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Coke Plays Spin The Bottle

Coca-Cola has formed partnerships with three small firms in a quest for the completely plant-derived soda bottle

by Alexander H. Tullo
January 23, 2012 | A version of this story appeared in Volume 90, Issue 4

Credit: Gevo
Gevo scientists are developing a route to p-xylene via isobutyl alcohol.
Gevo scientists
Credit: Gevo
Gevo scientists are developing a route to p-xylene via isobutyl alcohol.

The world’s largest beverage maker, Coca-Cola, has mapped out its solution to what is perhaps today’s biggest challenge for the plastics industry: a wholly renewable polyester soft-drink bottle. Last month, Coca-Cola inked joint development agreements with three companies—Gevo, Virent, and Avantium—that it says are best equipped to come up with the biobased compounds it will need for the more than 100 billion bottles it uses each year.

Since 2009, Coca-Cola has been using a bottle called the PlantBottle for products such as Coca-Cola and Dasani water. Like other beverage bottles, it is formed from polyethylene terephthalate (PET), which is made by reacting ethylene glycol (EG) with purified terephthalic acid (PTA). The PET in the PlantBottle uses biobased EG instead of petrochemical-based EG, making it about 30% renewable.

The chemistry of biobased EG is straightforward: Dehydrate ethanol to get ethylene and then convert ethylene into ethylene oxide and then EG via conventional routes. Since 2009, Coca-Cola has been sourcing its sugar- and molasses-derived EG from India Glycols.

But Coca-Cola wants to make a 100% biobased PET bottle, and the other 70% of the polymer is much more challenging. A route to PTA—or its precursor, p-xylene—hasn’t yielded to biology easily.

“We understand we can’t do it alone,” said Rick Frazier, Coca-Cola’s vice president for commercial product supply, at a press conference in New York City last month. “We need to work with partners.”

Credit: Coca Cola
Two PlantBottle packages from Coca Cola
Credit: Coca Cola

Each of the three firms Coca-Cola is partnering with has a different technology for getting to the aromatic part of the polyester molecule. Virent and Gevo are developing routes to p-xylene from carbohydrates. Avantium is developing a biobased substitute for PTA that would be the basis of a new kind of polyester.

The partnerships can be traced back to Coca-Cola’s PlantBottle launch in 2009, when the firm stated an interest in biobased PTA as well. The company was soon solicited by some 30 firms purporting to have routes to wholly biobased beverage bottles in the lab or on paper.

Coca-Cola vetted all of the potential partners, winnowing them down to three finalists, according to Scott Vitters, general manager of PlantBottle packaging. “A lot of this is about scale,” he says. One question he says Coca-Cola asked was, “Do we think this is a technology that can deliver on the scale necessary to meet our needs?”

Coca-Cola’s scale is huge. Last year, the company used about 7 billion bottles made with biobased EG, representing about 6% of its total plastic bottle volume. Coke aims to have biobased EG in all of its bottles by 2020. Its goal in 2009 was to start incorporating biobased PTA in bottles by 2020. The firm has accelerated that goal, and Vitters says it will have such bottles on the market within the “next few years.”

The interest in biobased bottles extends beyond Coca-Cola. Coke has partnered with H. J. Heinz, which is now packaging ketchup in PlantBottles. Coca-Cola rival Pepsi also has an effort to develop a wholly renewable PET bottle but has revealed few details.

Hand in glove with economies of scale is cost. Coca-Cola was looking for technologies that would eventually enable it to produce a bottle that is cheaper than its petroleum-derived counterpart.

Coke officials acknowledge they are generally paying more to use biobased EG than petrochemical EG, although at times the two are similarly priced, Vitters says. Improving the efficiency of the supply chain will help the company consistently acquire biobased EG at cost parity or even better.

William L. Tittle, director of strategy for the Americas and Asia at the consulting group Nexant, says it is unlikely that EG derived from sugar will ever compete with EG derived from low-cost petrochemical sources such as ethane from the Middle East or the U.S. Long term, Coca-Cola will need cellulosic sources of feedstocks to be more competitive.

