Michael Kotter

The Influence of Impregnation, Drying and Activation on the Activity and Distribution of Cuo on α-Alumina

The influence of the distribution of the active component on the activity of impregnation-type porous catalysts is demonstrated for CuO on alumina, activity being measured for oxidation of CO. The viscosity of the impregnating solution affects the distribution of the catalyst precursor (Cu(NO 3 ) 2 ) after impregnation and drying. The uniformity of the distribution of the active component and thereby the activity of the finished catalyst depend considerably on the procedure of impregnation and drying.

Partial Oxidation of o-Xylene to Phthalic Anhydride in a Structured Fixed Bed Containing a Sequence of Catalysts

It is shown that an elevated yield of phthalic anhydride (PAA) can be obtained in a fixed bed consisting of a sequence of different catalysts. A suitable sequence of catalysts can be determined by a computerized search, following the strategy of biological evolution on the basis of experimentally obtained kinetic data.

Selective catalytic reduction of nitrogen oxide by use of the Ljungstroem air heater as reactor: a case study

Abstract A new NO abatement strategy proposes the use of the Ljungstroem air heater of the power plant as a chemical reactor, covering the air heater elements with a catalyst. A simple model has been developed to predict the performance of such a catalyst air heater. The model calculations are based on kinetic data obtained by laboratory scale experiments. The comparison of the calculated results with preliminary experimental data of a full-scale installed catalyst air heater proves the validity of the approach chosen. The catalyst air heater provides substantial NO reduction potential without requiring major modifications of existing power plant equipment.

Structure and Selectivity Changes in Vanadia-Titania-Denox Catalysts

Summary The rapid evaporation of thin liquid films of precursor solutions containing vanadium and titanium followed by calcination is an adequate method to prepare active and selective catalysts for the SCR process. Catalysts useful for operation at temperatures above 350 °C can be obtained by modifying this preparation method. Addition of sulfuric acid to the precursor solution leads to high surface area catalysts with a low level of vanadia species weakly interacting with the titania carrier, if the vanadia loading does not exceed 10 wt%. Catalytic tests demonstrate that sulfate stabilization increases NO conversion while N 2 O formation is suppressed. The addition of tungsten is equally beneficial for high temperature operation of the catalyst. Quantitative information about activity and selectivity of the developed catalysts is obtained by rate measurements in a gradientless system.

Deposition Of Ternary Oxides As Active Components By Impregnation Of Porous Carriers

The ternary oxide coppermanganate is generated in highly dispersed form in the pores of inert α-Al 2 O 3 carriers by impregnation with a viscous solution containing both metals, drying and calcination. Kinetic data for this catalyst in the total oxidation of CO are compared with similar catalysts containing only CuO, MnO or CuO together with MnO as separate crystallites. In the case of ironmolybdate it is also possible to obtain crystallites of the ternary phase in the pores of α-alumina by way of impregnation, either with solutions containing ammoniummolybdate and ironnitrate or with the solution of ironmolybdate in a mixture of monoethanolamine and water. Properties of both types of catalysts and of catalysts consisting of pure ironmolybdate are compared, focusing on the selectivity in the partial oxidation of methanol to formaldehyde.

Experimental Setup to Determine Reaction Kinetic Datas of the Partial Oxidation of Propene to Acrolein

Improvement of commercial catalysts in a rational way requires precise kinetic data describing the dynamics of interacting consecutive and parallel reactions in or on the catalyst. Such data can only be obtained experimentally through simultaneous observation of several variables of composition, temperature etc. in space and time, in an open system containing the catalyst under consideration. A quantitative approach along these lines was considered not to be feasible in industrial practice, due to the necessity of observing and processing a huge amount of data. This difficulty can be surmounted if data storage and processing is delegated to a microcomputer which at the same time executes control of the state variables of the complex experimental setup. As an example the partial oxidation of propene to acrolein and acrylic acid was investigated on catalysts containing the elements Mo, Bi, Fe, Ni, Zn, K and Si as oxides in various proportions. The objective is to optimize the catalytic system used in industrial practice with respect to selectivity, which means that the raw material consumption in the production of acrylic fibers and coatings should be minimized.