A method for treating regenerated flue gas from catalytic conversion of inferior heavy oil

Abstract

This invention relates to a method for treating regenerated flue gas from the catalytic conversion of low-quality heavy oil. The method includes: contacting the low-quality heavy oil feedstock with a catalytic conversion catalyst in a catalytic conversion reactor to carry out a catalytic conversion reaction; separating the reaction stream to obtain reacted oil and gas and coke-laden catalyst; sending the catalyst to a first regeneration zone of a regenerator for first regeneration to obtain first flue gas and semi-regenerated catalyst; allowing the first flue gas and the semi-regenerated catalyst to rise into a second regeneration zone of the regenerator for second regeneration to obtain regenerated catalyst and second flue gas; and sending the second flue gas into a bio-fermentation unit to obtain ethanol, protein feed, and fermentation tail gas. The method provided by this invention enables the coke on the catalyst to be converted into flue gas with higher CO selectivity, significantly reducing carbon dioxide emissions.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals, specifically relating to a method for treating regenerated flue gas from the catalytic conversion of inferior heavy oil. Background Technology

[0002] Catalytic conversion is an important secondary processing technology for petroleum feedstocks and a major process for lightening heavy oil. Catalytic conversion catalyst regeneration involves coke burning, typically achieved by introducing regeneration gas into the catalyst regenerator and burning off the coke deposits on the catalyst under high-temperature conditions to restore catalyst activity. The CO2 emissions from catalyst coking during catalytic conversion are substantial, reaching 15%–50% of total refinery emissions. The catalyst regeneration process generates a large amount of heat, leading to excess heat. External heat recovery devices are needed to convert the heat generated during catalyst regeneration into steam energy and to recover energy from the high-temperature flue gas. Furthermore, the regeneration flue gas contains carbon monoxide, which often causes tail combustion, resulting in localized overheating of the regenerator, exacerbating catalyst deactivation, and potentially damaging the regeneration equipment due to overheating. While controlling the oxygen content in the flue gas can reduce tail combustion, the coking rate and intensity during catalyst regeneration will also decrease, still presenting a problem with exhaust emissions. Refineries generally use carbon monoxide combustion aids or flue gas carbon monoxide boilers to reduce carbon monoxide in the flue gas and recover energy.

[0003] To fully utilize the regenerated flue gas from catalytic conversion and recover energy, CN114768481A discloses a method for utilizing the waste heat of the regenerated flue gas from catalytic conversion and reducing energy consumption during the elimination of wet flue gas. By using an absorption heat pump, the low-temperature heat in the flue gas and desulfurization circulating liquid can be converted into high-temperature heat in the heat transfer medium, enhancing the utilization rate of heat. CN101457152A discloses a hydrocarbon-oil conversion method. During the regeneration process, the spent catalyst contacts water vapor and oxygen-containing gas in a gasifier to obtain syngas and a semi-regenerated catalyst. This method can increase the yield of carbon monoxide and hydrogen. Carbon monoxide can also be converted into hydrogen in subsequent processing, thereby achieving a higher hydrogen yield.

[0004] In existing technologies, the main approach is still to convert the energy generated by catalyst regeneration into heat from heat transfer media such as steam; while the method of producing hydrogen from the flue gas generated by the incomplete regeneration of coke also utilizes coke, the main form of carbon emission is carbon dioxide; and the method of directly contacting the spent catalyst with water vapor to produce syngas will greatly accelerate the deactivation of the catalyst. Summary of the Invention

[0005] The purpose of this invention is to increase the CO concentration in the catalyst regeneration flue gas so that the regeneration flue gas can be effectively utilized.

[0006] To achieve the above objectives, the present invention provides a method for treating inferior heavy oil catalytic conversion regeneration flue gas, the method comprising:

[0007] Inferior heavy oil feedstock is brought into contact with catalytic conversion catalyst in a catalytic conversion reactor to carry out catalytic conversion reaction. The reaction stream is separated to obtain reacted oil and gas and carbon deposits to be generated catalyst.

[0008] The catalyst to be generated is fed into the first regeneration zone of the regenerator for first regeneration to obtain first flue gas and semi-regenerated catalyst.

[0009] The first flue gas and the semi-regenerated catalyst are made to rise and enter the second regeneration zone of the regenerator for second regeneration, so as to obtain a regenerated catalyst and a second flue gas.

[0010] The second flue gas is fed into a biological fermentation unit to ferment the second flue gas, thereby obtaining ethanol, protein feed and fermentation tail gas;

[0011] The first regeneration zone is a rapid regeneration bed, and the second regeneration zone is a dilute phase bed; the regeneration temperature of the first regeneration zone is 600–900℃, and the bed density is 120–290 kg / m³. 3 .

