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. ------------------------ Yahoo! Groups Sponsor ---------------------~--> Tiny Wireless Camera under $80! Order Now! FREE VCR Commander! Click Here - Only 1 Day Left! http://us.click.yahoo.com/WoOlbB/7.PDAA/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/
