--- In firstname.lastname@example.org, Donald Allwright <[EMAIL PROTECTED]> wrote: > I am no chemist, so please correct me if I'm wrong. > > Your suggestion would involve splitting the Carbon-Carbon bonds in the > glycerol part of the molecule. This is certainly possible, as it's what > happens with catalytic cracking. However if you're doing this to the > glycerol part of the molecule you're probably also doing it to the > Carbon-Carbon bonds in the fatty acid chains as well.
The picture is not so dark :) Some catalysts (especialy organic ones - enzymes) are highly selective in that they would break only some of the links but not the other. But you are quite right, I too have a doubt for this direct conversion step. The breakage of glycerol is much more probable. There might even be some organisms which will ferment the glycerol for you and make methanol, as Ken Provost correctly pointed out. Or ethanol - this is much more probable, because methanol is very toxic to living organisms ant ethanol is less toxic :). so the fermenting bacteria or yeasts could do something like this: 2 CH2OH-CHOH-CH2OH + O2 ==> 2 CH3-CH2OH + 2 CO2 + 2 H2O We can then feed the resulting ethanol back into our process. Unfortunately ethanol will be hydrated, and will need some serious distilation/dehydration. The ethanol solution is a little less elegant than methanol. If you achieve the later, then you do not need to supply the methanol to your process at all. If you achieve the former, then you would only be recycling 1/3 of the input of ethanol into the process. You get 3 methanol molecules if you break 1 glycerol molecule apart, but you get only 1 ethanol for 1 glycerol (plus some carbon escapes in the form of CO2). so, has ANYONE here seen any mention on the web about such type of yeast/bacteria? could be interesting.... > And in any case I doubt having a catalytic cracker in your kitchen, Hmmm, IMHO, any biodiesel production process is not very suitable for the kitchen. You could do a demo project in a kitchen, but if you try to use biodiesel seriously, for your car, you will probably be scaling up to a drum-sized batches. It's more likely a backyard or a garage project. And once in backyard, there is much more freedom to toy with chemistry :) > plus a suitable supply of hydrogen As I said, hydrogen need not be provided in gaseous form, it might be some chemical. Like sodium borhydride NaBH4 + H2O ==> NaBO2 + 4H2 This chemical is stable, and releases hydrogen only in the presence of catalyst. Of course you would then need to secure the source of the sodium borhydride :). Good news is that borax, the final product of the above reaction can be recycled back into borhydride with the coal reforming. So in theory it could be recycled. Unfortunately this is far less user friendly process, and it is better left to the industries (though not insurmountable at home. Again, the catalyst is the key). (be sure to check http://www.millenniumcell.com/solutions/index.html for the interesting stuff about this chemical. These people are trying to get fuel cell car on top of this chemical process) So, lots of buts/ifs, but no showstoper problems in the overal design.... ------------------------ Yahoo! Groups Sponsor --------------------~--> Yahoo! Domains - Claim yours for only $14.70 http://us.click.yahoo.com/Z1wmxD/DREIAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> 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/