[0012] Optionally, the oxygen content in the regeneration gas introduced into the first regeneration zone is 20-100% by volume; preferably, the regeneration gas is selected from one or a mixture of several of air, oxygen-enriched air, oxygen, CO2 and fermentation exhaust gas.

[0013] Optionally, the CO content in the second flue gas is 10-50% by volume.

[0014] Optionally, the conditions for the first regeneration include: a regeneration temperature of 680–800°C; an average catalyst residence time of 0.6–20 min, preferably 1–10 min; an apparent gas linear velocity of 0.8–2.5 m / s; and a bed density of 150–250 kg / m³. 3 .

[0015] Optionally, the conditions for the second regeneration include: a temperature of 600–750°C, preferably 650–700°C; an average catalyst residence time of 0.6–15 min, preferably 1–5 min; an apparent gas linear velocity of 3–15 m / s; and a bed density not exceeding 120 kg / m³. 3 The preferred value is 60–100 kg / m³. 3 .

[0016] Optionally, the method for fermenting the second flue gas includes: purifying the second flue gas to obtain purified flue gas; feeding the purified flue gas into a fermenter and fermenting the purified flue gas under the action of acetic acid-producing bacteria to obtain fermentation mash and fermentation tail gas; separating the fermentation mash to obtain ethanol and protein feed; optionally, the method further includes: cooling the second flue gas before sending it to the biological fermentation unit.

[0017] Optionally, the method further includes: supplementing the bio-fermentation unit with hydrogen; the molar ratio of supplemented hydrogen to CO in the second flue gas is (2-30):1; preferably, the acetic acid bacteria are selected from one or a mixture of Clostridium autoethanogenum (DSMZ Germany) with microbial accession number DSM 19630 and Clostridium autoethanogenum (DSMZ Germany) with microbial accession number DSM 23693.

[0018] Optionally, the carbon content on the regenerated agent is 1.2 to 4% by weight; preferably, the carbon content on the regenerated catalyst is 0 to 0.15% by weight.

[0019] Optionally, the conditions for the catalytic conversion reaction include: a reaction temperature of 450–700°C, preferably 500–650°C, more preferably 510–630°C; a reaction time of 1–10 seconds, preferably 2–5 seconds; a weight ratio of the catalytic conversion catalyst to the low-quality heavy oil feedstock of (1–100):1, preferably (5–30):1; and the catalytic conversion reactor is selected from one or a combination of two of the following: a riser reactor, a fast bed reactor, and a fluidized bed reactor.

[0020] Optionally, the residual carbon content in the inferior heavy oil feedstock is 2-20% by weight, and the metal content is 0.1-200 mg / kg; preferably, the inferior heavy oil feedstock is selected from petroleum hydrocarbons and / or mineral oils, wherein the petroleum hydrocarbons are selected from one or more combinations of wax oil, residue oil, hydrogenated residue oil, inferior recycled oil, coal liquefaction oil, oil sands oil, biomass and plastic pyrolysis oil.

[0021] Through the above technical solution, the present invention enables the incomplete combustion of the spent catalyst with high carbon content in the first regeneration zone during the catalytic conversion of inferior heavy oil feedstock, so that the carbon deposits are converted into flue gas with higher CO selectivity, and the flue gas is used for bio-fermentation to produce ethanol and protein feed, thereby reducing the excess heat in the catalytic regeneration process and significantly reducing carbon dioxide emissions.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a flowchart illustrating a preferred embodiment of the present invention for treating inferior heavy oil catalytic conversion and regeneration flue gas.

[0025] Figure 2 This is a flowchart of a preferred embodiment of the catalytic conversion-regeneration unit of the present invention.

[0026] Figure 3 This is a flowchart of a preferred embodiment of the bio-fermentation unit provided by the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Regenerated gas; 2. Regenerator; 3. Regenerated catalyst; 4. Second flue gas; 5. Energy recovery unit; 6. Second flue gas; 7. Bio-fermentation unit; 8. Fermentation tail gas; 9. Ethanol; 10. Protein feed; 11. Steam;

[0029] 15. Purification device; 16. Purified flue gas; 17. Fermentation device; 18. Mash; 19. Distillation device; 20. Aqueous ethanol; 21. Ethanol dehydration device; 22. Bacterial residual distillate; 23. Protein separation device; 24. Protein concentrate; 25. Protein drying device;

[0030] 31. Inferior feedstock oil; 32. Catalytic conversion reactor; 33. Settler; 34. Reaction oil and gas; 35. Pre-regeneration inclined tube; 36. Second regeneration zone; 37. First regeneration zone; 38. Regeneration inclined tube; 39. First supplementary regeneration gas; 40. Pre-lifting medium; 41. External heat exchanger. Detailed Implementation

[0031] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0032] This invention provides a method for treating regenerated flue gas from the catalytic conversion of inferior heavy oil, the method comprising:

[0033] Inferior heavy oil feedstock is brought into contact with catalytic conversion catalyst in a catalytic conversion reactor to carry out catalytic conversion reaction. The reaction stream is separated to obtain reacted oil and gas and carbon deposits to be generated catalyst.

