CN117946723A - Quenching boiler for slowing down coking and carburizing, and preparation method and application thereof - Google Patents
Quenching boiler for slowing down coking and carburizing, and preparation method and application thereof Download PDFInfo
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- CN117946723A CN117946723A CN202211325790.1A CN202211325790A CN117946723A CN 117946723 A CN117946723 A CN 117946723A CN 202211325790 A CN202211325790 A CN 202211325790A CN 117946723 A CN117946723 A CN 117946723A
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- 238000004939 coking Methods 0.000 title claims abstract description 84
- 238000010791 quenching Methods 0.000 title claims abstract description 84
- 230000000171 quenching effect Effects 0.000 title claims abstract description 77
- 238000002360 preparation method Methods 0.000 title abstract description 9
- 238000005255 carburizing Methods 0.000 title abstract description 7
- 239000007789 gas Substances 0.000 claims abstract description 150
- 238000010438 heat treatment Methods 0.000 claims abstract description 83
- 230000001590 oxidative effect Effects 0.000 claims abstract description 47
- 238000006243 chemical reaction Methods 0.000 claims abstract description 41
- 238000000034 method Methods 0.000 claims abstract description 35
- 230000003647 oxidation Effects 0.000 claims abstract description 29
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 29
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 29
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000001301 oxygen Substances 0.000 claims abstract description 27
- 238000004227 thermal cracking Methods 0.000 claims abstract description 4
- UXJMPWMAAZYCMP-UHFFFAOYSA-N chromium(3+) manganese(2+) oxygen(2-) Chemical compound [O-2].[Cr+3].[Mn+2] UXJMPWMAAZYCMP-UHFFFAOYSA-N 0.000 claims description 53
- 239000010410 layer Substances 0.000 claims description 51
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 30
- 238000001816 cooling Methods 0.000 claims description 17
- 229910052739 hydrogen Inorganic materials 0.000 claims description 17
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 16
- 239000002344 surface layer Substances 0.000 claims description 15
- 229930195733 hydrocarbon Natural products 0.000 claims description 14
- 150000002430 hydrocarbons Chemical class 0.000 claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 13
- 239000000203 mixture Substances 0.000 claims description 12
- 239000000956 alloy Substances 0.000 claims description 10
- 229910045601 alloy Inorganic materials 0.000 claims description 10
- 239000011572 manganese Substances 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 239000001257 hydrogen Substances 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 7
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 6
- 229910052786 argon Inorganic materials 0.000 claims description 4
- 239000001307 helium Substances 0.000 claims description 4
- 229910052734 helium Inorganic materials 0.000 claims description 4
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 239000011573 trace mineral Substances 0.000 claims description 4
- 235000013619 trace mineral Nutrition 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- 239000011651 chromium Substances 0.000 claims description 2
- 239000003208 petroleum Substances 0.000 claims description 2
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 2
- 229910052721 tungsten Inorganic materials 0.000 claims description 2
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 claims 1
- AMWRITDGCCNYAT-UHFFFAOYSA-L manganese oxide Inorganic materials [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 claims 1
- 230000000116 mitigating effect Effects 0.000 claims 1
- 239000003209 petroleum derivative Substances 0.000 abstract description 7
- 238000012360 testing method Methods 0.000 description 41
- 238000005336 cracking Methods 0.000 description 27
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 15
- 229910000423 chromium oxide Inorganic materials 0.000 description 15
- 239000004215 Carbon black (E152) Substances 0.000 description 12
- 238000004230 steam cracking Methods 0.000 description 12
- 230000003197 catalytic effect Effects 0.000 description 7
- 238000000197 pyrolysis Methods 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 238000011065 in-situ storage Methods 0.000 description 5
- 239000006185 dispersion Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000011159 matrix material Substances 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- 238000003763 carbonization Methods 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 238000012958 reprocessing Methods 0.000 description 2
- 238000010183 spectrum analysis Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000010622 cold drawing Methods 0.000 description 1
- 238000005235 decoking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000007750 plasma spraying Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000002352 steam pyrolysis Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
The invention relates to the field of petroleum hydrocarbon thermal cracking, and discloses a quenching boiler for slowing down coking and carburizing, and a preparation method and application thereof. The method comprises the following steps: (1) Contacting the reducing gas with a tube side furnace tube of a quenching boiler to perform a first heat treatment reaction to obtain a pretreated quenching boiler; (2) The oxidizing gas is contacted with the pretreatment quenching boiler to carry out a second heat treatment reaction, so as to obtain the quenching boiler with the double-layer oxide film on the inner surface of the tube side furnace tube; (3) Contacting the reducing gas with a quenching boiler with a double-layer oxidation film on the inner surface of a tube side furnace tube for a third heat treatment reaction to obtain the quenching boiler with the double-layer anti-coking oxidation film on the inner surface of the tube side furnace tube; wherein the content of oxygen in the reducing gas is 0ppm; the volume fraction of oxygen in the oxidizing gas is 6-22%. The preparation process of the quenching boiler is simple, and can obviously reduce coking and carburizing of the quenching boiler and prolong the operation period.
