Viscosity - was Re: [biofuels-biz] Fuel Quality Test for Small Producers
Hello Tom Nice to hear from you again. I hope you're fully recovered now after your accident. >Randall, > >I've been producing biodiesel for the past 6 years, until recently. I have a >scientific peer reviewed paper that shows an almost complete correlation >between the quality (completeness) of the reaction and the >viscosity. So, viscosity >is the best indicator of the quality of the reaction. A cheap ($5.99) >viscosity tester can be obtained from harbor freight). This is the >best and most >indicative test. A lot of people disagree with that. I presume you're talking of the paper by De Filippis et al? "Transesterification Processes for Vegetable Oils: A Simple Control Method for Methyl Ester Content". You can find it here: http://www.veggiepower.org.uk/report1.htm For a start, they weren't using a cheap $5.99 Marsh funnel-type viscometer but a Hoeppler micro-viscometer, Haake's MicroVisco 2 - this thing: http://www.thermo.com/eThermo/CDA/Products/Product_Detail/1,1075,1 01067494-108-X-108-18451,00.html Not quite the same thing. And yes, it matters when you're trying to distinguish the very small differences in viscosity between glycerides and methyl ester accurately enough to be sure that your reaction has gone far enough towards completion to fall within the quality standards: "Total glycerine (free glycerine and unconverted glycerides combined) - 0.240% by mass, max." (ASTM D-6751). A funnel viscometer (or a PET bottle and a straw) won't get you near that, maybe within 5%, not good enough. The "almost" in "almost complete correlation" is rather critical. This is what Mark (Girl Mark) said about viscosity tests as a quality measure: "What this test won't tell you: Again, mono- and diglycerides foul it up. The viscosity of MG and DG are close enough to biodiesel that home-scale viscosity measurements can't detect them, and, again, in unwashed fuel the methanol gives us even more inaccuracies to worry about. I do not recommend this test unless you're a fuels lab." She said much the same thing about the other "quality test" popular with some people, specific gravity (density). We say much the same: http://journeytoforever.org/biodiesel_make2.html#visco Viscosity testing "... a useful comparative indicator of biodiesel quality. Unfortunately, and despite claims to the contrary, that's all it is -- a comparative indicator: this batch is better than that batch. Even at the laboratory or industrial level, viscosity testing alone cannot tell you if the process has gone far enough before reaching equilibrium -- in other words that there are not unacceptably high levels of harmful unreacted and partly reacted materials in your fuel..." Aleks Kac said this in a message to the Biofuel list: "I've seen bio with a SG 0.885 g/l (excellent) and have a kinematic viscosity of 10.5 cSt (horrible) but an acceptable cetane number of ~50!" The De Filippis paper on viscosity testing was discussed at the Biodiesel list when it was first posted. Here's what Todd Swearingen said about it: >Date: Tue, 21 May 2002 12:36:15 -0400 >Subject: Re: [Biodiesel] Quality testing >Reply-To: [EMAIL PROTECTED] > >If only curves and viscosity worked that way. They might get you >ballpark, inside of 5% or a little less, depending upon the >precision of the person graphing the curve or the number of >experiments conducted. But a 2-5% uncompleted reaction will still >leave you with a wash tank, barrel or carboy filled with a mess >and a "fuel" that wants to strangle an engine on early morning >starts and spits out higher volumes of white smoke compared to >completely reacted biodiesel. > >They are also referring to more precision equipment than what has >been relied upon in previous conversations here or at the Maui >board, which further reduces any shoddiness in margin >calculations. > >Many industrial processes include in-line viscometers to let >operators and technicians know when they are at different levels >of a given process. This eliminates the need for as many "grab >samples" as use to be conducted. But they are only relied upon as >indicators, not absolutes, and almost invariably there are other >factors that are added to their processes after taking such >initial measurements which insure that the desired result has >been reached. These generally include prolonged dwell time and/or >temp and pressure modifications with a final "grab sample" >submitted for analysis to "seal the deal" of product integrity. > >Todd Swearingen > >- Original Message - >From: hcr_ii <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Tuesday, May 21, 2002 12:00 PM >Subject: [Biodiesel] Quality testing > >>Seems that you might be able to test quality based on an accurate >>measure of viscosity after all. >> >>"..They then used gas chromatography (GC)(the same analysis used >>by large fuel companies) to determine %methyl esters, %mono, di, and >>triglycerides still in the samples. They a
