G'day All,

Haven't been looking in much lately, and have noticed a change in direction in methanol recovery since I was here lately.

I was under the impression (please correct me if I'm wrong), that the methanol was being recovered from the glycerol, where most of the methanol was likely to be(?).

Now, everybody seems to be talking about recovering it from the bio itself.

Are we still recovering from the glyc as well? Which will be the most productive?

I am looking at the plumbers delight, which would be easily added to my existing setup.

Any suggestions?

The byproduct still has the vast majority of the methanol that is available to recover. But, some folks are looking at ways to get the excess meth back from the biodiesel too. There are a couple percent in there.

Of course, the energy economics are not as good for methanol recovery from the biodiesel itself. You have to heat up a lot more liquid to recover a liter of methanol. This is why some are attempting to recover the meth immediately following the primary reaction, since the biodiesel is still hot.

The concern is that, if you try to remove the meth while the biodiesel is still sitting on the byproduct, earlier work suggests you may drive the reaction backwards and unmake some of your biodiesel. That would be a bad thing. Draining the byproduct and then removing the meth from the hot biodiesel would be fine though.

Recovering the meth from the bio isn't as lucrative as recovery from the byproduct, but it's certainly not a bad thing to do for the environment.

On the other hand, these folks are trying to recover the meth from the whole batch, without first separating the byproduct, using a water pre-wash to "lock up" the reaction so it can't go backwards. A very interesting read:

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/4441089311/m/7941097391

HTH,

troy