RE: [biofuel] washing biodiesel in large processor
Hi Todd, This mixing method you describe looks much easier than bubble washing or mist washing. What I intend to do is to use the pump from my reactor vessel to mix the biodiesel and water. Presumably this is ok? You emphasise that it is important that the reaction be fully complete. From what I have been reading on Journeytoforever it seems that the best way to ensure that is to use the correct amount of lye, i.e. 3.5 or 4 grams plus titration plus plenty of excess methanol. I intend doing my first large batch soon (50 litres). It titrates at 2.4 so I am going to use say 6.4 grams/litre of lye plus 25% methanol to ensure a complete reaction. I have read the journeytoforever advice on the different amounts of methanol to use for different oils but as I am going to recover the methanol I don't think it matters if I use too much. I presume most of the excess methanol will end up in the glycerine and not the biodiesel. I would appreciate your advice on this. Is there anything radically wrong with what I have proposed above? Regards, Dermot -Original Message- From: Appal Energy [mailto:[EMAIL PROTECTED] Sent: 09 July 2004 00:36 To: biofuel@yahoogroups.com Subject: Re: [biofuel] washing biodiesel in large processor Ardis, You will find, after enough experimentation and out of pocket costs, that mechanical agitation in a wash tank is the least expensive, consumes the least energy, requires the least amount of time and leaves you with a finished product as good as or better than mist- or bubble-washing. Plain, pure and simple, mist- and bubble-washing have become institutionalized amongst home-brewers primarily due to the frequency of incomplete reactions that lend to washing problems. In short, they are both methods of treating incomplete reactions with little kid's gloves in the hopes that any resulting emulsion won't be too bad or too noticeable. The fact of the matter is that no wash method should be used on any batch unless it is known for certain that the reaction has completed. Unfortunately, many people fail to guarantee this for themselves, opting to just go ahead and wash it gently. The method of guarantee is extremely simple. Put one ounce of what is believed to be finished fuel in a baby food jar (or similar) with an equal amount of water. Seal the jar and shake violently for 15 seconds. Completed fuel should begin to separate instantly and there should be two distinct layers in less than ~30 seconds. If it takes longer than this or if an emulsion layer forms any thicker than the normal paper thin interface layer between oil and water, you've got a batch that has not completed. The degree of incompletion can vary. If the fuel/water separate slowly but are by-and-large complete in a matter of 1-2 minutes and there is no emulsion layer other than the interface, there's no great need to retreat the reaction if the fuel is intended for personal use. If you have an emulsion beyond the thin interface layer the batch needs to be retreated. No amount of light mist- or bubble-washing can change this - unless, of course, you don't care what grade of fuel you run through your engine. The wash test and mechanical washing (motor, prop and shaft) work well no matter what method you use - acid/base or straight base, single or double stage. Some concern has been expressed in the past over the use of air to dry fuel, the concern being fuel oxidation. It's beyond me why those who express such concern (and rightfully so) don't say word one about bubble washing doing the exact same thing. Others express concern with pump- or prop-washed fuel not clearing as quickly as mist- or bubble-washed. There's sound reason for this, all things being equal. Pumps and propellers have the ability of better mixing the fuel and water (atomizing it), bringing both in more frequent contact with each other. This means greater surface to surface contact between water molecules and all suspended/dissolved impurities. Fifteen minutes with a 1/2 hp motor and 4 - 6 prop in a 200 gallon wash tank or bigger will achieve the same thing or more as an all-day-affair with a mist- or bubble-washer. This allows for hours of washing time to be converted to settling time, in turn hastening the entire wash process. Anyway, when all is said and done and no matter what wash method you choose, you'll best serve your own interests if you make sure that your reaction is complete before attempting any type of wash. All bubble- and mist-washing tend to do is offer brewers the opportunity to wash an incompletely reacted batch with one eye closed and sometimes the other eye squinted. Todd Swearingen - Original Message - From: ardis streeter [EMAIL PROTECTED] To: biofuel@yahoogroups.com Cc: [EMAIL PROTECTED] Sent: Wednesday, July 07, 2004 7:29 PM Subject: [biofuel] washing biodiesel in large processor Hi,all ' I was wondering if anyone could tell me which way might be best for washing large batches of biodiesel??My
