Pepsi has a 100% Biodegradable Bottle

Pepsi announced they will introduce a 100% renewably sourced PET bottle in 2012. The technology used to make the bottle is disturbingly unclear. It is a conventional PET bottle with similar molecular weight to standard.

PET bottles are made from ethylene oxide and terephthalic acid. There are a number of ways to get bioethylene including waste gas from landfills, dehydration of ethanol or heat treatment of biomass.  Terephthalic acid can be made from lignin according the NREL via oxidation of p-xylene.