Description
Technical Field
The invention relates to the field of petroleum hydrocarbon thermal cracking, in particular to a quenching boiler for slowing down coking and carburizing, and a preparation method and application thereof.
Background
Ethylene is a basic feedstock for the petrochemical industry. Ethylene production, scale of production and technology mark a state petrochemical development. The current process for producing ethylene is based on the tube furnace petroleum hydrocarbon steam cracking technology, and it is counted that about 99% of ethylene and 50% or more of propylene in the world are produced by this process. In the process of preparing ethylene and propylene by petroleum hydrocarbon steam pyrolysis in a tubular furnace, high-temperature pyrolysis gas is coked on the inner wall of a tube side furnace tube of the quenching boiler in the process of recovering heat through the quenching boiler, carburization of the inner wall of the tube side furnace tube of the quenching boiler can be caused if the high-temperature pyrolysis gas runs for a long time under the condition of coking, and the coking and carburization can reduce the heat transfer efficiency of the quenching boiler and can influence the online time of the quenching boiler. The quenching boiler has the advantages of excessively short on-line time and frequent hydraulic or mechanical decoking, increases more labor cost, consumes a large amount of energy, reduces effective production time and shortens the service life of equipment.
The tube side furnace tube of the quenching boiler is mainly made of 15Mo3 material, and the material mainly comprises metal elements such as Fe, cr and the like. At high temperature, petroleum hydrocarbon interacts with iron in the metal of the tube side furnace tube of the quenching boiler to dehydrogenate and deposit carbon, namely iron element has remarkable catalytic effect on coking on the inner surface of the tube side furnace tube of the quenching boiler. As the temperature decreases (below 500 ℃), low temperature coking based on catalytic coking begins to dominate.
At present, two main methods are adopted to slow down the coking and carburization of a quenching boiler: adding coking inhibitor into cracking raw material and coating anti-coking coating on inner surface of tube of quenching boiler tube. The method of adding coking inhibitor to passivate the inner surface of the furnace tube or gasify the coke is adopted, so that not only can pollution be brought to downstream products, but also special injection equipment is required to be added, and the method has poor effect on low-temperature coking; the method of coating the inner surface of the furnace tube with the anti-coking coating is adopted, so that an isolation coating with excellent mechanical property and thermal stability is formed on the inner surface of the furnace tube, and the contact between petroleum hydrocarbon materials and metal elements on the inner surface of the furnace tube is isolated, thereby reducing the catalytic coking activity of the metal elements on the inner surface of the furnace tube and slowing down the whole coking process of the quenching boiler. The furnace tube with the anti-coking coating has two different preparation modes, one is formed by means of plasma spraying, hot sputtering, high-temperature sintering, chemical vapor deposition and the like, and the furnace tube with the metal or nonmetal oxide protective layers such as chromium oxide, silicon oxide, aluminum oxide, titanium oxide and the like on the inner surface is formed, and the defect that the combination of the protective layers and the furnace tube matrix is not firm enough and is easy to peel off is overcome; the other is a furnace tube with an oxide protection layer which is generated in situ on the inner surface of the furnace tube through specific atmosphere treatment at a certain temperature, and the furnace tube has the advantages that the bonding force between the protection layer and the furnace tube matrix is strong, and the furnace tube is not easy to peel off.
The Canada NOVA chemical company proposes a technical scheme for treating the inner surface of a cracking furnace tube under low oxygen partial pressure by taking a mixed gas of hydrogen and water vapor as a treatment atmosphere, and a lot of patents including US5630887A, US6436202B1, US6824883B1, US7156979B2, US7488392B2 and the like are applied for the technical scheme. However, the adoption of the technical scheme can not effectively solve the problems of coking and carburization of the current quenching boiler.
Disclosure of Invention
The invention aims to solve the problems of coking and carburization of a quenching boiler in the prior art, and provides a quenching boiler for slowing down the coking and carburization, and a preparation method and application thereof.