Re: [biofuel] washing biodiesel in large processor
Hi Todd, Ardis I agree with Todd, it's confirmed by what we've found and what we do and what the people we work with have found. Ardis, You will find, after enough experimentation and out of pocket costs, that mechanical agitation in a wash tank is the least expensive, consumes the least energy, requires the least amount of time and leaves you with a finished product as good as or better than mist- or bubble-washing. Plain, pure and simple, mist- and bubble-washing have become institutionalized amongst home-brewers primarily due to the frequency of incomplete reactions that lend to washing problems. I'm afraid that's right. In short, they are both methods of treating incomplete reactions with little kid's gloves in the hopes that any resulting emulsion won't be too bad or too noticeable. The fact of the matter is that no wash method should be used on any batch unless it is known for certain that the reaction has completed. Unfortunately, many people fail to guarantee this for themselves, opting to just go ahead and wash it gently. The method of guarantee is extremely simple. Put one ounce of what is believed to be finished fuel in a baby food jar (or similar) with an equal amount of water. Seal the jar and shake violently for 15 seconds. Completed fuel should begin to separate instantly and there should be two distinct layers in less than ~30 seconds. If it takes longer than this or if an emulsion layer forms any thicker than the normal paper thin interface layer between oil and water, you've got a batch that has not completed. The degree of incompletion can vary. If the fuel/water separate slowly but are by-and-large complete in a matter of 1-2 minutes and there is no emulsion layer other than the interface, there's no great need to retreat the reaction if the fuel is intended for personal use. If you have an emulsion beyond the thin interface layer the batch needs to be retreated. No amount of light mist- or bubble-washing can change this - unless, of course, you don't care what grade of fuel you run through your engine. The wash test and mechanical washing (motor, prop and shaft) work well no matter what method you use - acid/base or straight base, single or double stage. We use all methods that can be called methods and then some, and that's the case. Some concern has been expressed in the past over the use of air to dry fuel, the concern being fuel oxidation. It's beyond me why those who express such concern (and rightfully so) don't say word one about bubble washing doing the exact same thing. Indeed. For my part, I didn't say anything about air-drying but I did say something about bubble-washing and oxidation: Meeting the German or Austrian standard isn't difficult, but the Euro standard might be, especially if we think bubblewashing is a great idea. Might have to drop bubblewashing, go for simple stirring instead (and making the stuff properly in the first place). Might have to use an additive as well. And, might have to drop soy too. Something tells me the ASTM standard isn't about to adopt these Euro oxidation limits any time soon. Bubble-washing certainly promotes oxidation. I've been sent some lab test results on that, or rather a precis of them. Those folks are no longer doing bubble-washing or air-drying. They use pumps and stirrers to wash. Others express concern with pump- or prop-washed fuel not clearing as quickly as mist- or bubble-washed. There's sound reason for this, all things being equal. Pumps and propellers have the ability of better mixing the fuel and water (atomizing it), bringing both in more frequent contact with each other. This means greater surface to surface contact between water molecules and all suspended/dissolved impurities. Fifteen minutes with a 1/2 hp motor and 4 - 6 prop in a 200 gallon wash tank or bigger will achieve the same thing or more as an all-day-affair with a mist- or bubble-washer. This allows for hours of washing time to be converted to settling time, in turn hastening the entire wash process. Faster, results as good or better. We still do bubble-washing, but then we do just about everything else too, except mist-washing, I really do think that's a blind alley, along with other well-known blind alleys. If this were just a production facility rather than also for demonstration, testing, investigation, we'd probably drop bubble-washing, or mostly anyway. It does have its advantages, especially if you're not in a hurry, and oxidation of an oil like canola/rapeseed or better (ie lower Iodine Values) isn't a problem as long as you use it quickly. We do a lot of demos all over Japan, and we hold these very popular monthly biodiesel seminars here, and when we demonstrate bubble-washing (easy to transport and easy to scale down to desktop-size if need be) it's a handily visual example of how washing works, but it's also a good way of introducing the subject of oxidation - after all, that's what the fish-tank aerator
