CN110964559B - A catalytic cracking method and device for producing light olefins - Google Patents

Abstract

Translated fromChinese

本发明涉及一种生产低碳烯烃的催化裂化方法和装置，该方法包括：将第一重质原料引入第一提升管反应器的下部与来自第一提升管反应器底部的第一催化裂化催化剂接触并进行第一催化裂化反应；将第二重质原料引入第二提升管反应器第一反应段的下部与来自第一反应段底部的第二催化裂化催化剂接触并进行第二催化裂化反应；将第一反应段所得反应油剂送入第二反应段中并与来自第二反应段下部的齐聚烯烃一起在第二反应段中进行第三催化裂解反应，得到第二反应产物和第二待生催化剂。采用本发明的方法和装置进行催化裂化，乙烯、丙烯和轻芳烃产率高。

The invention relates to a catalytic cracking method and device for producing light olefins. The method comprises: introducing a first heavy feedstock into the lower part of a first riser reactor and a first catalytic cracking catalyst from the bottom of the first riser reactor contacting and carrying out the first catalytic cracking reaction; introducing the second heavy raw material into the lower part of the first reaction section of the second riser reactor to contact the second catalytic cracking catalyst from the bottom of the first reaction section and carry out the second catalytic cracking reaction; The reaction oil obtained in the first reaction section is sent into the second reaction section and the third catalytic cracking reaction is carried out in the second reaction section together with the oligomeric olefin from the lower part of the second reaction section to obtain the second reaction product and the second reaction product. waiting catalyst. Using the method and device of the invention for catalytic cracking, the yields of ethylene, propylene and light aromatic hydrocarbons are high.

Description

Translated fromChinese

一种生产低碳烯烃的催化裂化方法和装置A catalytic cracking method and device for producing light olefins

技术领域technical field

本发明涉及一种生产低碳烯烃的催化裂化方法和装置。The present invention relates to a catalytic cracking method and device for producing light olefins.

背景技术Background technique

低碳烯烃(乙烯、丙烯)和轻芳烃(苯、甲苯和二甲苯，简称BTX)是基本的化工原料。目前，BTX主要来源于轻烃重整工艺和蒸汽热裂解工艺，低碳烯烃主要来源于天然气、轻质石油烃类蒸汽热裂解和烃油催化裂化。随着原油的重质化，轻烃原料缺乏日益严重，以重油为原料通过催化裂化生产低碳烯烃的技术路线逐渐受到重视。然而，常规的催化裂化工艺低碳烯烃和芳烃的产率不高，其低碳烯烃产率不超过重油原料的15％。Light olefins (ethylene, propylene) and light aromatics (benzene, toluene and xylene, referred to as BTX) are the basic chemical raw materials. At present, BTX mainly comes from light hydrocarbon reforming process and steam thermal cracking process, and low-carbon olefins mainly come from natural gas, light petroleum hydrocarbon steam thermal cracking and hydrocarbon oil catalytic cracking. With the heavierization of crude oil, the shortage of light hydrocarbon raw materials is becoming more and more serious. However, the yield of light olefins and aromatics in the conventional catalytic cracking process is not high, and the yield of light olefins does not exceed 15% of the heavy oil feedstock.

中国专利CN104560154A公开了一种多产低碳烯烃和轻芳烃的烃类催化转化方法，该方法将重质烃类原料与催化剂在第一提升管反应器接触反应，将轻汽油组分和C4组分注入第二提升管的上游，将馏程为200-390℃的中质烃类原料注入第二提升管的中部，在580～680℃的条件下进行催化裂化反应；将第二反应器中产生的反应混合物引入流化床反应器继续反应。Chinese patent CN104560154A discloses a method for catalytic conversion of hydrocarbons with high yields of light olefins and light aromatic hydrocarbons. The method contacts and reacts heavy hydrocarbon feedstocks and catalysts in a first riser reactor, and converts light gasoline components and C4 groups into It is injected into the upstream of the second riser, and the medium hydrocarbon feedstock with the distillation range of 200-390°C is injected into the middle of the second riser, and the catalytic cracking reaction is carried out under the condition of 580-680°C; The resulting reaction mixture is introduced into the fluidized bed reactor to continue the reaction.

中国专利CN1237477A公布了一种用于流化催化转化的提升管反应器，该反应器沿垂直方向从下至上依次为互为同轴的预提升段、第一反应区、直径扩大了的第二反应区、直径缩小了的出口区，在出口区末端有一水平管。该反应器既可以控制第一反应区和第二反应区的工艺条件不同，又可以使不同性能的重油原料进行分段裂化，得到所需目的产品。Chinese patent CN1237477A discloses a riser reactor for fluidized catalytic conversion. The reactor consists of a coaxial pre-lift section, a first reaction zone, and a second enlarged diameter along the vertical direction from bottom to top. The reaction zone, the outlet zone of reduced diameter, has a horizontal tube at the end of the outlet zone. The reactor can not only control the process conditions of the first reaction zone and the second reaction zone to be different, but also carry out staged cracking of heavy oil feedstocks with different properties to obtain the desired target product.

