Process development for low temperature CO oxidation in the presence of water and halogen compounds

A new process has been developed to oxidize CO at low temperatures (<423 K) in vent streams that also contain halogenated compounds and water, A PdCl2 -CuCl2 catalyst supported on carbon was successfully implemented to treat t he oxidation reactor vent stream of a terephthalic acid plant that containe d water, CH3Br and other organic compounds in addition to CO. The CH3Br rem ained intact during the treatment and did not deactivate the catalyst. In t his catalyst system, palladium remained as a molecular Pd(II) species while solid Cu2Cl(OH)(3) was the active copper phase. The formation of stable Cu 2Cl(OH)(3) was essential for activity and stability of the catalyst, After obtaining a stable catalytic activity for six months in a pilot plant test with a side stream of real vent gases, the first installation and operation of the process were made successfully to handle 50,000 Nm(3)/h of vent str eam in a terephthalic acid plant. (C) 1999 Elsevier Science B.V. All rights reserved.