[0034] The catalyst to be generated is fed into the first regeneration zone of the regenerator for first regeneration to obtain first flue gas and semi-regenerated catalyst.

[0035] The first flue gas and the semi-regenerated catalyst are made to rise and enter the second regeneration zone of the regenerator for second regeneration, so as to obtain a regenerated catalyst and a second flue gas.

[0036] The second flue gas is fed into a biological fermentation unit to ferment the second flue gas, thereby obtaining ethanol, protein feed and fermentation tail gas;

[0037] The first regeneration zone is a rapid regeneration bed, and the second regeneration zone is a dilute phase bed; the regeneration temperature of the first regeneration zone is 600–900℃, and the bed density is 120–290 kg / m³. 3 .

[0038] This invention involves the incomplete combustion of the spent catalyst with high carbon content during the catalytic conversion of inferior heavy oil feedstock in a regenerator, which allows the carbon deposits to be converted into flue gas with higher CO selectivity. The flue gas is then used for bio-fermentation to produce ethanol and protein feed, reducing excess heat during catalytic regeneration and significantly lowering carbon dioxide emissions.

[0039] It should be noted that the separated reaction oil and gas can be sent to a subsequent separation system to obtain various catalytic conversion products. After separation by the subsequent separation system, fractions such as dry gas, liquefied petroleum gas, stable gasoline and catalytic diesel can be obtained. The separation method can be a conventional technique in the field, and this invention does not limit it, so it will not be described in detail here.

[0040] In this invention, the catalyst to be generated first enters the first regeneration zone and undergoes first regeneration by contacting regeneration gas, resulting in first flue gas and semi-regenerated catalyst. The first flue gas and semi-regenerated catalyst then ascend into the second regeneration zone for second regeneration, resulting in second flue gas and regenerated catalyst. The second flue gas exchanges heat with deoxygenated water or saturated steam before being sent to the bio-fermentation unit. The regenerated catalyst can be entirely recycled back to the catalytic conversion reactor. At least a portion of the catalytic conversion catalyst used in the catalytic conversion reaction is regenerated catalyst, preferably all of it. In some preferred embodiments of this invention, the regenerated catalyst obtained from the second regeneration is further degassed before being returned to the catalytic conversion reactor for recycling.

[0041] In some specific embodiments of the present invention, the regeneration temperature of the first regeneration zone can be 600℃, 650℃, 670.1℃, 680℃, 700℃, 740℃, 780℃, 800℃, 805.3℃, 850℃, or 900℃, or any temperature within the aforementioned range, or a temperature range composed of any two values. Furthermore, the bed density of the first regeneration zone can be 120 kg / m³.3 150kg / m 3 180kg / m 3 200kg / m 3 250kg / m 3 261kg / m 3 275kg / m 3 290kg / m 3 It can be any bed density within the aforementioned range, or any range of values ​​within the aforementioned range.

[0042] In some preferred embodiments of the present invention, the regenerator is provided with an external heat exchanger for regulating the regeneration temperature and generating steam. The type, connection and operation of the heat exchanger are well known to those skilled in the art.

[0043] In some embodiments of the present invention, the oxygen content in the regeneration gas introduced into the first regeneration zone is 20-100% by volume to improve the selectivity of CO in the second flue gas. For example, the oxygen content in the regeneration gas introduced into the first regeneration zone is 20% by volume, 21% by volume, 25% by volume, 25.33% by volume, 30% by volume, 35% by volume, 36.77% by volume, 40% by volume, 50% by volume, 60% by volume, 70% by volume, 80% by volume, 90% by volume, or 100% by volume, or any value within the aforementioned range, or any range of values.

[0044] In some embodiments of the present invention, the regenerated gas is selected from one or a mixture of several of air, oxygen-enriched air, oxygen, CO2 and fermentation exhaust gas.

[0045] It should be noted that when the regeneration gas introduced into the first regeneration zone is a mixture of one or more of the following: bio-fermentation exhaust gas, air, oxygen-enriched air, oxygen, and CO2, the bio-fermentation exhaust gas, air, oxygen-enriched air, oxygen, and CO2 can be mixed before entering the first regeneration zone, or they can enter the first regeneration zone separately. When they enter the first regeneration zone separately, the gas inlet can be located at the bottom, middle, or other heights of the first regeneration zone.

