Application FDCA has a large potential as a replacement for terephthalic acid, a widely used component in various polyesters, such as polyethylene terephthalate (PET) and polybutyleneterephthalate (PBT). PET has a market size approaching 4 billion lb/yr, and PBT is almost a billion lb/yr. The market value of PET polymers varies depending on the application, but