美国专利US5009769中公开的烃类裂化方法采用双提提升管反应器裂化不同性质的烃类原料。蜡油和渣油注入第一根提升管，在剂油重量比5-10、停留时间1-4秒的条件下裂化；直馏汽油、直馏中间馏分油和催化重汽油注入第二根提升管，在剂油重量比3-12、停留时间1-5秒的条件下裂化。两根提升管末端进入同一个沉降器中，且共用后续分馏系统。The hydrocarbon cracking process disclosed in US Pat. No. 5,009,769 utilizes a double lift riser reactor to crack hydrocarbon feedstocks of different properties. Wax oil and residual oil are injected into the first riser, and cracked under the conditions of a weight ratio of 5-10 to oil and a residence time of 1-4 seconds; straight-run gasoline, straight-run middle distillate and catalytic heavy gasoline are injected into the second riser Pipe, cracked under the conditions of agent oil weight ratio of 3-12 and residence time of 1-5 seconds. The ends of the two risers enter the same settler and share the subsequent fractionation system.

中国专利CN1299403A公开了一种由重质烃原料选择性生产C2-C4烯烃的两段催化裂化方法。该方法包括：在常规大孔沸石催化裂化催化剂存在下，在由催化裂化装置组成的第一反应段中将重质原料转化成较低沸点产物。将所生成的较低沸点产物中的石脑油馏分进入由反应区、汽提区、催化剂再生区和分馏区组成的第二反应段中，在500-600℃温度下与含约10-50重量％平均孔径小于约0.7纳米的沸石催化剂接触形成裂化产物。Chinese patent CN1299403A discloses a two-stage catalytic cracking method for selectively producing C2-C4 olefins from heavy hydrocarbon feedstocks. The method includes converting the heavy feedstock to lower boiling products in a first reaction section consisting of a catalytic cracking unit in the presence of a conventional large pore zeolite catalytic cracking catalyst. The naphtha fraction in the resulting lower boiling point product is entered into the second reaction section consisting of a reaction zone, a stripping zone, a catalyst regeneration zone and a fractionation zone, and at a temperature of 500-600 ° C with a mixture containing about 10-50 The wt % zeolite catalyst having an average pore size less than about 0.7 nanometers is contacted to form a cracked product.

美国专利US7323099公开了一种选择性生产低碳烯烃的两段催化裂化方法。在第一反应区，重质原料在含大孔和中孔分子筛催化剂的催化转化下，生产富含烯烃的汽油组分，第一反应区生成的富含烯烃汽油组分再在第二反应区在含中孔分子筛催化剂的催化转化下，生成低碳烯烃。US Patent US7323099 discloses a two-stage catalytic cracking process for the selective production of light olefins. In the first reaction zone, the heavy feedstock is catalyzed by a catalyst containing macropore and mesopore molecular sieves to produce an olefin-rich gasoline component, and the olefin-rich gasoline component generated in the first reaction zone is regenerated in the second reaction zone. Under the catalytic conversion of a catalyst containing a mesoporous molecular sieve, light olefins are generated.

以上技术虽然在增加催化裂化丙烯产率方面取得了比较明显的进步，然而其增加催化裂化丙烯选择性和产率的局限性依然很大。Although the above technologies have made significant progress in increasing the catalytically cracked propylene yield, they still have great limitations in increasing the catalytically cracked propylene selectivity and yield.

发明内容SUMMARY OF THE INVENTION

本发明的目的是提供一种生产低碳烯烃的催化裂化方法和装置，采用本发明的方法和装置进行催化裂化，乙烯、丙烯和轻芳烃产率高。The purpose of the present invention is to provide a catalytic cracking method and device for producing low-carbon olefins, and the method and device of the present invention are used for catalytic cracking, and the yields of ethylene, propylene and light aromatics are high.

为了实现上述目的，本发明提供一种生产低碳烯烃的催化裂化方法，该方法包括：In order to achieve the above object, the present invention provides a catalytic cracking method for producing light olefins, the method comprising:

将第一重质原料引入第一提升管反应器的下部与来自第一提升管反应器底部的第一催化裂化催化剂接触并进行第一催化裂化反应，得到第一反应产物和第一待生催化剂；The first heavy raw material is introduced into the lower part of the first riser reactor to contact the first catalytic cracking catalyst from the bottom of the first riser reactor and carry out the first catalytic cracking reaction to obtain the first reaction product and the first to-be-grown catalyst ;

将第二重质原料引入第二提升管反应器第一反应段的下部与来自第一反应段底部的第二催化裂化催化剂接触并进行第二催化裂化反应；其中，所述第二提升管反应器由下至上包括流体连通的第一反应段和第二反应段，且第一反应段的内径小于第二反应段的内径；The second heavy feedstock is introduced into the lower part of the first reaction section of the second riser reactor to contact the second catalytic cracking catalyst from the bottom of the first reaction section and carry out a second catalytic cracking reaction; wherein, the second riser reaction The device includes a first reaction section and a second reaction section in fluid communication from bottom to top, and the inner diameter of the first reaction section is smaller than the inner diameter of the second reaction section;