Re: [biofuel] washing biodiesel in large processor
Ardis, You will find, after enough experimentation and out of pocket costs, that mechanical agitation in a wash tank is the least expensive, consumes the least energy, requires the least amount of time and leaves you with a finished product as good as or better than mist- or bubble-washing. Plain, pure and simple, mist- and bubble-washing have become institutionalized amongst home-brewers primarily due to the frequency of incomplete reactions that lend to washing problems. In short, they are both methods of treating incomplete reactions with little kid's gloves in the hopes that any resulting emulsion won't be too bad or too noticeable. The fact of the matter is that no wash method should be used on any batch unless it is known for certain that the reaction has completed. Unfortunately, many people fail to guarantee this for themselves, opting to just go ahead and wash it gently. The method of guarantee is extremely simple. Put one ounce of what is believed to be finished fuel in a baby food jar (or similar) with an equal amount of water. Seal the jar and shake violently for 15 seconds. Completed fuel should begin to separate instantly and there should be two distinct layers in less than ~30 seconds. If it takes longer than this or if an emulsion layer forms any thicker than the normal paper thin interface layer between oil and water, you've got a batch that has not completed. The degree of incompletion can vary. If the fuel/water separate slowly but are by-and-large complete in a matter of 1-2 minutes and there is no emulsion layer other than the interface, there's no great need to retreat the reaction if the fuel is intended for personal use. If you have an emulsion beyond the thin interface layer the batch needs to be retreated. No amount of light mist- or bubble-washing can change this - unless, of course, you don't care what grade of fuel you run through your engine. The wash test and mechanical washing (motor, prop and shaft) work well no matter what method you use - acid/base or straight base, single or double stage. Some concern has been expressed in the past over the use of air to dry fuel, the concern being fuel oxidation. It's beyond me why those who express such concern (and rightfully so) don't say word one about bubble washing doing the exact same thing. Others express concern with pump- or prop-washed fuel not clearing as quickly as mist- or bubble-washed. There's sound reason for this, all things being equal. Pumps and propellers have the ability of better mixing the fuel and water (atomizing it), bringing both in more frequent contact with each other. This means greater surface to surface contact between water molecules and all suspended/dissolved impurities. Fifteen minutes with a 1/2 hp motor and 4 - 6 prop in a 200 gallon wash tank or bigger will achieve the same thing or more as an all-day-affair with a mist- or bubble-washer. This allows for hours of washing time to be converted to settling time, in turn hastening the entire wash process. Anyway, when all is said and done and no matter what wash method you choose, you'll best serve your own interests if you make sure that your reaction is complete before attempting any type of wash. All bubble- and mist-washing tend to do is offer brewers the opportunity to wash an incompletely reacted batch with one eye closed and sometimes the other eye squinted. Todd Swearingen - Original Message - From: ardis streeter [EMAIL PROTECTED] To: biofuel@yahoogroups.com Cc: [EMAIL PROTECTED] Sent: Wednesday, July 07, 2004 7:29 PM Subject: [biofuel] washing biodiesel in large processor Hi,all ' I was wondering if anyone could tell me which way might be best for washing large batches of biodiesel??My processor is capable of processing up to 200 gallons at a time.I am still building the processor so I was looking for some imfo.from experenced biodiesel producers.So far I have the stainless pick up tank done,the methanol,lye mix tank done,the processing tank with heat exchangers and mixer done.Currently I am building the wash tank and was wondering if bubble washing or top mist washing would be better for a tank that is 46 inches in dia. and aprox. 90 inches high.The tank will hold aprox. 480 gallons.Also was wondering if the tank needs an agitoror or if the wash tank should be set up with a pump to stir the fuel,water wash?? Also would like to know if the wash water should be pre-heated because well water is around 55 degrees,would this cause a problem with proper washing.Thanks for any help|| __ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links
