PTA Technology from Dow

From Raw Materials to Market-leading PET Resin

PET is playing an increasingly significant role as one of the basic performance polymers used in fiber, film, packaging containers, engineering resin and binder resins. During the 1990s, PET became the material of choice for blow-molded bottles, replacing glass, PVC and aluminum, with the advantages of lower cost, lighter weight and excellent clarity in addition to its high mechanical strength. PET's increasing market share, particularly in packaging, is largely due to a steady progression of frequent and economical innovation; most importantly, the development of a technology for terephthalic acid purification, PTA technology.

The Raw Materials

Among various di-carboxylic acid components of the polyesters, purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) are the two commercially viable intermediates. PTA, due to its better flexibility and competitive cost, is and will continue to be preferred over DMT as a raw material for polyester production by major manufacturers around the world, and will continue to replace DMT in the integrated polyester chain.

Dow and PTA

Dow's participation in the PTA business began in Italy in 1968 with the start-up of the Porto Marghera plant. In 1974 the Ottana plant started-up with a design capacity of 80,000 MT/y. Dow first licensed PTA technology in 1987. Since then, important process improvements were developed and implemented in the Ottana plant. For example, the capacity was boosted to 150,000 MT/y in a first step in 1992 and to 170,000 MT/y in a second step during 1998, doubling the nameplate capacity, thanks to significant R&D efforts and technological innovations developed by Dow's engineering team. Since 1987 over 3.8 million MT/y has been licensed in 10 sites, in 6 countries. Today, Dow is one of the most successful licensors of PTA technology in the world.

Main Features of Dow's PTA Technology

• Proven and reliable technology
• Low energy consumption and environmental impact
• Lower maintenance requirement
• Innovative systems for agitation and PTA solids separation
• Over 30 years in operation, maintenance and use
• Full guarantees of on-going assistance and technology renewal
• Freedom to generate and supply any technology innovation
• Continuous R&D work and innovation development
• Strong engineering and R&D capability
• Flexibility in meeting the licensee's requirements