DE1645739B2 - Process for the hydro refining of stable and unstable petroleum hydrocarbon fractions - Google Patents

Description

This invention relates to the subject matter characterized in the claim.

GB-PS 7 19 231 relates to a process for the desulphurization of mixtures of cracked and untreated heavy gasoline at pressures below 10.5 kg / cm ² . In this process, the dehydration of heavy fuels is promoted due to the temperature and pressure conditions used. US Pat. No. 2,958,654 teaches a process for the simultaneous desulfurization of reforming feedstocks and heating oils, wherein the feed does not contain an unstable material. In the process of US Pat. No. 3,094,481, a mixture of cracked heavy gasoline and circulated hydrogenated heavy gasoline is hydrogenated in the vapor phase at elevated temperature and pressure. The treated mixture contains no gas oil or other hydrocarbon fractions that boil above the heavy gasoline range. A process is also known from US Pat. No. 2,910,433 in which a middle distillate which ^{boils essentially above 240 °} C. is treated with hydrogen in the presence of at least 2 volumes of a circulated treated oil of the same nature, with at least some of the oil remains in the liquid phase.

The object of the invention was now to provide a process for the joint hydro refining of stable and unstable petroleum hydrocarbon fractions in a single treatment unit of the usual type and using the same conditions and in the presence of the same catalysts to create the refined products that one have significantly reduced sulfur and nitrogen content and a lowered bromine number. Because of the Use of sulfur-sensitive catalysts in petroleum refineries and, as a result, ever sharper future legal provisions to protect the environment, there is a considerable need for processes with the help of which it is possible in a simple manner and in conventional devices to largely remove the sulfur to eliminate the petroleum fractions. There is also a need for such a method, which in a can be carried out in a single treatment unit, as conventional hydrogen desulfurization or refining processes are expensive and complicated in terms of apparatus, since the individual fractions, such as Heavy gasoline, distillation gas oil, coke heavy gas oil, coker gas oil and steam-cracked fractions

ίο must be treated separately from each other.

This object has now been achieved by the process according to the invention, in which various types of cracked and untreated heavy gasoline and gas oil are hydrogenated in a mixture, with a large number of stable products with a low sulfur content being obtained in an unexpected manner and dilute unstable ingredients, and to control the heat applied during the hydrogenation. The inventive presence of a gas oil in the mixture to be treated has the surprising result that. the deposition of the diolefin-rich, unstable fractions that tend to polymerize on the heat exchangers and the catalysts is prevented. Furthermore, the presence of the heavy gasoline component in the mixture leads to an increased hydrogenation of the olefins and to a better conversion of the polycyclic aromatics present into lighter ones

such cracking naphthenes. The fact that the invention Process for the desulphurisation of a large number of feed materials can be carried out in a single treatment unit, in which for all Charging materials the same conditions and

Jj catalysts are applied is an essential Savings in investment and operating costs are given.

According to one embodiment of the invention, coke grease from the coking of petroleum return

4 (i would be mixed with a mixture of gas oils Coking process converts heavy residual heating oils into gasoline, gas oil, and petroleum coke. That Delayed Coking Process and the Fluid Coking Process are currently in common use in the United States.

4> These processes are described in a report by W. Martin and LE Wills under the title "Coking Petroleum Residues", published in Advances in Petroleum Chemistry and Refining, Volume II, 1959, pages 357-433. Coker gasoline has an end boiling point of approximately 23O ⁰ C; however, it is not always necessary to desulfurize and stabilize the entire fraction. The process according to the invention is particularly advantageous with what is known as coke gasoline with a boiling range of 93 to 232 ° C. Coke gasoline contains 1000 to 10,000 ppm sulfur and large amounts of olefins and diolefins, for example 10 to 50 percent by volume or 1 to 20 percent by volume. If a refinery has a fairly large coker unit, fill it up

ho correspondingly large amounts of coke heavy fuel at. These must be treated before mixing with the gasoline detergent. Processing includes usually hydrogen desulfurization and reforming. The inventive method creates

b5 a simple and cheap way to make Coke grease for the subsequent quality improvement. From 1 to 40 Percent by volume, preferably 10 to 25 percent by volume,

Coke grease, based on the total mixture of coke grease and gas oil, hydro refineries will.

