Search

KR-20260062942-A - Method and system for producing low-carbon olefins from hydrocarbon feedstocks

KR20260062942AKR 20260062942 AKR20260062942 AKR 20260062942AKR-20260062942-A

Abstract

The present invention relates to a method for producing low-carbon olefins from hydrocarbon feedstocks, wherein the method comprises the steps of: contacting a hydrocarbon feedstock with a first catalyst in a dense fluidized bed of a first catalytic conversion reactor having a catalyst density of 100-700 kg/ m³ to generate a catalytic conversion reaction, setting the reaction temperature to 550-800°C to obtain a first reaction stream containing a reaction gas containing low-carbon olefins and a first catalyst to be regenerated; subsequently lowering the temperature of the first reaction stream to 450-530°C in a cooling zone; and separating and obtaining low-carbon olefins from the first reaction stream. In the present invention, by cooling the reaction stream in the cooling zone, the control of the catalytic decomposition reaction and the thermal decomposition reaction is optimized, and by immediately replenishing the heat of the reaction zone, deep reactions during the low-temperature reaction process are effectively suppressed, and the yield and selectivity of the low-carbon olefins are improved.

Inventors

  • 수 유하오
  • 리 하오톈
  • 바이 쉬후이
  • 왕 치페이
  • 양 원제
  • 왕 루이린

Assignees

  • 차이나 페트로리움 앤드 케미컬 코포레이션
  • 시노펙 리서치 인스티튜트 오브 페트롤리움 프로세싱 컴퍼니, 리미티드

Dates

Publication Date
20260507
Application Date
20240830
Priority Date
20230831

Claims (18)