In order to achieve the above object, a first aspect of the present invention provides a method for producing a quenching boiler that slows down coking and carburization, characterized in that the method comprises:
(1) Contacting the reducing gas with a tube side furnace tube of a quenching boiler to perform a first heat treatment reaction to obtain a pretreated quenching boiler;
(2) The oxidizing gas is contacted with the pretreatment quenching boiler to carry out a second heat treatment reaction, so as to obtain the quenching boiler with the double-layer oxide film on the inner surface of the tube side furnace tube;
(3) Contacting the reducing gas with a quenching boiler with a double-layer oxidation film on the inner surface of a tube side furnace tube for a third heat treatment reaction to obtain the quenching boiler with the double-layer anti-coking oxidation film on the inner surface of the tube side furnace tube;
Wherein the content of oxygen in the reducing gas is 0ppm; the volume fraction of oxygen in the oxidizing gas is 6-22%.
In a second aspect, the present invention provides a coking and carburization reducing quench boiler made by the above process.
In a third aspect, the invention provides the use of a coking and carburized quench boiler as described above in petroleum hydrocarbon cracking.
Through the technical scheme, the quenching boiler for slowing down coking and carburizing provided by the invention and the preparation method and application thereof have the following beneficial effects:
The quenching boiler for slowing down coking and carburizing provided by the invention has simple preparation process and is easy to realize. The quenching boiler prepared by the method can inhibit the catalytic coking, condensation coking and the whole coking process in the tube side furnace tube of the quenching boiler, and effectively improve the anti-carbonization performance of the tube side furnace tube, thereby prolonging the on-line time and the service life of the quenching boiler.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
In a first aspect, the present invention provides a method of making a coking and carburized quenching boiler, comprising:
(1) Contacting the reducing gas with a tube side furnace tube of a quenching boiler to perform a first heat treatment reaction to obtain a pretreated quenching boiler;
(2) The oxidizing gas is contacted with the pretreatment quenching boiler to carry out a second heat treatment reaction, so as to obtain the quenching boiler with the double-layer oxide film on the inner surface of the tube side furnace tube;
(3) Contacting the reducing gas with a quenching boiler with a double-layer oxidation film on the inner surface of a tube side furnace tube for a third heat treatment reaction to obtain the quenching boiler with the double-layer anti-coking oxidation film on the inner surface of the tube side furnace tube;
Wherein the content of oxygen in the reducing gas is 0ppm; the volume fraction of oxygen in the oxidizing gas is 6-22%.
The invention solves the problems of coking and carburization of a quenching boiler by forming an oxide film on the inner surface of a tube side furnace tube of the quenching boiler, namely, a method of carrying out heat treatment step by sequentially adopting reducing gas, oxidizing gas and reducing gas, and a double-layer anti-coking oxide film is generated on the inner surface of the tube side furnace tube of the quenching boiler in an in-situ growth mode, and the obtained double-layer anti-coking oxide film has strong bonding force with a base body of the tube side furnace tube of the quenching boiler and is suitable for long-term use.
The quenching boiler tube side furnace tube inevitably has residues on the inner surface of the furnace tube in the processing and manufacturing process, and the residues not only can influence the service performance of the furnace tube in service, but also can influence the generation of an anti-coking oxidation film on the inner surface of the furnace tube in subsequent treatment. The reducing gas is adopted to perform high-temperature pretreatment on the quenching boiler tube side furnace tube, so that on one hand, residues on the inner surface of the furnace tube can be thoroughly removed, and on the other hand, the dispersion performance of metal on the inner surface of the furnace tube is improved, and the next step of heat treatment of oxidizing gas is facilitated to form a double-layer oxide film; and reducing gas is adopted again to cool the alloy furnace tube with the double-layer oxide film on the inner surface to room temperature, so that the double-layer oxide film is further formed into a double-layer anti-coking oxide film with a compact and stable lower layer of chromium oxide and a surface layer of chromium manganese oxide.
Further, by controlling the oxygen content in the reducing gas to be 0ppm, when the volume fraction of oxygen in the oxidizing gas is 6-22%, a compact and stable anti-coking oxidation film can be formed on the inner surface of the furnace tube.
In the present invention, the oxygen content of the reducing gas of 0ppm means that the reducing gas does not contain oxygen or is a gas capable of generating oxygen.
In the invention, the oxygen content in the reducing gas and the oxidizing gas is measured by a micro oxygen analyzer and a constant oxygen analyzer respectively.
Further, the volume fraction of oxygen in the oxidizing gas is 13-22%.
According to the present invention, the oxidizing gas includes air and at least one gas selected from the group consisting of nitrogen, helium and argon.
According to the present invention, the reducing gas includes carbon monoxide, hydrogen, and at least one gas selected from the group consisting of nitrogen, helium, and argon.
According to the present invention, the content of carbon monoxide and hydrogen is 80vol% or less, preferably 60 to 80vol%, based on the total volume of the reducing gas.