“It is cellulosic ethanol which is the endgame,” Tittle says. “Food to EG in competition with shale gas ethane is not going to cut it.” Coke and its partners say they want to use a variety of feedstocks, especially nonfood sources of biomass.

A biobased route to p-xylene should help with the economics of biobased bottles, Tittle notes, because p-xylene is derived from oil, which is more expensive than ethane. He says routes to biobased p-xylene start to become cost competitive when oil prices are above $90 per barrel, as they are today.

All three of Coke’s new partners are making major steps toward commercialization. Virent’s process begins with water-soluble carbohydrates such as sugar or industrial starches. A proprietary catalyst partially deoxygenates the carbohydrates into alcohols and ketones. The next step uses acid condensation and reformation to get a mixture of hydrocarbons similar to the reformate produced in a refinery.

About 70% of the mixture is an aromatics stream containing xylenes, toluene, and benzene. The aromatics can be treated with conventional processing to yield as much as 50% p-xylene.

Virent is no stranger to big-name backers. Among its investors are Shell, Cargill, and Honda. The company already operates a 10,000-gal-per-year pilot plant in Madison, Wis., and is planning a commercial-scale facility by 2015. Kieran Furlong, Virent’s director of chemicals, says the plant would likely produce 60,000 metric tons of the “bio-reformate” per year.

Gevo’s yeast-based fermentation process converts cornstarch-derived sugar into isobutyl alcohol. To make p-xylene the company dehydrates the alcohol into isobutylene, reacts two isobutylene molecules to make octene, and then performs a dehydrocyclization reaction to make a stream of aromatics that contain more than 90% p-xylene.

Christopher Ryan, Gevo’s chief operating officer, says the isobutyl alcohol technology can be retrofitted onto existing ethanol plants at minimal capital cost. Gevo’s first plant, a former ethanol facility in Luverne, Minn., will start up with 18 million gal of annual isobutyl alcohol capacity later this year. A 38 million-gal plant in Redfield, S.D., will open in 2013.

In addition to Coca-Cola, Gevo is working with Lanxess to make butyl rubber derived from isobutylene. It already has an agreement to develop biobased PET, for use in fibers, with Japan’s Toray Industries. “Typically, we will rank high when people want to make a biobased product from a C4,” Ryan says.

Gevo is operating a pilot isobutylene plant outside of Houston. For the rest of the process, the company hopes to have a pilot plant running by the end of the year. Ryan says it is too early to reveal a commercialization timeline.

Avantium is unique because the task before it is to introduce an entirely new polymer into Coca-Cola’s massive supply chain. The Dutch firm’s process begins with a catalytic reaction to make methoxymethylfurfural and other hydroxymethylfurfural ethers from six-carbon sugars such as glucose and fructose. Another catalyst transforms the ethers into furan dicarboxylic acid (FDCA), which can be reacted with ethylene glycol to make polyethylene furanoate (PEF).

Avantium claims that PEF is a better oxygen and carbon dioxide barrier than PET. “The way we look at PEF is that this could be the next-generation polyester that can solve all the problems with PET at a competitive price,” Avantium Chief Executive Officer Tom B. van Aken says. The barrier properties of PET, he notes, aren’t good enough for very small plastic containers.

The company is currently starting up a 40-metric-ton-per-year FDCA pilot plant in Geleen, the Netherlands. Commercial plans call for a 50,000-metric-ton plant to be constructed by 2015.

Coca-Cola’s involvement accelerates Avantium’s commercial plans, van Aken says. “We now get access to more financial resources, but maybe even more important than that, the technical resources of the Coca-Cola Co.” For instance, Coke has been testing PEF since the beginning of last year, and it intends to test the extent to which PEF can be processed in conventional PET recycling streams.

All three companies are getting technical and financial assistance from Coca-Cola, though actual amounts haven’t been disclosed. Coke is setting milestones and other targets. And it is lending its expertise in sustainable agriculture.

Even though the three biobased chemical companies are working on different solutions to the same problem, all the parties involved insist they are not competitors. Coke emphasizes that the PET bottle market is so huge that no single company could possibly meet all the demand for a biobased version. “We are all winners,” said Lee Edwards, Virent’s CEO, at the press conference. “We are all here with the Coca-Cola Co.” ◾


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