Polymerisation in the Presence of Sulphide Catalysts

Weisser, Otto; Landa, S.

doi:10.1016/b978-0-08-017556-0.50016-2

Cited by 8 publications

(10 citation statements)

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“…When hydrodesulfurization reactions occur, the produced hydrogen sulfide causes the sulfurization of the catalyst precursor, so that the metal oxides in the ores are transformed into metal sulfides which are catalytically more stable. The produced metal sulfides have an irregular crystal structure that facilities the hydrogenation reactions of formed free radicals by thermal cracking. , Ores and their sulfides species have a perfectly developed lattices in their crystalline structure, vacancies of active metal and a random distribution of the various nonactive catalytically compounds. These features may prevent adsorption, dissociation and subsequent transport of hydrogen to free radicals. ,, …”

Section: Results and Discussionmentioning

confidence: 99%

Partial Upgrading of Heavy Crude Oil by Slurry-Phase Hydrocracking with Analytical Grade and Ore Catalysts

Quitian

Ancheyta

2016

Energy Fuels

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A heavy crude oil of 13°API and a viscosity of 6100 cSt at 37.8 °C was used to study the effect of different hydrocracking catalysts at low severity conditions in a slurry-phase batch reactor. The evaluated catalysts were Mo and Fe analytic grade oxides and ores (molybdenite, hematite, and magnetite) from different Mexican mine sites. The effect of the concentration of catalysts on heavy oil upgrading was studied in the range of 0−13 333 ppm of active metal (Mo or Fe). The results showed that the required minimum concentration of catalyst to obtain upgraded crude oil with suitable properties for transportation (API gravity > 16 and viscosity at 37.8 °C < 250 cSt) is 5000 ppm. At the evaluated operating conditions, coke formation is not observed and the selectivity toward gases is low. Mo showed better hydrogenation capacity than Fe, which is observed by an increase in the light fraction composition and reduction of the heavy vacuum gasoil and vacuum residue. Depending on the concentration, type, and active metal content of the catalysts, vacuum residue conversion in the range of 37−49% was obtained.

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Section: Results and Discussionmentioning

confidence: 99%

Partial Upgrading of Heavy Crude Oil by Slurry-Phase Hydrocracking with Analytical Grade and Ore Catalysts

Quitian

Ancheyta

2016

Energy Fuels

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“…The drop in selectivity toward hydrogen is attributed to catalyst sulfur poisoning with the formation of NiS. Nickel sulfide particles have low activity in the dehydrogenation, but it can to some extent catalyze hydrocracking and cracking reactions, leading to a decrease in hydrogen purity. Nevertheless, these results show the possibility of producing CO-free hydrogen from fuels containing considerable amounts of sulfurous compounds.…”

Section: Fuel Partial Dehydrogenationmentioning

confidence: 99%

High-Purity Hydrogen Generation via Dehydrogenation of Organic Carriers: A Review on the Catalytic Process

et al. 2018

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High-purity hydrogen delivery for stationary and mobile applications using fuel cells is a subject of rapidly growing interest. As a consequence, the development of efficient storage technologies and processes for hydrogen supply is of primary importance. Promising hydrogen storage techniques rely on the reversibility and high selectivity of liquid organic hydrogen carriers (LOHCs), for example, methylcyclohexane, decalin, dibenzyltoluene, or dodecahydrocabazole. LOCHs have high gravimetric and volumetric hydrogen density, and they involve low risk and capital investment because they are largely compatible with the current transport infrastructure used for fossil fuels. A further advantage comes from the high purity (close to 100%) of the hydrogen generated by dehydrogenation, suitable to directly feed fuel cells without the need for bulky purification modules. Partial dehydrogenation (PDH) of liquid fuels has recently emerged as a transition technology for hydrogen delivery purposes. The principle is to extract from fossil fuels a small fraction of the available hydrogen, which can be used for fuel cell applications, while the dehydrogenated hydrocarbon mixture maintains suitable properties for its use as fuel. With this technology, the large energy demand of dehydrogenation processes can be satisfied by implementing a heat exchanger between the engine and the dehydrogenation reactor, overcoming one of the main constraints associated with the use of organic liquids as hydrogen carriers. This method qualifies itself as a transition technology toward more electrified transportations, in which the main propulsion is still obtained by fuel combustion, although the electrical utilities or auxiliary propulsion are powered by fuel cells. This paper provides a review of the effort that has been directed toward the utilization of organic liquids as hydrogen carriers, with particular focus on the design of the catalytic dehydrogenation process and on the recent approach of fuel partial dehydrogenation.

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“…The two dppe phosphorus atoms are both trans to the phosphido bridge, as predicted from the large 31P-31P coupling constant (118 Hz). The acetylide is u-bound to Fe(l) and ir-bound to Fe (2), giving asymmetry to the molecule in the solid state. However, the molecule exhibits a dynamic motion of the acetylide as described above.…”

Section: Methodsmentioning

confidence: 99%