将第一反应段所得反应油剂送入所述第二反应段中并与来自第二反应段下部的齐聚烯烃一起在第二反应段中进行第三催化裂化反应，得到第二反应产物和第二待生催化剂；The reaction oil obtained in the first reaction section is sent into the second reaction section and the third catalytic cracking reaction is carried out in the second reaction section together with the oligomeric olefin from the lower part of the second reaction section to obtain the second reaction product and the second to-be-grown catalyst;

将所得第一反应产物、第一待生催化剂、第二反应产物和第二待生催化剂进行分离，所得第一待生催化剂和第二待生催化剂引入再生器中进行再生，得到再生催化剂；Separating the obtained first reaction product, the first waiting catalyst, the second reaction product and the second waiting catalyst, and introducing the obtained first waiting catalyst and the second waiting catalyst into a regenerator for regeneration to obtain a regenerated catalyst;

将所得再生催化剂作为第一催化裂化催化剂和第二催化裂化催化剂返回第一提升管反应器和第二提升管反应器；returning the obtained regenerated catalyst to the first riser reactor and the second riser reactor as the first catalytic cracking catalyst and the second catalytic cracking catalyst;

将第一反应产物和第二反应产物进行分离，得到干气产物、液化气产物、汽油产物、柴油产物和重油产物。The first reaction product and the second reaction product are separated to obtain a dry gas product, a liquefied gas product, a gasoline product, a diesel product and a heavy oil product.

可选的，以齐聚烯烃的重量为基准，所述齐聚烯烃中C8-C10烯烃含量不低于60重量％。Optionally, based on the weight of the oligomeric olefin, the content of C8-C10 olefins in the oligomeric olefin is not less than 60% by weight.

可选的，所述齐聚烯烃制备步骤包括：Optionally, the oligomeric olefin preparation step includes:

将C4烃和/或C5烃与齐聚催化剂在齐聚反应器中接触并进行齐聚反应，得到齐聚产物；将齐聚产物在30-80℃下进行气液分离，得到含有C4烃和/或C5烃的气体产物和液态的所述齐聚烯烃。The C4 hydrocarbons and/or C5 hydrocarbons are contacted with the oligomerization catalyst in an oligomerization reactor and oligomerization is carried out to obtain an oligomerization product; /or gaseous product of C5 hydrocarbons and said oligomeric olefin in liquid state.

可选的，所述齐聚反应的条件包括：反应温度为200-400℃，反应压力为2-5兆帕，液时体积空速为0.5-4小时^-1；所述齐聚催化剂含有MFI结构的分子筛；所述齐聚反应器为固定床反应器或流化床反应器。Optionally, the conditions of the oligomerization reaction include: the reaction temperature is 200-400 ° C, the reaction pressure is 2-5 MPa, and the liquid hourly volume space velocity is 0.5-4 h^-1 ; the oligomerization catalyst contains MFI Structured molecular sieve; the oligomerization reactor is a fixed bed reactor or a fluidized bed reactor.

可选的，所述C4烃和/或C5烃来自催化裂化、蒸汽裂解、焦化和甲醇制烯烃中的一种或多种工艺。Optionally, the C4 hydrocarbons and/or C5 hydrocarbons come from one or more processes of catalytic cracking, steam cracking, coking and methanol to olefins.

可选的，所述C4烃和/或C5烃由第一反应产物和/或第二反应产物进行分离所得。Optionally, the C4 hydrocarbons and/or C5 hydrocarbons are obtained by separating the first reaction product and/or the second reaction product.

可选的，所述第一重质原料选自加氢尾油、减压瓦斯油、原油、渣油、煤液化油、油砂油、页岩油和动植物油脂中的一种或多种；所述第二重质原料选自加氢尾油、减压瓦斯油、原油、渣油、煤液化油、油砂油、页岩油、动植物油脂和所述重油产物中的一种或多种；所述重油产物的馏程为330-550℃。Optionally, the first heavy raw material is selected from one or more of hydrogenated tail oil, vacuum gas oil, crude oil, residual oil, coal liquefied oil, oil sand oil, shale oil and animal and vegetable oils and fats. The second heavy raw material is selected from hydrogenation tail oil, vacuum gas oil, crude oil, residual oil, coal liquefied oil, oil sand oil, shale oil, animal and vegetable oil and the heavy oil product one or A variety of; the distillation range of the heavy oil product is 330-550 ℃.

可选的，所述第一催化裂化反应的条件包括：反应温度为450-550℃，停留时间为0.1-5秒，剂油重量比为4-15，催化剂密度为50-100千克/米³；Optionally, the conditions of the first catalytic cracking reaction include: the reaction temperature is 450-550° C., the residence time is 0.1-5 seconds, the weight ratio of catalyst oil is 4-15, and the catalyst density is 50-100 kg/^m3 ;

所述第二催化裂化反应的条件包括：反应温度为520-640℃，停留时间为0.1-2秒，剂油重量比为4-15，催化剂密度为50-100千克/米³；The conditions of the second catalytic cracking reaction include: the reaction temperature is 520-640° C., the residence time is 0.1-2 seconds, the weight ratio of the catalyst to oil is 4-15, and the catalyst density is 50-100 kg/m³ ;

所述第三催化裂化反应的反应条件包括：反应温度为510-630℃，停留时间为0.1-5秒，剂油重量比为5-25，催化剂密度为100-300千克/米³。The reaction conditions of the third catalytic cracking reaction include: the reaction temperature is 510-630° C., the residence time is 0.1-5 seconds, the weight ratio of catalyst oil is 5-25, and the catalyst density is 100-300 kg/m³ .

