Hi everyone My wife and I worked on titration until pretty late last night, at least late for me. I am a morning person and I pruned and thinned a massive area of PiƱon & Cedar wood and then loaded it prior to beginning our first titration of WVO. I say this because I'd rather not have people telling me I am not tip-top with my labwork. Tired is all. Anyway, yesterday evening we finally had all of the equipment and chemicals in place. Saturday morning, I did some test runs using the TI-83 & Vernier LabPro Data logger. It is the Vernier Data Logger that is the most useful of the two for our needs. It has a USB interface and the data logger software was easy enough to figure out. I started out with the stainless-steel temperature sensor as we have a decent thermometer to check against. Very nice readout on the screen and easy to understand. I then removed the pH sensor from its soaking bath bottle. We set it in tap water first and got a pH reading of 7.5, rinsed it in distilled water and gently cleaned it with a paper towel, next dipping the sensor end in fresh distilled water, pH 7.
With readings of that which we could expect, we then moved on to basic titration. If you all will bear with me a moment, I do have some questions. I will intertwine my questions right into the JtF web site directions for basic titration. Our hope is to clarify these directions for ourselves and for other newbies as well. We believe that there are several statements found here and in the email list which are contradictory at best. "Basic titration An electronic pH meter is best, but you can also use pH test strips (or litmus paper), or phenolphthalein solution (from a chemicals supplier)." I suggest sorting the test equipment according to preference. We were ridiculed for using litmus paper. Why list it second if it is preferred as a third choice? Phenolphthalein sounds very interesting. Why not give more information on the setup and use of this test? Yes we followed the links. "Dissolve 1 gram of lye in 1 liter of distilled or de-ionized water (0.1% w/v lye solution)." Here, according to JtF, we are in the absolute most important first step Titration, which a newbie is going to perform! Standard procedure in all technical writing as far as I am aware it to define all abbreviations!!!! Why throw out a statement like: "(0.1% w/v lye solution)" and not simply define (w/v?) This is making an already completely new process unnecessarily cloudy in the mind of the newbies. Ok, this is the second sentence in a half page description of how to do the most important step in making biodiesel. "In a smaller beaker, dissolve 1 ml of dewatered WVO 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." Smaller beaker than what? WVO oil is redundant. Again, if the pH Meter is the "best" tool and listed first in the sentence above, why are we jumping back to phenolphthalein? If this is the preferred test, why not say so in the first sentence? "Using a graduated syringe, add the 0.1% lye solution drop by drop to the oil-alcohol-phenolphthalein solution, stirring all the time. It might turn a bit cloudy, keep stirring. Keep on carefully adding the lye solution until the solution stays pink (actually magenta) for 15 seconds." See above. We are using a continuous readout pH meter. What is the pH we are looking for here! Yes Keith, layered information is great, but why push it when it is unnecessary? We are jumping all over the place in order to do one simple step. Different methods are combined in the same paragraph. This could be the reason newbies are confused. "Take the number of milliliters of 0.1% lye solution you used and add 3.5 (the basic amount of lye needed for virgin oil). This is the number of grams of lye you'll need per liter of oil." Sheesh, I am sorry, but I have a question about every sentence in this basic titration. "Take the number of milliliters of 0.1% lye solution you used and add 3.5" ?? This is sloppy writing. Are you saying add a number of milliliters to 3.5 grams? If it took 1.6 mL of lye solution then are we supposed to add 1.6 g to 3.5 g? I don't think so. How about a formula here? It would be clearer if you stated all of the proper terms, weight, volume, etc. No wonder so many questions appear on the email list about titration. "With a pH meter or test strips, use the same procedure without adding the phenolphthalein. Add the 0.1% lye solution drop by drop as before until the pH reaches 8.5." Duh! Why not just add this value to the sentence above to aid the newbies who are learning the procedure and keep them from jumping around. Also, please be consistent with the numbers throughout the directions. A pH of 8.5 is mentioned and then a pH of 8-9 is mentioned. This leads one to believe it does not really need to be exact. I know it is difficult for many folks to take criticism. I am not so arrogant to think I could criticize people that are so far ahead of us in this extremely important sustainable Biofuels research. I will offer to help. First I have to get a handle on what it is we are doing with the titration. It is always acceptable to use the Scientific Method so that others may follow the directions and achieve the same results. In fact, an experiment is never valid unless someone else can perform the exact same experiment and achieve the same results. It is amazing how versatile and yet precise the Scientific Method is for achieving this goal. If different processes need to be used for different materials and equipment, then describe each process separately using the Scientific Method Example 1. The pH meter method. Purpose: To determine the amount of additional lye necessary to bring Waste Vegetable Oil to a pH of 8.5. Materials and Equipment: List every single piece of equipment and every single separate material that will be used. If abbreviations are to be used later, they should be identified here. 1. A pH meter 2. An accurate gram scale. 3. How many beakers and in what size? 4. How many sealable glass containers and in what size? 4. One Liter (L) Waste Vegetable Oil (WVO) 5. Don't forget safety equipment. 6. Distilled water. 7. etc. Procedure/Method: List in order every single step including safety equipment and procedures necessary. If it is important, list the temperatures at which the materials need to be. 1. In the two Liter sealable jar, add one L of Distilled Water 2. Wearing gloves and protective eye goggles, measure out 1 gram (g) lye and add it to measured distilled water. Make sure to close lye container and glass jar in order to avoid contamination. 3. Remove water from WVO. 4. Next step. Etc. Data/Results: Only list the facts. Do not speculate or editorialize. 1. At x Temperature, the WVO had no evidence of water present. 2. Formulas and calculations. The formula for converting the lye in the titrated mL solution to grams would be used here and the results recorded. Formula, calculations = x grams of lye to bring one L of WVO to a pH of 8.5 Conclusion: Here is where all the opinions and speculations can occur. 1. X amount of grams of lye will need to be added to the 3.5 grams of lye to be used in the Journey to Forever process of making biodiesel with this particular batch of WVO. This sample of WVO was very similar in quality to pure vegetable oil as it had no water and a beginning pH of 6.9. Although each batch of WVO obtained from the same source should be tested, this source (Name the Source) appears to produce very clean WVO. Sources of Error: List everything that might have adversely affected the process and describe how it might have be avoided in the next experiment or procedure. 1. The humidity due to heavy rains could have affected water content of the lye. If conditions are not similar during the process of making the biodiesel with this particular batch of WVO, the results might be different. It would be best to maintain constant conditions throughout the entire process. Measuring materials in plastic bags could also prevent moisture contamination and that process should be in the procedure. 2. etc. Example 2. The Litmus Paper method. Repeat the steps of Scientific Method. We will provide the steps we used once we are able to effectively complete the process. Sincerely, Brian and Nell Rodgers _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/