DE1964095A1 - Process for desulphurization of petroleum - Google Patents

Description

Patent assessor Homberg, December 12, 1969

Dr. G. Schupfner m _{6 a}

c / o Deutsche Erdöl AG ^y

4102 Homberg / Ndrh. ■

Baumstrasse 31

OJEXiOO DEVELOPMENT CORPORATION

135 East 42nd Street New York, N.Y. 10017

UNITED STATES.

Process for the desulphurization of petroleum

The invention relates to the removal of sulfur compounds from crude oil and thus the production of heavy fuel oils with a low sulfur content.

The hydrogenative desulfurization of light petroleum hydrocarbons has been carried out for many years. In petroleum, sulfur is in the form of mercaptans, sulfides, disulfides and complex structures containing ring systems such as thiophene are present. In catalytic desulfurization ("Sweeteners") lighter petroleum fractions such as gasoline, naphtha and In kerosene, the sulfur is mostly in the form of easily removable mercaptans, which are not so vigorous desulfurization conditions demand and contribute to a long service life of the catalytic converters. The life of the catalysts the desulfurization of such lighter fractions is further enhanced by the fact that few polynuclear aromatic compounds are present in the feedstock.

009829/1404

Until recently, however, no serious attempts were made been used to desulfurize heavy petroleum stills, as these are usually burned as industrial heating oils became. Because of the more and more urgent air pollution control it has become necessary to switch to industrial heating oils with little To fall back on sulfur content.

The catalytic desulfurization of heavy residual oils is however much more difficult than "with the lighter fractions. During the hydrative desulphurization of residual oils Impurities such as metals and carbon residues and the like from the feed are deposited on the catalyst. In addition, polynuclear condensed aromatics tend to accumulate on the catalyst and form more coke-like ones Deposits decompose. These deposits cause inactivation of the catalyst, and help is given for products with a fixed maximum value for the S content by increasing the reaction temperature. That in turn increases but also the rates at which metals, decomposition products and other impurities settle on the catalyst deposit and lead to a progressively increasing rate of inactivation of the catalyst. When the reactor temperature has risen to the maximum permissible value or when the conversion to light hydrocarbons occurs If the desired extent is reached, the reactor must be shut down and the catalyst regenerated or replaced.

The invention relates to a process for the desulfurization of crude oil containing distillation residues, characterized in that a starting material which contains at least 1% coal residue according to Conradson and of which at least 10% by volume is below about 538 ° J3 boiling, subjected to a first catalytic ijäitschulfelung ·, the product into a lighter! fraction with a boiling point below about ^: 538 ⁰ C and a heavy fraction, the lighter fraction is subjected to a second catalytic desulphurization

009820/1404

ORIGINAL INSPECTED

and the doubly desulphurised lighter one with the heavier one Faction united.

The invention assumes that the desulfurization Catalyst used by distillation residues due to the deposition of metals and the like on the catalyst is inactivated, but the rate of inactivation is used for desulfurization of the heavy components is not as great as the inactivation rate for desulfurization of the lighter components. Another The starting point is the observation that the inactivation rate of the catalyst in the desulfurization of the heavy components of the feed, not so great, though the lighter components are present in the feed as they would be if one only desulfurized the heavy component alone would. It has been found that after prolonged operation the lighter part of the desulphurized product becomes one may have greater sulfur content than the same fraction of the feed. By using a partially inactivated Accordingly, the sulfur present in the higher-boiling compounds is selectively removed from the catalyst. Separates if the lower-boiling compounds are removed, they are desulphurized in a second reactor that contains a catalyst, which is not so heavily contaminated, and eventually combines it with the higher boiling compounds, so becomes the total sulfur decrease is considerably increased. This allows the contaminated catalyst to be used continuously long beyond the expected service life.

The method of the invention will be explained in more detail with reference to the drawing, which is a flow diagram for a in Figure 1 Embodiment of the new method reproduces.

