Re: [Biofuel] 1L Acid/Base Test Batch: Questions
Hello Sean Thanks, Keith. I just checked the KOH .pdf data sheet at TheChemistryStore.com, where I bought the KOH) it says it's 100%. That doesn't seem exactly right, but it could explain the washing, given that I threw in a little extra. And: The KOH is 90%. That's what I get for reading the data sheet instead of the web page. Then 3.1 g 100% NaOH x 1.4025 = 4.34775 g 100% KOH = 4.83 g of 90% KOH per litre of oil. A titration is a good idea. I was lazily avoiding it . . . You can't avoid it unless you use virgin oil. In fact for your initial acid-base process tests you should be using virgin oil, not WVO, one step at a time. People often want to go straight from nowhere to acid-base so they can avoid learning titration - lousy reason, and you can't avoid it anyway. Some people avoid biodiesel altogether because of the titration problem and opt for an SVO system instead. Then they want to use WVO with it and think all they have to do is filter, filter, filter, the three alleged rules of SVO. Nope, it needs high-quality oil = titration. It's easy enough, you just have to be a bit rigorous. And, yeah, the final volume thing is weird. Undoubtedly, I lost a little here and there in transferring stuff to and from different containers, but certainly no more than 20 mL. Some of the Methanol has also surely evaporated . . . Usually nearly all of it just condenses on the underside of the lid or whatever and falls back in. If you're not using something with a lid then you should be. I must be missing something. Yes, 24% is not a trivial amount. That's surely your problem, if there is one. Yet you got quite good results anyway, remarkable. Well, I keep saying it's very flexible. I think if you tighten everything up so you end up with the quantities you started with you should be just fine. Good luck! Keith Anyway, thanks much for the response. -Sean On Tue, 2006-04-25 at 05:33 +0900, Keith Addison wrote: Hello Sean Hi, Folks: I'm kind of new to the list; I've spent a lot of time in the archives already, and I know this ground has been covered. But any advice/input any of you want to share would be great. Oh, and: I'm an English professor, not a chemist, so my apologies for what must seem like sloppy lab documentation to some of you! Looks okay to me, but then I'm a journalist not a chemist. :-) You need to know the purity of the KOH. It's unlikely to be pure, more likely 92% or 85%. You can find the equivalent amounts to use here: http://journeytoforever.org/biodiesel_make2.html#koh If you have some NaOH for comparison you might be able to do a sort of comparative titration which will tell you the right amount of KOH to use. It also helps to titrate the oil, even with the acid-base method - though you won't use the titration result in the process itself, it always helps to know as much as you can about your oil, especially with first test batches, and titration tells you more than anything else will. I'm a little puzzled because it seems you're using 1 litre of oil, which should total 1,200 ml with the methanol, but you have 800 ml of biodiesel and 110 ml of by-product, so 290 ml seems to be missing. Still, the by-product ratio is not far off. Anyway, you're doing well, IMHO. The wash separates at least, albeit somewhat slowly, and you don't mention an emulsion layer, though it sounds like you really beat it up. Keep going, refine and improve and check whatever you can, and you'll get there. For reprocessing, use 10% methanol and whatever you decide the KOH equivalent is of 3.5 g NaOH per litre of oil. I doubt the pauses made much difference. HTH. Best Keith Over the weekend, I tried my first test batch of acid/base stuff; I've had plenty of success making this using both the conventional and base/base reactions (I had quite a lot of success with the latter, actually). Here are the specs: de-watered vegetable oil (a mixture, fairly clean used fairly lightly) H2SO4 (95%-98%) KOH (purity?) Methanol 1. I warmed the veg oil to 95F added--while stirring--80mL of Methanol 2. I stirred that (on a little magnet stirrer) until a suspension clearly formed and added 1mL of H2SO4 3. After 20 minutes or so I paused the stirring to move the beaker back to the heating pad to warm it again 4. Continued stirring for 80 more minutes 5. Let the mixture rest for 20 hours 6. Dissolved 4.9 g of the KOH (because I'm not sure about its purity) into 120ML of Methanol 7. Heated the oil-Methanol-H2SO4 blend to 135F 8. Slowly added the methoxide to the blend, while stirring 9. Twice, during the hour of stirring, I had to pause to re-heat the oil; in all, stirred for about 75 minutes 10.Settlement seemed very slow--it took a couple of hours to settle into distinct layers 11.The glycerine layer is only about 110mL 12.The
[Biofuel] 1L Acid/Base Test Batch: Questions
