DE2713343A1 - METHOD OF REMOVING SULFUR AND NICKEL FROM HEAVY HYDROCARBON FEED MATERIALS - Google Patents

Description

Dr D. Thomsen PATE N ANWALTS OFFICE

& Phone (089) 530211

W. We i η ka uf f Te ^ m-AdZ, ¹² , 2713343

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T Cable address I. PATENT LAWYERS MOncnen: Frankfurt / M .:

Dr. rer. nat. O. Thomsen Dlpl.-Ing. W. Weinkauff

(Fuchshohl 71)

DrMdrwr Bank AQ, Munich, account “S74237

8000 Munich 2 Kaiser-Ludwig-Platz · March 25, 19 77

Mobil Oil Corporation New York, N.Y., USA

Process for removing sulfur and nickel from heavy hydrocarbon feedstocks

The invention relates to a method for removing sulfur and nickel from feed materials containing these elements heavy hydrocarbons.

Heavy hydrocarbon material, such as petroleum residue fractions, that is, the heavy fractions produced in atmospheric and vacuum crude distillation columns, are typically distinguished in that they are primarily used as feed materials for most refining processes Line undesirable because of its high metal and sulfur content

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are. The presence of high concentrations of metals and sulfur and their compounds precludes effective use such residues as feed materials for cracking, hydrocracking and coking, and limit the extent to which such residues can be used as fuel oil. Perhaps the only highly undesirable feature of such feed materials is the high metal content. The main metal impurities are nickel and vanadium, with iron and small amounts of copper also occur occasionally. In addition, trace amounts of zinc are found in some feed materials and sodium. Because the vast majority of these metals, when found in crude oil, have very large hydrocarbon molecules are connected, the heavier fractions of the raw distillation contain practically all of the raw material present Metals, these being particularly concentrated in the asphalt residue fraction. The metal impurities are typically large organometallic complexes such as metal porphyrins and asphalts.

Methods for desulfurizing such feed materials are known; but many of these procedures are for removal not suitable for metals. In US Pat. No. 3,720,602, a process for hydrated desulfurization is practically free of metal Hydrocarbon feedstocks described. This process involves the use of a special one containing vanadium Catalyst and the injection of water into the desulphurisation reactor to cool and increase the cata-

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analyzer activity. Water injected in this way is separated from the products emerging from the reactor for recycling. Injection of water between the catalyst beds of a multiple bed desulfurization reactor is disclosed in U.S. Patent No. 3,753,894. It is reported here that the processing of petroleum residues with hydrogen plus 10 volume percent water acts to suppress the normal rate of catalyst deactivation, particularly during the initial period of product make-up.

Further publications regarding the use of water in desulphurisation are available. Asphaltene-containing dark or black oil is desulfurized by adding between 2.0 and about 30 percent by weight of water to the oil, which is then reacted with hydrogen under desulfurization conditions over a desulfurization catalyst according to US Pat. No. 3,501,396. US Pat. No. 3,453,206 discloses that in the multistage hydrorafining of crude oil and the heavier hydrocarbon fractions obtained therefrom, water can be added in the second or catalytic stage if the maximum proportion of hydrocarbons with a boiling point in the gasoline range is desired are, in contrast to the maximum proportion of hydrocarbons in the middle distillate. US Pat. No. 3,471,398 and US Pat. No. 3,475,324 both relate to improved hydrocarbon quenching methods in the desulfurization of high boiling point hydrocarbons. These patents disclose that it is

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has proven suitable to occasionally add water in admixture with the feed material to the reaction zone; however, the use of water is usually not necessary or desirable.

None of the above-mentioned references disclose the novel removal method of the present invention of sulfur and metal.

The invention relates to an improved method for desulfurizing and removing nickel from these elements containing heavy hydrocarbon feedstocks. This process comprises the following stages:

a) adding a stream rich in hydrogen to the feed material,

b) Reacting the mixture of step (a) in one

Reaction zone with a desulfurization catalyst under desulfurization conditions,

c) injecting water into the reaction zone at a molar ratio of water to hydrogen from about 0.05 to 0.5,

d) Separating a light gas stream, which contains H-, H ₂ O, H ₂ S and light hydrocarbons, from the product stream leaving the reaction zone.

