DE2851420A1 - METHOD AND DEVICE FOR CRACKING HEAVY LIQUID HYDROCARBONS - Google Patents

Description

PATENTANWÄLTE A. »3RÜNECKER H. KINKELDEY

- .. DR-ING

L 8 b I 4 2 Ü W. STOCKMAlR

.OR-INa-AlElCAUECH

K. SCHUMANN

DR PBl NAT. · 0M - PHYS

P. H. JAKOB

DtPL-ING

G. BEZOLD

DR RBI NAT-OPL-CHBA

8 MUNICH

MAXIMLUAN STREET

P 13 271

Method and device for cracking egg of heavy liquid hydrocarbons

The invention relates to a method for cracking heavy liquid hydrocarbons that produce coals " Contains substance residue.

In Japanese Patent Application No. 97 679/1976 (U.S. Patent Application No. 824 171) a process for the grazing of hydrocarbons has already been proposed. This

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Process is suitable for cracking heavy liquid Hydrocarbons and its essential characteristic consists in that a mist from a representative from the group of basic compounds of alkali metals, alkaline earth metals and mixtures thereof is used and the amount of the molten salt is 0.01 to 1 part by weight 1 part by weight of the hydrocarbon. It was however, found that a mixture of the molten salt and the carbon residue becomes viscous and the Has a tendency to stick to the wall of the cracking reactor, and sometimes the inlet for the hydrocarbon feed becomes plugged when the amount of molten Salt is low and the molten salt and the heavy liquid hydrocarbons are mixed together at a low temperature and when the heavy ones are cracked liquid hydrocarbon containing a large amount of carbon contains residue to which water vapor is not supplied in a large amount ”, From the commercial point of view From a point of view, it is desirable to decrease the amount of water vapor as much as possible, and very much high molten salt temperature is undesirable from the standpoint of equipment materials. In addition, heavy hydrocarbons should not be preheated above a certain temperature, to prevent thermal decomposition from occurring before they are introduced into a cracking reactor. In addition, it is desirable that the molten salt be recycled without any regeneration process can be.

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285H20

Efforts have therefore been made for a long time to develop a method which satisfies the above-mentioned conditions and the above-mentioned disadvantages of cracking heavy oils which have a high hydrocarbon residue contain, not own.

The aim of the present invention is to provide a method and a device for cracking hydrocarbons, with no clogging near the feed inlet for the heavy liquid hydrocarbons occurs. The aim of the invention is also to provide a method for cracking hydrocarbons, in which the water vapor consumption is very low. target The invention is also to provide a process for cracking hydrocarbons, in which significantly less Amounts of circulated molten salt are used »The invention also aims to provide a Indicate a method for cracking hydrocarbons, in which a molten salt without treatment to reduce, setting of the carbon content can be re-used. Another goal of the invention is to provide a Specify a method for cracking hydrocarbons, in which the carbon is produced by the water-gas reaction is eliminated with steam. Another object of the invention is to provide a method for cracking To indicate hydrocarbons that only use a small amount of heat and that in a compact Apparatus can be carried out. Object of the invention

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it is also to provide a process for cracking hydrocarbons in which only a small amount of a Heat transfer media is used and there is no risk of fire. Finally, the aim of the invention is to specify a process for cracking hydrocarbons that is free from carbon deposits and tarry materials in the heat decomposer and is in the deterrent.

The invention relates to a process which is characterized in that heavy liquid hydrocarbons, that contain a carbon residue cracks

(A) in the presence of a molten salt of a member from the group of the basic compounds of Alkali metals, alkaline earth metals and mixtures thereof,

(B) at least a portion of the molten salt in the form of a mist is used _t

(C) the amount of the molten salt more than 1 part by weight, but not more than 10 parts by weight to 1 part by weight of heavy liquid hydrocarbons,

(D) the amount of residual carbon not more than 0.03 part by weight per 1 part by weight of the molten salt is and

(E) the amount of water vapor, the reaction time, the reaction temperature and the amount of the molten salt are so related to each other adjusted (controlled) that the weight ratio between the carbon after cracking and the molten salt is not more than 0.002.

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ORIGINAL INSPEOIED

285-420

The invention is described below with reference to Attached drawing, which shows in schematic form a device for the implementation of the invention Method can be used, explained in more detail.