[0046] In some embodiments of the present invention, the method of the present invention can obtain a second flue gas rich in CO, wherein the CO content in the second flue gas is 10-50% by volume. By controlling the combustion conditions during the regeneration process of the inferior heavy oil catalytic conversion catalyst, the spent catalyst can be fully regenerated and a second flue gas rich in CO can be obtained, thereby increasing the CO content in the fermentation feed gas and reducing heat loss.

[0047] By controlling the regeneration conditions in the first regeneration zone, this invention can better convert the coke on the spent catalyst in the catalytic conversion into carbon monoxide, enabling the coke to be converted into flue gas with higher CO selectivity, significantly reducing CO2 emissions, and ensuring that the carbon content on the regenerated catalyst is no more than 0.15% by weight.

[0048] In some embodiments of the present invention, the conditions for the first regeneration include: a regeneration temperature of 680–800°C; an average catalyst residence time of 0.6–20 min, preferably 1–10 min; an apparent gas linear velocity of 0.8–2.5 m / s; and a bed density of 150–250 kg / m³. 3 By controlling the regeneration temperature and bed density in the first regeneration process, the coke deposits on the catalyst can be converted into CO. By controlling the average residence time of the catalyst and the apparent linear velocity of the gas, incomplete combustion of the coke can be achieved, while also taking into account the energy required for the regeneration process.

[0049] In some embodiments of the present invention, the conditions for the second regeneration include: a temperature of 600–750°C, preferably 650–700°C; an average catalyst residence time of 0.6–15 min, preferably 1–5 min; an apparent gas linear velocity of 3–15 m / s; and a bed density not exceeding 120 kg / m³. 3 The preferred value is 60–100 kg / m³. 3 .

[0050] In some embodiments of the present invention, the method for fermenting the second flue gas includes:

[0051] The second flue gas is purified to obtain purified flue gas.

[0052] The purified flue gas is fed into a fermenter, where it is fermented by acetic acid-producing bacteria to obtain fermentation mash and fermentation tail gas.

[0053] The fermentation mash was separated to obtain ethanol and protein feed.

[0054] Optionally, the method further includes: cooling the second flue gas before sending it to the bio-fermentation unit.

[0055] In some embodiments of the present invention, the microorganism used in the biofermentation process is a strain of *Clostridium autoethanogenum*, deposited at the German Microbiological and Cell Culture Collection (DSMZ) with accession number DSM19630; or the microorganism used is a pure biological isolate of *Clostridium autoethanogenum*, deposited at the DSMZ with accession number DSM23693. These microorganisms have been described in patent applications such as CN103415612A.

[0056] It should be noted that the gas purification device is used to remove trace amounts of dust, trace amounts of oxygen, ammonia nitrogen, sulfides, chlorides, and other impurities from the flue gas, while simultaneously pressurizing it to obtain purified flue gas; the fermentation device is used to ferment the purified flue gas to obtain mash and fermentation tail gas; the fermentation device includes, but is not limited to, stirred reactors, airlift reactors, or other similar bioreactors; the distillation device is used to distill the mash to obtain ethanol, bacterial residual distillate, and sterile residual distillate; the distillation device includes, but is not limited to, crude distillation columns, rectification columns, and combined columns, with the mash entering the crude distillation column, and the top distillate from the crude distillation column entering the rectification column and combined column; the ethanol obtained after distillation contains Some water needs to be removed by an ethanol dehydration device to obtain anhydrous ethanol. The ethanol dehydration device can use molecular sieve dehydration or vaporization permeation membrane dehydration. The anhydrous ethanol obtained by dehydration can be mixed with denaturant to obtain fuel ethanol, or it can be used as a chemical raw material for further synthesis and polymerization. The bacterial protein separation device is used to centrifuge and concentrate the bacterial residual water to obtain centrifuged concentrate and centrifuged clear liquid. The bacterial protein separation device includes, but is not limited to, horizontal screw centrifuge, disc centrifuge, plate and frame filter press and other devices for bacterial separation. The protein drying device is used to dry the centrifuged concentrate to obtain protein feed. The protein drying device includes, but is not limited to, spray drying and drum drying.

[0057] In some embodiments of the present invention, the method further includes: supplementing the bio-fermentation unit with hydrogen; the molar ratio of the supplemented hydrogen to CO in the second flue gas is (2-30):1, so as to fully ferment the second flue gas.

[0058] In some embodiments of the present invention, the carbon content on the regenerating agent is 1.2 to 4% by weight. The method provided by the present invention achieves effective utilization of carbon deposits and reduces carbon dioxide emissions by incompletely burning the regenerating agent with a high carbon content in the first regeneration zone and using the flue gas for bio-fermentation.

