Biodiesel and Dyes Synthesis Lab Abstract The goal of this lab was twofold The first goal was synthesize biodiesel from vegetable oil and the second goal was to synthesize three different dyes The biodiesel was synthesized using KOH and a methoxide solution Used oil was also titrated to determine the amount of NaOH needed to use in order to make biodiesel from used oil For 4 mL of used oil we found that 2 9 mL of NaOH was needed complete the titration From that we concluded to synthesis a 250 mL sample of biodiesel 181 25 mL of 0 1 M NaOH would be required Introduction Biodiesel The purpose of this lab was to produce biodiesel from vegetable oil through the transesterification of methodoxide The order of steps that will occur in this lab are preparation of methoxide synthesis of the biodiesel separation of the biodiesel testing the biodiesel with gas chromatography and determination of the fatty free acid content of the oil used by titration Animal fats and vegetable oils are made up of triglycerides which can be made into biodiesel through transesterification Methanol and ethanol are most commonly used in this process because of the hindrances in larger alcohols In transesterification an alcohol reacts with an glycerol which produces another ester This ester in turn reacts with methanol in the formation of fatty acid methyl esters and glycerol One thing that requires attention in this process is fatty free acids Fatty free acids are produced as oil is broken down In order for these to be converted in transesterification they first have to be converted into esters Note that fatty free acids can be neutralized with excess base this produces glycerol Another thing that s important to this lab is that the stating materials be free of water If they are not saponification rather than transesterification Saponification is the process through which soap is produced from fats More specifically it is the base hydrolysis of triglycerides to form the sodium salt of a carboxylate In selecting the base to use for this experiment the rate of dissolution of methanol by the base was taken into consideration KOH dissolved much quicker than NaOH in methanol and so it was used Also another thing had to be considered when considering the base That was the purity of the base used The purer the base the less needed to be used and vice versa Dyes In this lab several dyes are prepared Those dyes are phenolphthalein fluorescein and methyl red Both phenolphthalein and methyl red are used as pH indicators Methyl red turns red in acidic solutions while phenolphthalein turns pink in basic solutions The mechanisms behind these two indicators are quite similar Both are compounds have colored ions that can be formed through the addition of base or acid Methyl red forms a cation in acidic conditions that is red in color Phenolphthalein on the other hand has an anion that forms in basic conditions and is purple By altering the concentrations of acid and bases in a solution these ions can be made and that s why these compounds can be used as indicators This also accounts for the pH ranges for which the indicators are useful Fluorescein on the other had is used as a fluorescent tracer in many applications It is a dark orange red powder that is soluble in both water and alcohol It is used as a tracer because it glows when exposed to UV radiation The mechanism behind this fluorescence is driven by electrons continuously being excited by photons which are provided by UV radiation The first thing that occurs is internal conversion This is the conversion of some of the energy from the electron being converted to heat The internal conversion energy is usually only a small fraction of the overall excitation energy The electrons then fall down from the excited state As the electrons fall a wavelength of light is emitted which is what is visible This cycle is continued as long as a source of light is provided Fluorescein has commonly been used as a tracer to detect ophthalmic lesions such as corneal ulcerations in human It was found in a recent study that fluorescein can be used as a highly rapid efficient and sensitive indicator of skin damage in fish 2 Methods and Materials Biodiesel Part Preparing the methoxide solution Into a 500 mL flask 250 mL of fresh unused vegetable oil were measured out A stir bar and a thermometer were added The flask was placed on the hotplate The oil was heated while stirring up to 55oC It was maintained at 55oC for 10 min While the oil was heating 50 mL of Methanol was measured out into a 125 mL flask To the methanol 1 41 grams of KOH was added The flask was covered with Parafilm to prevent absorption of water The contents of the flask were swirled until all of the KOH dissolved Transesterification When the oil temperature reached 55 oC the methoxide solution was added to the oil ensuring that the stirring speed was sufficient to mix the solution completely The temperature was brought back up to 55 oC and the temperature was maintained for 1 hour Determining FFA content Into a clean 125 mL flask 40 mL of 2 propanol was measured out To the flask 4 mL of used waste oil was added and swirled The mixture was warmed with the hotplate and was swirled periodically until the solution was clear and not cloudy To the solution 3 drops of phenolphthalein indicator was added The mixture was swirled About 20 mL of 0 1M NaOH solution was placed in the 100 mL beaker The 10 mL Mohr pipette was filled and was drained lowering the level to the 0 mark While swirling the oil and propanol mixture the NaOH was added dropwise from the pipette until the solution turned pink and persisted for at least 15 seconds The result was divided by four Finishing After the reaction had progressed for an hour the flask was removed from the heat and was poured into a clean poly bottle While being careful not to allow any of the glycerin layer to get in the Biodiesel layer was poured off into a separate container Half as much deionized water compared to Biodiesel was added to the container and was agitated not vigorously The Biodiesel was allowed to separate and the water was drained off This process was repeated until the wash water is no longer cloudy The washed Biodiesel was allowed to dry until it was clear Wash Test Into a clear poly bottle 150mL of the Biodiesel was placed To the bottle 150 mL of deionized water was added The bottle was capped tightly The bottle was shaken vigorously for approximately 10 15 seconds and then