In the invention, the volume ratio of the carbon monoxide to the hydrogen is 1:0.2-5.
According to the invention, when the content of carbon monoxide and hydrogen in the reducing gas is controlled to meet the range, the effects of thoroughly removing residues on the inner surface of the tube of the quenching boiler tube side, improving the dispersion performance of metal on the inner surface of the tube and facilitating the subsequent sequential reprocessing of the oxidizing gas and the reducing gas to form a compact stable coking-resistant oxidation film can be obtained.
According to the present invention, the conditions of the first heat treatment reaction include: heating from room temperature to 800-1000 ℃ at a heating rate of less than or equal to 150 ℃/h, and preserving heat for more than 10 hours.
In the invention, when the conditions of the first heat treatment are controlled to meet the above range, the method can thoroughly remove residues on the inner surface of the furnace tube, improve the dispersion performance of metal on the inner surface of the furnace tube and facilitate the subsequent secondary treatment of oxidizing gas and reducing gas to form a compact stable oxide film.
Further, the conditions of the first heat treatment include: heating from room temperature to 850-950 ℃ at a heating rate of 100 ℃/h or less, and treating for 10-40 hours.
In the present invention, in the first heat treatment reaction, the flow rate of the reducing gas is 100 to 800mL/min, preferably 200 to 600mL/min.
According to the invention, when the flow rate of the reducing gas is controlled to meet the range, residues on the inner surface of the tube side furnace tube of the quenching boiler can be thoroughly removed, the dispersion performance of metal on the inner surface of the furnace tube is improved, and the subsequent sequential reprocessing of the oxidizing gas and the reducing gas is facilitated to form a compact stable oxide film.
According to the present invention, the conditions of the second heat treatment reaction include: the treatment temperature is 800-1000 ℃ and the treatment time is more than 10 hours.
In the present invention, when the conditions for controlling the second heat treatment reaction satisfy the above-described ranges, a double oxide film having a lower layer of chromium oxide and a surface layer of chromium manganese oxide can be formed on the inner surface of the furnace tube.
Further, the conditions of the second heat treatment reaction include: the reaction temperature is 850-950 ℃, and the reaction time is 10-100h, preferably 10-50h.
In the present invention, in the second heat treatment reaction, the flow rate of the oxidizing gas is 100 to 800mL/min, preferably 200 to 600mL/min.
In the invention, when the flow rate of the oxidizing gas is controlled to meet the range, the oxidizing gas can be fully contacted with the pretreated alloy furnace tube, and a double-layer anti-coking oxidation film is formed on the inner wall of the alloy furnace tube.
According to the present invention, the conditions of the third heat treatment reaction include: cooling from 800-1000 ℃ to room temperature at a cooling rate of less than or equal to 100 ℃/h.
In the invention, when the third heat treatment reaction is controlled to meet the range, the double-layer anti-coking oxidation film formed on the inner surface of the final alloy furnace tube can be more compact and stable.
Further, the conditions of the third heat treatment reaction include: cooling from 850-950 ℃ to room temperature at a cooling rate of 50 ℃/h or less.
In the third cooling heat treatment reaction, the flow rate of the reducing gas is 20-200mL/min, preferably 50-100mL/min.
In the present invention, when the flow rate of the reducing gas is controlled to satisfy the above range, the effect of forming a dense and stable double-layer anti-coking oxidation film by the reducing gas treatment can be obtained.
According to the invention, the double-layer anti-coking oxidation film comprises a chromium oxide layer positioned at the lower layer and a chromium manganese oxide film positioned at the surface layer.
In the invention, the lower layer refers to a part close to the inner wall of the alloy furnace tube, and the surface layer refers to a part far away from the inner wall of the alloy furnace tube.
According to the present invention, the chromium manganese oxide film includes chromium manganese oxide and a metal element.
According to the invention, the composition of the chromium manganese oxide is Mn xCr3-xO4, and the x value is 0.5-2.
According to the invention, the tube side furnace tube of the quenching boiler is subjected to heat treatment by sequentially adopting the reducing gas, the oxidizing gas and the reducing gas, so that the inner surface of the tube side furnace tube of the quenching boiler can be ensured to form a double-layer anti-coking oxidation film with compact and stable structure through in-situ growth, the obtained double-layer anti-coking oxidation film is firmly combined with the furnace tube matrix, the catalytic coking phenomenon can be obviously inhibited or reduced, the carburization degree of the quenching boiler is reduced, and the service life of the quenching boiler is prolonged.
Furthermore, in the surface oxide film on the inner surface of the tube side furnace tube of the quenching boiler treated by the method, the content of iron element is low, so that the catalytic coking in the hydrocarbon cracking process can be inhibited, the running period of the quenching boiler is prolonged, and the long-term use requirement of the quenching boiler is met.