009829 / UO4 or, g, nal

In Figure 1, the feed is via line 11 with hydrogen introduced into the desulfurization reactor 13 from line 12. The outlet of the reactor 13 is passed through line 14 into a high pressure separator 15, from which hydrogen ' escapes via line 16 and the separated liquid goes via line 17 into the low-pressure separator 18. gas is separated and sent via line 19 to a recovery plant; the bottoms go into one via line 20 Fractionation column 21. Additional gas is withdrawn via line 22, naphtha is removed via line 23, and the

The remainder of the liquid product, which ^{boils up to approximately 538 °} C., is transferred to the second desulfurization reactor 24 via line 25. The petroleum stream introduced via line 25 is sulfurized with hydrogen from line 26, and the discharge from reactor 24 is conducted via line 29 into high-pressure separator 30. There the hydrogen is separated off and returned to the reactor 13 via line 12. The liquid portion of the discharge from the high-pressure separator 30 is fed into the low-pressure separator 33 via line 32. Gas is drawn off via line 40 and fed to a recovery system. The liquid discharge of the low-pressure separator 33 is sent via line 35 into the fractionation column 46, where it is separated into a light fraction,

™ which is withdrawn via line 50, a middle fraction, withdrawn via line 52 and a heavy fraction, withdrawn via line ^. The heavy fraction is combined with the fraction which has a boiling point at about 538 ^° C. and flows in line 54 . Fresh hydrogen can be introduced into the system via line 57. Some of the hydrogen that is obtained in the high pressure separator 15 can be sent back to the reactor 13 via line 60. To regulate the temperature, it is expedient to send some of the hydrogen from line 60 into reactor 13 via lines 71 and 72. The temperature of the reactor 24 can be regulated in a similar manner by introducing hydrogen via lines 75 and 76.

009829/1404 originally inspected

The procedure of ^ r-iinctang; can be used for a variety of BeseKvukvKgeii, including crude oil, at atmospheric pressure and., -., α vacuum obtained distillation residue, shale oils, Xeerranaole, MckstancLsöle'- and the like. The coating material Vv the catalytic reactor should be at least 1 % Conradson- ^T l: lilc.isstolf and also contain at least 10% hydrocarbons with a boiling point below about 5-3 ° 0 * A part of the leiλ1 ::; ·? ι material that arises in the process according to the invention as a partial product _t can sweckmäßigerweise zurückgefv "> xi * · -r-lems, -um least to supplement the present in the feed lighter material part. the Beschikkungen contain typical-vweise tar and metals, both usually a ^r if the life and activity of the catalyst have harmful Si ^- Hf Iu3.

Depending on the desired degree of desulphurization and the material used, the reaction conditions can be modified. In the first reactor the temperature of the catalyst bed may be about 316 to 482 ⁰ C, preferably from about 3 ^ 3 - ¹ ^ Hr be ⁰ Q. The hydrogen partial pressure should be about 35 j 2-211, preferably 70.3-141 atmospheres. Hydrogen can be introduced into reactor 13 at a rate of about 177-3560, preferably 533-1780 ΉίβΡ / wP oil. Space velocities of 0.3-1.5 parts by volume of oil per part by volume of catalyst and hour are preferred, but space velocities of 0.1-10.0 can also be used. In the second reactor 24, the temperature may be about 232 to 482 ⁰ C, the hydrogen partial pressure is about 21.1 - atm 212, the hydrogen rate en about 89-3560 NNR / m ^ oil and space velocities 0.1 - 20.0 . Preferred reaction conditions are: temperature 260-427 ⁰ C, hydrogen partial pressure from 35.2 to 105 atm, ^ -Speeds of about 178-890 NnrVnr ⁵ oil and space velocities of about 0,5 - 10.

009829/1404

The hydrogen can come from any suitable source, such as electrolyte hydrogen, H ₀ obtained from the partial combustion of a hydrocarbon with subsequent conversion and purification or Hp obtained as a by-product of catalytic reforming and the like. The hydrogen should have a purity of at least 50% Satisfactory results have been obtained with hydrogen which has a purity of 75-90% by volume.

