Cracking Of Residual Oil Research Articles

Upgrading of Residual Oils.

Upgrading of residual oils by thermal cracking and coking, catalytic cracking over nickel ores and iron oxides, and hydrodesulfurization, as well as hydrodemetallization, has been studied.Thermal cracking and coking residual oils were conducted under reduced pressures as well as at atmospheric pressure with gas-flow. The coke thus produced was found to have good coking properties for metallurgical use as synthetic coals.In the cracking of residual oils over nickel ores, it has been proven that the nickel ores have cracking and demetallizing activities. In addition, nickel oxide in the ores has been reduced selectively during the cracking reaction and easily leached out with an aqueous solution of ammonium carbonate. These findings suggest the possibility of combining petroleum refining with metal smelting. This study has been extended to a new process in which residual oils are cracked over iron oxides, generating hydrogen from steam and the by-product coke.Kinetic studies of hydrodesulfurization of residual oils have disclosed that reaction order varies with a change in reaction temperature.Further, studies of hydrodemetallization catalysts have been reviewed.

Vanadium-Zeolite Interactions in Fluidized Cracking Catalysts

Abstract Metal levels on equilibrium fluidized cracking catalysts (FCC) have been increasing through the years (Fig. 1), indicating that the study of the physicochemical properties of metal resistant FCC has remained an important topic to refiners [1]. After the crude oil price collapse of 1986, Ni levels on equilibrium FCC have remained fairly constant whereas V levels have somewhat decreased owing to the greater availability (and lower cost) of high-quality crudes; Fig. 2. At the metals levels shown in Fig. 1, Ni and V catalyze the undesirable cracking of hydrocarbons in the gasoline boiling range, thus increasing coke and hydrogen yields. Vanadium-induced activity losses can be easily circumvented with the proper catalyst management and increased makeup rates. However, should refiners in the future undertake the cracking of residual oils or crack certain readily available crudes from Venezuela and Mexico, metals (especially V) will probably increase well above the levels shown in Fig. 1 and novel FCC will have to be found to negate the severe effects of V on cracking activity.

Catalytic cracking of oil residues on catalysts based on activated aluminium alloys

A study has been made of the two-stage process of catalytic cracking of straight-run residual oil on nickel-alumina alloys. It has been shown taht in stage I - cracking of residual oil - the yield of white petroleum products is higher (32·04 wt.%) and their quality is better (benzine fractions contain fewer unsaturated hydrocarbons) compared with similar processes using iron oxide catalysts. Stage II - steam gasification of the coked catalyst - proceeds at a temperature of 800°C with the formation of synthesis gas containing up to 83·57 vol.% H 2. The phase composition of the support and the nickel-containing catalyst based on it was studied. The phase composition of the initial support specimen comprised γ-Al 2O 3, In and In 2O 3. After cracking, breakdown of the crystal structure of metallic In and In 2O 3 and transition of low-temperature γ-Al 2O 3 to a high-temperature crystallized modification of γ-Al 2O 3 occur. The composition of the support after gasification is identical to the composition of the support after cracking. With low cracking temperatures (450, 500°C) crystalline Ni and NiO phases are formed on the nickel-alumina catalyst. It was shown that increase in the cracking temperature leads to reduction of NiO to Ni, and then to breakdown of the crystal structure of the catalyst and subsequent formation of Ni and Ni 3S 2 phases. The γ-Al 2O 3 and metallic Ni phases are stable in relation to gasification and regeneration processes.

A practical model of thermal cracking of residual oil.

A practical model of the thermal cracking of residual oil was developed. It is basically a lumping model stating reactions of hypothetical components, commonly used in petroleum refining reactions. Four lumped components were defined to represent polymerization and condensation of residue as a minimum requirement. Cracked product was arbitrarily divided into four lumps.Introduction of the atmospheric equivalent temperature to rate constants in the Arrhenius form made quantative descriptions of the effect of phase equilibrium states in the reactor on the reaction rate distinctively clear.Incorporating the residence-time distributions, the model predicted the performance of various types of thermal cracking reactors such as batch, semi-batch and CSTR (complete stirred-tank reactor), not only in laboratory experiments but also in commercial operation.

4673486 Process for thermal cracking of residual oils : Tadaak Orihashi, Hiroshi Tsuji, Kazuhiko Ogawa, Masa Hayashitani, Seiji Terada, Tsugio Miyagawa, Hideo Isozaki, Kobe, Japan assigned to Jushitsuyu Taisaku Gijutsu Kenkyu Kumiai

4673486 Process for thermal cracking of residual oils : Tadaak Orihashi, Hiroshi Tsuji, Kazuhiko Ogawa, Masa Hayashitani, Seiji Terada, Tsugio Miyagawa, Hideo Isozaki, Kobe, Japan assigned to Jushitsuyu Taisaku Gijutsu Kenkyu Kumiai

Residual oil cracking with hydrogen generation.