Specifically, the content of the iron element is 40wt% or less with respect to the total weight of the chromium manganese oxide film.
In the invention, the content of metal elements in the surface oxide film on the inner surface of the tube side furnace tube of the quenching boiler before treatment is measured by an X-ray energy spectrum analysis (EDS) method.
According to the invention, the composition of the tube side furnace tube alloy of the quenching boiler comprises: cr:1.0-20wt%, mo:0.2-0.6wt%, mn:0.3-0.8wt%, si:0.3-2wt%, C:0.1-0.2wt%, O: less than 5wt%, fe:76.4-98wt% of trace elements: 0-1wt%.
According to the invention, the trace element is at least one of Al, nb, ti, W and rare earth elements.
In the present invention, the first heat treatment reaction, the second heat treatment reaction, and the third heat treatment reaction may be performed in an apparatus capable of maintaining a certain atmosphere, which is conventional in the art, and for example, may be at least one of a tube furnace, a pit furnace, and an atmosphere box furnace.
In a second aspect, the present invention provides a coking and carburization reducing quench boiler made by the above process.
In the invention, the inner surface of the tube side furnace tube of the quenching boiler contains a double-layer anti-coking oxidation film. The double-layer anti-coking oxidation film comprises a chromium oxide film positioned at the lower layer and a chromium manganese oxide film positioned at the surface layer.
In the invention, the double-layer anti-coking oxidation film is formed by in-situ growth.
In the invention, the inventor researches and discovers that the reason why the quenching boiler can slow down coking and carburization is as follows: the technical scheme of the invention is adopted to perform reducing gas heat treatment on the tube side furnace tube of the quenching boiler, and then oxidizing gas and reducing gas are further subjected to step-by-step heat treatment, so that a double-layer anti-coking oxidation film with strong bonding force with the furnace tube matrix is generated on the inner surface of the tube side furnace tube of the quenching boiler in situ, and the iron element in the tube section is shielded. When the pyrolysis gas is used for recovering heat through the quenching boiler, the oxide film on the inner wall of the tube side furnace tube can isolate the pyrolysis gas from contact with iron elements on the inner surface of the tube side furnace tube, so that the catalytic coking, condensation coking and the whole coking process in the tube section are inhibited, the anti-carbonization performance of the tube section is effectively improved, and the on-line time and the service life of the quenching boiler are prolonged.
In a third aspect, the invention provides the use of a coking and carburized quench boiler as described above in thermal cracking of petroleum hydrocarbons.
In the present invention, the pyrolysis reaction may be performed according to a conventional naphtha pyrolysis process in the prior art. Specifically, the cracking temperature is 830-850 ℃, and the water-oil ratio is 0.5-0.55.
In the present invention, room temperature refers to 25℃unless otherwise specified.
The present invention will be described in detail by examples. In the following examples:
The 15CrMoG pipe is a common material for a tube side furnace tube of a quenching boiler;
The elemental composition of the furnace tube alloy and the content of the elements in the surface layer oxide film on the inner surface of the furnace tube after treatment are measured by adopting an X-ray energy spectrum analysis (EDS) method;
the oxygen content of the reducing gas is measured by a micro oxygen analyzer;
The oxygen content in the oxidizing gas is measured by a constant oxygen analyzer;
The coking amount of the furnace tube is calculated after the concentration of CO and H 2 in the burnt gas is measured on line by adopting an infrared instrument and the volume of the burnt gas is measured on line by adopting a wet gas flowmeter;
The pyrolysis raw oil is naphtha, and the physical properties are as follows: distillation range 33.4-162.8deg.C, specific gravity D 20: 0.7358g/mL.
Example 1
Cold drawing seamless steel pipe of 15CrMoG pipeThe elemental composition of the furnace tube alloy is (wt%): cr:1.03, mo:0.47, mn:0.58, si:0.32, C:0.16, O:2.13, fe:95.07 and the others 0.24. Step-by-step heat treatment is carried out on the small test furnace tube:
(1) The method comprises the steps of adopting a gas mixture of CO, H 2 and N 2 as reducing gas, and performing first heat treatment on a furnace tube to obtain a pretreatment small-scale furnace tube, wherein the oxygen content in the reducing gas is 0ppm, and the volume ratio of CO to H 2 is 1:1, 70vol% of CO and H 2, the balance of N 2, the flow rate of the reducing gas of 400mL/min, the heating rate of 80 ℃/H, the treatment temperature of 900 ℃ and the treatment time of 15 hours;
(2) Performing a second heat treatment on the pretreatment small test furnace tube by adopting an oxidizing gas consisting of air and N 2, wherein the volume fraction of O 2 is 16%, the flow rate of the oxidizing gas is 400mL/min, and the conditions of the second heat treatment are as follows: the treatment temperature is 900 ℃ and the treatment time is 15 hours;
(3) The same gas mixture of CO, H 2 and N 2 as the step (1) is used as reducing gas, and the furnace tube is subjected to third cooling heat treatment to room temperature, except that: the flow rate of the reducing gas is 80mL/min, and the conditions of the third cooling heat treatment are as follows: the cooling rate is 40 ℃/h, and the temperature is reduced from 900 ℃ to room temperature.