The gas oil mixture with which the hydraulic refining plant is fed comprises gas oils which have been prepared for catalytic cracking by means of a hydrogen treatment. The mixture will preferably contain a larger amount of gas oil which has been obtained as a recycle stream in the catalytic cracking of petroleum fractions. This material boils, depending on the fractions removed in the catalytic cracking, in the range from 149 to 482 ° C do not form part of this invention. The gas-oil mixture contains 20 to 90 percent by volume, preferably 40 to 90 percent by volume, of catalytic gas oil. The mixture can also 0 to 50 volume percent, preferably 10 to 50 volume percent, coker gas oil containing the coker gas oil boiling in the range of 221 to 51O ⁰ C for seii.es high sulfur and StickstoffgehaJts and also because of its high OlefingehaJts and related instability unsuitable for cracking without hydroforming. Another preferred component of the gas oil mixture is vacuum gas oil, which is obtained as a side stream from the vacuum distillation column. Gas oil mixtures consist, for example, of 40 to 90 percent by volume catalytic return oil and 10 ^: -> is 60 percent by volume coker gas oil; 40 to 90 volui. jzent catalytic return oil and 10 to 60 volume percent unprocessed vacuum gas oil. The preferred mixture consists of 40 to 90 volume percent catalytic recycle oil, 5 to 30 volume percent coker gas oil, and 5 to 30 volume percent raw gas oil. The gas oil mixture contains at least 5 percent by weight, preferably 5 to 40 percent by weight, of polycyclic aromatic rings.

The following table 1 gives test results, which the components according to a Embodiment of the invention. Procedure identify in more detail.

The sequence of the process steps of the process according to the invention is conventional. The gas oils are mixed and the heavy gasoline is combined with the gas oils in a suitable manner to form a homogeneous mixture. A hydrogen containing gas containing 70 to 100 percent hydrogen is mixed with the hydrofining feed and these materials are contacted with a hydrofining catalyst in a suitable reactor. A conventional fixed bed reactor is used, or a series of reactors employing essentially the same conditions and catalysts. After the hydrogenation stage, a gas stream containing low levels of hydrocarbons, H2S and ammonia is separated from the liquid products in a separator. The gas flow is cooled and the lower hydrocarbons are separated. After H ₂ S and ammonia have been removed, the hydrogen-containing gas is returned to the hydro refining plant, with substitute hydrogen being added if necessary.

Table I. Koker Coker gas oil Unedited Catalytic Feed components heavy gasoline Gas oil Return oil 0.79 0.92 0.92 0.90 - 20.7 12.3 20.4 Specific weight 15.6 "C / 15.6 ° C (g / ml) 0.24 1.09 2.22 0.62 Aromatic rings (wt%) 286 1814 381 207 Sulfur (wt%) 55.0 17.1 9.1 5.0 Nitrogen (ppm) Bromine number (g / 100 g) 134 334 368 281 Distillation ("C): 147 357 393 335 Start of boiling 149 362 402 341 5 159 377 426 355 10 172 390 451 363 30th 188 406 479 371 50 212 - - 386 70 2-7.8 451 - 391 90 264 - - - 95 End of boiling point

The liquid hydrogenation products are fed to a distillation tower. In a preferred Embodiment, the hydrogenation products are separated, with a reforming feed a boiling range of 93 to 204 ° C, a middle distillate fraction with a boiling range of 204 to 343 ° C and a catalytic cracking feed having a boiling range of 343 to 566 ° C is obtained. In Another embodiment, the distillation is adjusted so that a jet fuel fraction with a Boiling range from 149 to 288 ° C is separated.

The method according to the invention is illustrated below with reference to the drawing, which is a schematic flow diagram a preferred embodiment of the method is explained in more detail.

In the drawing, line I is 70

Percentage by volume of unprocessed heavy gasoline (33 to 194 ° C) fed to collecting line 2, where the fractions are mixed. Raw heavy or straight-run gasoline is a non-olefinic hydrocarbon fraction boiling in the range of about 10 to 240 ° C and obtained by atmospheric distillation, vacuum distillation, or flash distillation of a crude oil. Raw heavy gasoline contains approximately 100 to 800 ppm sulfur.

Through line 3, 3 percent by volume of coke heavy gasoline with a boiling range of 93 to 204 ° C, preferably 104 to 180 "C, which results from the coking of petroleum residues, fed to the manifold 2.