Viscosity - was Re: [biofuels-biz] Fuel Quality Test for Small Producers
Hey Tom, Are you sure it was the viscometer that prodded you towards a nearly perfect sample or was it your methods? I would tend to believe that it was a number of indicators that you relied on to give you reason to be somewhat confident in submitting a sample for testing, that and great familiarity with what you are doing and what measure lends what result. There is one test that no one has mentioned that can lend to determining if a reaction has completed or not. (No. It's not the "frog in a blender" wash test.) It's the simple refrigeration of a sample. If the sample begins to cloud at a temp higher than what the ester should cloud at you can bank on there being a problem. We've seen different samples treated exactly in the same manner do exactly that when set on a cold floor overnite (~45*F). They were all from the same feedstock. But some were a higher ratio of oil/fat than others. Two of the eight showed no clouding and washed like a dream. Three had but 1/4 or less clouding at the bottom. They washed rather half-baked, forming more emulsion than they would have if complete. The remaining three showed several inches of cloudiness, which was to be expected, as the volume of the glycerin cocktail was a bit deficient. There wasn't even the first thought of washing these. Just another simple test, presuming the lady of the house doesn't mind the bottom shelf of her refrigerator being used for cloud point testing. Todd Swearingen --- In biofuels-biz@yahoogroups.com, [EMAIL PROTECTED] wrote: > Keith, > > As always, I'm wonderfully impressed with your filing system for a summary on > a topic. I agree that the viscometer test will not provide an absolute test > for the completion of the esterification reaction, unless one runs a detailed > calibration curve for a particular oil against results from a GC. And, also, a > cheap viscometer will not produce results as good as a more sophisticated > instrument. > > However, a relative measure of the quality of a batch process may still be > the best method of obtaining feedback on an inherently variable process. Without > some convenient, cheap feedback method, how is a small volume producer able > to understand the effect of the reaction parameters? We have seen here on this > listserve that it is not practical to have contracted analysis of every batch, > nor to support an in-house laboratory. Do you suggest a better method of > quality control? > > Note that the viscometer method, even with a cheap instrument, got me to > within 8/100 of 1% of the required ASTM level of total glycerin for the one sample > I had tested. If I had not been so cheap with the methanol, going from 18% > used in my usual reaction to, say, 22%, the reaction might have gone to near > completion. > > My goal is to help the small producer find a way to make an acceptable > biodiesel. Can we find ways to guide people towards a better product, or will it be > a series of roadblocks for everyone without nearly unlimited time and money? I > suspect that those limited number of current commercial producers wish us to > believe that few, if any, others can make quality biodiesel. I don't believe > that myself. > > Tom Leue > > > > In a message dated 11/14/03 5:08:37 AM, [EMAIL PROTECTED] writes: > > > > Hello Tom > > > > Nice to hear from you again. I hope you're fully recovered now after > > your accident. > > > > >Randall, > > > > > >I've been producing biodiesel for the past 6 years, until recently. I have > > a > > >scientific peer reviewed paper that shows an almost complete correlation > > >between the quality (completeness) of the reaction and the > > >viscosity. So, viscosity > > >is the best indicator of the quality of the reaction. A cheap ($5.99) > > >viscosity tester can be obtained from harbor freight). This is the > > >best and most > > >indicative test. > > > > A lot of people disagree with that. I presume you're talking of the > > paper by De Filippis et al? "Transesterification Processes for > > Vegetable Oils: A Simple Control Method for Methyl Ester Content". > > You can find it here: > > http://www.veggiepower.org.uk/report1.htm > > > > For a start, they weren't using a cheap $5.99 Marsh funnel-type > > viscometer but a Hoeppler micro-viscometer, Haake's MicroVisco 2 - > > this thing: > > http://www.thermo.com/eThermo/CDA/Products/Product_Detail/1,1075,1000 0 > > 01067494-108-X-108-18451,00.html > > > > Not quite the same thing. And yes, it matters when you're trying to > > distinguish the very small differences in viscosity between > > glycerides and methyl ester accurately enough to be sure that your > > reaction has gone far enough towards completion to fall within the > > quality standards: "Total glycerine (free glycerine and unconverted > > glycerides combined) - 0.240% by mass, max." (ASTM D-6751). > > > > A funnel viscometer (or a PET bottle and a straw) won't
