Comparison of MoS2Catalysts Prepared from Mo-Micelle and Mo-Octoate Precursors for Hydroconversion of Cold Lake Vacuum Residue: Catalyst Activity, Coke Properties and Catalyst Recycle

2012 ◽  
Vol 26 (5) ◽  
pp. 2768-2778 ◽  
Author(s):  
Hooman Rezaei ◽  
Shahrzad Jooya Ardakani ◽  
Kevin J. Smith
Keyword(s):  
Catalyst Activity ◽  
Vacuum Residue ◽  
Catalyst Recycle ◽  
Cold Lake

scholarly journals Hydroformylation of Higher Olefins in Aqueous Biphasic Medium Using Rhodium-Sulfoxantphos Catalyst: Activity and Selectivity Study

2020 ◽  
Vol 32 (8) ◽  
pp. 2061-2066 ◽  
Author(s):  
Nitin S. Pagar ◽  
Raj M. Deshpande
Keyword(s):  
Reaction Rate ◽  
Catalyst Activity ◽  
Water Soluble ◽  
Effect Of Temperature ◽  
Complex Catalyst ◽  
Catalyst Recycle ◽  
Aqueous Biphasic ◽  
Biphasic Medium ◽  
Methyl Pyrrolidone ◽  
Higher Olefins

Hydroformylation of higher olefins such as 1-hexene, 1-octene, 1-decene and 1-dodecene has been studied in an aqueous biphasic medium using water-soluble Rh-sulfoxantphos complex catalyst. The effect of temperature, presence of various co-solvents and concentration of co-solvent on the reaction rate and chemo and regioselectivity was investigated. N-Methyl pyrrolidone (NMP) was found to be the best co-solvent, which enhances the rate dramatically (4-96 fold) as compared to the reactions in aqueous-organic biphasic medium for hydroformylation of higher olefins. Catalyst recycle study was performed to check the leaching of metal in organic phase.

A study of Cold Lake Vacuum Residue hydroconversion in batch and semi-batch reactors using unsupported MoS2 catalysts

2010 ◽  
Vol 150 (3-4) ◽  
pp. 244-254 ◽  
Author(s):  
Hooman Rezaei ◽  
Xuebin Liu ◽  
Shahrzad Jooya Ardakani ◽  
Kevin J. Smith ◽  
Maureen Bricker
Keyword(s):  
Batch Reactors ◽  
Vacuum Residue ◽  
Mos2 Catalysts ◽  
Cold Lake

Preparation and Evaluation of Skeletal Cobalt-Molybdenum Hydrodesulfurization Catalysts

1995 ◽  
Vol 60 (4) ◽  
pp. 568-575
Author(s):  
Karel Sporka ◽  
Jiří Hanika ◽  
Vladimír Jůn
Keyword(s):  
Aqueous Solutions ◽  
Active Component ◽  
Catalyst Activity ◽  
Gas Oil ◽  
Gamma Alumina ◽  
Molybdenum Sulfides ◽  
Hydrodesulfurization Catalysts ◽  
Hds Catalysts ◽  
Kinetics Of ◽  
Preparation And Evaluation

Preparation of skeletal Co-Mo catalysts by controlled impregnation of aluminosilicate skeletons containing deposited gamma-alumina with aqueous solutions of active component precursors has been investigated. The activity of the laboratory catalysts in gas oil hydrodesulfurization has been determined. Kinetics of impregnation of skeletal supports, the effect of their type, and the dependence of catalyst activity on the content of cobalt and molybdenum sulfides are reported. HDS skeletal catalysts prepared were compared with the extruded types. It was found that skeletal HDS catalysts show the higher activity (related to the content of alumina and Co-Mo sulfides) than the extruded ones due to the less significant effect of internal diffusion. However, if the activity is related to the same volume of catalyst bed, the activity of skeletal catalysts is only one fourth of that of the extruded types.

Kinetics of carbon monoxide methanation on a Ni/SiO2 catalyst

1990 ◽  
Vol 55 (7) ◽  
pp. 1678-1685
Author(s):  
Vladimír Stuchlý ◽  
Karel Klusáček
Keyword(s):  
Carbon Monoxide ◽  
Reaction Rate ◽  
Catalyst Activity ◽  
Adsorbed Hydrogen ◽  
Reaction Products ◽  
Co Methanation ◽  
Molar Ratios ◽  
Rate Determining Step ◽  
Higher Temperature ◽  
Kinetics Of

Kinetics of CO methanation on a commercial Ni/SiO2 catalyst was evaluated at atmospheric pressure, between 528 and 550 K and for hydrogen to carbon monoxide molar ratios ranging from 3 : 1 to 200 : 1. The effect of reaction products on the reaction rate was also examined. Below 550 K, only methane was selectively formed. Above this temperature, the formation of carbon dioxide was also observed. The experimental data could be described by two modified Langmuir-Hinshelwood kinetic models, based on hydrogenation of surface CO by molecularly or by dissociatively adsorbed hydrogen in the rate-determining step. Water reversibly lowered catalyst activity and its effect was more pronounced at higher temperature.

scholarly journals Glycerol Hydrogenolysis with In Situ Hydrogen Produced via Methanol Steam Reforming: The Promoting Effect of Pd on a Cu/ZnO/Al2O3 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Yuanqing Liu ◽  
Chau T. Q. Mai ◽  
Flora T. T. Ng
Keyword(s):  
Steam Reforming ◽  
Catalyst Activity ◽  
Promoting Effect ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis ◽  
Glycerol Dehydration ◽  
Effect Of Pd ◽  
Al2o3 Catalyst ◽  
Reaction Equilibrium