可选的，所述第一重质原料与第二重质原料单位时间的进料重量比为1：(0.01-0.35)，所述第一重质原料与齐聚烯烃的单位时间进料重量比为1：(0.03-0.3)。Optionally, the feeding weight ratio of the first heavy raw material to the second heavy raw material per unit time is 1: (0.01-0.35), and the feeding weight per unit time of the first heavy raw material and the oligomeric olefin The ratio is 1:(0.03-0.3).

可选的，所述第一反应段的上部从所述第二反应段的底部伸入所述第二反应段中；Optionally, the upper part of the first reaction section extends into the second reaction section from the bottom of the second reaction section;

所述第一反应段的顶部封口，所述第一反应段上部的侧壁设置有多个通过反应油剂的开口。The top of the first reaction section is sealed, and the side wall of the upper part of the first reaction section is provided with a plurality of openings for passing the reaction oil.

可选的，所述方法还包括：Optionally, the method further includes:

将所得汽油产物或汽油产物的部分馏分进行加氢精制处理，得到加氢精制汽油；其中，所述汽油产物的部分馏分的初馏点为70-85℃，终馏点为140-150℃；所述加氢精制处理的条件包括：氢分压为2-15兆帕，反应温度为200-400℃，氢油体积比为100-1000，体积空速为0.5-5小时^-1；The obtained gasoline product or a partial fraction of the gasoline product is subjected to hydrorefining treatment to obtain hydrorefined gasoline; wherein, the initial boiling point of the partial fraction of the gasoline product is 70-85° C., and the final boiling point is 140-150° C.; The conditions of the hydrorefining treatment include: the partial pressure of hydrogen is 2-15 MPa, the reaction temperature is 200-400° C., the volume ratio of hydrogen to oil is 100-1000, and the volume space velocity is 0.5-5 hours^-1 ;

将所得加氢精制汽油进行溶剂抽提，得到苯、甲苯和二甲苯；其中，所述溶剂抽提的条件包括：温度为80-120℃，抽提溶剂选自环丁砜、N-甲基吡咯烷酮、二乙二醇醚、三乙二醇醚、四乙二醇、二甲基亚砜和N-甲酰基吗啉醚中的一种或多种，溶剂与加氢精制汽油的体积比为2-6。The obtained hydrorefined gasoline is subjected to solvent extraction to obtain benzene, toluene and xylene; wherein, the conditions for the solvent extraction include: the temperature is 80-120° C., and the extraction solvent is selected from sulfolane, N-methylpyrrolidone, One or more of diethylene glycol ether, triethylene glycol ether, tetraethylene glycol, dimethyl sulfoxide and N-formyl morpholine ether, and the volume ratio of solvent to hydrorefined gasoline is 2- 6.

可选的，以第一催化裂化催化剂的重量为基准，所述第一催化裂化催化剂包括0-50重量％的沸石、5-95重量％的无机氧化物和0-70重量％的粘土；Optionally, based on the weight of the first catalytic cracking catalyst, the first catalytic cracking catalyst comprises 0-50% by weight of zeolite, 5-95% by weight of inorganic oxide and 0-70% by weight of clay;

以第二催化裂化催化剂的重量为基准，所述第二催化裂化催化剂包括0-50重量％的沸石、5-95重量％的无机氧化物和0-70重量％的粘土。The second catalytic cracking catalyst comprises 0-50 wt% zeolite, 5-95 wt% inorganic oxide, and 0-70 wt% clay, based on the weight of the second catalytic cracking catalyst.

可选的，以沸石的重量为基准，所述沸石包括25-100重量％的平均孔径小于0.7纳米的择形沸石和0-75重量％的大孔沸石，所述择形沸石选自ZSM系列沸石、ZRP沸石、镁碱沸石、菱沸石、环晶石、毛沸石、A沸石、柱沸石和浊沸石中的一种或多种，所述大孔沸石选自Y型沸石、β型沸石、L型沸石、稀土Y型沸石、稀土氢Y型沸石、超稳Y型沸石和稀土超稳Y型沸石中的一种或多种；Optionally, based on the weight of the zeolite, the zeolite includes 25-100% by weight of a shape-selective zeolite with an average pore diameter of less than 0.7 nanometers and 0-75% by weight of a large-pore zeolite, and the shape-selective zeolite is selected from the ZSM series One or more of zeolite, ZRP zeolite, ferrierite, chabazite, ring spar, erionite, A zeolite, pillar zeolite and turbidite, the large pore zeolite is selected from Y-type zeolite, beta-type zeolite, One or more of L-type zeolite, rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultra-stable Y-type zeolite and rare earth ultra-stable Y-type zeolite;

所述无机氧化物为二氧化硅和/或三氧化二铝，所述粘土为高岭土和/或多水高岭土。The inorganic oxide is silica and/or alumina, and the clay is kaolin and/or halloysite.

