----- Original Message ----- From: <[EMAIL PROTECTED]>
> I was asked today why there was a ban on feeding cotton meal and oil > to stock (the Japanese found residual pesticide in Australian beef) > but the oil was recommended for human cooking. > Does anyone know how or if the contaminants can be removed? Harry the cottenseed oil that I process comes from 2 sources. ETA Food Services Cottenseed Oil, Ingredients, Cottenseed Oil, Antioxidant (319) 0.01%, Antifoam (900) and "Formula 40" from Peerless Holdings. Depends upon which source local fish and chip shop buys from. Was going to lubch on fish and chips tomorrow but now you have me worried with that residue bit. Might quiz the suppliers. > I'm in the midst of my first cotton seed batch. > Some one asked about using the centrifuge for testing purity. I do > intend to test some product by adding more alcohol and lye to a > sample and seperating the glycerol with the centrifuge but I'm > waiting for some proper centifuge tubes. Might be able to help you out there Harry. Seem to have a glut of glass graduated centrifuge tubes, 15mml capacity. Contact me via my email address and we will see if they will fit your centrifuge. Ran a test using the centrifuge today with the aim of determining yield vs mixing time. 1L beaker,500ml Cottenseed oil 55 deg C, 3g NaOH dissolved in 200ml methanol, hotplate stirrer (temp maintained 55 deg C), 5cm spin bar, fastest speed spin bar would take (dimple on oil surface but no vortex). 15ml sample extracted every 15min, centrifuged and ammount of glycerine deposit read. On addition of methanol extra stirring was given to ensure mixing. Oil/methanol mix murky at first but after 10-15 min stirring cleared and liquid had esterlike smell. Results were inconclusive. 15ml gave 1.6ml deposit after 15min reaction. This remained fairly constant up till the 1 hour mark where it climbed to 1.8ml. However it dropped back after that. The centrifuge tube was being filled with a 10ml graduated pipette. First fill OK, sucked up dumped straight in. Top up to 15 ml mark involved refilling pipette and draining pipette slowly till 15ml mark was reached. Noticed during the latter stages of this test that the glycerine was actually settling out in the pipette as it was slowly drained, thereby enriching the test sample. Will make two batches, stir one for 15min only the other for two hours, let them settle overnight and then test for completemess of reaction by adding more methoxide,mix,cenrtifuge. I was ammazed at how quickly the glycerine separates out. Just allowing it to stand in the tube without centrifuging gave a deposit of 1.45ml (granted not as pure) after 20 minutes. Depending upon results will increase NaOH ammount, but suspect 6g/L is near optimum for this oil as last time I tried increased ammounts ended up with whitish gel amongst the glycerine. Would prefer to er on low side than have to deal with that stuff on a larger scale. I view of rapid settling of glycerine am looking at drawing it off early in process, washing on remaining glycerine(Idaho 20-20-20 technique) and heat drying. If I can get the washing side worked out this cottenseed looks to be a good feedstock for BD production. Any suggestions anyone? 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/
