| Procedure | Detailed informsation focusing on the basic stages of biodiesel production	Ιστοσελίδα στα Ελληνικά Πατήστε Εδώ
| Prοcedure | Pretreatment of oil | Chemical Reaction | Filtering Methods | | Washing Methods | Drying Methods |

		1. Procedure (jump to top) Process of Production (Multimedia which has been created by the students, on the computer, representing the real form of our unit and the stages of biodiesel production) 2. Pretreatment of oil (jump to top) If the oil used in the production, contains high quantities of water or excessively free fat acids, then during the reaction the production of emulsion is increased whilst the production of pure biodiesel is decreased. Pre-treating oil can lead to more predictable reaction and to more consistency during biodiesel procedure. In order to have high quality biodiesel we need to take various measures of preparation regarding the oil that will be used. The parameters that should be taken into account are the following: 2.1 Collecting appropriate oil: The oil should be checked before it is collected. This is possible using optical check. That is to say that the oil will be checked optically for presence of undesirable quantity of water, crude substances, colour etc.. Moreover the oil can be checked by implementing a quantitative analysis and then collecting only oil with characteristic less than 2 or 3 g/l. 2.2 Time: It is recommended that the oil is left for certain weeks or months in open, hot and dry space, so the impure oil is left at the bottom of the tank. Therefore, the oil that remains on top is clean and can be used for the procedure. 2.3 Filtering: Filtering oil before its use helps producing bigger quantity and better quality biodiesel. During filtration, oil is separated from various residues and substances that would have caused problems in the quality of the final product. 2.4 Heating: It is recommended that the oil is heated before it is used in the procedure, something that we also apply, in order to evaporate the water that oil contains. Moreover, heating helps in preventing the creation of emulsions in the product. Heating is possible using a boiler, as it happens in our school biodiesel unit.   3. Chemical Reaction (jump to top) In chemical terminology biodiesel is fat acids methyl esters and it is produced with the transesterification of vegetable oil or animal fat with methanol. The chemical transformation of triglycerides to fat acids methyl esters is the result of their reaction with methanol, with the use of catalyst (hydroxide of sodium [NaOH] or hydroxide of potassium [KOI], using 25% proportion) as appears below::   Triglycerides +  Methanol  --> (NaOH or ΚΟΗ) --> methyl esters of fat acids + glycerin Note: The hydroxide potassium (KOH) appears to be more efficient for biodiesel production. This happens firstly, because the glycerin remains humid, something particularly important at the wintry period. Also the remains potassium which are spread in glycerin, help the creating of glycerin compost. 4. Filtering Methods (jump to top) There are various methods for filtering oil, depending on the quantity of oil and the producer’s budget for filtration. The companies which deal with biodiesel production tend to heat oil first and then filter it while it is still hot, using high speed pumps. However, most individuals appear to use gravity infiltration (that is to say filtering) before they heat the oil, because of the simplicity and the low cost of this method. The following filters may be used for filtering the oil: - Bag Filters - Cartridge Filters - Blue Jean Filter - Bag Filter Housings 5. Washing Methods (jump to top) At the end of every batch, various residues remain in the final product, independently of the quality of oil that was used or the quality of reaction that took place. This residues include (mainly) soap, a small amount of leftover methanol, a small amount of leftover (lye), and some free glycerin. For this reason, washing the product before its use is essential. Washing the product can be done immediately, after the removal of glycerin, after the reaction. For the best possible cleanliness of the product, it is recommended that it is washed 2 - 3 times. The washing methods that can be used are the following: 5.1 Bubble Wash (Wet Wash) 5.2 Mist Wash (Wet Wash) 5.3 MAGNESOL (Dry Wash) 5.4 Eco 2 Pure (Dry Wash) Biodiesel "floats" on the surface of the water and with the use of an air pump, bubbles are creted in the water. These bubbles are combined with the impurities and afterwards they dispse them into the water, which is afterward drained out from the product. This system cleans biodiesel by using water in the form of spraying. The water remains inj the bottom combined with the various impurities and it is then removed at the final stage of wash. During this method, a process of mixing and absorbing pyritic magnesium salts into the product seperates impurities from pure biodiesel. Eco2Pure is simply a form of cellulose that is based on the composition of the technologies of absorption.Eco2Pure constitutes today, economically, the best solution among other methods of dry wash. 6. Drying Methods (jump to top) The method of heating biodiesel for drying purposes is the most popular and the most reliable. However, somebody can also use a fan of hot air, for that purpose. In general, there are numerous ways of accelerating the drying process of the final product. Some of them include: Increasing the movement of the air round the stocking space (a fan can be used to move air.) Increasing the amount of biodiesel which comes in contact with air (bigger and more open stocking space/reservoir can be used) Increasing air temperature (hot air may hold more water vapour rather than cold air) Draining air in biodiesel in the form of bubbles 7. Attention! (jump to top) If the process stages are not carried out properly and the biodiesel that is used is not pure then the following dangers appear: Erosion of injectors of fuels Damage in plastic parts of the machine, as rings etc Obstruction in the injectors of fuels Problems in the fuel flow though the filter of fuel.  Damage in the diesel pump Damage in the reservoirs of fuels Bacillar increases and obstruction of lines of fuels of/filters