本发明还提供一种生产低碳烯烃的催化裂化装置，该装置包括第一提升管反应器、第二提升管反应器、沉降器、汽提器和再生器；The invention also provides a catalytic cracking device for producing light olefins, the device comprises a first riser reactor, a second riser reactor, a settler, a stripper and a regenerator;

所述第一提升管反应器的底部设置有催化剂入口，下部设置有第一重质原料入口，顶部设置有油剂出口；A catalyst inlet is arranged at the bottom of the first riser reactor, a first heavy raw material inlet is arranged at the lower part, and an oil agent outlet is arranged at the top;

所述第二提升管反应器由下至上依次包括流体连通的预提升段、第一反应段、第二反应段和出口段，所述第二反应段的内径大于第一反应段的内径，所述预提升段的底部设置有催化剂入口，所述第一反应段的下部设置有第二重质原料入口，所述第二反应段的下部设置有齐聚烯烃入口，所述出口段的顶部设置有油剂出口；The second riser reactor includes, from bottom to top, a pre-lift section, a first reaction section, a second reaction section and an outlet section that are fluidly connected in sequence, and the inner diameter of the second reaction section is larger than the inner diameter of the first reaction section, so The bottom of the pre-lifting section is provided with a catalyst inlet, the lower part of the first reaction section is provided with a second heavy raw material inlet, the lower part of the second reaction section is provided with an oligomeric olefin inlet, and the top of the outlet section is provided with There are oil exports;

所述沉降器位于所述汽提器上方且二者流体连通，所述沉降器侧面设置有油剂入口、顶部设置有油气出口，所述汽提器的底部设置有催化剂出口，所述再生器设置有催化剂入口和催化剂出口；The settler is located above the stripper and the two are in fluid communication. The settler is provided with an oil inlet on the side and an oil and gas outlet on the top. The bottom of the stripper is provided with a catalyst outlet. The regenerator A catalyst inlet and a catalyst outlet are provided;

所述第一提升管反应器的油剂出口和所述出口段的油剂出口与所述沉降器的油剂入口连通，所述再生器的催化剂入口与所述汽提器的催化剂出口连通，所述再生器的催化剂出口与所述第一提升管反应器的催化剂入口和预提升段的催化剂入口连通。The oil outlet of the first riser reactor and the oil outlet of the outlet section are communicated with the oil inlet of the settler, the catalyst inlet of the regenerator is communicated with the catalyst outlet of the stripper, The catalyst outlet of the regenerator communicates with the catalyst inlet of the first riser reactor and the catalyst inlet of the pre-lift section.

可选的，所述第一反应段的上部从所述第二反应段的底部伸入所述第二反应段中；Optionally, the upper part of the first reaction section extends into the second reaction section from the bottom of the second reaction section;

所述第一反应段的顶部封口，所述第一反应段上部的侧壁设置有多个通过反应油剂的开口。The top of the first reaction section is sealed, and the side wall of the upper part of the first reaction section is provided with a plurality of openings for passing the reaction oil.

可选的，所述装置还包括齐聚反应器和气液分离器，所述齐聚反应器设置有C4烃和/或C5烃入口以及齐聚产物出口，所述气液分离器设置有进料口、气体产物出口和齐聚烯烃出口，所述齐聚反应器的齐聚产物出口与所述气液分离器的进料口连通，所述气液分离器的齐聚烯烃出口与所述第二反应段的齐聚烯烃入口连通；Optionally, the device further comprises an oligomerization reactor and a gas-liquid separator, the oligomerization reactor is provided with a C4 hydrocarbon and/or C5 hydrocarbon inlet and an oligomerization product outlet, and the gas-liquid separator is provided with a feed port, gas product outlet and oligomerization olefin outlet, the oligomerization product outlet of the oligomerization reactor is communicated with the feed port of the gas-liquid separator, and the oligomerization olefin outlet of the gas-liquid separator is connected to the first The oligomeric olefin inlets of the two reaction sections are connected;

所述装置还包括用于分离油气的分离系统，所述分离系统设置有油气入口、干气出口、液化气出口、汽油出口、柴油出口、重油出口、以及C4烃和/或C5烃出口，所述重油出口与第一反应段的第二重质原料入口连通，所述C4烃和/或C5烃出口与齐聚反应器的C4烃和/或C5烃入口连通。The device also includes a separation system for separating oil and gas, the separation system is provided with an oil and gas inlet, a dry gas outlet, a liquefied gas outlet, a gasoline outlet, a diesel outlet, a heavy oil outlet, and a C4 hydrocarbon and/or C5 hydrocarbon outlet, so The heavy oil outlet communicates with the second heavy feedstock inlet of the first reaction section, and the C4 hydrocarbon and/or C5 hydrocarbon outlet communicates with the C4 hydrocarbon and/or C5 hydrocarbon inlet of the oligomerization reactor.

本发明发明人意外发现，通过将重质原料与催化剂反应后的油剂同齐聚烯烃进行反应，相比于将C4-C5烃组分直接进行回炼相比，能够提高乙烯、丙烯和轻芳烃产率，降低干气和焦炭的产率。The inventors of the present invention have unexpectedly found that by reacting the oil after the reaction of the heavy raw material with the catalyst and the oligomeric olefin, compared with the direct refining of the C4-C5 hydrocarbon components, the ethylene, propylene and light weight can be improved. Aromatic yields, reduced dry gas and coke yields.

