Alecs' comment is interesting, but I got less smoke on base/base ester. I also got considerably more byproduct using less methanol (15% instead of 20+%). I do not think there was much unreacted oil in either product.
For the record, I get less mpg than from 100% petroleum ultra low sulphur diesel - it's down by 3 to 5% on bases base reacted and 10% on my acid reacted ester. My "tests" were most unscientific, and the comments are mine alone. I found the acid/base ester was more smokey and less calorific than the base/base ester. The acid ester was also much darker than the base ester made from similar quality used oils. Alecs has already said that darker ester can mean more glycerides. But, if that means more energy, how does it square with the observed power outputs? At constant moderate speed, the base methyl ester can be slightly better than petroleum. When the power is used, it is definitely worse. I think the reason is that the oxygen content improves combustion so at low power you do better. At higher power the simple maths of energy in - power out come to play. Blends with petroleum bear that out. A B20 has been proven to give 1% to 2% better mpg than 100% petroleum (can't remember the research body, but it might have been TEAGASC of Eire). We do need some proper research using properly tested esters made by both processes. Quite possibly my results were just an aberration. It was not scientifically made or tested, but the results were consistent enough to raise the question. In the mean time a commercial producer would be wise to keep high FFA feedstock away from the better quality feedstock. Then the esters can be separated and priced accordingly. Truck operators will notice immediately if their mileage is down. One upset and they won't be back. :( Dave Dave --- In [EMAIL PROTECTED], Keith Addison <[EMAIL PROTECTED]> wrote: > >On fuel quality we have to be "whiter than white" and be seen to be > >so. > > > >Dave > > Hi Dave > > Indeed yes. You raised some previous questions about quality. > > >High FFA fats can be acid esterified - see Alecs Kak's recipe on > >www.journeytoforever.org. However, I would add that you do need to > >titrate. High levels of FFA need longer in the acid stage so how long > >is enough if you don't know the FFA content. > > <snip> > > >I'm not convinced the calorific value is as good as plain base > >reacted ester so would appreciate what you find out on that. > > Also: > > >I have tested some ester made using the acid/base/base process. It > >worked fine and I got less byproduct than when I use the normal > >base/base process. However, on base/base ester, my car's fuel trip > >computer will register about 44 mpg after about 5 miles of 70mph > >driving. > > > >With the acid/base product it would struggle to 40mpg under the same > >conditions. Yesterday I added 4 gals of base/base to the tank which > >already contained about 4 gals of acid/base fuel. Within 5 miles, my > >trip computer was showing 44mpg and rising. This is the second time I > >have had this result, so it's not a oneoff event. > > > >We need to be careful. If we try to sell acid/base fuel as being the > >same as base/base fuel then we have to be sure it really IS the same. > > > >I'm sure my acid reacted fuel lost something - oxygens maybe? Is it > >simply stripping the glycerols from FFA, leaving the FFA to mix in > >with the ester made by the base reaction process? This could explain > >the low calorific value. > > > >Proper research is needed on this question. > > I forwarded this to Aleks. Here's his response. > > "Biodiesel has a lower calorific value per litre than triglics mixes > (oil/fat). If he does make more mpg on base bio, this means that he > is driving on something else than methyl esters. I presume that this > would be a mix of methyl/mono-/di-/(possible tri-) glcerids. That's > called sloppy biodiesel. True, it packs more carbon into the > cylinders, but it also emits acroleins. I'm (almost) ashamed to say : > I use it (offroad). It > really packs more power because it has a higher density. On the other > hand, I can > see my exhaust fumes and this isn't quite good. > > "Re titration - determinig exact reaction time is a pain because ffa > levels vary wildly. I established two categories: > 1. up to heavily used liquid fat and medium used solid fat : 1.75 hrs > 2. more than medium used solid fat and up : 2.25 hrs > Longer reaction times just cost time and energy. You get a little > better results, but the price is high." > > Best > > Keith Addison Biofuels at Journey to Forever http://journeytoforever.org/biofuel.html Biofuel at WebConX http://www.webconx.com/2000/biofuel/biofuel.htm 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/