Through line 4 is 2 percent by volume of steam-cracked heavy gasoline (58 to 124 ° C), which by Pyrolysis of petroleum fractions with a boiling range of 17 to 593 ° C has been supplied. That The most famous process of this type is the steam-baking of heavy gasoline for the production of ethylene, Propylene and / or acetylene. Steam-cracked heavy gasoline or pyrolysis gasoline is used in these processes depending on the characteristics of the feed and the cracking conditions as a by-product in amounts im Range from 1 to 20% gained. Typical engineering procedures are discussed in Hydrocarbon Processing, November 1965, Volume 44, No. 11, pages 165 to 166 and 203 to 208. Steam-cracked heavy fuels, especially those from the cracking of heavier raw materials, are in one because of the presence of monoolefins and conjugated diolefins Amount of 20 to 50 percent by weight and a correspondingly high bromine number of 40 to 150 (ASTM method) extremely unstable. Steam-cracked heavy fuels boil in the range of 38 to 204 ° C. It can be from 0.5 to 40 percent by volume, preferably from 0.5 to 15 percent by volume, steam-cracked heavy gasoline treated with hydrogen together with the other materials in a mixture.

Line 5 is 10 percent by volume catalytic gas oil with a boiling range of 209 to 346 ° C fed into the manifold 2. Depending on the sulfur content, catalytic gas oils contain the Crude oils from which they are derived, from 0.5 to 3% sulfur. In the mixture can be from 5 to 40 Percent by volume, preferably 10 to 25 percent by volume, catalytic gas oil may be contained.

Through the line 6 in the collecting line 2 8 percent by volume of distillation gases! (unprocessed) with a boiling range of 239 b ^; s 347 ° C introduced This component is obtained by atmospheric or vacuum distillation of crude oil. The gas oil contains from 0.5 to 3% sulfur. It can be fed to the collecting line in an amount of 5 to 40 percent by volume, preferably 10 to 25 percent by volume.

7 volume percent coker gas oil (182 to 377 ° C) is fed through line 7 to collecting line 2 its relatively great instability to heat. 5 to 40 percent by volume, preferably 10 to 25 percent by volume, of coker gas oil is added to the mixture in collecting line 2 .

The mixture in the manifold 2 contains from 10 to 70 percent by volume of the unstable components described above, that is, the group consisting of coke gasoline, steam-cracked heavy gasoline, coker gas oil and mixtures thereof . Preferably the mixture contains 10 to 70 volume percent gas oil of straight run gas oil and / or catalytic gas oil. In a particularly preferred embodiment , at least four of the five fractions indicated above are present in the total mixture in amounts in the ranges as indicated below for the respective fraction.

More suitable Salary in

Preferred
Salary in

(a) Coke heavy fuel 1 to 40 1 to! 0

(b) Steam cracked 0.5 to 40 0.5 to 15
Heavy fuel

(c) Catalytic gas oil 5 to 70 5 to 25

(d) Unprocessed 5 to 70 5 to 25
Gas oil

(e) Coker gas oil 5 to 40 5 to 25

If a special component, such as steam

If the mixture is not intended to contain cracked coke grease, increased amounts of any or all of the other ingredients can be used in order to increase the amount of the mixture up to 100 percent by volume . The selection of the

The j5 blending ingredients are based on the availability of the components, the properties of each ingredient, the hydrogen desulfurization catalyst, the hydro refining conditions, and the type of product desired. The mixture has a boiling range from 10 to 649 ° C., preferably from 21.1 to 538 ° C. and particularly preferably from 29 to 399 ° C.

The constituents are mixed in the collecting line 2 and additional hydrogen is added through line 8. The reaction mixture is heated in the heater 9 to a temperature of 316-399 ^C C, and then passed via line 11 for Hydroraffinierungsreaktor 12th Circulating hydrogen is introduced into line 11 through line 10

Hydro refining is carried out in some

conventional hydrogen desulfurization reactor

Recirculation of the product and multi-bed reactors are not required. The reactor system may comprise a plurality of reactors and a catalyst regenerator, but this is not shown. The reaction is carried out under usual conditions; that is, at a temperature in the range 260-510 ⁰ C, preferably 316-399 ° C, a pressure in the range of 22 to 142 kg / cm ^2, preferably 26 to 43 kg / cm ^2, a space flow velocity of 0.5 up to 5 volumes / hour / volume and with a ratio of water: substance to mixture of 44.5 to 5343 m ³ per m ³ , preferably 53.5 to 107 m ³ per m ³ . It is a hydrogen-containing gas containing 70 to 100 percent by volume H2, used Suitable conventional catalysts consist of an oxide or sulfide of a metal of Group VI of the Periodic Table of the Elements with an oxide or sulfide of iron, cobalt or nickel that on a

