how about pressure and temperature? would it be more reliable and less sensitive to moisture if one was able to do it in a pressure vessel at higher temperatures? anton
-----Original Message----- From: Ken Provost [mailto:[EMAIL PROTECTED] Sent: Monday, January 07, 2002 1:09 PM To: biofuel@yahoogroups.com Subject: [biofuel] Re: Biodiesel from ethanol Livio asks: >Do you know the difference of using ethanol or methanol in the >process of producing biodiesel?? because over here in Italy I can't >find cheap methanol. It's somewhat more difficult to use ethanol, but it can be done. The alcohol must be anhydrous, and the oil must be totally dry as well. More caustic is required (NaOH or KOH can be used), and soap production (and thus emulsification) is therefore worse. The oil must also be cleaner than with methanol (ie, lower in free fatty acids). Ethanol must be used in greater excess than when using methanol, so recovery of the unused ethanol from the glycerol phase is usually desirable. This is in turn complicated by the fact that the recovered ethanol is always contaminated with water (a byproduct of the soap production), and so must be dried chemically before it can be reused for biodiesel production. If this all sounds discouraging, it should.....but the advantages include the greater availability of ethanol worldwide, the relative ease of producing your own ethanol as compared to methanol, and the fact that the carbon in ethanol was only recently removed from the atmo- sphere, and therefore can be returned to it (via combustion) without adding to the net level of CO2 in the air. For this reason alone, I think pursuing the use of ethanol is a worthy goal -- good luck. 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/ ------------------------ Yahoo! Groups Sponsor ---------------------~--> FREE COLLEGE MONEY CLICK HERE to search 600,000 scholarships! http://us.click.yahoo.com/vf6MrB/4m7CAA/ySSFAA/FGYolB/TM ---------------------------------------------------------------------~-> 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/