The cracking of residual oils with simultaneous hydrogen generation has been carried out. In this process, the by-product coke deposited on the surface of the catalyst is partially oxidized in the regenerator with the formation of carbon monoxide, and the heat of reaction generated is utilized for cracking of the feed. Carbon monoxide works as a reducing agent for converting triiron tetraoxide (Fe3O4) in the catalyst to ferrous oxide (FeO), which in turn, is converted to Fe3O4 by its reacting with steam to generate hydrogen. A large amount of hydrogen can be produced from the process without coke formation. The amount of hydrogen production is large enough to desulfurize the product distillates produced from the process. Feasibility of the process for upgrading residual oils has been confirmed by the results of 0.6 BPD- and 250 BPD- pilot plants.

Residual oil cracking with generation of hydrogen (Part 3). Behavior of sulfur in residual oil cracking process.

The behavior of sulfur in the cracking of residual oils with generation of hydrogen has been investigated. In the cracker, most of the sulfur contained in the feed oil is transferred to a 560°C+cracked oil fraction and coke. No metal sulfide has been detected by sulfur print analysis in the catalyst after the cracking reaction. In the regenerator, the sulfur in the coke deposited on the catalyst has been burned with air to produce gaseous sulfur compounds, which react with ferrous oxide, and the sulfur is fixed in the catalyst as iron sulfide. The sulfur content in the gas from the regenerator is approximately 200ppm that corresponds to 0.35% of the sulfur fed to the regenerator, while the percent of gasification of carbon is 58. In the hydrogen generator, the iron sulfide is partially desulfurized by steam.

Coke Deposition on Product Transfer-line in Residual Oil Cracking

Coke Deposition on Product Transfer-line in Residual Oil Cracking

Effect of reaction temperature on cracking of residual oil over nickel oxide ore.

Kuwait vacuum residue was cracked over a nickel oxide ore catalyst and over porcelain Raschig rings at 450-650°C, and the yields and properties of the cracked products were investigated. The gas yield increased and the yield of Fraction R (boiling point 510°C+) decreased with increase in the reaction temperature, while coke yield remained almost constant. Higher yields of hydrogen and distillates were observed over the catalyst than over Raschig rings. It was inferred that the cracking and coking activities of the catalyst were due to the partially reduced state of the iron and nickel oxides which were reduced by hydrocarbon vapors during the cracking reaction. The cracked oil obtained over the nickel oxide ore catalyst had high contents of C10-C15 linear α-olefins.

Effect of calcination temperature of nickel oxide ore on cracking of residual oil and on mechanical strength.

Effect of calcination temperature of nickel oxide ore on cracking of residual oil and on mechanical strength.

Cracking of Residual Oil by Use of Dual Spouted Bed Reactor with Three Chambers (Part 2)

Cracking of Residual Oil by Use of Dual Spouted Bed Reactor with Three Chambers (Part 2)

Cracking of Residual Oil by Use of Dual Spouted Bed Reactor with Three Chambers (Part 1)

Cracking of Residual Oil by Use of Dual Spouted Bed Reactor with Three Chambers (Part 1)

Thermal Cracking of Residual Oils

As environmental regulations to prevent sulfur oxide emissions will become stricter in the future, it will be necessary to effectively thermal-crack residual oils of high sulfur contents by-produced in refineries.On the other hand, it is conceivable that the steel industry in Japan will, in the future, suffer from shortage of coking coals having high fluidity for producing blast furnace cokes.Therefore, it is considered very urgent and significant, from the viewpoints of petroleum refining as well as steel manufacturing, to produce binder pitches or syn-thetic coals from residual oils.For the purpose as described above, many companies have been making studies on production of high aromatic binder pitches or synthetic coals by thermal cracking of residual oil.In the present paper, the results of those studies are described and some pro-cesses of thermal cracking which are now on the way of commercialization are reviewed.

Cracking of Residual Oils over Nickel Ores

Studies have been made on cracking of residual oils over nickel ores. It has become apparent that the nickel ores have catalytic activity of dehydrogenation which accelerates coking of a heavy fraction containing most of vanadium and nickel in the feed, resulting in low metal content in oil products. It has been found that the product oil thus obtained by cracking of the residual oil over the nickel ore can be hydrodesulfurized more easily than the atmospheric residual oil. It has also been found that most of nickel contained in the nickel ore used for the cracking reaction can be extracted with aqueous solution of ammonium carbonate. This suggests that the cracking process can be utilized as a pretreatment in the nickel leaching process.