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.

scholarly journals Bio-DEE Synthesis and Dehydrogenation Coupling of Bio-Ethanol to Bio-Butanol over Multicomponent Mixed Metal Oxide Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 660
Author(s):  
Izabela S. Pieta ◽  
Alicja Michalik ◽  
Elka Kraleva ◽  
Dusan Mrdenovic ◽  
Alicja Sek ◽  
...  
Keyword(s):  
Active Sites ◽  
Internal Combustion Engines ◽  
Mixed Oxides ◽  
Catalyst Activity ◽  
Product Distribution ◽  
Coke Deposition ◽  
Precipitation Method ◽  
Mixed Metal Oxide ◽  
Low Carbon ◽  
Municipal Solid Wastes

Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods from municipal solid wastes (MSWs) are sought for application as energy carriers or direct drop-in fuels/chemicals in the near-future low-carbon power generation systems and internal combustion engines. Among the studied energy vectors, C1-C2 alcohols and ethers are mainly addressed. This study presents a potential bio-derived ethanol oxidative coupling in the gas phase in multicomponent systems derived from hydrotalcite-containing precursors. The reaction of alcohol coupling to ethers has great importance due to their uses in different fields. The samples have been synthesized by the co-precipitation method via layered double hydroxide (LDH) material synthesis, with a controlled pH, where the M(II)/M(III) ≈ 0.35. The chemical composition and topology of the sample surface play essential roles in catalyst activity and product distribution. The multiple redox couples Ni2+/Ni3+, Cr2+/Cr3+, Mn2+/Mn3+, and the oxygen-vacant sites were considered as the main active sites. The introduction of Cr (Cr3+/Cr4+) and Mn (Mn3+/Mn4+) into the crystal lattice could enhance the number of oxygen vacancies and affect the acid/base properties of derived mixed oxides, which are considered as crucial parameters for process selectivity towards bio-DEE and bio-butanol, preventing long CH chain formation and coke deposition at the same time.

scholarly journals Kinetic Modelling of Low Temperature Direct Coal Liquefaction: Consideration of Dynamic Catalyst Activity

2021 ◽  
Author(s):  
Ethan Gabriel Hammond ◽  
Shaheen Amed Faizal Moonsamy ◽  
David Lokhat ◽  
Milan Carsky
Keyword(s):  
Low Temperature ◽  
Kinetic Modelling ◽  
Catalyst Activity ◽  
Coal Liquefaction ◽  
Direct Coal Liquefaction

scholarly journals Commercial Investigation of the Ebullated-Bed Vacuum Residue Hydrocracking in the Conversion Range of 55–93%

ACS Omega ◽  
2020 ◽  
Vol 5 (51) ◽  
pp. 33290-33304
Author(s):  
Dicho Stratiev ◽  
Svetoslav Nenov ◽  
Ivelina Shishkova ◽  
Borislav Georgiev ◽  
Georgi Argirov ◽  
...  
Keyword(s):  
Vacuum Residue ◽  
Conversion Range

scholarly journals Iron Tetrasulfonatophthalocyanine-Catalyzed Starch Oxidation Using H2O2: Interplay between Catalyst Activity, Selectivity, and Stability

ACS Omega ◽  
2021 ◽  
Author(s):  
Homer C. Genuino ◽  
Tim G. Meinds ◽  
J. O. P. Broekman ◽  
Marcel Staal ◽  
Jelle Brinksma ◽  
...  
Keyword(s):  
Catalyst Activity ◽  
Starch Oxidation

scholarly journals Proline/arginine dipeptide repeat polymers derail protein folding in amyotrophic lateral sclerosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Babu ◽  
Filippo Favretto ◽  
Alain Ibáñez de Opakua ◽  
Marija Rankovic ◽  
Stefan Becker ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Protein Folding ◽  
Neurodegenerative Diseases ◽  
Catalyst Activity ◽  
Coding Region ◽  
Prolyl Isomerase ◽  
X Ray Crystallography ◽  
Hexanucleotide Repeat ◽  
Lateral Sclerosis ◽  
Dipeptide Repeat

AbstractAmyotrophic lateral sclerosis and frontotemporal dementia are two neurodegenerative diseases with overlapping clinical features and the pathological hallmark of cytoplasmic deposits of misfolded proteins. The most frequent cause of familial forms of these diseases is a hexanucleotide repeat expansion in the non-coding region of the C9ORF72 gene that is translated into dipeptide repeat polymers. Here we show that proline/arginine repeat polymers derail protein folding by sequestering molecular chaperones. We demonstrate that proline/arginine repeat polymers inhibit the folding catalyst activity of PPIA, an abundant molecular chaperone and prolyl isomerase in the brain that is altered in amyotrophic lateral sclerosis. NMR spectroscopy reveals that proline/arginine repeat polymers bind to the active site of PPIA. X-ray crystallography determines the atomic structure of a proline/arginine repeat polymer in complex with the prolyl isomerase and defines the molecular basis for the specificity of disease-associated proline/arginine polymer interactions. The combined data establish a toxic mechanism that is specific for proline/arginine dipeptide repeat polymers and leads to derailed protein homeostasis in C9orf72-associated neurodegenerative diseases.

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