A preferred idea of the invention is that heavy liquid hydrocarbons containing a carbon contain residue, be cracked,

(A) in the presence of a molten salt of a representative from the group of basic compounds of the alkali metals and the alkaline earth metals _s "mixtures thereof,

(B) wherein at least a portion of the molten salt is used in the form of a mist,

(C) the amount of the molten salt more than 1 wt '- _9, however, is not more than 10 parts by weight part to 1 weight _fr -part of the heavy liquid hydrocarbons

(D) the amount of residual carbon not more than 0.03 part by weight per 1 part by weight of the molten salt is and

(E) the amount of water vapor, the reaction time, the reaction temperature and the amount of the molten salt so on each other adjusted (controlled) ^ that the weight ratio between the carbon after cracking and the molten salt is not more than 0.002.

Representative examples of heavy liquid hydrocarbons used in the process of the invention are crude oil, heavy oil, light oil from low-pressure distillation, the soil residue from the low-

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pressure distillation and the like. These heavy liquid hydrocarbons contain a carbon residue, such as asphalthene, resins, high polymer compounds and the like, which produce carbon when heated.

Clogging at the heavy liquid hydrocarbon feed inlet occurs when the viscosity of the mixture of the heavy liquid hydrocarbon and the molten salt is remarkably high. It is therefore necessary to lower the viscosity in order to prevent clogging at the feed inlet. The amount of carbon residue (Conradson carbon), therefore, is not more than 0.03 wt "parts by 1 part by weight of the molten salt, preferably 0 _s 005 to 0.020 wt""parts to 1 part by weight of the molten salt «

If the amount of residual carbon in the heavy liquid hydrocarbon based on the molten Salt, above the upper limit, has a mixture of the molten salt and carbon residue the tendency to stick to the cracking reactor wall. On the other hand, if the amount is too small, that is The amount of molten salt is unnecessarily large, so that such a process is not economical.

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When the temperature of the mixture is lowered, the viscosity increases rapidly. Therefore, the amount of the melted Salt more than 1 part by weight, but not more than 10 parts by weight, preferably not more than 5 parts by weight to 1 part by weight of the heavy liquid hydrocarbon. In a range above the upper limit the viscosity of the mixture does not noticeably increase and it is considered from an economical point of view undesirable to use such a large amount of molten salt. In an area below the lower one Limit, however, the mixture of the molten salt and the carbon residue becomes viscous and they has a tendency to close to a wall of a cracking reactor stick and sometimes the heavy liquid hydrocarbon feed inlet becomes plugged where water vapor is not present in large quantities *

A molten salt is preferred which serves to reduce the carbon content (formed in the cracking reactor) by the water gas reaction as much as possible. Therefore, according to the invention, a member from the group of the basic compounds of the alkali metals, alkaline earth metals and mixtures thereof is used as the molten salt in order to prevent a mixture of the molten salt and the carbon residue from becoming viscous so that it clogs the inlet for the heavy liquid hydrocarbon , a molten salt with a melting point of not higher than 450 ^° C. is preferably used, the use of one with a melting point of not higher than 400 ° C. being particularly preferred. For example, a mixture of Li ₂ CO. (F. 618 C),

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Na ₂ CO (F. 851 ° C) and K ₂ CO (F. 891 ⁰ C), preferably an equimolar mixture thereof (the eutectic point is 385 ⁰ C), is used. Some of these compounds can be in the form of sulfide or sulfite. Around. To cause the water gas reaction in the cracking reaction, there is water vapor in the reaction system · The amount of water vapor is not critical. However, it is not economical to use it in a large amount, but if the amount is too small, the water gas reaction cannot sufficiently occur. In general, the weight ratio between water vapor and the heavy liquid hydrocarbon is 0.5 to 5.0, preferably 0.5 to 2 ^ 0 «

At least part of the molten salt is in shape A mist is used and this allows even a small amount of the molten salt to come into intimate contact be brought with the heavy liquid hydrocarbon to make the water gas reaction run smoothly * The average particle size of the molten salt is usually no more than 300 microns, preferably no more than 100 microns. The molten salt mist can be easily produced by using it a venturi nozzle and passing water vapor *

Another method of producing the mist can be the use of a pressure nozzle * such as a single-hole nozzle, a collision spray valve, a spiral spray valve and the like; a rotation method, such as «with a

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rotating disk, rotating plate, rotating spray and the like; a method of generation a gas atomizing spray such as an air or gas atomizing nozzle and the like, and a vibration method. In addition, the mist can be obtained by dissolving or suspending the salt in one heavy liquid hydrocarbons or in water that is used as dilution vapor, and introducing the resulting solution or suspension into the cracking apparatus

Among these methods of making a mist is the method in which at least a portion of the molten Gas is misted before the molten salt is mixed with the heavy liquid hydrocarbon, is preferred.

