Hello Joe >Hi Tom; > >Yes if you had an incomplete reaction washing becomes very >problematic. It is important to make sure the reaction is complete. >The oil I get looks almost black when sitting in a 20 liter pail. >In a 3/8" tube it is about the color of maple syrup (if you are >familiar with that - sorry I am canadian eh?) When it is reacted it >is a much lighter straw color normally. Darker usually indicates >incomplete in my experience, but this is all relative to how dark >the oil is at the start I guess. The process I use is very similar >to the way I inject methoxide as you suggest. I don't want a >homogeneous mixture. What I am doing is adding a very small stream >of water into a much larger stream of ester and letting it settle >back through the batch to the bottom where it gets picked up again >and metered into the flow. The valve is barely cracked open. It >works when you are carful, but it still means the reactor is tied up >for a couple of days with washing. I do this because I have very >little space and no room for wash tanks and my need for fuel is very >low since I walk to work. If I needed more and I had the space I >would go for a separate wash tank and a mist nozzle for the water.
That you don't need. See: Mist-washing http://journeytoforever.org/biodiesel_bubblewash.html#mist Or read the whole page. Best wishes Keith >Joe > >Thomas Kelly wrote: > >>Joe, >> Pump washing appeals to me in principle. A nice closed system. >>No welding involved. I can see that the mix is homogenized and can >>even see the separation as it occurs through the clear vinyl >>tubing. In my only attempt at it my wash water remained milk white >>even after 7washes.....good separation of water & BD, but the wash >>water stayed white. >> It was only a 18L batch. The pump was a 1/2hp clearwater pump. >>The BD washed very easily when I switched to stir washing, but upon >>reprocessing 1L of washed and dried BD I got some glycerine. I was >>being rough with the product of an incomplete reaction. >> I think I understand your wash setup, but don't understand the >>actual process. >> When you pump wash do you stop the pump when all the water has >>been pumped in from the bottom or do you continue pumping to >>achieve a homogeneous mixture of water and BD? >> Couldn't the water be introduced from outside the tank while >>the BD is circulating? ..... in a manner similar to how we add >>methoxide during reaction? >> I have been making quality BD on my recent batches and have >>75L in my settling tank. I found a small pump that pumps about >>3L/min. I'm tempted to connect it to my wash tank and give it a go. >>See if using a smaller pump and high quality BD I can use pump >>washing. >> And Joe, Thanks for the visual aids for the titration station. >>If I ever get the time, maybe I'll give it a try. >> >> Best Wishes, >> Tom >>----- Original Message ----- >> >>From: <mailto:[EMAIL PROTECTED]>Joe Street >>To: <mailto:Biofuel@sustainablelists.org>Biofuel@sustainablelists.org >>Sent: Friday, November 04, 2005 12:32 PM >>Subject: Re: [Biofuel] pump washing >> >>Hi Jonathan; >> >>One suggestion for you. I pump wash my fuel and my pump picks up >>fuel from above the water level and dumps it at the top of the >>tank. I also have a fitting at the bottom of the tank with a ball >>valve connected to a plastic 1/4 inch line that feeds into a tee at >>the inlet of the pump. The judicious use of that ball valve is >>critical to a good wash, especially in the early washes. Basically >>I turn the pump on and let it recirculate the fuel and then while >>watching the boundary between the fuel and water in the clear >>plastic tube at the bottom of the tank I slowly crack the ball >>valve open until I see the water start to slowly move torard the >>pump inlet. Too much water will result in emulsion at the pump >>impeller. As the fuel gets cleaner at later wash stages it will >>tolerate more water. 1/4 inch poly line is enough to carry plenty >>(too much actually) of water. >> >>Cheers >>Joe >> >>Jonathan Schearer wrote: >> >>>Is anyone using circulating pump to wash their fuel? I performed >>>a wash test on my first batch from my processor and it seperated >>>nicely. I then pumped it into my wash tank added equal volume of >>>water and circulated it from bottom back into top of tank. The >>>water was cold the first time and I changed that to warm water for >>>the rest of the washes. I had to was the fuel 5 times before it >>>was acceptable to me. I let the pump run too long the first >>>time-45 minutes. It homogenized quite well:) The next 4 times I >>>only ran it for about 5 minutes or just until mixture homogenized. >>>Is the pump mixing the wash too well? I have not tried the bubble >>>wash or the stirring method. I guess I thought that the pump >>>would be similar to the stirrer. Any thoughts? _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
