Hello Leif >Dear Group~ > >I feel like I'm missing a critical piece of information regarding FFA >and transesterification. > >Ideal vegetable oil is triglycerides. Due to factors (like water >contamination, exposure to excessive heat, or long storage times) the >triglycerides can break into mono and di-glycerides, also known as free >fatty acids and enemy of transesterification.
No, that's not right. FFAs form this way, not mono- and diglycerides. Well, they can, to an extent, but it doesn't interfere with the process, and FFAs do. >We add a base catalyst to facilitate the cracking of the triglyceride. >Aren't mono and di-glycerides (aka FFAs) Not aka FFAs. FFAs are Free Fatty Acids - free of a glycerine molecule. >formed when the triglyceride >is cracked? If so, why can't the FFA's bond with the added methyl >alcohol to form methyl esters? That would be esterification, not transesterification. Hence the acid-base process - esterification of the FFAs followed by transesterification of the glycerides. >If FFAs are not formed when the base >cracks the triglyceride what is formed? > >I think part of the answer to this question lies in the difference >between FFAs and esters. What am I missing here? FFAs and esters are different. FFAs and mono- and diglycerides are also different, and I think that's what you're missing. It's explained here: How the process works http://journeytoforever.org/biodiesel_make2.html#howprocess What are Free Fatty Acids? http://journeytoforever.org/biodiesel_make2.html#wotffa Best wishes Keith >~leif Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