The double-layer anti-coking oxidation film with the lower layer of chromium oxide and the surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube through the stepwise heat treatment of the reducing gas, the oxidizing gas and the reducing gas. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 20.68wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reaction is carried out in the small test furnace tube after step-by-step treatment, and the cracking conditions are as follows: the cracking temperature is 845 ℃, and the water-oil ratio is 0.5. Experimental results show that the coking amount of the small test furnace tube is reduced by 92.12 weight percent compared with that of the untreated small test furnace tube.
Example 2
The same small test tubes as in example 1 were subjected to a stepwise heat treatment of a reducing gas, an oxidizing gas, and a reducing gas, except that: the conditions for the first heat treatment of the reducing gas are: the treatment temperature is 800 ℃ and the treatment time is 20 hours; the conditions for the second heat treatment of the oxidizing gas are: the treatment temperature is 800 ℃, the treatment time is 20 hours, and the conditions of the third cooling heat treatment of the reducing gas are as follows: the treatment temperature was 800℃to room temperature, and the other treatment conditions were the same as in example 1.
The double-layer anti-coking oxidation film with the lower layer of chromium oxide and the surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube through the stepwise heat treatment of the reducing gas, the oxidizing gas and the reducing gas. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 36.38wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reactions were carried out in staged tubes with the same cracking feed and cracking conditions as in example 1. The coking amount of the small test furnace tube is reduced by 45.12 weight percent compared with that of an untreated small test furnace tube.
Example 3
The same small test tubes as in example 1 were subjected to a stepwise heat treatment of a reducing gas, an oxidizing gas, and a reducing gas, except that: the conditions for the first heat treatment of the reducing gas are: the treatment temperature is 1000 ℃, the treatment time is 10 hours, and the conditions of the second heat treatment of the oxidizing gas are as follows: the treatment temperature is 1000 ℃, the treatment time is 10 hours, and the conditions of the third heat treatment of the reducing gas are as follows: the treatment temperature was 1000℃to room temperature, and the other treatment conditions were the same as in example 1.
The double-layer anti-coking oxidation film with the lower layer of chromium oxide and the surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube through the stepwise heat treatment of the reducing gas, the oxidizing gas and the reducing gas. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 28.89wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reactions were carried out in staged tubes with the same cracking feed and cracking conditions as in example 1. The coking amount of the small test furnace tube is reduced by 65.28 weight percent compared with that of an untreated small test furnace tube.
Example 4
The same small test tubes as in example 1 were subjected to a stepwise heat treatment of a reducing gas, an oxidizing gas, and a reducing gas, except that:
(1) The method comprises the steps of adopting a gas mixture of CO, H 2 and N 2 as reducing gas, and performing first heat treatment on a furnace tube to obtain a pretreatment small-scale furnace tube, wherein the oxygen content in the reducing gas is 0ppm, and the volume ratio of CO to H 2 is 1:0.3, 50vol% of CO and H 2, the balance N 2, a reducing gas flow rate of 150mL/min, a heating rate of 110 ℃/H, a treatment temperature of 800 ℃ and a treatment time of 42 hours;
(2) Performing a second heat treatment on the pretreatment small test furnace tube by adopting an oxidizing gas consisting of air and N 2, wherein the volume fraction of O 2 is 10%, the flow rate of the oxidizing gas is 150mL/min, and the conditions of the second heat treatment are as follows: the treatment temperature is 800 ℃ and the treatment time is 42 hours;
(3) The same gas mixture of CO, H 2 and N 2 as the step (1) is used as reducing gas, and the furnace tube is subjected to third cooling heat treatment to room temperature, except that: the flow rate of the reducing gas is 40mL/min, and the conditions of the third cooling heat treatment are as follows: the cooling rate is 70 ℃/h, and the temperature is reduced from 800 ℃ to room temperature;
The double-layer anti-coking oxidation film with the lower layer of chromium oxide and the surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube through the stepwise heat treatment of the reducing gas, the oxidizing gas and the reducing gas. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 39.25wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reactions were carried out in staged tubes with the same cracking feed and cracking conditions as in example 1. The coking amount of the small test furnace tube is reduced by 40.84 weight percent compared with that of an untreated small test furnace tube.
