Resource utilization method and system of petroleum coke

Abstract

The invention relates to a resource utilization method and system of petroleum coke, and belongs to the technical field of petroleum fractions. The utilization method comprises the following steps: calcining the first part of petroleum coke to obtain high-temperature flue gas and calcined coke; pyrolyzing the second part of petroleum coke by taking the high-temperature flue gas as a heat source to obtain pyrolytic coke, pyrolytic gas and low-temperature flue gas; mixing the pyrolytic coke with the first part of petroleum coke, and calcining; condensing the pyrolysis gas to obtain tar; preparing a prebaked anode by taking low-temperature flue gas as a heat source and taking calcined coke, coal pitch and tar as raw materials through hot press molding; and by taking the condensed pyrolysis gas as a fuel, roasting the hot-press molded prebaked anode to obtain a prebaked anode product. High-temperature flue gas generated by calcining the first part of petroleum coke is used for pyrolyzing the second part of petroleum coke; and the residual gas phase after condensation of pyrolysis gas generated by pyrolysis is used for the roasting process of the prebaked anode. And multi-link utilization of petroleum coke, high-temperature flue gas and pyrolysis gas is achieved, and the energy-saving effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of energy substitution and energy conservation and emission reduction, and specifically relates to a method and system for resource utilization of petroleum coke. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Petroleum coke is a byproduct of crude oil refining. It is a product formed by separating light oil and heavy oil from crude oil through distillation and converting the heavy oil through thermal cracking. The main elements are carbon, which accounts for more than 80%, hydrogen 1.5%-8%, and the rest are oxygen, nitrogen, sulfur and metal elements. Depending on its sulfur content, it can be used as fuel for thermal power plants and cement plants, and can also be used for carbon materials such as pre-baked anodes and graphite electrodes for aluminum and steelmaking.

[0004] The general process of the pre-baked anode industry is as follows: petroleum coke is calcined in a calcining furnace (tank or rotary) to prepare calcined coke, and the calcined coke and coal tar pitch are formed and then put into a ring roasting furnace for roasting to obtain the finished product. For a tank calcining furnace, the heat comes from the volatile matter released by the pyrolysis of petroleum coke during the calcination process. The combustion of this volatile matter produces high-temperature flue gas to power the tank calcining furnace and recover waste heat to generate electricity or steam; the ring roasting furnace uses natural gas and the volatile matter released during its own roasting as the heat source, and consumes 45 to 65 Nm of natural gas per ton of product. 3 At present, the entire prebaked anode production system generally has problems such as low degree of intensiveness and unreasonable energy use, and the economic output needs to be improved. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method and system for resource utilization of petroleum coke, in which the petroleum coke is calcined and pyrolyzed according to a set ratio, and the high-temperature flue gas generated by calcination and the pyrolysis gas generated by pyrolysis are utilized in multiple links to prepare products such as calcined coke and prebaked anodes, thereby realizing resource utilization.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] In a first aspect, a method for resource utilization of petroleum coke comprises the following steps:

[0008] S1. calcining the first part of petroleum coke to obtain high-temperature flue gas at 1000-1450° C. and calcined coke;

[0009] S2, pyrolyzing the second portion of petroleum coke using the high-temperature flue gas as a heat source to obtain pyrolysis coke, pyrolysis gas and low-temperature flue gas at 200-250° C.;

[0010] S3, mixing the pyrolysis coke with the first portion of petroleum coke for calcining;

[0011] S4, condensing the pyrolysis gas to obtain tar;

[0012] S5. Using low-temperature flue gas as a heat source, and calcined coke, coal tar and tar as raw materials, hot pressing and molding are used to prepare prebaked anodes.

[0013] S6. Using the condensed pyrolysis gas as fuel, the prebaked anode raw material after hot pressing is roasted to obtain a prebaked anode product.

[0014] The optional mass ratio of the first part of petroleum coke to the second part of petroleum coke is (5-7): (3:5).

[0015] Optionally, a set proportion of high temperature flue gas is used for waste heat power generation.

[0016] Optionally, in S1, the calcination temperature is 1000-1350°C.