  1. In a method for producing low-carbon olefins from hydrocarbon raw materials, In a dense fluidized bed of a first catalytic conversion reactor having a catalyst density of 100-700 kg/ m³ , a hydrocarbon feedstock is brought into contact with the first catalyst to generate a catalytic conversion reaction, and the reaction temperature is set to 550-800℃ to obtain a first reaction stream containing a low-carbon olefin-containing reaction gas and a first catalyst to be regenerated, and subsequently, the temperature of the first reaction stream is lowered to 450-530℃ in a cooling zone, and Subsequently, a low-carbon olefin is obtained by separating it from the first reaction stream above, and A method for producing a low-carbon olefin from a hydrocarbon feedstock, characterized by including the step of cooling a first reaction stream by installing a cooling zone at a location where the catalyst density is reduced to 80% to 20% of the catalyst density in the mill fluidized bed, preferably at a location where the catalyst density is reduced to 70% to 30% of the catalyst density in the mill fluidized bed.
  2. In paragraph 1, In the above cooling zone, Cooling is performed using a cooling medium; said cooling medium is cooling water and/or a cooling catalyst; said cooling water is at least one selected from liquefied gas, refined gasoline, stabilized gasoline, diesel, heavy diesel, water, and olefins having eight or more carbon atoms; or A method for producing a low-carbon olefin from a hydrocarbon raw material, wherein the temperature is lowered using a heat remover; and the cooling water in the heat remover is at least one selected from liquefied gas, refined gasoline, stabilized gasoline, diesel, heavy diesel, water, and an olefin having eight or more carbon atoms.
  3. In paragraph 1 or 2, A method for producing low-carbon olefins from hydrocarbon feedstocks, wherein, during the reaction, heat is supplied to a fluidized bed; preferably, said heat supply is carried out using a heating medium and/or a thermal catalyst; said heating medium is at least one of high-temperature steam and steam decomposition gas.
  4. In any one of paragraphs 1 through 3, A method for producing a low-carbon olefin from a hydrocarbon feedstock, wherein in a cooling zone, the temperature of the first reaction stream is lowered to 450-530°C within 0.5-2 seconds, preferably 0.5-1 second, and preferably to 480-500°C.
  5. In any one of paragraphs 1 through 4, A method for producing low-carbon olefins from hydrocarbon feedstocks, wherein the catalyst density in the first catalytic conversion reactor of the first catalyst in the first catalytic conversion reactor is 300-600 kg/ m³ , preferably 400-500 kg/ m³ .
  6. In any one of paragraphs 1 through 5, The conditions of the catalytic conversion reaction include a reaction temperature of 600-700 ℃, preferably 650-700 ℃; a reaction time of 0.1-20 s, preferably 0.1-10 s, more preferably 0.2-5 s, particularly preferably 0.2-0.5 s; and a reaction pressure of 0.05-2 MPa, preferably 0.1-1 MPa, more preferably 0.1-0.6 MPa; A method for producing low-carbon olefins from hydrocarbon raw materials, wherein the weight ratio of the catalyst to the hydrocarbon raw material is (1-200):1, preferably (10-100):1.
  7. In any one of paragraphs 1 through 6, The above-mentioned first catalytic conversion reactor sequentially comprises a first lifting section, an expanding section, a dense fluidized bed section, a cooling zone, a shrinking section, and a second lifting section from bottom to top; The angle between the side wall and the axis of the above-mentioned enlarged section is 5-60 degrees; The ratio of diameter to height of the above-mentioned dense fluidized bed section is (0.1-20):1, preferably (0.1-10):1; The angle between the side wall and the axis of the above-mentioned axial section is 5-60 degrees; The head portion of the first lifting section is equipped with a thermal catalyst inlet and a lifting medium inlet; A raw material inlet is installed in the middle portion of the first lifting section, or a raw material inlet is installed on the side wall of the expansion section; A gas-solid mixed fluid distributor is further installed at the end of the first lifting section; A method for producing low-carbon olefins from hydrocarbon feedstocks, wherein the cooling zone is installed downstream of the above-mentioned mill fluidized bed section and is installed at a location where the catalyst density is reduced to 80% to 20% of the catalyst density in the mill fluidized bed, and preferably at a location where the catalyst density is reduced to 70% to 30% of the catalyst density in the mill fluidized bed.
  8. In any one of paragraphs 1 through 7, Based on the total weight of the first catalyst, the first catalyst comprises 1-50 wt% molecular sieve, 5-99 wt% inorganic oxide, and 0-70 wt% clay; and/or The above molecular sieve is at least one selected from ZSM-5 series molecular sieves and SAPO series molecular sieves; preferably, it is a mesoporous ZSM-5 series molecular sieve; more preferably, it is at least one selected from ZSM5, ZSM11, ZSM12, ZSM23, ZSM35, ZSM38, ZSM48, SAPO34, SAPO11, and SAPO47; and/or The Si/Al ratio of the above molecular sieve is 10-1000; and/or The above inorganic oxide is one or more selected from silicon dioxide and aluminum oxide; and/or A method for producing low-carbon olefins from hydrocarbon raw materials, wherein the clay is one or more selected from kaolin, halloysite, montmorillonite, diatomite, saponite, rectolite, sepiolite, atapulgite, hydrotalcite, and bentonite.
  9. In any one of paragraphs 1 through 8, The above hydrocarbon raw material is introduced in a gaseous state; and/or The content of C5 - C8 olefins in the above hydrocarbon raw materials is 50-100 wt%, preferably 80-100 wt%, more preferably 90-100 wt%; and/or The above hydrocarbon feedstocks include C5 or higher fractions produced from an alkane dehydrogenation unit, C5 or higher fractions produced from a refinery catalytic cracking unit, C5 or higher fractions produced from an ethylene plant steam cracking unit, C5 or higher olefin-rich fractions that are MTO byproducts, and A method for producing low-carbon olefins from a hydrocarbon feedstock, wherein at least one is selected from an olefin-rich fraction of C 5 or higher that is an MTP byproduct.
  10. In any one of paragraphs 1 through 9, The above method comprises the step of performing gas-solid separation on the cooled first reaction stream to obtain a low-carbon olefin-containing reaction gas and a first catalyst to be regenerated, performing coke combustion regeneration treatment on the first catalyst to be regenerated, and then returning it to the first catalyst conversion reactor as the first catalyst to be regenerated; A step of fractionating the above low-carbon olefin-containing reaction gas to obtain low-carbon olefin and olefin-rich raw material streams; A method for producing low-carbon olefins from hydrocarbon raw materials, further comprising the step of recirculating the above olefin-rich raw material stream to use as a hydrocarbon raw material.
