Has anyone tried anything with organometallic catalysts? I was perusing over a paper about some fluorinated tin catalysts that were used for 2 phase esterification/transesterification reactions. It seemed at least partially promising, they were using what would probably be some expensive stuff. Pretty much they had an organic phase with the stuff to be esterified, and mixed it with a flurocarbon phase with the catalyst. The yields were very good under mild conditions. The only thing I didn't like was the partition coefficients for the catalyst - although very low (0 for stuff like benzne, but getting up to 3/4 with some slightly more polar ones), you would still start to loose these big ugly (and probably none to pleasant) fluoro-organic-tin catalysts into the BD, and I don't know how good that would be for your car, or the environment. I would imagine that even though BD tends to have very large non-polar hydrocarbon moeities, the ester end might start solubilizing the stuff a bit..

jeez.. the fluorocarbon better be recyclable.. 40 bucks for 25 mL...

These are great for some one doing a PhD but for industrial or home use are a NO-NO. very expensive.
I could buy two new cars or run my car for 30 years for the price of a quantity require to produce biodiesel in good quantities.

Last time I look at them they were about US$1500 per pound.

I mean:

1 How much biodiesel could you get per day from let's say a kilo of this catalyst?

2 How long does it last?

3 How likely is it to be poisoned by feedstock impurities?

You're right... even with the recycling they say can be done, it still starts getting up into the couple of dollars per litre range, for the catalyst alone... so that's no good...