Hi, Folks: I'm kind of new to the list; I've spent a lot of time in the archives already, and I know this ground has been covered. But any advice/input any of you want to share would be great. Oh, and: I'm an English professor, not a chemist, so my apologies for what must seem like sloppy lab documentation to some of you! Over the weekend, I tried my first test batch of acid/base stuff; I've had plenty of success making this using both the conventional and base/base reactions (I had quite a lot of success with the latter, actually). Here are the specs: de-watered vegetable oil (a mixture, fairly clean used fairly lightly) H2SO4 (95%-98%) KOH (purity?) Methanol I warmed the veg oil to 95F added--while stirring--80mL of Methanol I stirred that (on a little magnet stirrer) until a suspension clearly formed and added 1mL of H2SO4 After 20 minutes or so I paused the stirring to move the beaker back to the heating pad to warm it again Continued stirring for 80 more minutes Let the mixture rest for 20 hours Dissolved 4.9 g of the KOH (because I'm not sure about its purity) into 120ML of Methanol Heated the oil-Methanol-H2SO4 blend to 135F Slowly added the methoxide to the blend, while stirring Twice, during the hour of stirring, I had to pause to re-heat the oil; in all, stirred for about 75 minutes Settlement seemed very slow--it took a couple of hours to settle into distinct layers The glycerine layer is only about 110mL The biodiesel layer is 800mL After 4 hours of settling, I washed the biodiesel violently agitating it with about 600mL of fresh (though hard) water Two distinct layers formed, but it took a couple of hours 12 hours after the first wash, I drained the wash water added another 600mL of fresh This second wash stage is also separating very slowly--still lots of white settling out. Questions: Would my pauses during mixing (and the fluctuating temperature) have greatly affected the reaction? Could the wash difficulty be the result of too much KOH in the initial reaction? Should I have around 80mL of additional precipitate from the reaction--or even more, given the total amount of the bd layer? Once I'm finished washing this batch (another couple of washes), I'm planning to take 100mL and re-react it, to see if I get a bit more glycerin. Any thoughts on how much KOH/Methanol I should try for that? Thanks much! Sean ___ 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/
Re: [Biofuel] 1L Acid/Base Test Batch: Questions
Hello Sean Hi, Folks: I'm kind of new to the list; I've spent a lot of time in the archives already, and I know this ground has been covered. But any advice/input any of you want to share would be great. Oh, and: I'm an English professor, not a chemist, so my apologies for what must seem like sloppy lab documentation to some of you! Looks okay to me, but then I'm a journalist not a chemist. :-) You need to know the purity of the KOH. It's unlikely to be pure, more likely 92% or 85%. You can find the equivalent amounts to use here: http://journeytoforever.org/biodiesel_make2.html#koh If you have some NaOH for comparison you might be able to do a sort of comparative titration which will tell you the right amount of KOH to use. It also helps to titrate the oil, even with the acid-base method - though you won't use the titration result in the process itself, it always helps to know as much as you can about your oil, especially with first test batches, and titration tells you more than anything else will. I'm a little puzzled because it seems you're using 1 litre of oil, which should total 1,200 ml with the methanol, but you have 800 ml of biodiesel and 110 ml of by-product, so 290 ml seems to be missing. Still, the by-product ratio is not far off. Anyway, you're doing well, IMHO. The wash separates at least, albeit somewhat slowly, and you don't mention an emulsion layer, though it sounds like you really beat it up. Keep going, refine and improve and check whatever you can, and you'll get there. For reprocessing, use 10% methanol and whatever you decide the KOH equivalent is of 3.5 g NaOH per litre of oil. I doubt the pauses made much difference. HTH. Best Keith Over the weekend, I tried my first test batch of acid/base stuff; I've had plenty of success making this using both the conventional and base/base reactions (I had quite a lot of success with the latter, actually). Here are the specs: de-watered vegetable oil (a mixture, fairly clean used fairly lightly) H2SO4 (95%-98%) KOH (purity?) Methanol 1. I warmed the veg oil to 95F added--while stirring--80mL of Methanol 2. I stirred that (on a little magnet stirrer) until a suspension clearly formed and added 1mL of H2SO4 3. After 20 minutes or so I paused the stirring to move the beaker back to the heating pad to warm it again 4. Continued stirring for 80 more minutes 5. Let the mixture rest for 20 hours 6. Dissolved 4.9 g of the KOH (because I'm not sure about its purity) into 120ML of Methanol 7. Heated the oil-Methanol-H2SO4 blend to 135F 8. Slowly added the methoxide to the