porous support such as alumina. Silica-alumina, bauxite, kieselguhr. Magnesium oxide or zirconium dioxide is deposited. The preferred catalyst is cobalt molybdate or nickel molybdate on silica containing alumina. The hydro-refined reaction products are fed to the hot separator 14 via line 13. This separation is carried out at 149 to 260 ° C. and 2b to 43 kg / cm ² . This gives the possibility. To avoid heat loss. The reaction products are fed through line 15 to fraction column 22 at a temperature of 149 to 260 "C, so that less energy is required for the distillation. A gas containing low levels of hydrocarbons, hydrogen and H2S is passed through line 16 to cooler 17 and then via the line 18 to the cold separator 19. The cold separator operates at a temperature of 27 to 66 ° C. and a pressure of 26 to 43 kg / cm ^2. Hydrogen and H2S are fed to a cleaning system (not shown); Line 10 is fed back into the circuit. Liquefied low hydrocarbons from the cold separator are discharged via the

Table II
Starting material test results

Line 21 is fed into line 15 for distillation in fractionation column 22. The number of fractions and the specific sections may be arbitrarily set, but it is in a preferred embodiment, a light hydrocarbon fraction through the line 23, a C5-71 ° C gasoline fraction 24, through line a 71 ⁰ C to 12rC- C (, - naphthenic fraction for reforming via line 25, a 121 ° C to 177 ° C fraction for reforming into a gasoline component via line 26 and a 177 ° C to 371 ° C premium heating oil via line 27 These fractions all have a substantially reduced sulfur content and they are in a condition which makes them suitable for use as the end product or for further processing in contact with sulfur-sensitive catalysts.

example 1

The following table II shows test results of typical starting material components that can be used in a preferred embodiment of the invention.

Unbear Steam- Koker Unbear Coker gas oil Katalyi. worked crackles heavy worked cracked Heavy Heavy petrol Gas oil Gas oil petrol petrol Specific weight 15.6 C / 15.6 C (g / ml) 0.73 0.84 0.76 0.86 0.89 0.93 Sulfur (ppm) 630 2223 6150 1.10 *) 2.16 *) 1.93 *) Mercaptane number 27 0.2 12.2 15.2 21.6 25.9 Bromine number (ASTM method) 1.3 140 118 7.4 53.6 16.7 Basic N (ppm) <1 - 44 71 641 56 Total N (ppm) <1 13th 75 169 1400 400 ASTM distillation (C) Start of boiling 33 58 104 239 182 209 10% 63 76 119 288 239 251 50% 113 87 132 311 288 299 90% 161 103 152 329 353 343 End of boiling point 194 124 180 345 377 346 Composition (vol .-%) **) Aromatics 11th 48 14th 35 51 67 Monoolefins 0 37 34 0 28 6th Diolefins 0 14th 12th 0 10 traces Saturated verb 89 1 40 65 11th 27

*) Weight percent (instead of ppm). **) Typical values for these types of raw materials.

From Table II it can be seen that the entire, unstable fractions, that is to say the steam-cracked Heavy gas, coke gas and coker gas oil contain high amounts of olefins and diolefins. the Bromine numbers are also high.

Such is referred to as an unstable fraction or a mixture of unstable fractions The bromine number contains 10 to 50 percent by volume of olefin and 1 to 20 percent by volume of diolefins

Fraction is in the range from 40 to 140.

Table III below shows the desulfurization results for the 6-component feed used in of the drawing as lines 1 and 3 to 7 are indicated. The reaction conditions were: 343 ° Q 2 volume mina / volume / hour, 36 kg / cm ² and 893 m ^{3 of} 85% H ₂ per m ³ . The catalyst was cobalt molybdate on silica containing alumina.

ίο

Table III Sulfur content

Feed components

33-194 ⁰ C unprocessed naphtha 104-180 ⁰ C Kokerschwerbenzin

58-124 ⁰ C steam-cracked heavy gasoline 209-346 ⁰ C catalytically cracked gas oil
239-347 ° C Heavy atmospheric gas oil 182-377 ⁰ C Coker gas oil
total

Hydro refining product

Factions

Ci to C ₄

C ₅ X71 ° C

71X121 ° C

121X177 ° C

177X371 ° C
total

It can be seen that the C5-71 ° C fraction, which is classified as Motor gasoline is used because of the reduced sulfur content to around 1 ppm in is highly suitable. The 91-121 ° C and 121-177 ° C fractions are suitable for reforming net because the sulfur content of these fractions is low enough that they can be used without any danger with one Platinum catalyst can be brought into contact. The fuel oil fraction has a sulfur content of 0.12 Percentage by weight that they can be used as premium fuel oil or for blending with fuel oil components, which have a higher sulfur content, makes it suitable.