  11. In any one of paragraphs 1 through 10, The above method is, A step of obtaining a second reaction stream containing a light oil-containing reaction gas and a second regeneration target catalyst by contacting heavy hydrocarbon oil with a second catalyst in a second catalytic conversion reactor to carry out a second catalytic conversion reaction; A step of mixing a second reaction stream containing the light oil-containing reaction gas and the second regeneration target catalyst with a first reaction stream, and performing a first separation on the mixed mixed stream to obtain a mixed reaction stream containing low-carbon olefin and a mixed regeneration target catalyst; A method for producing low-carbon olefins from hydrocarbon raw materials, comprising: a step of fractionating a mixed reaction stream containing the low-carbon olefin to separate dry gas, low-carbon olefins, and a fraction of C5 or higher, and performing a second separation on the fraction of C5 or higher and returning the separated olefin-rich raw material stream to the first catalytic conversion reactor; and a step of performing coke combustion regeneration on the mixed regeneration target catalyst, and returning the catalyst after regeneration to the first catalytic conversion reactor as a first regeneration catalyst and to the second catalytic conversion reactor as a second regeneration catalyst.
  12. In Paragraph 11, The above heavy hydrocarbon oil is at least one selected from vacuum gas oil (VGO), atmospheric gas oil (AGO), coking gas oil (CGO), deasphalted oil (DAO), vacuum residue oil (VR), atmospheric residue oil (AR), heavy aromatic raffinate oil, liquefied coal oil, oil sands oil, and shale oil; and/or The conditions of the second catalytic conversion reaction described above comprise a reaction temperature of 500-600 °C, preferably 530-580 °C; a reaction pressure of 0.01-1 MPa, preferably 0.05-1 MPa; and a reaction time of 0.01-80 s, preferably 0.1-60 s; and/or A method for producing low-carbon olefins from hydrocarbon feedstocks, wherein the weight ratio of the second catalyst and the heavy hydrocarbon oil is (1-100):1, preferably (3-50):1.
  13. In Article 11 or Article 12, A method for producing low-carbon olefins from hydrocarbon raw materials, wherein a second cooling zone is installed downstream of the reaction zone of the second catalytic conversion reactor, and when the temperature of the second reaction stream containing the light oil-containing reaction gas and the second regeneration target catalyst in the second catalytic conversion reactor exceeds 530°C, the temperature of the second reaction stream is lowered to 530°C or lower.
  14. In a system for producing low-carbon olefins from hydrocarbon raw materials, The above system includes a first catalytic conversion reactor, and The first catalytic conversion reactor above sequentially includes a first lifting section, an expanding section, a dense fluidized bed section, a cooling zone, a shrinking section, a second lifting section, and an upper outlet from bottom to top; The angle between the side wall and the axis of the above-mentioned enlarged section is 5-60 degrees; The ratio of diameter to height of the above-mentioned dense fluidized bed section is (0.1-20):1, preferably (0.1-10):1; The angle between the side wall and the axis of the above-mentioned axial section is 5-60 degrees; A catalyst inlet and a lifting medium inlet are installed in the head portion of the first lifting section; A raw material inlet is installed in the middle portion of the first lifting section; or a raw material inlet is installed on the side wall of the expansion section; A gas-solid mixed fluid distributor is further installed at the end of the first lifting section; A system for producing low-carbon olefins from hydrocarbon raw materials, characterized in that the cooling zone is installed downstream of the above-mentioned mill fluidized bed section and is installed at a location where the catalyst density is reduced to 80% to 20% of the catalyst density in the mill fluidized bed, and preferably at a location where the catalyst density is reduced to 70% to 30% of the catalyst density in the mill fluidized bed.
  15. In Paragraph 14, A fluid distributor for introducing a cooling medium is installed in the above cooling zone, and the fluid distributor is installed annularly along the circumferential direction of the catalytic conversion reactor, or A system for producing low-carbon olefins from hydrocarbon raw materials, wherein a heat remover installed along the circumferential direction of the catalytic conversion reactor is installed in the cooling zone above.
  16. In paragraph 14 or 15, An immediate heat supplementation system is installed in the above-mentioned fluidized bed section, and the immediate heat supplementation system includes a catalyst supplement pipe for introducing heat into the above-mentioned fluidized bed section, or The above-mentioned immediate heat supplementation system is a system for producing low-carbon olefins from hydrocarbon raw materials, comprising a heat supply unit installed in the above-mentioned fluidized bed section.
  17. In any one of paragraphs 14 through 16, It further includes a regenerator, a sedimentation tank, a separation tower, and an alkane-olefin separation device, The upper outlet of the first catalytic conversion reactor is connected to the inlet of the sedimentation tank, the catalyst outlet of the sedimentation tank is connected to the regenerator, the reaction gas outlet of the sedimentation tank is connected to the inlet of the separation tower, and the outlet of the separation tower is connected to the inlet of the alkane-olefin separation device. The olefin-containing oil outlet of the above-mentioned alkane-olefin separation device is connected to the raw material inlet of the above-mentioned first catalytic conversion reactor, and A system for producing low-carbon olefins from hydrocarbon raw materials, wherein the regeneration catalyst outlet of the above-mentioned regenerator is connected to the catalyst inlet of the above-mentioned first catalytic conversion reactor.
  18. In any one of paragraphs 14 through 17, It further includes a second catalytic conversion reactor, wherein the second catalytic conversion reactor is a lift tube reactor, and The lift tube reactor of the second catalytic conversion reactor is equipped with a lower heavy hydrocarbon oil raw material inlet, a bottom catalyst inlet, a free-lifting medium inlet, and an upper outlet. The upper outlet of the second catalytic conversion reactor is connected to the inlet of the sedimentation tank, and A system for producing low-carbon olefins from hydrocarbon raw materials, wherein the regeneration catalyst outlet of the regenerator is connected to the catalyst inlet of the first catalytic conversion reactor and the catalyst inlet of the second catalytic conversion reactor.