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e) separating H ₂ O from the light gas stream leaving behind an essentially dry light gas stream,

f) recycling of the separated H-O for injection in stage (c),

g) separating the H ₂ S from the dry light gas stream leaving a hydrogen-rich stream,

h) returning the hydrogen-rich stream to the feed material for admixture and

i) recovering a product substantially free of nickel and sulfur from the product stream from the reaction zone.

Fig. 1 is a schematic representation of the method of the invention;

FIGS. 2, 3, 4 and 5 indicate the removal of sulfur, nitrogen, nickel and vanadium in percent at different H ₂ O / H ₂ and N ₂ / H ₂ molar ratios.

The method according to the invention is directed to improved desulfurization and demetallization of feed materials of heavy hydrocarbons, which can be any metal- or sulfur-containing material, preferably material containing residue fractions. Examples are starting

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materials such as atmospheric and vacuum residues, vacuum gas oils, tar sands, bitumen, return oils, shale oils and the like. From what has been said so far, it should be clear that the feed material can be a complete raw material. However, since the high metal and sulfur components of a crude oil tend to be concentrated in the higher boiling fractions, the process of the present invention usually applies to a bottom fraction of a petroleum, that is, one obtained by distilling a crude oil to remove lower boiling materials. Consequently, the supply of materials used herein boiling heavy hydrocarbons is generally greater than about 204 ⁰ C (400 ⁰ F), preferably above about 343 C (650 ⁰ F) and have specific weights of about 0 to about 30 API (API = American Petroleum

Institutes). A general range of properties of heavy hydrocarbon feed materials for use are suitable in the method according to the invention, as well as the Properties of a particular feed material are listed in Table I.

Table I.

An atmospheric pressure back area generally stood for Arabic light oil

Sulfur, wt% 1 - 10 3.85 Nitrogen, wt% 0.1-3 0.22 Oxygen, wt .-% 0-10 0.13 Metals total, tpm 10-3000 65 Vanadium, tpm 10-2000 49 Nickel, tpm 1 - 300 13th 709840/0961

'* ■ 27133A3

Catalysts which can be used to promote the desulfurization reactions contain at least one metallic component from Groups VIb and VIII of the Periodic Table, deposited on a refractory inorganic oxide support or binder. The preferred metal component can be an oxide or sulfide of nickel or cobalt, especially the latter, and an oxide or sulfide of molybdenum or tungsten. The Group VIII metal is generally present in amounts from 1 to 15 percent by weight while the Group VIb component is present in amounts from 5 to 25 percent by weight. The refractory inorganic oxide carrier can include alumina, silica, zirconia, magnesia, titania, boron oxide, strontia, hafnia, and mixtures thereof. Aluminum oxide or aluminum oxide stabilized with silicon dioxide are particularly preferred, the aluminum oxide making up the greater proportion. A typical catalyst consists of 3% CoO, 10% MoO ₃ , 5% SiO ₂ on aluminum oxide. The catalysts are usually presulphided before they are used.

Table II lists suitable reaction conditions for the catalytic desulfurization of heavy hydrocarbon feedstocks on.

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Table II Desulfurization conditions General area preferred

Pressure (psig) 500-3000 1000-2000

Temperature, ⁰ C 250-500 350-45O

hourly Liquid roughness

ming speed (IHSV) 0.2-5 0.5-2

Hydrogen flow rate (scf / bbl) 1000 - 20,000 4000 - 12,000

The effectiveness of the novel desulfurization and demetallization process of the present invention is based in part on the effects of water injection on the hydraulic machining of the heavy feed materials. This finding is described in detail below; Briefly, however, it was found that the injection of water into the reaction zone at certain H ₂ 0 / H ₂ molar ratios enhances both the removal of sulfur and nickel. In addition, the injection of water in the particularly specified amount has, as has been found, no disadvantageous influence on the removal of nitrogen, the aging of the catalyst or the physical properties of the catalyst, such as, for example, its surface. Thus, the new process disclosed herein results in increased removal of sulfur and nickel without relying on undesirable changes in process variables such as an increase in pressure or temperature. In fact, the partial pressure of expensive hydrogen is greatly reduced by using the invention.