Since the process does not use steam scrapers, the products are dry. Since the products are not circulated, no additional heat is required to heat the circulating stream. The heat requirement is also reduced by feeding the entire hydro-refined mixture to a hot separator v i before fractionation. By operating in this manner, the forerunners and hydrogen are removed and a hot liquid is obtained which requires very little, if any, heat input prior to fractionation. In addition to the energy savings, there is also a reduction in the size of the heat exchange device. There will be savings

Table IV

70
3
2

10
8th

J
100

10
30th
30th
25th
100

630 ppm

6150 ppm

2223 ppm

1.93% by weight 1.10% by weight 2.16% by weight

~ 1 ppm
~ 1 ppm
1-2 ppm <5ppm
0.12% by weight

from 20 to 40% over the cost of conventional hydro refining units.

Example 2

A hydrorefining charge was prepared using the four ingredients in Table I. The gas oil mixture contained 18 volume percent coker gas oil, 22 volume percent raw gas oil and 60 volume percent catalytic gas oil. 21.4 volume percent coke heavy gasoline was mixed with 78.6 volume percent gas oil blend to make a charge. The hydro refining was carried out at a temperature of 357 ° C., a pressure of 57 kg / cm ³ , a hydrogen to oil ratio of 214 m ^{3 of} 80% hydrogen per m ^{3 of} feed and a space velocity of 1.0. The catalyst was cobalt molybdate on alumina. After hydrogenation, the products became catalytic! Crack charge with a boiling range from 351 to 490 ⁰ C, a heating oil with a boiling range from 203 to 330 ⁰ C and a reforming charge with a boiling range from 127 to 211 ° C fractionated. Tables IV and V show the results of the hydrogenation of the gas oil mixture with and without added coke gasoline under the same reaction conditions. Table IV compares the fractions of the catalytic cracking feed.

Gas oil charging alone 0.89 Δ Coke grease im Weight percent product Gas oil mixture Loading product 14.9 -0.02 feed carbon present in percent by weight 0.89 Δ Specific weight 15.6 ° C / I5.6 ° C (g / cm ³ ) 0.91 34.0 21% 0.91 13.3 -0.02 AR *) 18.8 0.15 13% 18.5 29.8 28% NO**) 39.4 0.02 85% 38.6 0.15 23% Sulfur (wt%) 0.99 355 75% 0.99 0.02 85% Conradson coking test 0.08 3 38% 0.08 330 75% Nitrogen (ppm) 574 *) AR = carbon present in the aromatic rings in 59% 574 3 42% Bromine number 7.3 **) NR = In the naphthenic rings 773 59%

In the case of the use of gas oil feed alone, the decrease in the aromatically bound was Carbon 21%. However, if you added coke oil to the gas oil feed, it was a humiliation of the aromatically bound ring carbon of 28%. This increased conversion of heavy polycyclic aromatic compounds

Table V

The more easily crackable naphthenes increase the value of the product; there is any loss of value in other hydrorefining products.

The following table V shows the preparation the fuel oil fraction and the reforming charge.

Reforming charge product Heating oil product feed 0.77 feed 0.88 Specific weight 15.6 ° C / 15.6 ° C (g / ml) 0.78 0.003 0.89 0.04 Sulfur (wt%) 0.186 0 0.66 24 Nitrogen (ppm) 140 0.7 305 1.6 Bromine number (ASTM method) 58.3 17.0

The sulfur content, nitrogen content and the bromine number are based on one for the intended use these fractions brought an acceptable level. Equivalent results will be obtained when preparing the load is varied within the limits given above.

1 sheet of drawings

Claims (1)

Claim: Process for the hydrofining of stable and unstable petroleum hydrocarbon fractions with a hydrogen-containing gas in the presence of a hydrogen desulfurization catalyst at a temperature of 260 to 510 ° C, a pressure in the range of 22 to 142 kg / cm ² , with a space flow rate of 0.5 to 5 volumes / hour / volume and 443 to 534.3 m ^{3 of} hydrogen per cubic meter of feed and recovery of petroleum hydrocarbon fractions with reduced sulfur and nitrogen contents and reduced bromine number, characterized in that a mixture of 20 to 80 percent by volume of unprocessed heavy gasoline, 70 to 10 percent by volume of distillation gas oil and / or catalytic gas oil and 10 to 70 percent by volume of an unstable hydrocarbon fraction containing coke gasoline, steam-cracked heavy gasoline and / or coker gas oil, the unstable fraction having a content of 10 to 50 percent by volume olefins and 1 to 20 percent by volume diolefins, maintain is changing.