Published September 2013
Terephthalic acid and dimethyl terephthalate are consumed primarily to produce linear, saturated polyester resins, fibers and films by combination with glycols. Nearly all worldwide consumption of TPA and DMT is for the production of intermediate polyethylene terephthalate (PET) polymer. PET polymer, also referred to as reactor-grade polyester or PET melt-phase resin, is consumed primarily in the production of polyester fibers, polyester film and solid-state (bottle-grade) resins. PET engineering resins are produced not only from melt-phase PET, but also from recycled postconsumer and postindustrial materials.
More than 60% of DMT/TPA produced in the world is used to manufacture PET polymer for polyester fibers. Another 31% goes into the manufacture of PET solid-state resin for bottles and other packaging applications. The manufacture of film, PBT and other minor products such as cyclohexanedimethanol (CHDM), terephthaloyl chloride and copolyester-ether elastomers accounts for the remainder of DMT/TPA consumption. DMT/TPA for PET solid-state resins has grown strongly during the last decade, following the strong growth in the consumption of bottled water globally and growth in the consumption of soft drinks and other premium beverages in the developing world.
The following pie chart shows world consumption of DMT/TPA:
Asia is the largest DMT/TPA-consuming region, although its consumption is almost entirely TPA-based (Japan consumes a small amount of DMT for PET resin production). Asia will account for about 85% of the world's DMT/TPA volume growth in the next five years.
During 2002–2007, demand for DMT/TPA grew at an average annual rate of just over 7%. However, during 2008, the market, impacted by the economic recession, experienced its first-ever contraction, and only a modest recovery occurred in 2009. For 2007–2012, demand grew at an average annual rate of almost 4%. For the next five years, global demand is expected to increase at an average annual rate of 5.5%.
There is interest in recycling PET, especially when virgin polymer prices are relatively high. The portion of PET that is recycled is high compared with most other resins. Most recycled PET is utilized as waste polymer for reprocessing, but processes have also been developed to chemically regenerate monomers or oligomers. The impetus for development of these processes is the assumption that chemical intermediates would find acceptability in a broader range of higher-value-added applications. Although there is significant capacity for regeneration, the amount of PET reprocessed is much smaller than the amount that is recycled as resin.