Re: Viscosity - was Re: [biofuels-biz] Fuel Quality Test for Small Producers
Keith, As always, I'm wonderfully impressed with your filing system for a summary on a topic. I agree that the viscometer test will not provide an absolute test for the completion of the esterification reaction, unless one runs a detailed calibration curve for a particular oil against results from a GC. And, also, a cheap viscometer will not produce results as good as a more sophisticated instrument. However, a relative measure of the quality of a batch process may still be the best method of obtaining feedback on an inherently variable process. Without some convenient, cheap feedback method, how is a small volume producer able to understand the effect of the reaction parameters? We have seen here on this listserve that it is not practical to have contracted analysis of every batch, nor to support an in-house laboratory. Do you suggest a better method of quality control? Note that the viscometer method, even with a cheap instrument, got me to within 8/100 of 1% of the required ASTM level of total glycerin for the one sample I had tested. If I had not been so cheap with the methanol, going from 18% used in my usual reaction to, say, 22%, the reaction might have gone to near completion. My goal is to help the small producer find a way to make an acceptable biodiesel. Can we find ways to guide people towards a better product, or will it be a series of roadblocks for everyone without nearly unlimited time and money? I suspect that those limited number of current commercial producers wish us to believe that few, if any, others can make quality biodiesel. I don't believe that myself. Tom Leue In a message dated 11/14/03 5:08:37 AM, [EMAIL PROTECTED] writes: > Hello Tom > > Nice to hear from you again. I hope you're fully recovered now after > your accident. > > >Randall, > > > >I've been producing biodiesel for the past 6 years, until recently. I have > a > >scientific peer reviewed paper that shows an almost complete correlation > >between the quality (completeness) of the reaction and the > >viscosity. So, viscosity > >is the best indicator of the quality of the reaction. A cheap ($5.99) > >viscosity tester can be obtained from harbor freight). This is the > >best and most > >indicative test. > > A lot of people disagree with that. I presume you're talking of the > paper by De Filippis et al? "Transesterification Processes for > Vegetable Oils: A Simple Control Method for Methyl Ester Content". > You can find it here: > http://www.veggiepower.org.uk/report1.htm > > For a start, they weren't using a cheap $5.99 Marsh funnel-type > viscometer but a Hoeppler micro-viscometer, Haake's MicroVisco 2 - > this thing: > http://www.thermo.com/eThermo/CDA/Products/Product_Detail/1,1075,1 > 01067494-108-X-108-18451,00.html > > Not quite the same thing. And yes, it matters when you're trying to > distinguish the very small differences in viscosity between > glycerides and methyl ester accurately enough to be sure that your > reaction has gone far enough towards completion to fall within the > quality standards: "Total glycerine (free glycerine and unconverted > glycerides combined) - 0.240% by mass, max." (ASTM D-6751). > > A funnel viscometer (or a PET bottle and a straw) won't get you near > that, maybe within 5%, not good enough. The "almost" in "almost > complete correlation" is rather critical. > > This is what Mark (Girl Mark) said about viscosity tests as a quality > measure: "What this test won't tell you: Again, mono- and > diglycerides foul it up. The viscosity of MG and DG are close enough > to biodiesel that home-scale viscosity measurements can't detect > them, and, again, in unwashed fuel the methanol gives us even more > inaccuracies to worry about. I do not recommend this test unless > you're a fuels lab." > > She said much the same thing about the other "quality test" popular > with some people, specific