本发明的其他特征和优点将在随后的具体实施方式部分予以详细说明。Other features and advantages of the present invention will be described in detail in the detailed description that follows.

附图说明Description of drawings

附图是用来提供对本发明的进一步理解，并且构成说明书的一部分，与下面的具体实施方式一起用于解释本发明，但并不构成对本发明的限制。在附图中：The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached image:

图1是本发明所提供的装置一种具体实施方式的结构示意图。FIG. 1 is a schematic structural diagram of a specific embodiment of the device provided by the present invention.

图2是本发明对比例4所使用的装置一种具体实施方式的结构示意图。FIG. 2 is a schematic structural diagram of a specific embodiment of the device used in Comparative Example 4 of the present invention.

附图标记说明Description of reference numerals

1 第一提升管反应器 11 喷嘴 12 管线1 First riser reactor 11Nozzle 12 Line

13 流量控制阀13 Flow control valve

2 第二提升管反应器 21 喷嘴 22 管线2Second riser reactor 21Nozzle 22 Line

23 流量控制阀 24 开口 25 预提升段23Flow control valve 24Opening 25 Pre-lift section

26、第一反应段 27 第二反应段 28 出口段26. Thefirst reaction section 27 Thesecond reaction section 28 The outlet section

29 喷嘴29 Nozzles

3 沉降器 31 一级旋风分离器 32 二级旋风分离器3 Settler 31 Primary Cyclone Separator 32 Secondary Cyclone Separator

4 汽提器 41 挡板 42 管线4Stripper 41Baffle 42 Line

43 流量控制阀43 Flow control valve

5 再生器5 Regenerators

101 提升管反应器 111 喷嘴 112 管线101Riser reactor 111Nozzle 112 Line

113 流量控制阀 114 流化床反应器113Flow control valve 114 Fluidized bed reactor

103 沉降器 131 一级旋风分离器 132 二级旋风分离器103 Settler 131Primary Cyclone Separator 132 Secondary Cyclone Separator

104 汽提器 141 挡板 142 管线104Stripper 141Baffle 142 Line

143 流量控制阀143 Flow Control Valve

105 再生器105 Regenerator

具体实施方式Detailed ways

以下对本发明的具体实施方式进行详细说明。应当理解的是，此处所描述的具体实施方式仅用于说明和解释本发明，并不用于限制本发明。Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

在本发明上下文中，除非有特殊的说明，术语“低碳烯烃”均指C2-C4烯烃，“轻芳烃”均指苯、甲苯和二甲苯。In the context of the present invention, unless otherwise specified, the term "light olefins" refers to C2-C4 olefins, and "light aromatics" refers to benzene, toluene and xylene.

本发明提供一种生产低碳烯烃的催化裂化方法，该方法包括：The invention provides a catalytic cracking method for producing light olefins, the method comprising:

将第一重质原料引入第一提升管反应器的下部与来自第一提升管反应器底部的第一催化裂化催化剂接触并进行第一催化裂化反应，得到第一反应产物和第一待生催化剂；The first heavy raw material is introduced into the lower part of the first riser reactor to contact the first catalytic cracking catalyst from the bottom of the first riser reactor and carry out the first catalytic cracking reaction to obtain the first reaction product and the first to-be-grown catalyst ;

将第二重质原料引入第二提升管反应器第一反应段的下部与来自第一反应段底部的第二催化裂化催化剂接触并进行第二催化裂化反应；其中，所述第二提升管反应器由下至上包括流体连通的第一反应段和第二反应段，且第一反应段的内径小于第二反应段的内径；The second heavy feedstock is introduced into the lower part of the first reaction section of the second riser reactor to contact the second catalytic cracking catalyst from the bottom of the first reaction section and carry out a second catalytic cracking reaction; wherein, the second riser reaction The device includes a first reaction section and a second reaction section in fluid communication from bottom to top, and the inner diameter of the first reaction section is smaller than the inner diameter of the second reaction section;

将第一反应段所得反应油剂送入所述第二反应段中并与来自第二反应段下部的齐聚烯烃一起在第二反应段中进行第三催化裂化反应，得到第二反应产物和第二待生催化剂；The reaction oil obtained in the first reaction section is sent into the second reaction section and the third catalytic cracking reaction is carried out in the second reaction section together with the oligomeric olefin from the lower part of the second reaction section to obtain the second reaction product and the second to-be-grown catalyst;

将所得第一反应产物、第一待生催化剂、第二反应产物和第二待生催化剂进行分离，所得第一待生催化剂和第二待生催化剂引入再生器中进行再生，得到再生催化剂；Separating the obtained first reaction product, the first waiting catalyst, the second reaction product and the second waiting catalyst, and introducing the obtained first waiting catalyst and the second waiting catalyst into a regenerator for regeneration to obtain a regenerated catalyst;

将所得再生催化剂作为第一催化裂化催化剂和第二催化裂化催化剂返回第一提升管反应器和第二提升管反应器；returning the obtained regenerated catalyst to the first riser reactor and the second riser reactor as the first catalytic cracking catalyst and the second catalytic cracking catalyst;

将第一反应产物和第二反应产物进行分离，得到干气产物、液化气产物、汽油产物、柴油产物和重油产物。The first reaction product and the second reaction product are separated to obtain a dry gas product, a liquefied gas product, a gasoline product, a diesel product and a heavy oil product.

