... maybe that's an overly dramatic title for this post, but...
I'm inadvertently started this bubble drying trend a few months ago and now I have some questions about it all. (I got the idea from one of the U of Idaho papers, though it isn't a common practice for some reason). I had spammed all the lists I knew of with the info at the time, with some questions that I still haven't got good answers to. The jury's still out for me on what exactly is happening during 'bubble drying' or 'haze clearing'. My initial questions (about whether clear fuel equals dry fuel) were based on this: I first tried bubbledrying in the middle of an intense week-long rainstorm. I make fuel outside and I had all my tanks tightly swathed in tarps. The humidity outside was extreme. I bubbled my humid air through washed but hazy fuel and in 24 hours the haze had cleared completely. I was at first questioning how this worked at all, in that humidity. Now, it at first doesn't seem too strange. After my list-spamming a couple of people immediately wrote back (one was a chemist friend writing from Nevada in the desert, who tried the bubbledrying right away and got haze clearing in 2 or 3 hours of bubbledrying hot dry air through it) and reminded me that in bubbling air through the biodiesel there would be much more contact between the dissolved water and the air, than with just allowing dry air movement over the surface (which isn't an option for those of us with the rainy seasons anyway, unless you have a shed for drying your fuel). Others suggested that humid air in the rain might still not be it's carrying capacity for moisture absorption and can still absorb more moisture under some conditions, and when being bubbled through the wet biodiesel it absorbs water better than the well washed biodiesel retains it for a couple of reasons. So we put that clear fuel in people's cars and kept doing this bubbledrying practice. But i still wonder, is clear fuel necessarily dry fuel? As has been pointed out a lot, the better you wash it, the faster it will clear out haze, as there is no soap left to hang on to the water. People sometimes insist that exposing the fuel to warm air or air movement is necessary. I pointed out that I have had quite a few sealed buckets of washed fuel that cleared just from settling, with no interaction with air (see below). this makes sense from any perspective of course- though I didn't keep track of how long it took. If it's well washed the water will settle as well as evaporate. Anyway, here's the catch about bubble drying: I had taken some samples of both unwashed and some washed fuel and I had sealed them in mason jars. The point was to have a couple of educational samples to show people the difference. Well, lo and behold, the samples sat in my room and one day I noticed that the formerly crystal clear washed and 'dried' fuel had become ' hazy' again within a couple of weeks, and I hadn't opened the jar or done anything that could have introduced water, or allowed it any contact with moisture in the air. I had pulled the sample off the top of the tank of fuel and there's no chance that any bulk water got in during that process either. I hadn't previously noticed bubbledried fuel reverting to a hazy state, because finished fuel doesn't sit around for long around here- as soon as it's done it goes into someone's car. Cold will make biodiesel haze (or cloud) but that's not what was happening- temperature was definitely not a factor and the fuel was hazy at the same ambient temps as when I pulled the clear' sample initially. I pulled another pair of comparison samples on the next 'bubble dried' batch and it happened again- stuff that looked bright and clear became murky just through sitting for a couple of weeks. That second sample also dropped out some whitish stuff, which could be unrelated and is something that happens if you settle out water outdoors with colder temps (there's a couple of things that could be). Now, there's a couple of other things going on here- 1. a lot of us have all been using the same source this very odd, old oil that causes massive emulsification and washing problems. People have had trouble washing it regardless of their equipment and biodiesel making/washing technique. Trying to chase down the source of the washing problems, I've adjusted for temperature, lye quantity, methanol, and agitation, and it has slightly corrected the washing problems, but only somewhat- it still doesn't wash or test like normal fuel. The oil is ancient- has been sitting around getting stockpiled in drums on the factory's parking lot for a year or two- so there could be a lot going on there. Ken Provost from Biofuel got some particilarly nasty oil from the same source and found it to be partly polymerized- and in his case it made biodiesel with a weird viscosity as well, something aobut two biodiesel molecules bonded together just like the polymerized oils he started with. 2. I was basing my decisions on when to stop washing just on clarity of wash water- I was out of pH strips (having just bought some that gave me wildly erroneous readings in water, buffer solution, etc). SO I am not 100% convinced that it was perfectly well washed fuel for either sample to begin with, and like I said, we have had a lot of trouble with this fuel in the washing stages. I was going to repeat this experiment yet another time with some more definitely 'properly washed' fuel- but the most recent batch I washed (tested it this time, and washed it an extra time just to make sure) went crystal clear on me before I had a chance to do anything with it. It cleared while sitting in a tightly sealed drum, in two or three days, before I even tried to bubbledry it. So much for the 'air movement is absolutely necessary' theory. So I've got a couple of questions for the chemists. I am of course wondering if clear fuel=dried fuel, and is there some chemical reaction going on here - some kind of reaction between some component of air and some component of WVO biodiesel that could result in either hazing or clearing, which would be a reversible reaction that would explain the fuel reverting to hazing over time? I have possible access to a gas chromotography guy now and analysing the two samples (washed and hazy, washed, bubbledried, and clear) might be a good use of his time. Any ideas on what he could be looking for there? Stumped, Mark [Non-text portions of this message have been removed] Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