[0059] In some embodiments of the present invention, the conditions for the catalytic conversion reaction include: a reaction temperature of 450–700°C, preferably 500–650°C, more preferably 510–630°C; a reaction time of 1–10 seconds, preferably 2–5 seconds; and a weight ratio of the catalytic conversion catalyst to the inferior heavy oil feedstock of (1–100):1, preferably (5–30):1.

[0060] In some embodiments of the present invention, the catalytic conversion reactor is selected from one or a combination of two of the following: riser reactor, fast bed reactor, and fluidized bed reactor.

[0061] In some embodiments of the present invention, the residual carbon content in the inferior heavy oil feedstock is 2-20% by weight, and the metal content is 0.1-200 mg / kg.

[0062] In some embodiments of the present invention, the inferior heavy oil feedstock is selected from petroleum hydrocarbons and / or mineral oils, wherein the petroleum hydrocarbons are selected from one or more combinations of wax oil, residue oil, hydrogenated residue oil, inferior recycled oil, coal liquefaction oil, oil sands oil, biomass and plastic pyrolysis oil.

[0063] It should be noted that the method of the present invention has a wide range of applicability. The spent catalysts of carbon deposits generated from the catalytic conversion of the above-mentioned various hydrocarbon oil feedstocks can all be converted into flue gas with high CO selectivity through the above-mentioned regeneration process.

[0064] In some embodiments of the present invention, the catalytic conversion catalyst used in the catalytic conversion reaction may include 15-65% by weight of natural minerals, 10-30% by weight of inorganic oxides, and 25-75% by weight of zeolite.

[0065] The zeolite, as the active component, is preferably one or a mixture of more than one of the following: Y zeolite, mordenite, β zeolite, and zeolite with MFI structure (e.g., ZSM series zeolite and / or ZRP zeolite); the natural mineral is selected from one or more of kaolinite, hydrous kaolinite, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite, and rettoite; and the inorganic oxide is selected from one or more of silicon dioxide, aluminum oxide, zirconium oxide, titanium dioxide, and amorphous aluminum silicate.

[0066] In some embodiments of the present invention, the catalytic conversion reactor may be a conventional catalytic conversion reactor known to those skilled in the art. The catalytic conversion reactor may be selected from one or a combination of two of the following: a riser reactor, a fast bed reactor, and a fluidized bed reactor. For example, it may be a catalytic conversion riser reactor connected in series with a fluidized bed reactor.

[0067] The riser reactor can be selected from equal-diameter riser reactors and / or equal-linear-velocity riser reactors, with equal-diameter risers being preferred.

[0068] The fluidized bed reactor is located downstream of the riser reactor and connected to the outlet of the riser reactor. The riser reactor includes a pre-rise section and at least one reaction zone from bottom to top. In order to ensure that the feed oil can react fully and according to different product quality requirements, there can be 2 to 8 reaction zones, preferably 1 to 3.

[0069] In this invention, water vapor can also be injected into the catalytic conversion reactor. The water vapor is preferably injected in the form of atomized steam. The weight ratio of the injected water vapor to the hydrocarbon feedstock can be (0.01-1):1, preferably (0.05-0.25):1.

[0070] The method of the present invention can be implemented based on a system for the biological utilization of catalytic conversion flue gas, which includes a catalytic conversion reaction-regeneration unit, an energy recovery unit, and a bio-fermentation unit.

[0071] Figure 1 A flowchart illustrating a preferred embodiment of the present invention is shown below. Figure 1 The present invention provides a detailed description of the method for treating regenerated flue gas from the catalytic conversion of inferior heavy oil.

[0072] Regenerated gas 1 is introduced into regenerator 2 to contact the catalyst to be regenerated for regeneration, resulting in second flue gas 4 and regenerated catalyst 3. Regenerated catalyst 3 is recycled back to the catalytic conversion-regeneration unit to continue the reaction.

[0073] The second flue gas 4 is introduced into the energy recovery unit 5 for heat exchange, yielding steam 11 and cooled second flue gas 6. The cooled second flue gas 6 is then introduced into the biological fermentation unit 7 as fermentation feed gas, yielding fermentation tail gas 8, ethanol 9, and protein feed 10. Part of the fermentation tail gas 8 is recycled back to the regenerator 2 via pipeline.