根据本发明，齐聚烯烃是本领域技术人员所熟知的，是指C4烃和/或C5烃经齐聚反应所得C6以上烃组分。本发明中，以齐聚烯烃的重量为基准，所述齐聚烯烃中C8-C10烯烃含量可以不低于60重量％，优选不低于80重量％，其余组分可以为C7以下或C11以上的烯烃。本领域技术人员可以采用现有技术进行制备齐聚烯烃，例如所述齐聚烯烃制备步骤可以包括：将C4烃和/或C5烃与齐聚催化剂在齐聚反应器中接触并进行齐聚反应，得到齐聚产物；将齐聚产物在30-80℃下进行气液分离，得到含有C4烃和/或C5烃的气体产物和液态的所述齐聚烯烃。所述齐聚反应的条件可以包括：反应温度为200-400℃，反应压力为2-5兆帕，液时体积空速为0.5-4小时^-1；所述齐聚催化剂可以含有MFI结构的分子筛，MFI结构的分子筛可以包括ZSM-5、ZSM-8、ZSM-11、ZSM-12、ZSM-22、ZSM-23、ZSM-35、ZSM-38、ZSM-48和ZRP系列沸石中的一种或多种，其硅铝比可以大于50:1，所述催化剂可以经P、Mg、Ca、Fe、Cu、Cr、Ga和V中的一种或多种改性。所述齐聚反应器可以为固定床反应器或流化床反应器。According to the present invention, oligomeric olefins are well known to those skilled in the art, and refer to the hydrocarbon components above C6 obtained by the oligomerization of C4 hydrocarbons and/or C5 hydrocarbons. In the present invention, based on the weight of the oligomeric olefin, the C8-C10 olefin content in the oligomeric olefin may be no less than 60% by weight, preferably no less than 80% by weight, and the remaining components may be below C7 or above C11 alkenes. Those skilled in the art can use the prior art to prepare oligomeric olefins, for example, the oligomeric olefin preparation step may include: contacting C4 hydrocarbons and/or C5 hydrocarbons with an oligomerization catalyst in an oligomerization reactor and performing an oligomerization reaction , to obtain an oligomerization product; the oligomerization product is subjected to gas-liquid separation at 30-80° C. to obtain a gas product containing C4 hydrocarbons and/or C5 hydrocarbons and the liquid oligomerized olefin. The conditions of the oligomerization reaction may include: the reaction temperature is 200-400 ° C, the reaction pressure is 2-5 MPa, and the liquid hourly volume space velocity is 0.5-4 h^-1 ; the oligomerization catalyst may contain MFI structure. Molecular sieve, molecular sieve with MFI structure can include one of ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and ZRP series zeolites. one or more, the ratio of silicon to aluminum can be greater than 50:1, and the catalyst can be modified by one or more of P, Mg, Ca, Fe, Cu, Cr, Ga and V. The oligomerization reactor may be a fixed bed reactor or a fluidized bed reactor.

一种实施方式，以重量计并以所述齐聚催化剂的重量为基准，所述齐聚催化剂可以包括50-80重量％的杂原子M-ZSM-5分子筛和20-50重量％的粘结剂，M可以选自Fe、Cr、Ga和V中的一种或多种，所述粘结剂可以为氧化铝或氧化硅。In one embodiment, the oligomerization catalyst may comprise, by weight and based on the weight of the oligomerization catalyst, 50-80% by weight of the heteroatom M-ZSM-5 molecular sieve and 20-50% by weight of the binder The binder, M can be selected from one or more of Fe, Cr, Ga and V, and the binder can be aluminum oxide or silicon oxide.

根据本发明，齐聚反应中所述C4烃和/或C5烃可以来自催化裂化、蒸汽裂解、焦化和甲醇制烯烃中的一种或多种工艺，也可以由第一反应产物和/或第二反应产物进行分离所得。According to the present invention, the C4 hydrocarbons and/or C5 hydrocarbons described in the oligomerization reaction may come from one or more processes of catalytic cracking, steam cracking, coking and methanol to olefins, or may be obtained from the first reaction product and/or the second The two reaction products are separated.

根据本发明，重质原料是本领域技术人员所熟知的，例如，所述第一重质原料可以选自加氢尾油、减压瓦斯油、原油、渣油、煤液化油、油砂油、页岩油和动植物油脂中的一种或多种；所述第二重质原料可以选自加氢尾油、减压瓦斯油、原油、渣油、煤液化油、油砂油、页岩油、动植物油脂和所述重油产物中的一种或多种；所述重油产物的馏程(常压)可以为330-550℃，优选350-530℃。According to the present invention, the heavy feedstock is well known to those skilled in the art, for example, the first heavy feedstock can be selected from hydrogenation tail oil, vacuum gas oil, crude oil, residual oil, coal liquefied oil, oil sands oil , one or more of shale oil and animal and vegetable oils; the second heavy raw material can be selected from hydrogenation tail oil, vacuum gas oil, crude oil, residual oil, coal liquefied oil, oil sand oil, One or more of rock oil, animal and vegetable oil and the heavy oil product; the distillation range (normal pressure) of the heavy oil product can be 330-550°C, preferably 350-530°C.

