----- Original Message ----- From: <[EMAIL PROTECTED]>
> Paul have you tried acidifying your washing water?10ml of 35% HCl/L > of water. Yes Harry, have tried 10 to 20% vinegar in wash water, Adding citric acid dissolved in methanol to BD prior to washing, using MGSO4 in wash water to similate hard water. All worked better than plain water giving less emulsion. Best was citric acid in methanol. Haven't tried HCl, bit worried about salt formation/disposal. The quantities that you quote could involve quite a cost. Have thought of using Glacial acetic acid instead of vinegar to prepare acetic acid wash water, could be more economical, will check. >A small amount of steam at the last glycerol seperation > stage seems to remove soaps with the glycerol. (this is the glycerol > I intend to keep as a hand cleaner.) 10-20mls of water/L to the hot > product then heat to partially boil off the water. Thanks will give this a try. >Some of the polymerisation may be soap bases misceles. Perhaps the above may help with this. Filtered some of the BD which had set to gel. Almost all of it went through a Watman No 1. Yet to see if it gels again. Will try 80/20 mix BD/Dino D and see if that gels. (this is the mix I intend to use in the Toyota). >I now use less NaOH than I used to. Most of my problems (except the gelling) appear to be from using too much NaOH. I jumped in using the figure of 6-7g/L as suggested by Mike Pelly. However the feedstock of cotten seed oil that I use has been very well looked after and gives a titration of only 0.55ml. This indicates the need for only about 4g/L NaOH. >and rely on initial homogenisation to achieve a good percentage of product. Yes I agree that the initial homegenation is very important. Extra stirring at this stage is very beneficial. My 500ml batches usually follow this sequence. Heating of oil to 55 deg C (sometimes higher if methoxide is of lower temp so that temp of mix will be 55 deg C) Addition of methoxide with vigorous stirring. Unless extra stirring is given methoxide tends to float on top of oil. The methoxide oil mix is dark brown and opaque, it thickens (viscosity increases). Vigorous stirring continued until after about 7 minutes the mixture clears to mid brown and the viscosity drops. At this stage mixture has an ester like smell to it. If stirring is stopped at this stage the glycerol starts to deposit. Some of my batches settled overnight forming a "skin" on the surface. I believe that this is the remnants of the reaction mixture left on the side of the beaker above the main body of the mix. Attention to washing this back into the mix during mixing reduced the tendency for a "skin" to form. Regards Paul. Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html 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/