[0074] Figure 2 This is a preferred embodiment of the catalytic conversion-regeneration unit. Inferior feedstock oil 31 is introduced into the catalytic conversion reactor 32, where it contacts the regenerated catalyst, which has been lifted by the pre-lifting medium 40 from the regeneration inclined tube 38, to undergo a catalytic conversion reaction. The reacted material undergoes gas-solid separation in the settling tank 33, yielding reacted oil gas 34 and a spent catalyst. The reacted oil gas 34 is fed into the oil gas stabilization system, while the spent catalyst enters the regenerator 2 via the spent catalyst inclined tube 35. In the first regeneration zone 37 of the regenerator 2, it undergoes a first regeneration process by contacting the regeneration gas, yielding first flue gas and a semi-regenerated catalyst. The regeneration gas includes fermentation tail gas 8 and first supplementary regeneration gas 39.

[0075] The first flue gas and the semi-regenerated catalyst rise into the second regeneration zone 36 of the regenerator 2 for a second regeneration, resulting in a regenerated catalyst and second flue gas 4. The regenerated catalyst is then heated by an external heat exchanger 41.

[0076] Figure 3 This is a preferred embodiment of the bio-fermentation unit in the method provided by the present invention. The cooled second flue gas 6 is introduced into the purification device 15 as the bio-fermentation feed gas for purification to remove impurities from the first flue gas. The resulting purified flue gas 16 is introduced into the fermentation device 17 via pipeline, where it is fermented by Clostridium difficile, a microorganism that produces its own ethanol, to obtain fermentation tail gas 8 and mash 18. The fermentation tail gas 8 is introduced into the first regeneration zone of the regenerator.

[0077] The mash 18 is fed into distillation apparatus 19 for separation to obtain aqueous ethanol 20 and bacterial residue 22. Aqueous ethanol 20 is fed into ethanol dehydration apparatus 21 for dehydration to obtain ethanol 9. Bacterial residue 22 is fed into protein separation apparatus 23 for separation to obtain concentrated protein 24. Concentrated protein 24 is then fed into protein drying apparatus 25 for drying to obtain protein feed 10.

[0078] The method provided by this invention can not only reduce carbon dioxide emissions from catalytic devices, but also produce ethanol and protein feed from flue gas through bio-fermentation, thereby achieving full utilization of resources, reducing pollution, and improving the economic and social benefits of the petrochemical industry.

[0079] The present invention will be further described in detail below through examples, but these examples are not intended to limit the invention. In the following examples, unless otherwise specified, the experimental instruments and raw materials involved are all commercially available products.

[0080] In the following examples, the first regeneration zone of the regenerator is a rapid phase bed, and the second regeneration zone is a dilute phase bed. The microorganism used in the biofermentation unit, Clostridium autoethanogenum, DSM 19630, was purchased from the German Culture Collection (DSMZ, Germany).

[0081] The inferior heavy oil feedstock used in the examples and comparative examples was hydrotreated residue oil, the properties of which are shown in Table 1.

[0082] Table 1

[0083]

[0084]

[0085] The catalytic conversion catalysts used in the examples and comparative examples are commercially available under the brand name CDOS, manufactured by Changling Branch of Sinopec Catalyst Co., Ltd., and their properties are shown in Table 2. Before use, they were hydrothermally aged at 800°C in 100% steam for 17 hours.

[0086] Table 2

[0087] Catalytic conversion catalyst CDOS Chemical composition, weight % <![CDATA[SiO2]]> 38.2 <![CDATA[Al2O3]]> 54.5 Physical properties <![CDATA[BET specific surface area, m 2 / g]]> 108 <![CDATA[Substrate area, m 2 / g]]> 60 <![CDATA[Micropore area, m 2 / g]]> 48 <![CDATA[Total pore volume, cm 3 / g]]> 0.181 <![CDATA[Micropore volume, cm 3 / g]]> 0.022 Activity (17h), % 54

[0088] Example 1

[0089] This embodiment illustrates the method for treating regenerated flue gas from the catalytic conversion of inferior heavy oil according to the present invention, including:

[0090] use Figures 1 to 3 The process shown was tested. Inferior heavy oil feedstock (properties shown in Table 1) was fed into a catalytic conversion reactor and contacted with regenerated catalyst from a regenerator for catalytic conversion. The reacted material underwent gas-solid separation in a settling tank, yielding reacted oil gas and a spent catalyst. The conditions in the catalytic conversion reactor included: a reaction temperature of 510℃, a catalyst-to-oil ratio of 6, and a reaction time of 3 seconds; the carbon content on the spent catalyst was 1.83% by weight.

[0091] The separated, unregenerated catalyst enters the first regeneration zone of the regenerator through an inclined tube, where it undergoes first regeneration by contacting the regeneration gas, yielding first flue gas and semi-regenerated catalyst. The conditions for the first regeneration include: a regeneration temperature of 700℃; a gas apparent linear velocity of 2 m / s; and a bed density of 250 kg / m³. 3 The average residence time of the catalyst was 8 min; the regeneration gas was O2 + CO2, including 63.23 vol% CO2 and 36.77 vol% O2.

