Plant De Triomphe

Shell Chemical believes that a $100 million polymerization plant that it is starting up in Montreal is the final ingredient it needs to cook up success for polytrimethylene terephthalate fibers.

The plant, a 50-50 joint venture called PTT PolyCanada and owned by Shell and Quebec government-owned Société Générale de Financement du Québec (SGF), was completed in May. Commercial production at the 95,000-metric-ton-per-year facility, the largest PTT plant in the world and Shell's first continuous-reactor unit, is set to begin this fall.

Though it is often called a new polymer, PTT was discovered in the 1940s. It is a polyester based on purified terephthalic acid and 1,3-propanediol (PDO), instead of the usual ethylene glycol used to make polyethylene terephthalate, the well-known textile fiber polymer and soda bottle plastic. The odd carbon in PTT acts like a hinge and lends the polymer a degree of flexibility not found in PET.

Chemists have known for a long time that PTT's structure imparts useful properties. Its limitation, according to Stanley Park, vice president of PDO/PTT for Shell, has been its cost. "The market is constrained not by our customers' ability to develop products but by our ability to sell polymer," he says.

The bottleneck for most of PTT's history has been PDO technology. According to Hoe Chuah, a senior staff research engineer at Shell Chemical, PDO was first commercialized in 1966, but because of the high costs of the acrolein-based production route, applications were limited to fine chemicals.

Then in the 1990s, Shell developed a hydroformylation route to PDO that also resurrected the prospects for PTT. Shell completed a 75,000-metric-ton-per-year PDO plant in Geismar, La., in 1999. Today, that plant supplies batch PTT reactors operated for Shell in Apple Grove, W.Va., by Mossi & Ghisolfi, which bought Shell's PET business in 2000.

DuPont, which makes PTT under the Sorona brand name, is also working on PDO technology. It has been buying PDO that Degussa makes via the acrolein route in Wesseling, Germany, to feed a PTT plant in Kinston, N.C. In addition, DuPont and sugar refiner Tate & Lyle are researching a fermentation-based route to PDO. The companies are planning a 45,000-metric-ton-per-year fermentation plant in Decatur, Ill., for 2006.

Now that the technical obstacles are behind PTT, Park is confident that the polymer will succeed in apparel and carpeting, where Shell says PTT has many advantages. In carpeting, Park says, PTT's advantages over nylon include a competitive price and a softer feel. Consumer care of the carpet is also easier than with nylon.

In textiles, the selling points of PTT include softness and stretch, making garments more comfortable than they would be if made from other polyesters. And garments made from PTT are said to wrinkle less and are easy to care for.

In the long run, Park says, Shell is more interested in selling PDO and licensing PTT production technology than in selling PTT itself. The Montreal plant is intended only to demonstrate the technology and provide commercial volumes for fibers customers. "We are building the plant to establish the technology," he says, adding that customers will likely construct future plants.

Park says the market has been growing at a 50% annual clip since PTT-based carpet was commercialized in 2001. It should hit 30,000 metric tons this year, and he expects demand to continue growing, reaching 1 million metric tons in a decade.

For Shell's partner, SGF, PTT PolyCanada is the culmination of a series of investments the company had been making in aromatic petrochemicals. It has a 49% stake in Interquisa Canada, a joint venture with Spain's Cepsa that completed a 500,000-metric-ton-per-year purified terephthalic acid plant last year in Montreal. SGF also has a 49% interest in the recently refurbished Coastal Petrochemical p-xylene joint venture with energy company El Paso Corp.

Henri A. Roy, SGF's chairman, president, and general manager, says SGF is trying to help rebuild the petrochemical industry in Quebec after decades of neglect. SGF felt so strongly about a PTT plant that the deal it offered Shell--50% equity, loans, and a grant--enticed Shell to shelve plans to build the unit on a Mossi & Ghisolfi site in Altamira, Mexico. "We see this investment as critical to Quebec because it is a new technology, a good partner, and there are synergies with the system that we are trying to create," Roy says.

Roy says SGF's direction in petrochemicals is not likely to change even though the company itself has come under fire for failed investments. For example, SGF's 50-50 carbon black joint venture with Kvaerner, called Karbomont, was dismantled last year after problems emerged with its novel plasma technology.

Following a review of its operations, SGF's new strategy calls for less emphasis on high-technology venture-capital start-ups but ongoing involvement in petrochemicals. "We haven't been good at addressing that sector of the market. Petrochemicals are still very much at the core of what SGF does," Roy says, noting that three or four new investment opportunities remain in the province.