title: Catalyst optimization strategy: selective oxidation of o-xylene to phthalic anhydride.
abstract: The oxidation of o-xylene and/or naphthalene to phthalic anhydride is one of the important industrial processes based on catalytic selective oxidation reactions. Vanadia--titania catalysts have been used in the industrial phthalic anyhdride process for the last 50 years. The operation parameters like the temperature range of operation, reactor inlet pressures, contact times, o-xylene loadings, etc. were constantly improved during this period of continuous process optimization so as to optimize catalyst performance and increase its life time. However, a fundamental understanding of the mutual interaction of the rather complex reaction network and the catalyst formulation is still missing. Recently, a detailed study of by-product formation as function of process conditions allowed us to develop a novel, improved reaction scheme for the catalytic oxidation of o-xylene. Based on this understanding, a detailed investigation was conducted for the first time of the by-product formation under varying operation conditions and as a function of the active mass variation exploiting high-throughput, as well as bench scales reactors. This high-throughput testing allowed us to relate reaction kinetics to novel catalyst formulations.
authors: Department of Oxidation Catalysis, Sud-Chemie R&D, Waldheimer Str. 13, D-83052 Bruckmuhl, Germany.
authors: Hans-Jörg
authors: HJ
authors: Wöelk
authors: Gerhard
authors: G
authors: Mestl
mesh_terms: D002384:Catalysis; D057166:High-Throughput Screening Assays; D009281:Naphthalenes / Q000737:chemistry; D010084:Oxidation-Reduction; D010796:Phthalic Anhydrides / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014639:Vanadium / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry*
chemical_list: D009281:Naphthalenes; D010796:Phthalic Anhydrides; D014992:Xylenes; D014639:Vanadium; C009495:titanium dioxide; C031721:naphthalene; D014025:Titanium; C043103:phthalic anhydride; C026114:2-xylene