Example 5
The same small test tubes as in example 1 were subjected to a stepwise heat treatment of a reducing gas, an oxidizing gas, and a reducing gas, except that:
(1) The method comprises the steps of adopting a gas mixture of CO, H 2 and N 2 as reducing gas, and performing first heat treatment on a furnace tube to obtain a pretreatment small-scale furnace tube, wherein the oxygen content in the reducing gas is 0ppm, and the volume ratio of CO to H 2 is 1:6, the volume percent of CO and H 2 is 85vol%, the rest is N 2, the flow rate of the reducing gas is 80mL/min, the heating rate is 160 ℃/H, the treatment temperature is 750 ℃, and the treatment time is 8 hours;
(2) Performing a second heat treatment on the pretreatment small test furnace tube by adopting an oxidizing gas consisting of air and N 2, wherein the volume fraction of O 2 is 5%, the flow rate of the oxidizing gas is 80mL/min, and the conditions of the second heat treatment are as follows: the treatment temperature is 750 ℃ and the treatment time is 8 hours;
(3) The same gas mixture of CO, H 2 and N 2 as the step (1) is used as reducing gas, and the furnace tube is subjected to third cooling heat treatment to room temperature, except that: the flow rate of the reducing gas is 15mL/min, and the conditions of the third cooling heat treatment are as follows: the cooling rate is 110 ℃/h, and the temperature is reduced from 750 ℃ to room temperature;
The double-layer anti-coking oxidation film with the lower layer of chromium oxide and the surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube through the stepwise heat treatment of the reducing gas, the oxidizing gas and the reducing gas. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 45.88wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reactions were carried out in staged tubes with the same cracking feed and cracking conditions as in example 1. The coking amount of the small test furnace tube is reduced by 31.56 weight percent compared with that of an untreated small test furnace tube.
Example 6
The same small test tubes as in example 1 were subjected to a stepwise heat treatment of a reducing gas, an oxidizing gas, and a reducing gas, except that: the conditions for the first heat treatment of the reducing gas are: the treatment temperature is 700 ℃, the treatment time is 25 hours, and the conditions of the second heat treatment are as follows: the treatment temperature is 700 ℃, the treatment time is 25 hours, and the conditions of the third heat treatment are as follows: the treatment temperature was 700℃to room temperature, and the other treatment conditions were the same as in example 1.
The double-layer anti-coking oxidation film with the lower layer of chromium oxide and the surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube through the stepwise heat treatment of the reducing gas, the oxidizing gas and the reducing gas. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 42.47wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reactions were carried out in staged tubes with the same cracking feed and cracking conditions as in example 1. The coking amount of the small test furnace tube is reduced by 36.39 weight percent compared with that of the untreated small test furnace tube.
Comparative example 1
The same pilot burner tube as in example 1, except that: the second heat treatment was carried out on the small test tube using only an oxidizing gas, the volume fraction of O 2 in the oxidizing gas was 16%, the treatment temperature was 900 ℃, and the treatment time was 55 hours, with the other conditions being the same as in example 1. An oxide film is formed on the inner wall surface of the small test tube, and the oxide film contains chromium oxide and iron element. The content of iron element in the oxide film on the inner surface of the furnace tube is 50.45wt% relative to the total weight of the oxide film.
Hydrocarbon steam cracking reactions were carried out in pilot burner tubes after the treatment with oxidizing gas, and the cracking feedstock and cracking conditions were the same as in example 1. The coking amount of the small test furnace tube after treatment is reduced by 17.37 weight percent compared with that of the small test furnace tube without treatment.
Comparative example 2
The same pilot burner tube as in example 1, except that: the furnace tube is subjected to the first heat treatment and the third heat treatment by adopting the reducing gas only. Other conditions were the same as in example 1, and no chromium oxide and chromium manganese oxide were formed on the inner wall surface of the furnace tube after the reducing gas treatment. The content of iron element on the inner surface of the furnace tube is 53.63wt%.
Hydrocarbon steam cracking reactions were carried out in pilot furnace tubes after reducing gas treatment, and the cracking feedstock and cracking conditions were the same as in example 1. The coking amount of the small test furnace tube after treatment is reduced by 9.78 weight percent compared with that of the small test furnace tube without treatment.
Comparative example 3
The same pilot burner tube as in example 1 was used, except that the hydrocarbon steam cracking reaction was carried out in the pilot burner tube without any treatment, and the cracking feedstock and cracking conditions were the same as in example 1. The coking amount of the small test furnace tube is 100wt%.