[0017] Optionally, in S2, the pyrolysis temperature is 150-700°C, and the high-temperature flue gas is converted into low-temperature flue gas.

[0018] Optionally, in S3, the pyrolysis coke and the first portion of petroleum coke are mixed and calcined.

[0019] Optionally, in S4, the pyrolysis gas is condensed at 300-400° C. to obtain tar and a residual gas phase.

[0020] Optionally, in S6, the gas phase obtained by condensing the pyrolysis gas in S4 is used as fuel to carry out a baking process for the prebaked anode.

[0021] Optionally, in S6, other gaseous fuels are mixed in the roasting process.

[0022] Optionally, in S6, the tail gas generated by preparing the prebaked anode and the flue gas emitted by waste heat power generation are purified and then discharged.

[0023] In a second aspect, a petroleum coke resource utilization system based on the above-mentioned petroleum coke resource utilization method comprises a calcining device, a pyrolysis device, a condensation device and a roasting device connected in sequence; the pyrolysis device and the condensation device are respectively connected to a prebaked anode forming device.

[0024] Optionally, the roasting device and the pre-baked anode forming device are respectively connected to a flue gas purification device.

[0025] Optionally, the calcining furnace is connected to a flue gas purification device via a waste heat power generation device.

[0026] Optionally, the calcining device is used to calcine petroleum coke to obtain high-temperature flue gas and calcined coke.

[0027] Optionally, the pyrolysis device is used to pyrolyze petroleum coke to obtain pyrolysis gas and pyrolysis coke.

[0028] Optionally, the condensing device is used to condense the pyrolysis gas to obtain tar and gas-phase fuel.

[0029] Optionally, the prebaked anode forming device is used to prepare prebaked anode raw materials of a set shape.

[0030] Optionally, the baking device is used to bake prebaked anode raw materials of a set shape to obtain a prebaked anode.

[0031] The beneficial effects of the present invention are:

[0032] The present invention provides a method and system for resource utilization of petroleum coke, wherein the first part of petroleum coke is calcined, and part of the high-temperature flue gas generated by the calcination is used for the pyrolysis of the second part of petroleum coke; the remaining gas phase after the pyrolysis gas generated by the pyrolysis is condensed and used for the roasting process of the pre-baked anode; the tar generated by the condensation is used for the molding process of the pre-baked anode, and the low-temperature flue gas converted from the high-temperature flue gas is further used for heating in the molding process; the pyrolysis coke generated by the pyrolysis is calcined together with the first part of the petroleum coke to avoid intermediate cooling; thus, the multi-link utilization of petroleum coke, high-temperature flue gas and pyrolysis gas is realized. The pyrolysis gas replaces the natural gas required in the original roasting process, has an energy-saving effect, and the cost saving is more valuable than burning electricity or steam in the calcination process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 This is a schematic diagram of the petroleum coke resource utilization system in Example 2 of the present invention.

[0035] Among them, 1. Calcination device; 2. Pyrolysis device; 3. Condensation device; 4. Roasting device; 5. Pre-baked anode hot pressing molding device; 6. Waste heat power generation device; 7. Flue gas purification device. DETAILED DESCRIPTION

[0036] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] In the following technical scheme, pyrolysis coke refers to: a solid product formed by decomposing petroleum coke by heating without contact with oxygen, with the volatile content reduced to less than 5%, and with improved density, mechanical strength and electrical conductivity, improved chemical stability and enhanced antioxidant properties;

[0039] Calcined coke refers to a petroleum coke product obtained by high-temperature calcination that meets certain indicators (water content, true density, mechanical strength, electrical conductivity and oxidation resistance, etc.). In the present invention, it refers to mixed calcined petroleum coke obtained by calcining a mixture of petroleum coke and pyrolytic coke.

[0040] Prebaked anode refers to: a carbon block produced with petroleum coke, asphalt coke, etc. as aggregate and coal tar as molding agent (binder), which is used as anode material for prebaked aluminum electrolytic cell. The preparation method includes: a molding process and a roasting process; in the molding process, the raw materials are mixed and prepared into a set shape; in the roasting process, the raw materials of the set shape obtained in the molding process are roasted into a prebaked anode product.