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A method using these findings is described below. Referring to FIG. 1, a heavy hydrocarbon feed stream 20 containing sulfur, nitrogen and oxygen heteroatoms and metals such as nickel and vanadium is mixed with a hydrogen rich gas stream 21 and the resulting mixture is placed in a furnace 22 heated before it is fed to the reaction zone 23. The reaction zone 23 contains desulfurization catalyst and may contain a number of beds. Water from a line 24, which includes both recycled water from a line 36 and water to make up from a line 35, as required, is fed into the reaction zone 23 in amounts of about 0.05 to 0.5 H ₂ O / H ₂ (molar ratios), preferably 0.05 to 0.2. If desired, a portion of the water can be injected into the reaction zone by admixture with the hydrogen-rich stream, this water being introduced via line 39. Used in these amounts, the water causes increased desulfurization and demetallization of the feed materials, as described below, as well as cooling or quenching. Water can be injected between beds when the reaction zone 23 contains multiple beds.

The products flowing off from the reaction zone in line 37 are passed through a heat exchanger 38 before they reach a separator 25. The heat exchanger 38 is used to control the temperature of the product stream containing H ₂ , H ₂ O, H ₂ S, light hydrocarbons and desulfurized and

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contains demetallized products to adjust the conditions for the separator 25, which is desirably a high pressure flash separator. The gases emerging from the separator 25, which _{comprise H 2} , H ₂ O, H ₂ S and light hydrocarbons, go overhead into line 27. The desulphurized and demetallized product is drawn off via line 26. The light gas stream in line 27 is fed into a cooler 28 in which water is condensed out of the light gas stream, a practically dry light gas stream 29 remaining. Water separated in this way reaches the water return line 36 for the injection as described above. The dry light gas stream 29 is passed to a hydrogen sulfide recovery system 30 where hydrogen sulfide is removed by contact with a basic scrubbing agent such as methylamine. The product stream 33 leaving the scrubber, a hydrogen-rich stream consisting of hydrogen and light hydrocarbons, is mixed with a supplementary hydrogen stream 34 to form the hydrogen-rich gas stream 21 described above.

According to the invention, they are practically free of sulfur and nickel Products are suitable for direct use, e.g. as fuel, or can be further processed. A desirable one Another processing use is catalytic cracking, particularly fluid catalytic cracking (FCC). The invention Products are particularly desirable as cracking feeds because of their low nickel and sulfur content

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it is known that nickel contributes significantly to catalyst poisoning in catalytic cracking.

example

Atmospheric pressure residue of Arabic light oil was mixed with hydrogen. Water preheated to 100 ° C. was added to the residue / hydrogen mixture at certain times over a batch sequence. The finished mixture was over a presulfided desulfurization catalyst with 3% CoO, 10% MoO, and 5% SiO ₂ on aluminum oxide in a trickle

bed reactor at a pressure of 49 kg / cm manometer (700 psig)

and temperatures from 399 ^° C to 427 ^° C (750 to 800 ^° F). The weight hourly space air velocity was 2. A standard batch sequence was used to flow the reactor at the lower temperature for 4 days without water, followed by 7 days of testing with water addition, followed by a return to the original anhydrous monitor aging conditions. The sequence was continued at the higher temperature. Table III illustrates the standard batch sequence.

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Table III Standard approach sequence

Days temperature
° C (° F) (75O) H ₂ O / H ₂ Gas circulation
(scf / bbl) 1-4 399 (750) O 85OO - 5 399 (750) 0.4 6.7 399 (750) 0.1 9000 - 8th 399 (750) 0.7 85OO - 9 399 (750) 0.4 10 399 (750) 0.5 11 399 (750) 1.2 8500 - 12.13 399 (80O) 0 8500 - 14.15 427 (800) 0 85OO - 16 427 (80O) 0.4 17.18 427 (800) 0.1 8000 - 19th 427 (800) 0.7 8000 - 20th 427 0.4 21.22 0 8500 - ■ 9OOO 12000 ■ 10000 ■ 90OO 12000 13000 ■ 9500 • 9000 • 9000 12000 ■ 9000 - 9000 12000 ■ 9000

including

The reaction products were separated from the water and dried over a 4 8 molecular sieve before analysis. It was found that the water layer did not contain any organic sulfur compounds, so the reported influences were not artificial products of any extraction process.

