Published November 1995
Shell Chemical Company recently announced plans to commercialize a new polyester, polytrimethylene terephthalate (PTT), which is claimed to combine the best characteristics of nylon and polyester. In this review, we evaluate a new process for manufacturing 1,3-propanediol (PDO), a key component of PTT, based on Shell patents for a single-step oxo reaction starting from ethylene oxide (EO). In addition to the new chemistry, the design assumes that local ethylene glycol (EG) operations would provide an outlet for a crude EO by-product stream. This assumption is based on Shell's stated intention of siting the plant at Geismar, Louisiana, which is already a major site for their current EO/EG and oxo operations.
Note: New PDO patents were issued to Shell, too late to be considered in this review. The patents indicate that Shell has developed a two-step oxo process, using a different catalyst from the one assumed for this study. Implications of the new patents are discussed briefly at the end of this review. Preliminary estimates of the impact of these innovations on product values are given.