blend, while stirring 9. Twice, during the hour of stirring, I had to pause to re-heat the oil; in all, stirred for about 75 minutes 10.Settlement seemed very slow--it took a couple of hours to settle into distinct layers 11.The glycerine layer is only about 110mL 12.The biodiesel layer is 800mL 13.After 4 hours of settling, I washed the biodiesel violently agitating it with about 600mL of fresh (though hard) water 14.Two distinct layers formed, but it took a couple of hours 15.12 hours after the first wash, I drained the wash water added another 600mL of fresh 16.This second wash stage is also separating very slowly--still lots of white settling out. Questions: 1. Would my pauses during mixing (and the fluctuating temperature) have greatly affected the reaction? 2. Could the wash difficulty be the result of too much KOH in the initial reaction? 3. Should I have around 80mL of additional precipitate from the reaction--or even more, given the total amount of the bd layer? Once I'm finished washing this batch (another couple of washes), I'm planning to take 100mL and re-react it, to see if I get a bit more glycerin. Any thoughts on how much KOH/Methanol I should try for that? Thanks much! Sean ___ 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/
Re: [Biofuel] 1L Acid/Base Test Batch: Questions
Thanks, Keith. I just checked the KOH .pdf data sheet at TheChemistryStore.com, where I bought the KOH) it says it's 100%. That doesn't seem exactly right, but it could explain the washing, given that I threw in a little extra. A titration is a good idea. I was lazily avoiding it . . . And, yeah, the final volume thing is weird. Undoubtedly, I lost a little here and there in transferring stuff to and from different containers, but certainly no more than 20 mL. Some of the Methanol has also surely evaporated . . . I must be missing something. Anyway, thanks much for the response. -Sean On Tue, 2006-04-25 at 05:33 +0900, Keith Addison wrote: Hello Sean Hi, Folks: I'm kind of new to the list; I've spent a lot of time in the archives already, and I know this ground has been covered. But any advice/input any of you want to share would be great. Oh, and: I'm an English professor, not a chemist, so my apologies for what must seem like sloppy lab documentation to some of you! Looks okay to me, but then I'm a journalist not a chemist. :-) You need to know the purity of the KOH. It's unlikely to be pure, more likely 92% or 85%. You can find the equivalent amounts to use here: http://journeytoforever.org/biodiesel_make2.html#koh If you have some NaOH for comparison you might be able to do a sort of comparative titration which will tell you the right amount of KOH to use. It also helps to titrate the oil, even with the acid-base method - though you won't use the titration result in the process itself, it always helps to know as much as you can about your oil, especially with first test batches, and titration tells you more than anything else will. I'm a little puzzled because it seems you're using 1 litre of oil, which should total 1,200 ml with the methanol, but you have 800 ml of biodiesel and 110 ml of by-product, so 290 ml seems to be missing. Still, the by-product ratio is not far off. Anyway, you're doing well, IMHO. The wash separates at least, albeit somewhat slowly, and you don't mention an emulsion layer, though it sounds like you really beat it up. Keep going, refine and improve and check whatever you can, and you'll get there. For reprocessing, use 10% methanol and whatever you decide the KOH equivalent is of 3.5 g NaOH per litre of oil. I doubt the pauses made much difference. HTH. Best Keith Over the weekend, I tried my first test batch of acid/base stuff; I've had plenty of success making this using both the conventional and base/base reactions (I had quite a lot of success with the latter, actually). Here are the specs: de-watered vegetable oil (a mixture, fairly clean used fairly lightly) H2SO4 (95%-98%) KOH (purity?) Methanol 1. I warmed the veg oil to 95F added--while stirring--80mL of Methanol 2. I stirred that (on a little magnet stirrer) until a suspension clearly formed and added 1mL of H2SO4 3. After 20 minutes or so I paused the stirring to move the beaker back to the heating pad to warm it again 4. Continued stirring for 80 more minutes 5. Let the mixture rest for 20 hours 6. Dissolved 4.9 g of the KOH (because I'm not sure about its purity) into 120ML of Methanol 7. Heated the oil-Methanol-H2SO4 blend to 135F 8. Slowly added the methoxide to the blend, while stirring 9. Twice, during the hour of stirring, I had to pause to re-heat the oil; in all, stirred for about 75 minutes 10. Settlement seemed very slow--it took a couple of hours to settle into distinct layers 11. The glycerine layer is only about 110mL 12. The biodiesel layer is 800mL 13. After 4 hours of settling, I washed the biodiesel violently agitating it with about 600mL of fresh (though hard) water 14. Two distinct layers formed, but it took a couple of hours 15. 