[0041] A method for resource utilization of petroleum coke comprises the following steps:

[0042] S1. calcining the first portion of petroleum coke to obtain high-temperature flue gas and calcined coke;

[0043] S2, pyrolyzing the second portion of petroleum coke using the high-temperature flue gas as a heat source to obtain pyrolysis coke, pyrolysis gas and low-temperature flue gas;

[0044] S3, mixing the pyrolysis coke with the first portion of petroleum coke for calcining;

[0045] S4, condensing the pyrolysis gas to obtain tar;

[0046] S5, using low-temperature flue gas as a heat source and calcined coke, coal tar pitch and tar as raw materials to prepare a prebaked anode by hot pressing;

[0047] S6. Using the condensed pyrolysis gas as fuel, the prebaked anode formed after hot pressing is baked to obtain a prebaked anode product.

[0048] In the above process, the high-temperature flue gas generated by calcining petroleum coke is utilized in the two processes of petroleum coke pyrolysis and pre-baked anode forming. The pyrolysis gas generated by the pyrolysis of petroleum coke is used in the roasting process of pre-baked anode. Tar is separated from the pyrolysis gas, and the tar replaces part of the coal tar raw material in the pre-baked anode forming process, thereby realizing the multi-step resource utilization of petroleum coke.

[0049] The optional mass ratio of the first part of petroleum coke and the second part of petroleum coke is (5-7): (3-5). This ratio mainly ensures that the high-temperature flue gas produced by calcination can achieve pyrolysis, while there is enough flue gas and heat to provide heat for the calcination process and waste heat to generate electricity, thereby meeting the electricity demand within the factory.

[0050] Optionally, a set proportion of high-temperature flue gas can be used for waste heat power generation to provide electricity for the entire plant, while also producing steam and excess electricity for external supply.

[0051] Optionally, in S1, the calcination temperature is 1000-1350°C, generating high-temperature flue gas of 1000-1450°C. The calcination can produce calcined coke, and the high-temperature flue gas is used in multiple links.

[0052] Optionally, in S2, the pyrolysis temperature is 150-700°C, producing pyrolysis coke and pyrolysis gas, and the high-temperature flue gas is converted into low-temperature flue gas of 200-250°C, which can be used in the subsequent forming process of roasting anodes.

[0053] Optionally, in S3, the pyrolytic coke and the first portion of petroleum coke are mixed and calcined, and the pyrolytic coke is calcined without cooling, so as to avoid heat loss.

[0054] Optionally, in S4, the pyrolysis gas is condensed at 300-400° C. to obtain tar and a residual gas phase, and the residual gas phase obtained by condensing the pyrolysis gas is used as fuel to carry out a baking process of the prebaked anode, thereby fully utilizing the pyrolysis gas.

[0055] Optionally, in S6, the gas phase obtained by condensing the pyrolysis gas in S4 is used as fuel to carry out a baking process for the prebaked anode.

[0056] Optionally, in S6, other gaseous fuels, such as natural gas, are mixed in the pre-baking process to supplement the fuel amount and obtain a set baking temperature.

[0057] Optionally, in S6, the tail gas generated by preparing the prebaked anode is discharged after purification, wherein the tail gas includes the tail gas generated by the baking process and the flue gas discharged by the hot pressing process.

[0058] A petroleum coke resource utilization system based on the above petroleum coke resource utilization method comprises a calcining device, a pyrolysis device, a condensation device and a roasting device which are connected in sequence; the pyrolysis device and the condensation device are respectively connected to a prebaked anode forming device.

[0059] Optionally, the calcining device is used to calcine petroleum coke to obtain high-temperature flue gas and calcined coke.

[0060] Optionally, the pyrolysis device is used to pyrolyze petroleum coke to obtain pyrolysis gas and pyrolysis coke.

[0061] Optionally, the condensing device is used to condense the pyrolysis gas to obtain tar and gas-phase fuel.

[0062] Optionally, the prebaked anode forming device is used to prepare prebaked anode raw materials of a set shape.

[0063] Optionally, the baking device is used to bake prebaked anode raw materials of a set shape to obtain a prebaked anode.