Suitable catalysts for the process of the invention are compounds of the metals from group 8 of the periodic table, such as the oxides or sulfides of cobalt, iron or winding or their mixtures; they are expediently used in conjunction with an oxide or sulfide of a metal of the 6th group, such as molybdenum or tungsten. Usually the catalyst is placed in the reactor in the form of the oxide, where a certain reduction or sulphidation can occur in the course of the reaction, so that after some operating time the catalyst is likely to consist of a mixture of the metal, metal sulphide and possibly the oxide. The compound of the metal of the 8th group can be represented in a proportion of about 1-20% by weight in the catalyst mixture. The proportion of the compound of the metal from the 6th group can make up about 5 - 40 % of the catalyst mixture. The hydrogenation-active components are usually applied to a refractory inorganic oxide such as AlpO ,, ZrO ₂ , SiOp, MgO or their mixtures as a carrier. Particularly suitable catalysts contain nickel and tungsten, cobalt and molybdenum or nickel and molybdenum on a refractory support. In order to obtain a particularly long service life, the catalyst used in the first reactor, which comes into contact with the feed, should have a specific surface area of at least

2 2

25O m / g, preferably at least 300 m / g and a pore

■ x

have volumes of at least 0.6 egg / g. The catalyst

for the first reaction zone should also be at least 2 wt .-% contain.

0 0 9 8 2 9/1 k 0 4 iAD ORIGiNAL

Although it can be seen from the drawing that the substrate flows from top to bottom through the fixed catalyst bed, it is possible to pass the reactants through the catalyst bed from bottom to top or in countercurrent. Further The catalyst can also be in the form of a slurry or are used as a fluid bed,

Example I.

In this example, the composition of the catalyst was as follows and features:

Table 1

Specific Surface area, ^m2 / g 312

Pore volume, cm * / g 0.66

Bulk density, kp / 1 2.307 Additive,% by weight

Co * 2.1

Mo * 11.0

SiO ₂ 2-4

Hest

* Used as oxides

The Einsatzmsterial was contained an obtained at atmospheric pressure distillation residue of crude oil Lago Medio, the 7 »4 wt .-% Oonradson-carbon, 1.85 wt .-% sulfur, and 65 vol .-% components having boiling point below 538 ⁰ C. The sulfur content of the fraction boiling up to 538 ° C. was 1.34 and the sulfur content of the fraction boiling above 538 ° C. was 2.65

In experiment Kr. 1 the reaction conditions were kept essentially constant, and the inactivation of the catalyst was indicated by the increase in the sulfur content in the product.

009829 / U (H BAOORfGlNAL

The reaction conditions and other data for experiment ITr. 1 Table 2 shows:

Table 2

Temp, of the catalyst bed, ⁰ O Hp partial pressure, atmospheric ratio, Nm ⁵ / m3 degree of purity of the gas charge, vol .-% EU low velocity, v / v / h operating time, h
ETi + V-ISTdeposit Ge \ r .-% sulfur, wt .-%:

Total product

Onset of boiling, 538 ° 0-538 ⁰ O +

*% By weight of the initial Catalyst loading ** Catalyst regenerates at 4924 hours with mixture at ⁰

412 5948 ** 105 20th 890 1.18 85 0.96 0.5 1.75 134 1630 1.5 • 9.5 0.35 1.13. 0.25 0.75. . 0.67 1.99

In Figure 2 of the drawing, the distribution of sulfur between the feed and the liquid products is shown. Curve A shows the sulfur content of the product after 134 hours of operation, curve B after 1630 hours of operation and Curve 0 after 5948 operating hours. From Figure 2 it can be seen that with the aged, once regenerated catalyst part of the product boiling below about 316 ° 0 actually has a higher sulfur content than the corresponding one. boiling fraction of the feed material.

