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Trans-Estrification BioDiesel Process
Reaction raw materials :
Jatropha Oil
Methanol (CH3OH) 99%+ pure
Pottasium hydroxide (must be dry)
Materials for Titration :
Isopropyl alcohol 99%+ pure
Distilled water
Phenolphthalein solution (not more than a year old, kept protected from strong light)
Materials for Washing :
Vinegar
Water
Manufacturing Process
Jatropha oil is filtered to remove any solid particles.
Jatropha oil is then heated to remove any water content (optional).
Titration is done to determine how much catalyst is needed.
Exact quantity of Potassium Hydroxide is then throughly mixed in Methanol till it disolves completely to get potassium methoxide.

Jatropha oil is heated if required (during winter), and mixed in the potassium methoxide while with agitator running.

It is then allowed to settle and glycerine is removed from bottom.
BioDiesel fraction is then washed and dried.
It is then checked for quality.

In transesterification, KOH and methanol are mixed to create pottasium methoxide (K+ CH3O-). When mixed in with the oil this strong polar-bonded chemical breaks the transfatty acid into glycerine and ester chains (biodiesel), along with some soap if you are not careful. The esters become methyl esters. They would be ethyl esters if reacted with ethanol instead of methanol.

PROCESS in DETAIL
Filtering : Filter the oil to remove solid particles. You may have to warm it up a bit first to get it to run freely, 35oC should be enough. A Cartridge filter is used for the same.

Removing the water : Heat the oil first to remove any water content. Waste oil will probably contain water, which can slow down the reaction and cause saponification (soap formation). The less water in the oil the better. Raise the temperature to 100oC, hold it there and allow any water to boil off. Run the agitator to avoid steam pockets forming below the oil and exploding, splashing hot oil. Or drain water puddles out from the bottom as they form, you can save any oil that comes out with the water later. When boiling slows, raise the temperature to 130oC for 10 minutes. Remove heat and allow to cool.
Regular source of oil does not need to have the water boiled off, in which case do not do it, boiling means extra energy and time.

Basic titration : Dissolve 1 gram of KOH in 1 liter of distilled or de-ionized water (0.1% KOH solution). You can use phenolphthalein solution to get end point. In a smaller beaker, dissolve 1 ml of dewatered oil in 10 ml of pure isopropyl alcohol. Warm the beaker gently by standing it in some hot water, stir until all the oil dissolves in the alcohol and the mixture turns clear. Add 2 drops of phenolphthalein solution.
Using a burette, add 0.1% KOH solution drop by drop to the oil alcohol phenolphthalein solution, stirring all the time, until the solution stays pink (magenta) for 10 seconds. Take the number of mls of 0.1% KOH solution you used and add 5.0. This is the number of grams of KOH you will need per liter of oil.

Test batches : The first few times you do this process, it is a good practice to first try out your KOH amounts on a 1 liter batch. This works really well and you do not need to heat up the oil too much, just enough so it will spin well. Start by mixing up the exact quantity of KOH and 200 ml of methanol. First make sure that vessels used are dry. Forming the exothermal potassium methoxide polar molecule will heat up the vessel a bit. Keep mixing until all the KOH has been dissolved.
Once the potassium methoxide is prepared, add to 1 liter of oil. Make certain all your weights and volumes are precise. If you are unsure of the titration result then use 5.0 grams of KOH per liter of oil. Smaller batches need only be run for about 15-20 minutes for separation to be completed before switching off. The settling takes some time to complete. The solution can be poured from the vessel into another container right after switching off the agitator. It is good to do a few batches with varying amounts of KOH recorded, so later when checking results one can choose the KOH quantity that did the best job. When too much KOH is used the result can be a troublesome gel that is tough to do anything with. When not enough KOH is used the reaction does not go far enough so some unreacted oil will be mixed with the biodiesel and glycerine. This will form three levels with biodiesel on top above unreacted oil with glycerine on the bottom. If there is too much water in the oil it will form soaps and settle right above the glycerine forming a fourth level in the container. This layer is not too easy to separate from the unreacted oil and glycerine layers.

Preparing the potassium methoxide : Generally the amount of methanol needed is 20% of the Jatropha oil by mass. The densities of these two liquids are fairly close, so 20% of methanol by volume should be about right. To be completely sure, measure out a half-liter of both fluids, weigh, and calculate exactly what 20% by mass is. Different oils can have different densities depending on what type of oil it originally was.
When transesterifying 100 liters of Jatropha oil, use 20 liters of methanol. The methanol is mixed into a solution with the KOH, creating potassium methoxide in an exothermic reaction (it gets warm from bonds forming). Keep all utensils the KOH comes in contact with as dry as possible.
CAUTION : Treat pottasium methoxide with extreme caution! Do not inhale any vapors! If any pottasium methoxide gets splashed on your skin, it will burn you without your feeling it (killing the nerves). Wash immediately with lots of water. Always have a hose running when working with pottasium methoxide. Pottasium methoxide is also very corrosive to paints. KOH reacts with aluminum, tin and zinc. Use glass, enamel or stainless steel containers, stainless steel is best.

Heating and mixing : Pre-heat Jatropha oil 48-54oC. A full speed propeller coupled to a electric motor works fine as a mixer. Too much agitation causes splashing and bubbles through vortexing and reduces mix efficiency. There should be a vortex just appearing on the surface. Adjust the speed, or the pitch or size of the stirrer to get the right effect. Alternately an electric pump plumbed to form a mixing loop for stirring the oil would do a nice job. Mount the pump above the level that glycerine will gel at, to prevent clogging up the pump.
Add the potassium methoxide to the oil while stirring, stir the mixture for 50 minutes to an hour. The reaction is often complete in 30 minutes, but longer is better. The transesterification process separates the methyl esters from the glycerine. The CH3O of the methanol then caps off the ester chains and OH from the KOH stabilizes the glycerine.

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