[0064] Optionally, the calcining device conveys high-temperature flue gas to the pyrolysis device; the pyrolysis device conveys pyrolysis coke to the calcining device, conveys pyrolysis gas to the condensing device, and conveys low-temperature flue gas to the prebaked anode forming device; the condensing device conveys tar to the prebaked anode forming device, and conveys gaseous fuel to the roasting device.

[0065] Optionally, the roasting device and the pre-baked anode forming device are respectively connected to a flue gas purification device for purifying the roasting tail gas and the cooled low-temperature flue gas before discharging.

[0066] Optionally, the calcining furnace is connected to the flue gas purification device through a waste heat power generation device, and the high-temperature flue gas generates electricity through the waste heat power generation device to provide electricity for the entire plant, and can also produce steam and excess electricity for external supply.

[0067] Example 1

[0068] A method for resource utilization of petroleum coke comprises the following steps:

[0069] S1. calcining the first part of petroleum coke at 1350°C to obtain high-temperature flue gas and calcined coke at 1450°C, and using 50-70% of the high-temperature flue gas for waste heat power generation;

[0070] S2, using the remaining high-temperature flue gas as a heat source to pyrolyze the second portion of petroleum coke at a pyrolysis temperature of 500°C to obtain pyrolysis coke and pyrolysis gas at about 500°C; at the same time, the high-temperature flue gas as a heat source preheats the low-temperature petroleum coke and cools it down to become low-temperature flue gas at 200-250°C;

[0071] S3, mixing the pyrolytic coke with the first part of petroleum coke for calcining, avoiding heat consumption caused by intermediate cooling, thereby obtaining calcined coke generated from the first part of petroleum coke and the second part of petroleum coke as raw materials;

[0072] S4, condensing the pyrolysis gas at 350° C. to obtain tar and a residual gas phase;

[0073] S5, using low-temperature flue gas as a heat source and calcined coke, coal tar pitch and tar as raw materials to prepare a prebaked anode by hot pressing;

[0074] S6. Using the condensed pyrolysis gas as a heat source, the prebaked anode formed by hot pressing is baked to obtain a prebaked anode finished product.

[0075] In the hot pressing process of S5, the main raw material is calcined coke, and tar and external coal tar are used as molding agents; in the roasting process of S6, the residual gas phase obtained in S4 and external natural gas are used as fuel; the exhaust gas generated by the hot pressing process and the roasting process and the flue gas emitted by waste heat power generation are discharged after purification.

[0076] The mass ratio of the first part of petroleum coke in S1 to the second part of petroleum coke in S2 is 1:1.

[0077] By implementing this embodiment, 60-100% of the natural gas in the existing roasting process can be replaced, which can significantly save energy and achieve good economic benefits.

[0078] Example 2

[0079] The petroleum coke resource utilization system used to implement the petroleum coke resource utilization method in Example 1 is as follows: Figure 1 As shown, it includes a calcining device 1, a pyrolysis device 2, a condensation device 3 and a roasting device 4 which are connected in sequence; the pyrolysis device 2 and the condensation device 3 are respectively connected to a pre-baked anode hot pressing molding device 5.

[0080] The calcining device 1 is a pot-type calcining furnace used for calcining petroleum coke. It uses the input petroleum coke and air as raw materials for calcination to obtain high-temperature flue gas and calcined coke. 30-50% of the high-temperature flue gas is transported to the pyrolysis device 2, and 50-70% of the high-temperature flue gas is transported to the waste heat power generation device 6.

[0081] The pyrolysis device 2 uses the high-temperature flue gas transmitted from the calcining device 1 as a heat source to pyrolyze the petroleum coke to obtain pyrolysis gas and pyrolysis coke; the pyrolysis device 2 is close to the calcining device 1, and can transport the pyrolysis coke back to the calcining device 1 to participate in calcination to become calcined coke within the time period when the pyrolysis coke has not been cooled down, so as to avoid heat loss; the pyrolysis gas is used to be transported to the condensing device 3; the high-temperature flue gas becomes low-temperature flue gas after releasing heat, and is transported to the pre-baked anode hot pressing molding device 5.

