Coke Ups The PlantBottle Ante
Dec16

Coke Ups The PlantBottle Ante

Carnegie Hall sits on the corner of 7th Ave. and 56th St. in Manhattan. How does one get there? Well, as the old adage goes, practice. (The Chemical Notebook took X1 express bus from Staten Island.) Nothing quite says “making it” in music like playing Carnegie Hall for the first time. Something similar happened yesterday, only a couple of blocks away, at the Time Warner Center on Columbus Circle. Three startup firms held a joint press conference with the biggest brand name of them call, The Coca Cola Company, to announce a collaboration in what has become one of the biggest challenges of the plastics industry: a wholly renewable polyethylene terephthalate bottle. The three firms were Gevo, Virent, and Avantium. (I’m abusing the term “startup” a little bit by lumping Avantium in because, as chemists know, Avantium is a well-established name in high-throughput screening.) Coca-Cola has had a PlantBottle on the market since 2009. The bottle is made from polyethylene terephthalate, but it is a different kind of PET. PET is made via the condensation of ethylene glycol with purified terephthalic acid. The PET in the plant bottle uses bio-based ethylene glycol (EG) instead of petrochemical-based EG. As a result, the plant bottle is 30% renewable. Not to denigrate the PlantBottle, but the chemistry to get to bio-EG is straight forward: dehydrate ethanol to get ethylene and then convert ethylene into EO/EG via conventional routes. The other 70% to go to a 100% bottle is a different matter altogether. Making PTA--or its common petrochemical precursor, paraxylene, hasn’t yielded to biology too easily. These are far more complex molecules. More work needs to be done before such a route can be commercially viable: Hence, yesterday’s event. “We understand we can’t do it alone,” noted Rick Frazier, Coke’s VP of commercial market supply. “We need to work with partners.” He said Coke vetted about 30 companies with possible solutions. The three firms he shared the dais with were the ones that made the cut. The three companies have very different routes to bio-based PET. Virent has a catalytic process to turn sugars in a range of hydrocarbons, including PX. Gevo ferments sugar into isobutanol, which after subsequent chemical reactions, is transformed into PX. Its technology is easily retrofitted into existing ethanol plants. Cheap ethanol plants are plentiful. Avantium is the oddball of the bunch. It uses a catalytic process to turn sugar into furan dicarboxylic acid. This is condensed with ethylene glycol to make polyethylene furanoate. This is a polyester that, according to the Avantium, exceeds PET in terms of oxygen barrier and temperature performance. The polymer might seem like a...

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