[0092] The first flue gas and the semi-regenerated catalyst undergo a second regeneration in the second regeneration zone of the regenerator to obtain a regenerated catalyst and a second flue gas. The conditions for the second regeneration include: a regeneration temperature of 680℃; a gas apparent linear velocity of 4 m / s; and a bed density of 90 kg / m³. 3 The average residence time of the catalyst is 3 minutes.

[0093] The regenerated catalyst is circulated back to the catalytic conversion reactor via pipeline; the second flue gas is cooled and purified by heat exchange with saturated steam and then sent to the bio-fermentation unit for fermentation to obtain fermentation tail gas, ethanol and protein feed; the temperature in the fermenter is 30℃, the pressure is 0.5MPa, the cell concentration is 9.05g / L, and the first flue gas feed rate is 5.5SCFM.

[0094] The reaction conditions and results are shown in Table 3.

[0095] Example 2

[0096] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Example 1, except that the regeneration temperature in the first regeneration zone is 740℃. The reaction conditions and results are shown in Table 3.

[0097] Example 3

[0098] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Example 1, except that the regeneration temperature in the first regeneration zone is 670.1℃. The reaction conditions and results are shown in Table 3.

[0099] Example 4

[0100] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Example 1, except that the regeneration temperature in the first regeneration zone is 805.3℃ and the catalyst bed density is 261kg / m³. 3 The reaction conditions and results are shown in Table 3.

[0101] Comparative Example 1

[0102] The catalytic conversion method for inferior heavy oil in this comparative example follows the appendix. Figure 2 The experiment was conducted using a process in which the second flue gas was not fed into the bio-fermentation unit for fermentation; the regeneration gas introduced into the first regeneration zone was air, and the bed density in the first regeneration zone was 200 kg / m³. 3 The apparent linear velocity of the gas in the second regeneration zone is 2 m / s. The reaction conditions and results are shown in Table 3.

[0103] Comparative Example 2

[0104] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this comparative example is basically similar to that in Example 1, except that the regenerated gas introduced into the first regeneration zone contains 79% by volume CO2 and 21% by volume O2; and the bed density in the first regeneration zone is 80 kg / m³. 3 The apparent linear velocity of the gas in the second regeneration zone is 8 m / s, and the bed density is 80 kg / m³. 3 ;

[0105] The reaction conditions and results are shown in Table 3.

[0106] Table 3

[0107]

[0108]

[0109] As can be seen from the results in Table 3, the method of the present invention can reduce carbon dioxide emissions, increase the added value of CO in the regeneration flue gas of inferior feedstock oil catalyst, and also increase the proportion of CO in the second flue gas, thus meeting the conditions for bio-fermentation. In Examples 1-4 of this application, by changing the regeneration conditions in the first regeneration zone, the selectivity of CO in the second flue gas can be improved, thereby increasing the amount of ethanol in the bio-fermentation products and reducing CO2 emissions.

[0110] In existing technologies, air is directly used to burn off the coke from the spent catalyst for regeneration. The coke deposits on the spent catalyst are mainly converted into carbon dioxide, and the energy stored in the coke cannot be effectively utilized, further exacerbating the problem of exhaust gas treatment. Compared to Comparative Example 2, this invention, by controlling the regeneration conditions of the spent catalyst in the first regeneration zone, ensures sufficient contact between the regeneration gas and the spent catalyst in the first regeneration zone for incomplete regeneration, thereby improving the selectivity of CO in the second flue gas and helping to reduce carbon emissions.

[0111] Example 5

[0112] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Example 1, except that the regenerated gas introduced into the first regeneration zone is O2+CO2, including 74.67% CO2 and 25.33% O2 ​​by volume.

[0113] The reaction conditions and results are shown in Table 4.

[0114] Example 6

[0115] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Embodiment 1, except that: the regenerated gas introduced into the first regeneration zone is O2 + fermentation tail gas, including 74.67% by volume CO2 and 25.33% by volume O2; the bed density in the second regeneration zone is 200 kg / m³. 3 .

[0116] The reaction conditions and results are shown in Table 4.

[0117] Example 7

[0118] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Example 1, except that the regenerated gas introduced into the first regeneration zone is O2+CO2, including 79.00% CO2 and 21.00% O2 by volume.

[0119] The reaction conditions and results are shown in Table 4.

[0120] Example 8

[0121] The treatment method for the regenerated flue gas from the catalytic conversion of inferior heavy oil in this embodiment is basically similar to that in Example 5, except that the residence time of the catalyst in the first regeneration zone is 5 minutes. The reaction conditions and results are shown in Table 4.

