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/1,1075,10000 01067494-108-X-108-1000000008451,00.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 also measured the density >>and viscosity of the mixtures at 20 and 37.8 C. Using the results >>from the GC they developed correlation curves between % conversion >>and the density and viscosity of the esters. So all you have to do is >>measure the viscosity or density at 20 or 37.8 C to figure your % >>conversion." >> >>You will find the source on the Maui board. And about funnel and PET bottle-and-straw viscometers: "Our resident chemist is more inclined to compare your viscometer with the "taste, smell and feel method" of determining whether or not a reaction has gone to completion. A better "shadetree" indicator of reaction completion for those without GC or LGC - which is almost everyone who has ever made or will ever make biodiesel - is what takes place in the wash." Indeed. I have to say that viscosity testing doesn't seem to have helped you much with quality Tom, and just where it would be expected not to help - glycerin content: http://archive.nnytech.net/sgroup/biofuels-biz/3152/1/ Date: 2003-07-28 From: [EMAIL PROTECTED] Subject: [biofuels-biz] Almost ASTM Fuel >My results were good, but not quite good enough. There are 14 >parameters tested under the ASTM standard. I passed 13 of them. The >last one was Total Glycerin: this is basically a measure of the >completeness of the overall reaction, breaking down the oil into >methylesters. The standard is no more than 0.25% total glycerine >from unreacted oil. My results came back at 0.33% total glycerine. >That is 7/1000 off of the standard. Everything else met the >specifications. It was Aleks who first told you about viscosity testing, on the Biofuel list just two years ago, but he didn't suggest it as a biodiesel quality test, he was discussing your problems with burning biodiesel in your mother's furnace. Here are the archive links to that discussion: http://archive.nnytech.net/index.php?view=9541&list=BIOFUEL From: [EMAIL PROTECTED] Date: 2001-11-04 Subject: Here in the frozen North http://archive.nnytech.net/index.php?view=9546&list=BIOFUEL From: "Aleksander <kac" <[EMAIL PROTECTED]> Date: Mon Nov 5, 2001 6:05am Subject: Biodiesel for heating was:Here in the frozen North... http://archive.nnytech.net/index.php?view=9566&list=BIOFUEL From: [EMAIL PROTECTED] Date: Mon Nov 5, 2001 10:38pm Subject: Re: [biofuel] Biodiesel for heating was:Here in the frozen North... http://archive.nnytech.net/index.php?view=9573&list=BIOFUEL From: "Aleksander <kac" <[EMAIL PROTECTED]> Date: Tue Nov 6, 2001 6:18am Subject: Re: Biodiesel for heating - viscosity http://archive.nnytech.net/sgroup/biofuel/9580/1/ From: [EMAIL PROTECTED] Date: Tue Nov 6, 2001 12:58pm Subject: Re: [biofuel] Re: Biodiesel for heating - viscosity http://archive.nnytech.net/index.php?view=9581&list=BIOFUEL From: "Aleksander <kac" <[EMAIL PROTECTED]> Date: Tue Nov 6, 2001 1:33pm Subject: Re: Biodiesel for heating - viscosit I think viscosity testing (and SG) can give people a false sense of confidence in the quality of their homebrew, and helps to enshrine some rather dubious practices as acceptable, or even as standard, though they do not help to achieve a quality product and more likely hinder it. Best Keith >Tom Leue > >In a message dated 11/11/03 9:07:16 AM, [EMAIL PROTECTED] writes: > > > > Greetings, > > > > I would appreciate learning if there is a fairly simple and affordable > > Fuel Quality test system for the home producer of biodiesel. > > > > Randal Son > > "Resist Convenience" ------------------------ 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! 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