The method according to the invention is particularly effective when it is used for external heating type cracking. Of course, the method according to the invention can also can be applied to the internal heating type cracking, however, in the case of the internal heating type cracking a large amount of high temperature gas used for heating, so that the above-mentioned partial cooling of the molten Salt can be avoided to a certain extent, so the method according to Japanese Patent Application No. 97 679/1976 on internal heating type cracking be applied.

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The cracking is usually carried out at 600 to 900 ° C, preferably at 700 to 850 ° C., for a period of from 0.001 to 2 seconds, preferably from 0.005 to 1.0 seconds, in particular from OJOL to 0.3 see. The reaction conditions, such as the amount of water vapor, the reaction time, the reaction temperature and the amount of molten Salt are so coordinated (adjusted or controlled) that the weight ratio between the the carbon discharged from the cracking reactor and the molten salt is not more than 0.002, preferably not more than 0.001 * In this way, the molten salt can be re-used without performing regeneration treatment · When the amount of carbon after the completion of the reaction is large, foaming of the molten salt occurs, so that separation the decomposition gas cannot be carried out smoothly.

To avoid side reactions, the from the. Cracking reactor discharged reaction mixture preferably quenched. The reaction mixture is on a Quenched temperature at which the molten salt does not solidify. This is usually the case for example around a temperature of 400 to 600 C, although it depends on the particular molten salt. After quenching, the molten salt is separated and recycled, and the cracked one Gas can be separated into its individual components and purified using methods like them

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be used in common ethylene production plants.

The invention is illustrated in more detail by the following examples and comparative examples, but without this to be limited.

Examples 1 to 3 and Comparative Examples 1 to 3

Referring to the accompanying drawing, steam 1 superheated to 750 C was generated using a heater 2 introduced into a venturi throat 7. The venturi throat section was provided with a small side bore with a diameter of 2 nm. An equimolar hole was made through the small lateral hole

Mixture of Na ₂ CO ₂ -K CO -Li ₂ CO ^ introduced, which was kept at 750 C as molten salt, to produce a mist from the molten salt

A mixture of Minas crude 3 (Conradson carbon residue 2.5% by weight) and steam 5 (10% of the total steam charge) was poured into one at 300.degree upper section 9 of a reactor pipeline 10 (with an outer diameter of 21.7 mm and an inner diameter 14.3 mm and a length of 11 m) of an external heating type, which is arranged below the venturi throat and was heated by a heater 11 to effect cracking.

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The Minas crude 3 and the steam 5 were through the heating devices 4 and 6 are heated. After cracking, the reaction mixture was put into a quench section 12 quenched to 500 ° C and then the molten salt and the cracked gas in the separator 13 were separated from each other separated. The cracked gas 17 separated in this way was transferred to a. Cleaning stage initiated and the molten salt thus separated was collected in a drum 14 by means of a pump 15, driven by a motor M and heated by a heater 16 for reuse returned. The reaction conditions and the reaction results are shown in the following table.

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Tabel

H ₀ example 1 4.0 2 4.0 3 4.0 Comparative example 4.0 2 4.0 3 4.0 1 OD
c η Yields of reac- ^ gi 1 Crude oil feed (kg / h) tion products _c > _H 4 12, Ö 20.0 40.0 1.2 12.0 12.0 Amount of the fed ge (Parts by weight C ₃ H, I. ro melted salt (kg / h) to 100% by weight of C ₉ H ,. 0.0083 0.005 0.0025 0.083 0.0083 0.0083 CD co carbon residue in that Parts of the Cpq 4.0 4.0 4.0 4.0 4.0 1.6 2 crude oil / molten salt Crude oil) C3 _R 800 780 760 800 700 800 ^ Water vapor charge (kg / h) '*) * ■ · O t ^ cracking temperature (C) ^ Carbon in the molten CO 0.0001 0.0002 0.0002 0.001 0.004 0.003 ω nen salt after the reaction / CO ₉
i &: ■ ' 2.2 2.0 1.8 2.1 1 4 1.6 ^ melted salt 12.2 11.0 9.9 12.1 8J0 15.2 ■ * ■,
0.3 0.3 W.
0.3 0.3 0.2 0.3 26.0 25.7 24.0 25.9 20.0 20.0 2.0 2.4 2.1 2.2 1.5 2.2 13.2 15 _? 0 14.3 13.6 11.0 9.5 0.2 0.2 0.2 0.2 0.2 0.2 7.0 9.2 9.2 7.0 6.0 5.0 16.0 14.8 11.5 14.5 12.0 12.4 1.1 0.8 0.7 1.0 0.4 0.5 13.5 11.5 10.5 12.4 5.0 6.2