[0122] Table 4

[0123]

[0124]

[0125] As can be seen from the results in Tables 3 and 4, compared with Example 1, Examples 5 and 7, by introducing regeneration gas with a lower O2 content into the first regeneration zone to perform incomplete regeneration of the carbonized catalyst, increased the amount of CO generated in the regeneration flue gas, thereby increasing the yield of ethanol and reducing CO2 emissions.

[0126] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0127] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0128] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for treating flue gas from the catalytic conversion and regeneration of inferior heavy oil, characterized in that, The method includes: Inferior heavy oil feedstock is brought into contact with catalytic conversion catalyst in a catalytic conversion reactor to carry out catalytic conversion reaction. The reaction stream is separated to obtain reacted oil and gas and carbon deposits to be generated catalyst. The catalyst to be generated is fed into the first regeneration zone of the regenerator for first regeneration to obtain first flue gas and semi-regenerated catalyst. The first flue gas and the semi-regenerated catalyst are made to rise and enter the second regeneration zone of the regenerator for second regeneration, so as to obtain a regenerated catalyst and a second flue gas. The second flue gas is fed into a biological fermentation unit to ferment the second flue gas, thereby obtaining ethanol, protein feed and fermentation tail gas; The first regeneration zone is a rapid regeneration bed, and the second regeneration zone is a dilute phase bed; the regeneration temperature of the first regeneration zone is 600–900℃, and the bed density is 120–290 kg / m³. 3 .

2. The processing method according to claim 1, wherein, The oxygen content in the regeneration gas introduced into the first regeneration zone is 20-100% by volume; Preferably, the regenerated gas is selected from one or a mixture of several of air, oxygen-enriched air, oxygen, CO2, and fermentation exhaust gas.

3. The processing method according to claim 1, wherein, The CO content in the second flue gas is 10-50% by volume.

4. The processing method according to claim 1, wherein, The conditions for the first regeneration include: a regeneration temperature of 680–800℃; an average catalyst residence time of 0.6–20 min, preferably 1–10 min; an apparent gas linear velocity of 0.8–2.5 m / s; and a bed density of 150–250 kg / m³. 3 .

5. The processing method according to claim 1, wherein, The conditions for the second regeneration include: a temperature of 600–750°C, preferably 650–700°C; an average catalyst residence time of 0.6–15 min, preferably 1–5 min; an apparent gas linear velocity of 3–15 m / s; and a bed density not exceeding 120 kg / m³. 3 The preferred value is 60–100 kg / m³. 3 .

6. The processing method according to claim 1, wherein, The method for fermenting the second flue gas includes: The second flue gas is purified to obtain purified flue gas. The purified flue gas is fed into a fermenter, where it is fermented by acetic acid-producing bacteria to obtain fermentation mash and fermentation tail gas. The fermentation mash was separated to obtain ethanol and protein feed; Optionally, the method further includes: cooling the second flue gas before sending it to the bio-fermentation unit.

7. The processing method according to claim 6, wherein, The method further includes: supplementing the bio-fermentation unit with hydrogen; the molar ratio of the supplemented hydrogen to CO in the second flue gas is (2-30):1; Preferably, the acetic acid bacteria are selected from one or a mixture of Clostridium autoethanogenum (DSMZ, Germany) with accession number DSM 19630 and Clostridium autoethanogenum (DSMZ, Germany) with accession number DSM 23693.

8. The processing method according to claim 1, wherein, The carbon content on the pre-generation agent is 1.2 to 4% by weight; Preferably, the carbon content on the regenerated catalyst is 0 to 0.15% by weight.

9. The utilization method according to claim 1, wherein, The conditions for the catalytic conversion reaction include: a reaction temperature of 450–700°C, preferably 500–650°C, more preferably 510–630°C; a reaction time of 1–10 seconds, preferably 2–5 seconds; and a weight ratio of the catalytic conversion catalyst to the inferior heavy oil feedstock of (1–100):1, preferably (5–30):

1. The catalytic conversion reactor is selected from one or a combination of two of the following: riser reactor, fast bed reactor, and fluidized bed reactor.

10. The processing method according to claim 1, wherein, The residual carbon content in the inferior heavy oil feedstock is 2-20% by weight, and the metal content is 0.1-200 mg / kg; Preferably, the inferior heavy oil feedstock is selected from petroleum hydrocarbons and / or mineral oils, wherein the petroleum hydrocarbons are selected from one or more combinations of wax oil, residue oil, hydrogenated residue oil, inferior recycled oil, coal liquefaction oil, oil sands oil, biomass and plastic pyrolysis oil.

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