[0082] The condensing device 3 is used to condense the pyrolysis gas transmitted from the pyrolysis device 2 to obtain tar, and the tar is transported to the pre-baked anode hot pressing molding device 5. The remaining gas phase after condensing and separating the tar is transported to the roasting device 4 as a gas phase fuel.

[0083] The roasting device 4 is used to roast the pre-baked anode raw material of a set shape prepared in the pre-baked anode hot pressing molding device 5, using the gas phase fuel and external natural gas delivered by the condensing device 3 as raw materials, and the generated exhaust gas is transported to the flue gas purification device 7.

[0084] The prebaked anode hot pressing forming device 5 is used to prepare prebaked anode raw materials of a set shape, wherein the hot pressing forming process uses the low-temperature flue gas output from the pyrolysis device 2 as the heat source, the calcined coke as the main carbon source, and the tar output from the condensation device 3 and the external coal tar as a mixture as the forming agent to achieve resource utilization, and the generated exhaust gas is transported to the flue gas purification device 7.

[0085] The waste heat power generation device 6 is a waste heat boiler, which is used to provide electricity for other equipment in the whole plant including the pre-baked anode hot pressing molding device 5, and at the same time produces steam and excess electricity for external supply, and the exhaust gas is transported to the flue gas purification device 7.

[0086] The flue gas purification device 7 is used to purify the exhaust gas discharged from the roasting device 4, the pre-baked anode hot pressing molding device 5 and the waste heat power generation device 6 and then discharge it into the atmosphere.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for resource utilization of petroleum coke, characterized in that: The following steps are involved: S1. calcining the first part of petroleum coke to obtain high-temperature flue gas at 1000-1450° C. and calcined coke; S2, pyrolyzing the second portion of petroleum coke using the high-temperature flue gas as a heat source to obtain pyrolysis coke, pyrolysis gas and low-temperature flue gas at 200-250° C.; S3, mixing the pyrolysis coke with the first portion of petroleum coke for calcining; S4, condensing the pyrolysis gas to obtain tar; S5. Using low-temperature flue gas as a heat source, and calcined coke, coal tar and tar as raw materials, hot pressing and molding are used to prepare prebaked anodes. S6. Using the condensed pyrolysis gas as fuel, the prebaked anode raw material after hot pressing is roasted to obtain a prebaked anode product.

2. The resource utilization method of petroleum coke according to claim 1, characterized in that: In S1, the calcination temperature is 1000 to 1350°C.

3. The resource utilization method of petroleum coke according to claim 1, characterized in that: In S2, the pyrolysis temperature is 150-700°C, and the high-temperature flue gas is converted into low-temperature flue gas.

4. The resource utilization method of petroleum coke according to claim 1, characterized in that: In S3, the pyrolysis coke and the first portion of petroleum coke are mixed and calcined.

5. The resource utilization method of petroleum coke according to claim 1, characterized in that S6 In the process, the prebaked anode is baked using the gas phase obtained by condensing the pyrolysis gas in S4 as fuel; Optionally, in S6, other gaseous fuels are mixed in the prebaking process.

6. The resource utilization method of petroleum coke according to claim 1, characterized in that: In S6, the tail gas generated by preparing the prebaked anode and the flue gas emitted by the waste heat power generation are discharged after being purified.

7. The resource utilization method of petroleum coke according to claim 1, characterized in that: Use a set proportion of high-temperature flue gas to generate waste heat power.

8. A petroleum coke resource utilization system based on the petroleum coke resource utilization method according to any one of claims 1 to 7, characterized in that: It comprises a calcining device, a pyrolysis device, a condensation device and a roasting device which are connected in sequence; the pyrolysis device and the condensation device are respectively connected to a pre-baked anode hot pressing molding device.

9. The resource utilization system of petroleum coke according to claim 8, characterized in that: The baking device and the prebaked anode hot pressing molding device are respectively connected to the flue gas purification device.

10. The resource utilization system of petroleum coke according to claim 8, characterized in that: The calcining furnace is connected to the flue gas purification device through a waste heat power generation device.

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