| Some makers of biodiesel are satisfied to let their | | | | up far less water. Brought to us by the University of |
| newly produced mixture simply sit untouched for | | | | Idaho, this technique, called Bubble Washing, utilizes |
| about a week to allow the bulk of the soap residues | | | | an aerator and an air stone, both of which you can |
| settle to the bottom before running the product | | | | buy for under $50 collectively at your local aquarium |
| through a filter and into their fuel tank. But for a | | | | supply shop,. |
| cleaner biodiesel that burns better, runs better, gets | | | | If the aerator you purchase comes with a filter, |
| better mileage, and minimizes wear and tear on your | | | | remove it now before proceeding. Add into a tank or |
| engine, you may wish to consider taking this stage of | | | | container filled halfway with biodiesel 30 milliliters of |
| the process a step further. | | | | vinegar for every 100 liters of biodiesel and then fill it |
| There are numerous ways to wash biodiesel, the | | | | just about the rest of the way with plain water. |
| simplest being to pour water with a dash of white | | | | Drop into the mixture the air stone that's attached to |
| vinegar mixed in into a translucent container made of | | | | the end of your aerator. It will immediately sink to |
| PVC or some other similar material, or a 5-7 gallon | | | | the tank's bottom. Once you turn the aerator on, |
| bucket, if washing large batches, fitted with a valve | | | | bubbles begin to emanate from the stone, rising up |
| at the bottom that can be opened or closed at will. | | | | through the tank, washing the fuel as it does so. |
| Then pour your biodiesel on top of it and gently stir, | | | | When the bubble arrives at the surface of the |
| avoiding agitating the soaps you're attempting to | | | | biodiesel, it then pops, releasing a water droplet that |
| remove. Afterwards, let the mixture sit for 12-24 | | | | then drops back through the mixture, washing it a |
| hours. | | | | second time. |
| At the end of this time the oil (biodiesel fuel) and the | | | | Now if washing your biodiesel this way only succeeds |
| water (cloudy with soap) will have separated, and | | | | in making it cloudier, then there's probably too much |
| you can decant the biodiesel out the top, and then | | | | alkali in your mixture. This can easily be reduced by |
| drain the soapy water out the bottom. | | | | adding a small amount of lemon juice or white vinegar |
| You'll want to repeat this process 1 or 2 more times, | | | | to the water you're washing with. |
| using fresh water each time (though after the 1st | | | | Let the bubble washing continue for 2 to 3 days. For |
| wash, you need not add any vinegar to the water | | | | faster results, you might choose to attach the pump |
| you use for subsequent batches.) In the interest of | | | | (aerator) to the side of your tank or container. The |
| preserving water, by the way, the remaining water | | | | vibrations assist in the separation process and help |
| from your 3rd wash could be used for the 1st wash | | | | expedite its completion. |
| on a subsequent batch. | | | | Periodically check the pH of the mixture as the |
| If, after 3 washings, there still seems to be residual | | | | process rolls along. Whether you wash your biodiesel |
| soaps remaining, they can then be removed by | | | | "manually" (as in the first method outlined) or using |
| slowly reheating the oil, decanting out the clean | | | | the latter bubble washing method, you should only |
| biodiesel and leaving the impurities behind. | | | | consider the process complete when the pH of your |
| There is, however, another way to wash your | | | | biodiesel reaches approximately 7-7.5 (neutral). |
| biodiesel that, while taking longer to complete, uses | | | | That's when you know you're good to go. |