“We are now able to produce premium quality PTA in one of the most modern production plants using the one-step filtration process” remarked customer officials on occasion of the successful start up of two Hi-Bar Oyster Filters.
One of the best technologies for PTA single step filtration is in operation. Two BOKELA Hi-Bar Oyster Filters are installed for the one-step filtration process in a PTA plant in mainland China. The plant, with technology from a process licensor, is designed for an annual PTA production of 600 kta. The filters’ task is filtration, washing out of unwanted substances (especially p-toluic acid) and high-grade dewatering of the product.
The Hi-Bar Oyster filters have now been started up successfully. According to the customer officials: “We are now able to produce premium quality PTA”: a sample analysis taken already 4 hours after the start-up showed an excellent p-tol level of only 84 ppm – much lower than the requested limit.
The fully automated pressure filtration plant can be operated via DCS without the need for a field operator. The smooth and stable filtration is controlled by an intelligent logic which is able to self-adjust the filter to changing process demands.
With the one-step process the BOKELA RPF replaces several pressure decanters, reslurry tank and subsequent atmospheric centrifuges or rotary vacuum filters. The plant layout is simple and the space demand is very low.
One of the big challenges is the discharge of the wet filter cake from 5.5 to 6 bar to atmospheric pressure. BOKELA relies on proven COPERION rotary valves with a very low gas leakage rate and a 100% discharge.
Not only the customer but also the engineering team of the process licensor are more than satisfied with the current filtration performance, the simple and reliable operation and the supervision works of the highly motivated BOKELA engineers.