009829 / UOA

ORIGINAL

- 9 ■
Example II

In -. Ϊ́ί-.3θΐ £ ν Example j which is a continuation of Example I A Li + ₁ v £ i »en feed and catalyst of the first reactor -, '■" rs. the same as in Example I. The catalyst in the two reactors was a conventional desulphurisation coefficient which contained> 3% by weight of cobalt and 10.0% by weight of molybdenum on Al ₂ O ₃

;. ¹ contained. Here, the flow was from the first Reekie: r fractionated, the boiling below 538 ⁰ C fraction in the reactor - 'desulfurized separated and the liquid product comparable to the 53% 3-boiling fraction of the flow of Eeaktor 1?. agree "

The reaction conditions and other data are in Table 3 put togetherϊ

Table 3 Reactor 1 1630 Reactor 2 412 379 Temp, of the catalyst bed, ⁰ O 105 0.15 52.7 H ₂ partial pressure, atm 890 0.71 356 H ₂ supply ratio, Hnr / m * oil > 85 80 Degree of purity of the Hp, vol .-% H, O ^ 2.0 Space velocity, v / v / h 134 5948 Operating time, h Sulfur content,% by weight: 0.05 0.19 in outflow reactor 2 0.20 0.62 Overall product

The data obtained show that the aged catalyst selectively desulfurizes the heavy portion of the feed and that the rate of inactivation for desulfurization of the lighter material is greater than the inactivation rate for the heavier material.

BATH ORIGINAL

00Q829 / U04

1964090

- ίο -

Example III

As the example shows, the inactivation rate of the catalyst for desulphurisation of the material boiling above 538 ° C is lower in the presence of lighter material than when the lighter material is not present Arabian Eohoil, and in Experiment 2 vacuum residue from Arabian Eohoil. It was the same catalyst as used in Example I, and the Eeaktxonsbedingungen were substantially maintained, only the temperature was changed in such a manner that in the 538 ⁰ C boiling fraction of the product a ßchwefelgehalt was observed of 1.6%.

Table 4 Attempt 1 attempt

Feed:

Density, ⁰ API 15.4 10.4

Sulfur content, wt% 3.1 3.7

Conradson coal residue, wt% 10.9 23.4

Metals, ppm

Ni 11 24

V 30 64

Distillation,% by volume

IBP below 538 ^° C 55.0

above 538 ⁰ C 45.0 100

Operating conditions

H ₂ partial pressure, atu 105 105

H ₂ ratio, Nm ⁵ A ⁵ oil 8.90 89O

H ₂ degree of unit, vol .- $ 6 85 85

Space velocity, v / v / h 0.5 0.5

Initial temperature, ⁰ C 393 393

Temperature after 64 days, ⁰ C 400 427

Sulfur in 538 ^° C. + .- fraction 1.6 1.59

009829/1

-u-

After experiment 2, the temperature to be expected in experiment 1 after 64 days of operation is 408 ^° C., since the charge for experiment only contains 45 vol. # Of material that boils ^{below 538 ° C.} The temperature of 400 ⁰ C found shows that the Iiiaktivierungsgeschwindigkeit the catalyst in Experiment 1 less than half as large as expected. Thus appears from the above examples that the desulfurization of about 538 ° C boiling fraction is more successful with a partially · inactivated catalyst when gas oil is present, although the desulfurization of the gas oil apparently ä by the pres- ence of the boiling over 538 ° C Faction is hindered.

BAD ORtGtNAL 009829/1 AOA

Claims (5)

Claims A process for the desulfurization of petroleum oil distillation residues, characterized in that a starting material which contains at least 1% carbon residue after Conradson and boil of at least 10 vol .-% below about 538 ⁰ C, subjected to a first catalytic desulfurization whose Product separates into a lighter fraction with a boiling point below about 538 ⁰ O and a heavy fraction, subjects the lighter fraction to a second catalytic desulfurization and combines the doubly desulfurized lighter fraction with the heavy fraction. 2) Method according to claim 1, characterized in that that the first desulfurization is carried out using cobalt and molybdenum or nickel and molybdenum catalysts will. 3) Method according to claim 1 or 2, characterized in that the starting material is a petroleum, the contains the residue of crude oil distilled at atmospheric pressure or in vacuo. 4) Method according to one of claims 1-3 »characterized in that the 1st desulfurization with a catalyst that has a specific surface area of at least 250 m / g and a pore volume of at least 0.6 cnr / g is carried out. 5) Method according to one of claims 1-4, characterized in that the 1st desulfurization with a catalyst which is at least 2 wt. %. SiO _{2 is} carried out. 009829 / UOA Blank page