so that you don’t have to siphon from their drums. If you aren’t ready to hunt down a supplier, you can buy a jug of oil at the store. But using virgin resources (and the plastic container they come in) is the less eco-friendly route, so for this purpose, we’ll discuss waste vegetable oil (WVO).
Ingredients and Supplies:
1 kitchen blender (that you can never again use for smoothies!)
3 beakers (one 1500ml, one 500ml and one 20ml)
Graduated syringe or eye dropper
A Petri dish
1+ gallons of waste vegetable oil (if you are using various sources, each source will have a different pH, so keep in mind that your findings need to be for a uniform batch)
5 grams Lye (KOH)
1 bottle Isopropyl Alcohol (Rubbing Alcohol)
1 liter Distilled Water
1 bottle Phenolphthalein Solution (pH indicator – available at pool/hot tub suppliers)
1 bottle of methanol (you can also use ethanol)
Step 1 ? Titration: Titration helps determine how much catalyst you must add by indicating the acidity of your oil.
Measure out 1g of lye in your Petri dish. Dissolve into one liter of distilled water. In 20ml beaker, dissolve 1ml of vegetable oil into 10ml of isopropyl alcohol. Swirl or warm very gently to dissolve the oil into alcohol and make the solution clear. Add 2 drops of pH indicator to this mixture and swirl to dissolve. Using your syringe or eye dropper, add 1 ml (only!) of lye solution to the alcohol and oil solution. Continue adding 1 ml at a time, swirling continuously, until it turns hot pink and holds its color for at least ten seconds. The number of milliliters of lye solution used, plus 3.5, equals the number of grams of lye you’ll need per liter of oil.
Step 2 ? Brewing:
Measure out 1 liter of filtered waste vegetable oil in your 1500ml beaker. Measure out 200ml of methanol in your 500ml beaker. Measure the number of grams of lye that you determined during titration in your Petri dish.
Pour methanol into your blender. Add lye. Blend at low speed until fully dissolved. This reaction creates sodium methoxide. Because of rapid evaporation, the rest of the process must be done straightaway. Be careful not to inhale or ingest this stuff!
Pour filtered vegetable oil into sodium methoxide solution in blender and blend for fifteen to twenty minutes. After blending, the mixture must be left alone to settle for at least eight hours, at which point you will have two layers: glycerin on the bottom and biodiesel on top. Both of these substances are non-toxic. The biodiesel goes in your tank, and the glycerin goes in your soap dispenser. You’ve reincarnated grease into two phenomenally useful substances. Amazing!
Whether you make it yourself or buy it, getting on the road with biodiesel is easy. If you already own a diesel vehicle, you can do it today. For more info on biodiesel or to get involved, check out the links below:
Iowa State biodiesel site (if you want nitty-gritty scientific details)
Excellent FAQ on Biodiesel at www.metaefficient.com
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