First, Dow announced that they had restarted ethylene production at their St. Charles, Louisiana plant, and in almost the same breath, stated that they are seeking building permits for a 1.5 million ton polyethylene plant, the largest such plant in the Dow portfolio. The new plant would take advantage of the ethane production surges resulting from the boom in fracking here in the US.
As for the other horse, the bio-based ethylene is from the joint venture with Mitsui in Brazil. Ethanol produced from fermented sugar cane is dehydrated to yield ethylene:
Sadly, while production of this green ethylene is continuing, Dow is declining to expand the operation citing the shale fracking strategy outlined above and legal/design issues in Brazil.
H3C-CH3H3C-CH2OH --> H2C=CH2 + H2O [*]
I wonder how long it will be before Dow announces the sale of their portion of the joint venture.
[*] Run the reaction backwards and you can produce high purity ethanol without having to use any nasty benzene to get past the azeotrope. Oh those clever chemical engineers!
Update: Doug Hawkins from Dow Chemical noticed that my chemical reaction wasn't quite ... copacetic. It is now. Thanks, Doug!