Comparative example 4
The same pilot burner tube as in example 1, except that: step (3) was not performed, and the other conditions were the same as in example 1. A double-layer anti-coking oxidation film with a lower layer of chromium oxide and a surface layer of chromium-manganese oxide film is formed on the inner wall surface of the furnace tube. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 48.38wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reaction is carried out in the small test furnace tube after step-by-step treatment, and the cracking conditions are as follows: the cracking temperature is 845 ℃, and the water-oil ratio is 0.5. Experimental results show that the coking amount of the small test furnace tube is reduced by 26.52wt% compared with that of the untreated small test furnace tube.
Comparative example 5
The same pilot burner tube as in example 1, except that: the oxygen content in the reducing gas was controlled to 10ppm, and the other conditions were the same as in example 1. A double-layer anti-coking oxidation film with a lower layer of chromium oxide and a surface layer of chromium-manganese oxide film is formed on the inner wall surface of the small test furnace tube. The surface chromium manganese oxide film contains chromium manganese oxide Mn 2CrO4 and iron element, and the content of the iron element in the chromium manganese oxide film is 49.27wt% relative to the total weight of the chromium manganese oxide film.
Hydrocarbon steam cracking reactions were carried out in staged tubes with the same cracking feed and cracking conditions as in example 1. The coking amount of the small test furnace tube is reduced by 20.18 weight percent compared with that of an untreated small test furnace tube.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.
Claims (10)
1. A method of making a coking and carburized quench boiler, the method comprising:
(1) Contacting the reducing gas with a tube side furnace tube of a quenching boiler to perform a first heat treatment reaction to obtain a pretreated quenching boiler;
(2) The oxidizing gas is contacted with the pretreatment quenching boiler to carry out a second heat treatment reaction, so as to obtain the quenching boiler with the double-layer oxide film on the inner surface of the tube side furnace tube;
(3) Contacting the reducing gas with a quenching boiler with a double-layer oxidation film on the inner surface of a tube side furnace tube for a third heat treatment reaction to obtain the quenching boiler with the double-layer anti-coking oxidation film on the inner surface of the tube side furnace tube;
Wherein the content of oxygen in the reducing gas is 0ppm, and the volume fraction of oxygen in the oxidizing gas is 6-22%.
2. The method of claim 1, wherein the volume fraction of oxygen in the oxidizing gas is 13-22%;
preferably, the oxidizing gas includes air and at least one gas selected from the group consisting of nitrogen, helium and argon.
3. The method according to claim 1 or 2, wherein the reducing gas comprises carbon monoxide, hydrogen and at least one gas selected from nitrogen, helium and argon;
preferably, the total content of carbon monoxide and hydrogen is 80vol% or less, preferably 60 to 80vol%, based on the total volume of the reducing gas.
4. A method according to any one of claims 1-3, wherein the conditions of the first heat treatment reaction comprise: heating from room temperature to 800-1000 ℃ at a heating rate of less than or equal to 150 ℃/h, and preserving heat for more than 10 hours.
5. The method of any of claims 1-4, wherein the conditions of the second heat treatment reaction comprise: the treatment temperature is 800-1000 ℃ and the treatment time is more than 10 hours.
6. The method of any of claims 1-5, wherein the conditions of the third heat treatment reaction comprise: cooling from 800-1000 ℃ to room temperature at a cooling rate of less than or equal to 100 ℃/h.
7. The method of any of claims 1-6, wherein the double layer anti-coking oxide film comprises a lower layer of chromia and a surface layer of chromia-manganese oxide film;
preferably, the chromium manganese oxide film includes chromium manganese oxide and a metal element;
Preferably, the composition of the chromium manganese oxide is Mn xCr3-xO4, and the x value is 0.5-2;
Preferably, the metal element is an iron element;
Preferably, the content of the iron element is 40wt% or less with respect to the total weight of the chromium manganese oxide film.
8. The method of any of claims 1-7, wherein the composition of the tube side furnace tube alloy of the quench boiler comprises: cr:1.0-20wt%, mo:0.2-0.6wt%, mn:0.3-0.8wt%, si:0.3-2wt%, C:0.1-0.2wt%, O: less than 5wt%, fe:76.4-98wt% of trace elements: 0-1wt%;
Preferably, the trace element is at least one of Al, nb, ti, W and rare earth elements.
9. A coking and carburization mitigating quench boiler made by the process of any of claims 1-8.
10. Use of a coking and carburized quenching boiler according to claim 9 for thermal cracking of petroleum hydrocarbons.
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