For the purification of flue gases from facilities producing purified terephthalic acid - PTA for short - and other applications exhausted at a high pressure, Dürr applies the Ecopure® HPX abatement system as a standard. The high-pressure PTA flue gas typically contains methyl acetate, methyl bromide, and carbon monoxide can be treated directly without prior decompression.
The flue gas from the process is heated to the required catalyst operating temperature by a combination of heat exchangers which operate on steam or preheated air and by a purified air heated air-to-air heat exchanger. After conversion of the pollutants on the catalyst, the purified flue gas is cooled and the heat is recovered in the air-to-air heat exchanger. The purified, pressurized flue gas is then routed to an expander for energy recovery, used for pneumatic conveying, or further treatment of hydrobromic acid.