Rune Myrstad

Hydrotreating of gas-oils: A comparison of trickle-bed and upflow fixed bed lab scale reactors*

Publisher Summary Hydrotreating reactions of distillates and gas-oils are industrially performed in trickle bed reactors, on the scale of several meters in diameter and height. For the development of new catalysts and processes in the laboratory, a realistic scale down of this process is necessary. The smaller the scale of the laboratory unit, the lower the investment and operating costs, smaller amounts of materials to handle and dispose off, and increased safety of the operation. Lab-scale reactors are usually much shorter than the industrial reactors and thus have different height to diameter ratios, leading to much lower linear gas and liquid velocities when operated at similar residence times. For catalyst testing with the purpose of discriminating among commercial catalysts not only should the ranking of catalysts be correct, the lab-scale or pilot testing operation should also allow the prediction of the full scale operation with respect to feedstock/operating conditions, catalyst, and product quality. To fulfill this ambition it follows that the testing must be done with real feedstocks. The choice of reactor type is then limited to either using trickle bed reactors, or up-flow fixed bed reactors. The purpose of this chapter is to give some experimental results comparing catalyst testing in bench scale/small pilot scale units employing trickle bed as well as upflow reactors, and comparing with activity data from commercial use of the same catalyst.

Catalyst Deactivation During One-Step Dimethyl Ether Synthesis from Synthesis Gas

Catalysts for direct synthesis of dimethyl ether (DME) from synthesis gas should essentially contain two functions, i.e., methanol synthesis and methanol dehydration. In the present work, the deactivation of both functions of hybrid catalysts during direct DME synthesis under industrially relevant conditions has been investigated with special focus on the influence of each reaction step on the deactivation of the catalyst function corresponding to the other step. A physical mixture of a Cu–Zn-based methanol synthesis catalyst and a ZSM-5 methanol dehydration catalyst was used. The metallic catalyst appears to deactivate due to Cu sintering, with no apparent effect from the methanol dehydration step under the conditions applied. The acid catalyst deactivates due to accumulation of hydrocarbon species formed in its pores. Synthesis gas composition, i.e.,

Spray drying of porous alumina support for Fischer-Tropsch catalysis

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Fischer–Tropsch synthesis in a microstructured reactor

H2/CO ratio and

Synthesis of dimethyl ether from syngas in a microchannel reactor—Simulation and experimental study

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Characteristics of an Integrated Micro Packed Bed Reactor-Heat Exchanger for methanol synthesis from syngas

CO2-content (which directly affects partial pressure of water), seems to influence the zeolite deactivation.Graphical Abstract