Monitoring Catalyst Concentration in Purified Terephthalic Acid Production 

Purified Terephthalic Acid (PTA) is a white crystalline powder used as a precursor in the production of common plastics such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). These materials are used in many different products, including polyester fibres, packaging, electronics and construction materials. Global production of PTA reached 61.2 million tons in 2016.

The production of PTA is a multi-step process involving hazardous and corrosive substances. The manufacturing process involves the oxidation of paraxylene in acetic acid. This process relies on a cobalt-manganese-bromide catalyst. The quantities of the catalyst must be carefully controlled to ensure high yields at high quality. Regular measurements of the catalyst concentration by X-ray fluorescence (XRF) analysis helps to monitor the reaction, ensuring just the right amount of catalyst is present in the solution.

Hitachi High-Tech’s X-Supreme8000 is a benchtop energy dispersive XRF analyser that can help you monitor your processes in PTA production. It’s simple to use, so can be operated by either laboratory or production staff. It provides rapid sample analysis with virtually no sample preparation. The X-Supreme8000 is the workhorse of many production facilities and is often in use 24/7. 

You can test for the catalyst elements cobalt, manganese and bromine simultaneously. High precision, fast measurement times and low detection limits are achieved with a high-reliability tungsten target X-ray tube and a high-resolution silicon drift detector with optimised measurement parameters. The use of a Helium purge under the sample helps reduce the potential adverse effects of a corrosive atmosphere. The X-Supreme’s rugged design means it can be located right next to the production process, helping to keep production delays to a minimum.

More information online