Description

Method and system for producing low-carbon olefins from hydrocarbon feedstocks The present invention relates to the field of petrochemicals, and specifically, to a method for producing low-carbon olefins from hydrocarbon raw materials and a system for carrying out the same. Low-carbon olefins are important raw materials for organic chemicals, and their consumption continues to show a trend of continuous increase. Technologies for producing low-carbon olefins from petroleum include steam cracking, fluid catalytic cracking in refineries, catalytic cracking, alkane dehydrogenation, and olefin disproportionation. A typical process for producing low-carbon olefins involves steam cracking to produce ethylene and propylene, which requires the consumption of large quantities of light hydrocarbons for the chemical industry, such as naphtha. However, Chinese crude oil tends to be heavy, so the production capacity of light oils for the chemical industry is currently insufficient to meet the demand for raw materials for low-carbon olefin production. Furthermore, as demand increases, it has become difficult to satisfy the market demand for low-carbon olefins using traditional steam cracking processes. Chinese published patent CN114763483A discloses a catalytic conversion method for producing ethylene and propylene, effectively increasing the yield of ethylene and propylene and lowering the selectivity of methane in the product by replacing alkane feedstocks with olefin-rich feedstocks. Chinese published patent CN115108876A discloses a catalytic conversion method for producing low-carbon olefins using organic oxygen-containing compounds as part of the feedstock, and by reacting olefin-rich feedstocks, heavy feedstocks, and organic oxygen-containing compound feedstocks in different reaction zones of a catalytic conversion reactor, the effects of each process line are fully utilized to improve the production volume and selectivity of low-carbon olefins (especially ethylene and propylene). In order to meet the demands of the petrochemical industry while simultaneously achieving corporate goals of quality improvement and increased efficiency, the field has been developing process lines to produce low-carbon olefins by cracking high-carbon olefins with five or more carbon atoms during the refining process. However, the yield and selectivity of low-carbon olefins in existing processes still require further improvement. The drawings are provided to aid in a further understanding of the present invention, constitute part of this specification, and are intended to be used to interpret the present invention together with the specific embodiments below, but are not intended to limit the present invention. FIG. 1 is a schematic diagram of one embodiment of a catalytic conversion reactor provided by the present invention. FIG. 2 is a schematic diagram of another embodiment of the catalytic conversion reactor provided in the present invention. FIG. 3 is a schematic diagram of another embodiment of the catalytic conversion reactor provided in the present invention. FIG. 4 is a schematic diagram of another embodiment of the catalytic conversion reactor provided in the present invention. FIG. 5 is a schematic diagram of one embodiment of a method for producing low-carbon olefins from hydrocarbon raw materials provided in the present invention. FIG. 6 is a schematic diagram of another embodiment of the method for producing low-carbon olefins from hydrocarbon raw materials provided in the present invention. Specific embodiments of the present invention are described in detail below. However, it should be noted that the scope of protection of the present invention is not limited by these specific embodiments but is determined by the appended claims. Within the context of the present invention, all unmentioned matters or details other than those explicitly described shall be directly applied without modification to matters known in the relevant field. Furthermore, any embodiment described herein may be freely combined with one or more other embodiments described herein, and any technical solution or concept formed thereby shall be deemed part of the initial disclosure or initial description of the present invention and shall not be deemed as new content not disclosed or anticipated in the present specification unless a person skilled in the art determines that the combination is clearly unreasonable. Unless otherwise specified, all percentages, parts, ratios, etc. mentioned herein are based on weight, except where basing them on weight does not conform to the common understanding of those skilled in the art. Specific embodiments of the present invention are described in detail below. However, it should be noted that the scope of protection of the present invention is not limited by such specific embodiments but is determined by the appended claims. In the context of the present invention, unless otherwise specified, all physical properties o