Rational Catalyst Design of Methanol Synthesis Catalysts

Abstract

Communications(smooth or rough). Even for the single air flow, a difference exists for velocities of 25 and 30 m/s. This is probably due to a rather poor tangential and axial grid resolution compared to the radial resolution. These constraints in grid resolution were chosen in order to reduce the need for CPU time. ConclusionThe implementation of a model is introduced, describing particle adhesion at a pipe wall in the pneumatic conveying of very fine particles, using existing software code (FLUENT 6). Basically, it could be shown that this model is suitable, in combination with the Euler-Lagrange approach, for describing the continuous and dispersed phase for the simulation of particle wall adhesion in a pipe. The influence of air velocity and loading on particle wall adhesion is determined qualitatively, in an accurate manner. Qualitatively, the modeling of wall roughness results in the correct values for pressure drop and particle wall collision frequency.The quantitative statement of the simulation has to be scrutinized since the grid resolution is obviously far from optimized. AcknowledgementsThe authors would like to thank the DFG for supporting this project financially in the scope of the SPP 1062.

Active Sites on Oxide Surfaces: ZnO‐Catalyzed Synthesis of Methanol from CO and H2

“…In our opinion, the activity of the Cu‐containing catalyst is determined by the strong interaction between Cu and ZnO 1− x ( x is equal to the number of O vacancies). The hydrogenation of CO 2 at the Cu‐ZnO 1− x interface is favored over the conversion of CO 34. For definite proof that methanol is formed by these two different reaction paths, spectroscopic analysis of the intermediates, calculation of transition states, and comparison of the results obtained by microkinetic modeling based on quantum chemical calculations with the data of kinetic measurements will be necessary.…”

A colloidal ZnO/Cu nanocatalyst for methanol synthesis

“…The catalytic test reactor was charged with the colloids (300 mg) and 200 ml of pure squalane, pressurised with the feed gas mixture and set to 443 K (Table 1). 21 The composition of gas phase was monitored by GC (Porapak and a molecular sieve column). The methanol concentrations were in the range up to 1%.…”

Reaction Network of Methanol Synthesis over Cu/ZnO Nanocatalysts

“…Evidently there must exist synergistic effects between the reducible ZnO and nanodispersed Cu, 22,24,25,[32][33][34] although no consensus has been reached yet on the actual mechanism 5,6,16,18,19,[21][22][23]28,[30][31][32] that explains the superior performance of the ICI catalyst. 50,59 obviously also induced by chemical interaction with (spectator) species present in the methanol synthesis process. This raises the general question if under reaction condition there will exist only one mechanism for each of the hydrogenation reactions or if a dynamic network of many parallel and competing reaction channels will prevail over Cu/ZnO given the vast space of structural and chemical possibilities, both of chemical species and catalyst surfaces, which eventually is set by the redox conditions of the surrounding gas phase.…”