12 hours after the first wash, I drained the wash water added another 600mL of fresh 16. This second wash stage is also separating very slowly--still lots of white settling out. Questions: 1. Would my pauses during mixing (and the fluctuating temperature) have greatly affected the reaction? 2. Could the wash difficulty be the result of too much KOH in the initial reaction? 3. Should I have around 80mL of additional precipitate from the reaction--or even more, given the total amount of the bd layer? Once I'm finished washing this batch (another couple of washes), I'm planning to take 100mL and re-react it, to see if I get a bit more glycerin. Any thoughts on how much KOH/Methanol I should try for that? Thanks much! Sean ___ 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):
Re: [Biofuel] 1L Acid/Base Test Batch: Questions
The KOH is 90%. That's what I get for reading the data sheet instead of the web page. On Tue, 2006-04-25 at 05:33 +0900, Keith Addison wrote: Hello Sean Hi, Folks: I'm kind of new to the list; I've spent a lot of time in the archives already, and I know this ground has been covered. But any advice/input any of you want to share would be great. Oh, and: I'm an English professor, not a chemist, so my apologies for what must seem like sloppy lab documentation to some of you! Looks okay to me, but then I'm a journalist not a chemist. :-) You need to know the purity of the KOH. It's unlikely to be pure, more likely 92% or 85%. You can find the equivalent amounts to use here: http://journeytoforever.org/biodiesel_make2.html#koh If you have some NaOH for comparison you might be able to do a sort of comparative titration which will tell you the right amount of KOH to use. It also helps to titrate the oil, even with the acid-base method - though you won't use the titration result in the process itself, it always helps to know as much as you can about your oil, especially with first test batches, and titration tells you more than anything else will. I'm a little puzzled because it seems you're using 1 litre of oil, which should total 1,200 ml with the methanol, but you have 800 ml of biodiesel and 110 ml of by-product, so 290 ml seems to be missing. Still, the by-product ratio is not far off. Anyway, you're doing well, IMHO. The wash separates at least, albeit somewhat slowly, and you don't mention an emulsion layer, though it sounds like you really beat it up. Keep going, refine and improve and check whatever you can, and you'll get there. For reprocessing, use 10% methanol and whatever you decide the KOH equivalent is of 3.5 g NaOH per litre of oil. I doubt the pauses made much difference. HTH. Best Keith Over the weekend, I tried my first test batch of acid/base stuff; I've had plenty of success making this using both the conventional and base/base reactions (I had quite a lot of success with the latter, actually). Here are the specs: de-watered vegetable oil (a mixture, fairly clean used fairly lightly) H2SO4 (95%-98%) KOH (purity?) Methanol 1. I warmed the veg oil to 95F added--while stirring--80mL of Methanol 2. I stirred that (on a little magnet stirrer) until a suspension clearly formed and added 1mL of H2SO4 3. After 20 minutes or so I paused the stirring to move the beaker back to the heating pad to warm it again 4. Continued stirring for 80 more minutes 5. Let the mixture rest for 20 hours 6. Dissolved 4.9 g of the KOH (because I'm not sure about its purity) into 120ML of Methanol 7. Heated the oil-Methanol-H2SO4 blend to 135F 8. Slowly added the methoxide to the blend, while stirring 9. Twice, during the hour of stirring, I had to pause to re-heat the oil; in all, stirred for about 75 minutes 10. Settlement seemed very slow--it took a couple of hours to settle into distinct layers 11. The glycerine layer is only about 110mL 12. The biodiesel layer is 800mL 13. After 4 hours of settling, I washed the biodiesel violently agitating it with about 600mL of fresh (though hard) water 14. Two distinct layers formed, but it took a couple of hours 15. 12 hours after the first wash, I drained the wash water added another 600mL of fresh 16. This second wash stage is also separating very slowly--still lots of white settling out. Questions: 1. Would my pauses during mixing (and the fluctuating temperature) have greatly affected the reaction? 2. Could the wash difficulty be the result of too much KOH in the initial reaction? 3. Should I have around 80mL of additional precipitate from the reaction--or even more, given the total amount of the bd layer? Once I'm finished washing this batch (another couple of washes), I'm planning to take 100mL and re-react it, to see if I get a bit more glycerin. Any thoughts on how much KOH/Methanol I should try for that? Thanks much! Sean ___ 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/ ___ 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/
