New process moves 100 percent bio-based PET bottle closer to commercial reality


Posted by Lisa McTigue Pierce -- Packaging Digest, 6/10/2011 1:02:05 PM




Skyrocketing resin prices have intensified the race to create plant-based PET bottles as replacements for petroleum-derived ones. This led to recent dual announcements, first by H.J. Heinz Co. of plans to use Coca-Cola's 30 percent plant-based PET PlantBottle for packaging its ketchup, and then by PepsiCo which announced a 100 percent plant-based PET bottle in the laboratory. Bio-based ethylene glycol is available and replaces 30 percent of the fossil fuel.

The more challenging issue has been how the other monomer of PET, namely the PTA component, can be replaced by a bio-based version to cost-effectively achieve 100 percent renewable PET packaging near-term.

The "holy grail" of a bio-based PTA may finally be a reality with the announcement by Virent on June 6, 2011, that it successfully made para-xylene (PX) from 100 percent renewable plant sugars. A patented catalytic process is used to convert the plant-based sugars into PX, identical to that made from petroleum. The conversion of PX to PTA is widely used in commercial chemistry. In essence, the bio-based PX fills in the "missing piece" to make a 100 percent bio-based PET bottle.

Further details on this remarkable achievement will be presented by Kieran Furlong, Virent's commercial manager-chemicals, in a late addition to the BioPlastek 2011 Forum program. The Forum will take place on June 27-29, 2011, at The Waldorf-Astoria in New York City.

Especially noteworthy is that the PX was made in Virent's 10,000 gal/year demonstration plant. Others who claim to have converted biomass directly to aromatic intermediates (including PX) are believed to have done so only in a lab environment.

Virent used U.S.-grown beet sugar as the feedstock in this demonstration. A similar process has been demonstrated at smaller scale with a variety of feedstocks.