Hydrodesulfurization high-activity catalysts

Ruthenium carbonyl-derived catalytic systems have also been studied in hydrodesulfuration [118, 119], Highly active catalysts for the hydrodesulfuration of diben-zothiophene have been obtained by supporting on alumina MHRu3(CO)n (M = group 1 metal), which was the product of the reaction between Ru3(CO)i2 and MOH. The activity increased from Li to Cs [119]. 

Hydrotreating of petroleum feedstocks have become more and more crucial not only for protecting environments but also for efficient utilization of natural resources. Extensive researches have been conducted to develop highly active catalysts for hydrotreating, in particular for hydrodesulfurization (HDS) [1-3]. 

Irrespective of the exact configuration around the promoter atom, we have a detailed picture of the Co-Mo-S phase on the atomic scale. Figure 9.23 summarizes schematically what a working Co-Mo/A1203 hydrodesulfurization catalyst looks like. It contains MoS2 particles with dimensions of a few nanometers, decorated with cobalt to form the catalytically highly active Co-Mo-S phase. It also contains cobalt ions firmly bound to the lattice of the alumina support, and it may contain crystallites of the stable bulk sulfide Co9S8, which has a low activity for the HDS reaction [49]. 

Cr- FILM from the different cationic forms of this clay [4], These materials exhibited dehydration and dehydrogenation activity in the decomposition of 2-propanol and ethanol. Cr-PILM catalysts activated by HjS/Hj mixture displayed also an interestingly high activity for thiophene hydrodesulfurization (HDS). Now, the Cr-PILM s have been prepared form different clays with the objective to obtain new porous materials with potential catalytic applicability. Their physicochemical properties and the catalytic behaviour for thiophene HDS have been investigated. 

It was observed that Pt/HZSM-5 was of higher catalytic activity than commercial C0M0/AI2O3 in the hydrodesulfurization of thiophene. Therefore, there is a possibility for using Pt/HZSM-5 as highly active, second generation hydrodesulfurization catalyst for petroleum feedstocks. 

Table 2 shows the process conditions applied in the pilot plant tests. Figure 1 gives the catalyst configurations. The two demetallization catalysts, KFRll and KFR 10 have a very high metal absorption capacity. KFR 11 is more metal tolerant than KFR 10. KFR 30 is a dual function catalyst for hydrodesulfurization and demetallization which is used as an intermediate stage in the catalyst system. KFR 50 is used as a downstream catalyst that has a high activity for desulfurization and is more coke resistant... 

PREPARATION OF HIGHLY ACTIVE ZEOLITE-BASED HYDRODESULFURIZATION CATALYSTS ZEOLITE-SUPPORTED Rh CATALYSTS... 

It is evident that 0.5wt%Na-5wt%Rh/USY catalyst shows higher and more stable catalytic activity for the hydrodesulfurization of thiophene than 5wt% Rh/USY and C0M0/AI2O3 catalysts. Therefore, it can be concluded that there is a possibility of usage of Na- Rh/USY as highly active second generation hydrodesulfurization catalyst for petroleum feedstocks. 

On the basis of the proposed mechanism, it can be possible to develop much more highly active zeolite-based hydrodesulfurization catalysts for petroleum feedstocks. 

Transition metal sulfides of the 3" row show high activity in hydrotreating reactions and some of them are studied as potential promoters of conventional catalysts in order to improve their performance. Carbon supported Pt sulfide was highly active in hydrodesulfurization (HDS) of thiophene and hydrodenitrogenation (HDN) of quinoline and pyridine [1,2]. The Pt/silica-alumina sulfide catalyst has been investigated as the promising candidate for deep HDS [3]. 

Platinum (metal)- and acid (oxide)-catalyzed processes were developed to convert petroleum to high-octane fuels. Hydrodesulfurization catalysis removed sulfur from the crude to prevent catalyst deactivation. The discovery of microporous crystalline alumina silicates (zeolites) provided more selective and active catalysts for many reactions, including cracking, hydrocracking, alkylation, isomerization, and oligomerization. Catalysts that polymerize ethylene, propylene, and other molecules were discovered. A new generation of bimetallic catalysts that were dispersed on high-surface-area (100-400 m /g) oxides was synthesized. 

Bimetallic Co-Mo-complexes with optimal localization on the support surface A way for highly active hydrodesulfurization catalysts preparation for different petroleum distillates... 

---