To compare the activity as a function of the Η ₂ Ο / Η ₂ ~ 709840/0 961

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Molar ratio was taken as a second order rate expression and conversion data was mathematically adjusted to preclude catalyst aging. In this way, the activity for the sulfur, nitrogen, nickel and vanadium removal at different H ₂ O / H ₂ ~ ratios is shown in FIGS. A check of the figures shows that the desulfurization _{activity is markedly improved at H 2} O / H ₂ molar ratios of about 0.05 to 0.5, in particular 0.05 to 0.2. Similarly, the removal of nickel is _{improved at H 2} O / H ₂ ratios> approx. 0.1. The nitrogen removal remains unchanged, while the vanadium removal falls slightly _{with increasing H 2} O / H _{2 ratios.}

In another series of tests, the water used in the above series of tests was replaced by equimolar ratios of N in order to separate the effects of water from those of diffusion and the laboratory trickle bed reactor. The results, also plotted in Figures 2 to 4, show that the beneficial effects of nickel and sulfur removal are based on water injection rather than the effects of reactor or diffusion. Surface data was obtained on recovered catalyst to test the possibility of increased catalyst destruction in the presence of steam. The calcined recovered catalyst showed a surface area of 295 m / g compared to a value of 280 for the fresh material. So in these studies, no degradation was observed.

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Claims (11)

PATENT CLAIMS 1 f A method for removing sulfur and nickel from a feed material containing these elements of heavy hydrocarbons, characterized in that a) the feed material with a hydrogen-rich one Mixed electricity, b) the mixture of step (a) in a reaction zone with a desulfurization catalyst Desulfurization conditions implemented, c) water in the reaction zone at a water / hydrogen molar ratio of from about 0.05 to injected about 0.5, d) a light gas stream containing H, HO, H ₂ S and light hydrocarbons is separated from the product stream leaving the reaction zone, e) from this light gas stream water, leaving behind a practically dry light gas stream separated, f) the separated water for injection in stage (c) returned, g) the hydrogen sulfide from the dry light gas stream leaving behind a hydrogen 709840/0961 ORIGINAL INSPECTED - ve- - separated from rich electricity, h) the hydrogen-rich stream is returned to the feed material for admixture and i) the practically nickel- and sulfur-free product from the product stream of the reaction zone is won. 2. The method according to claim 1, characterized in that that in step (b) at a pressure of about 35 to about 211 kg / cm Manometer (500 to 3000 psig) and a temperature of about to about 500 ⁰ C is desulfurized. 3. The method according to claim 1 or 2, characterized in that in step (b) a catalyst with at least one Metal component from group VIb or VIII of the periodic table, deposited on a refractory inorganic oxide support, is used. 4. The method according to claim 3, characterized in that a cobalt and molybdenum in oxide or sulfide form on aluminum oxide deposited containing catalyst is used. 5. The method according to any one of claims 1 to 4, characterized in that a feed material with a content from about 10 to about 3,000 ppm total metals and from about 1 to about 10 percent by weight sulfur is used. 709840/0961 6. The method according to any one of claims 1 to 5, characterized in that water in the reaction zone a water / hydrogen molar ratio of from about 0.05 to about 0.2 is injected. 7. The method according to any one of claims 1 to 6, characterized in that the separation of step (d) as a high-temperature flash separation he follows. 8. The method according to any one of claims 1 to 7, characterized in that the admixing of step (a) takes place with about 10OO to about 20,0OO scf H ₂ / bbl. 9. The method according to any one of claims 1 to 8, characterized in that in step (e) separated by condensation will. 10. The method according to any one of claims 1 to 9, characterized in that the sulfur and nickel-free product is passed into a catalytic cracking zone and catalytically cracked products are withdrawn from this zone. 11. The method according to any one of claims 1 to 10, characterized in that part of the water in the reaction zone is introduced by admixing with the hydrogen-rich stream. 70 9 3 40/0961