Continuation University ζ of the table As in As in - Within That melted As in Ver comment During one example example of 4 hours zene salt equal ■ 300 hour 1 1 the after foamed and Example 2 continuous Start the one more operational reaction use entered no ver clogged was not stuffing the possible; Reactor tubing a rain tion on; the ration was melted necessary Salt became like repeats without Regeneration - ■ ■ used

The invention has been described above with reference to preferred embodiments explained in more detail, but it is obvious to the person skilled in the art that they are thereon is by no means limited, but that these are changed and modified in many ways can without thereby departing from the scope of the present invention.

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Claims (1)

MITSUI PETROCHEMICAL INDUSTRIES, LTD "2-51 Kasumigaseki 3-chome, Chiyoda-ku, Tokyo, Japan MITSUI ENGINEERING & SHIPBUILDING CO », LTD. 6-4, Tsuiji 5-chome, Chuo-ku, Tokyo, Japan Claims 1 «The process for cracking of heavy liquid hydrocarbons containing carbon residues contain ,, characterized in _t that one carries out the cracking (a) in the presence of a molten salt of an agent from the group of basic compounds of alkali metals, alkaline earth metals and mixtures thereof, 909833/0539 ORJGINAU JL O - ■ ι '- ·. U (B) wherein at least a portion of the molten salt is used in the form of a mist, (C) the amount of the molten salt more than 1 part by weight, but not more than 10 parts by weight to 1 part by weight of heavy liquid hydrocarbons, (D) the amount of carbon residue not more than 0.03 part by weight to 1 part by weight of the molten salt and (E) the amount of water vapor, the reaction time, the reaction temperature and the amount of the molten salt are so coordinated (controlled) that the weight ratio between the carbon according to the Cracking and the molten salt is not more than 0.002. 2 _e method according to claim 1, characterized in _t that one uses a mixture of lithium carbonate, sodium carbonate and potassium carbonate as a molten salt. 3. The method according to claim 1 and / or 2, characterized in that at least part of the molten Salt is converted into a mist before the molten salt is mixed with the heavy liquid hydrocarbons mixes. 4. The method according to at least one of claims 1 to 3, characterized in that the amount of water vapor 0.5 to 5.0 parts by weight to 1 part by weight of the heavy liquid 909833/0539 ORIGINAL INSPECTED 285U20 Hydrocarbons, the reaction time 0.001 to 2 seconds and the reaction temperature is 600 to 900 ° C. 5. The method according to at least one of claims 1 to 4, characterized in that the average particle size of the molten salt in the mist is no more than 300 microns. 6. The method according to at least one of claims 1 to 5, characterized in that the average part size of the molten salt in the mist no more than 100 microns. 7. Device for cracking heavy liquid hydrocarbons, in particular for carrying out the Method according to one of Claims 1 to 6, characterized in that at the beginning of a cracking tube (10) a venturi device provided with a throttle section (7) is arranged which, in addition to a steam inlet, also has a narrow inlet opening for a molten salt in the Drosselabsclmitt that behind the Venturi device in the initial section (9) of the cracking tube an inlet device for a hydrocarbon-water vapor mixture is arranged, and that at the end of the cracking tube a separator (13) for separating the cracked Hydrocarbon provided by the molten salt is. 8. Apparatus according to claim 7 »characterized in that that to the hydrocarbon outlet of the separator 909833/0539 ORIGINAL 28bi 420 (13) a first end of a delivery line is connected and that the second end of the delivery line with the Throttle section (7) of the Venturi device is connected. 9. Device according to claim 8, characterized in that that in the delivery line a pump (15) is provided. 10. Apparatus according to claim 8 or 9, characterized in that that the delivery line has a heating device (16). 11. Device according to one of claims 7 to 10, characterized in that heating devices (4,6) are provided for the hydrocarbon (3) and the water vapor (5). 909 8 33/0539 OBIGiMAL INSPECTED