gravity (density). > > We say much the same: > > http://journeytoforever.org/biodiesel_make2.html#visco > Viscosity testing > "... a useful comparative indicator of biodiesel quality. > Unfortunately, and despite claims to the contrary, that's all it is > -- a comparative indicator: this batch is better than that batch. > Even at the laboratory or industrial level, viscosity testing alone > cannot tell you if the process has gone far enough before reaching > equilibrium -- in other words that there are not unacceptably high > levels of harmful unreacted and partly reacted materials in your > fuel..." > > Aleks Kac said this in a message to the Biofuel list: "I've seen bio > with a SG 0.885 g/l (excellent) and have a kinematic viscosity of > 10.5 cSt (horrible) but an acceptable cetane number of ~50!" > > The De Filippis paper on viscosity testing was discussed at the > Biodiesel list when it was first posted. Here's what Todd Swearingen > said about it: > > >Date: Tue, 21 May 2002 12:36:15 -0400 > >Subject: Re: [Biodiesel] Quality testing > >Repl
Re: Viscosity - was Re: [biofuels-biz] Fuel Quality Test for Small Producers
Todd, The biodiesel chilling test presumes that your feedstock remains the same or is similar from batch to batch. The cloud point of ASTM certified biodiesel varies greatly due to the feedstock. For instance, World Energy biodiesel from the Cincinnati plant, which contains much rendered animal fats, has a 10 degree higher cloud point or freeze point compared to Yellow Biodiesel which is based on only plant based oils (used to be). Then again, a batch of canola will yield a much lower cloud point for biodiesel than that made from partially hydrogenated soy. If we are basing our feedstock on yellow grease from dozens of changing sources, there is no way I can see as to how to predict the cloud point for a particular biodiesel. This brings up another point, BTW. In my business plan it is necessary to have a grease warehouse where large tanks allow equalization and stabilization of the feedstock. My current plan has 5 tanks, each 15' tall and containing 12,000 gallons each. This is the maximum allowed under NFPA Code 30 for indoor storage with minimal fire suppression requirements. Now, under this plan, one can get to know a typical oil's characteristics, something I was never able to do reliably, and predict its cold performance. This is another example of "do as I say, not as I do". Tom Leue In a message dated 11/21/03 1:53:44 AM, [EMAIL PROTECTED] writes: > Hey Tom, > > Are you sure it was the viscometer that prodded you towards a nearly > perfect sample or was it your methods? > > I would tend to believe that it was a number of indicators that you > relied on to give you reason to be somewhat confident in submitting > a sample for testing, that and great familiarity with what you are > doing and what measure lends what result. > > There is one test that no one has mentioned that can lend to > determining if a reaction has completed or not. (No. It's not > the "frog in a blender" wash test.) It's the simple refrigeration of > a sample. If the sample begins to cloud at a temp higher than what > the ester should cloud at you can bank on there being a problem. > > We've seen different samples treated exactly in the same manner do > exactly that when set on a cold floor overnite (~45*F). They were > all from the same feedstock. But some were a higher ratio of oil/fat > than others. Two of the eight showed no clouding and washed like a > dream. Three had but 1/4 or less clouding at the bottom. They washed > rather half-baked, forming more emulsion than they would have if > complete. The remaining three showed several inches of cloudiness, > which was to be expected, as the volume of the glycerin cocktail was > a bit deficient. There wasn't even the first thought of washing > these. > > Just another simple test, presuming the lady of the house doesn't > mind the bottom shelf of her refrigerator being used for cloud point > testing. > > Todd Swearingen > > - Homestead Inc. www.yellowbiodiesel.com [Non-text portions of this message have been removed] Yahoo! Groups Sponsor -~--> Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark Printer at MyInks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511 http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/9bTolB/TM -~-> Biofuels at Journey to Forever http://journeytoforever.org/biofuel.html List messages are archived at the Info-Archive at NNYTech: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: Viscosity - was Re: [biofuels-biz] Fuel Quality Test for Small Producers
Tom, Apologies. I wasn't as clear as needed relative to chilling samples. I shouldn't have used the term "cloud point" to indicate what happens when an incomplete reaction of WVO is chilled. And some further clarity should have been used between yellow grease and WVO. As you point out they aren't precisely interchangeble. We work primarily with yellow grease. The animal fat content can vary from day to day depending upon the source. But the fact that there is some part animal fat is consistent. When biodiesel is gradually cooled it clouds almost uniformly, in both washed and pre-washed state, whether the feedstock is SVO, WVO, yellow grease, or even 100% deer tallow. That is, of course, if the reaction was complete. However, with an incomplete reaction, gradual cooling will yield a rather quick appearance of solids from the bottom up. The solids that first appear are the unconverted animal fats, with the partially hydrogenated oils in lock step. This non-homogenous form of solidification is what I was referring to as yet another quick method of determining an incomplete reaction, at least for feedstocks with animal fat content. If the reaction appears to have completed, a quick wash can be used as further verification. That wash is a great deal easier to use as a determinant if the process being conducted is acid/base. Many straight base reactions have to overcome such a high percentage of FFAs and produce so much soap that a quick and vigorous sample washing will yield emulsification. A completed acid/base can be washed with a12 horsepower Evinrude in a 55-gallon drum without emulsifying. Todd Swearingen - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Friday, November 21, 2003 12:37 PM Subject: Re: Viscosity - was Re: [biofuels-biz] Fuel Quality Test for Small Producers > Todd, > > The biodiesel chilling test presumes that your feedstock remains the same or > is similar from batch to batch. The cloud point of ASTM certified biodiesel > varies greatly due to the feedstock. For instance, World Energy biodiesel from > the Cincinnati plant, which contains much rendered animal fats, has a 10 degree > higher cloud point or freeze point compared to Yellow Biodiesel which is > based on only plant based oils (used to be). Then again, a batch of canola will > yield a much lower cloud point for biodiesel than that made from partially > hydrogenated soy. If we are basing our feedstock on yellow grease from dozens of > changing sources, there is no way I can see as to how to predict the cloud point > for a particular biodiesel. > > This brings up another point, BTW. In my business plan it is necessary to > have a grease warehouse where large tanks allow equalization and stabilization of > the feedstock. My current plan has 5 tanks, each 15' tall and containing > 12,000 gallons each. This is the maximum allowed under NFPA Code 30 for indoor > storage with minimal fire suppression requirements. Now, under this plan, one can > get to know a typical oil's characteristics, something I was never able to do > reliably, and predict its cold performance. This is another example of "do as > I say, not as I do". > > Tom Leue > > In a message dated 11/21/03 1:53:44 AM, [EMAIL PROTECTED] writes: > > > > Hey Tom, > > > > Are you sure it was the viscometer that prodded you towards a nearly > > perfect sample or was it your methods? > > > > I would tend to believe that it was a number of indicators that you > > relied on to give you reason to be somewhat confident in submitting > > a sample for testing, that and great familiarity with what you are > > doing and what measure lends what result. > > > > There is one test that no one has mentioned that can lend to > > determining if a reaction has completed or not. (No. It's not > > the "frog in a blender" wash test.) It's the simple refrigeration of > > a sample. If the sample begins to cloud at a temp higher than what > > the ester should cloud at you can bank on there being a problem. > > > > We've seen different samples treated exactly in the same manner do > > exactly that when set on a cold floor overnite (~45*F). They were > > all from the same feedstock. But some were a higher ratio of oil/fat > > than others. Two of the eight showed no clouding and washed like a > > dream. Three had but 1/4 or less clouding at the bottom. They washed > > rather half-baked, forming more emulsion than they would have if > > complete. The remaining three showed several inches of cloudiness, > > which was to be expected, as the volume of the glycerin cocktail was > > a bit deficient. There wasn't even the first thought of washing > > these. > > >