根据本发明，催化裂化反应是本领域技术人员所熟知的，本发明由于将齐聚烯烃作为反应原料，从而降低反应苛刻度，例如，所述第一催化裂化反应的条件可以包括：反应温度(出口温度)为450-550℃，优选480-540℃，停留时间为0.1-5秒，优选为1-4秒，剂油重量比为4-15，催化剂密度为50-100千克/米³，反应绝压(出口处)为0.15-0.3兆帕，优选为0.18-0.28兆帕；所述第二催化裂化反应的条件可以包括：反应温度为520-640℃，优选540-620℃，停留时间为0.1-2秒，优选为0.5-1.2秒，剂油重量比为4-15，催化剂密度为50-100千克/米³；所述第三催化裂化反应的反应条件可以包括：反应温度为510-630℃，优选为530-610℃，停留时间为0.1-5秒，优选为1-4秒，剂油重量比为5-25，催化剂密度为100-300千克/米³，反应绝压(出口处)为0.15-0.3兆帕，优选为0.18-0.28兆帕。另外，所述第一提升管反应器和第二提升管反应器中还可以注入稀释剂，所述稀释剂选自水蒸气、低碳烷烃(C1-C4)和氮气中的一种或多种，优选水蒸气。稀释剂与第一重油原料的重量比可以为(0.01-2):1，优选(0.05-0.80):1。According to the present invention, the catalytic cracking reaction is well known to those skilled in the art, and the present invention reduces the severity of the reaction due to the use of oligomeric olefin as the reaction raw material, for example, the conditions of the first catalytic cracking reaction may include: reaction temperature ( The outlet temperature) is 450-550°C, preferably 480-540°C, the residence time is 0.1-5 seconds, preferably 1-4 seconds, the weight ratio of the catalyst to oil is 4-15, and the catalyst density is 50-100 kg/^m3 , The reaction absolute pressure (at the outlet) is 0.15-0.3 MPa, preferably 0.18-0.28 MPa; the conditions of the second catalytic cracking reaction may include: the reaction temperature is 520-640 ° C, preferably 540-620 ° C, the residence time It is 0.1-2 seconds, preferably 0.5-1.2 seconds, the weight ratio of the catalyst to oil is 4-15, and the catalyst density is 50-100 kg/^m3 ; the reaction conditions of the third catalytic cracking reaction can include: the reaction temperature is 510 -630°C, preferably 530-610°C, residence time is 0.1-5 seconds, preferably 1-4 seconds, agent-oil weight ratio is 5-25, catalyst density is 100-300 kg/^m3 , reaction absolute pressure ( outlet) is 0.15-0.3 MPa, preferably 0.18-0.28 MPa. In addition, a diluent may be injected into the first riser reactor and the second riser reactor, and the diluent is selected from one or more of steam, low carbon alkanes (C1-C4) and nitrogen. , preferably water vapor. The weight ratio of diluent to first heavy oil feedstock may be (0.01-2):1, preferably (0.05-0.80):1.

根据本发明，第一提升管反应器和第二提升管反应器的进料量可以根据需要进行选择，例如所述第一重质原料与第二重质原料单位时间的进料重量比(若第二重质原料为重油产物，则该比例也可以称为回炼比)可以为1：(0.01-0.35)，优选为1：(0.05-0.3)，在齐聚烯烃进料之前先将再生催化剂与第二重质原料进行反应，可以调整催化剂的活性，提高目标产物选择性。所述第一重质原料与齐聚烯烃的单位时间进料重量比(若制备齐聚烯烃的C4烃和/或C5烃来自第一反应产物和/或第二反应产物，则该比例也可以称为回炼比)可以为1：(0.03-0.3)，优选1:(0.05-0.3)，若将本装置的C4烃和/或C5烃制备齐聚烯烃，则可以根据第一反应产物和第二反应产物中C4烃和/或C5烃的产率，调整齐聚烯烃的单位时间进料量，一般情况下，C4烃和/或C5烃的产率越高，则齐聚烯烃单位时间进料量越大。According to the present invention, the feed amount of the first riser reactor and the second riser reactor can be selected as required, for example, the feed weight ratio of the first heavy raw material to the second heavy raw material per unit time (if The second heavy raw material is a heavy oil product, then the ratio can also be referred to as the recycle ratio) can be 1: (0.01-0.35), preferably 1: (0.05-0.3), before the oligomerization of olefin feed, the regeneration When the catalyst reacts with the second heavy raw material, the activity of the catalyst can be adjusted and the selectivity of the target product can be improved. The feed weight ratio per unit time of the first heavy feedstock to the oligomeric olefin (if the C4 hydrocarbons and/or C5 hydrocarbons for the preparation of the oligomeric olefins come from the first reaction product and/or the second reaction product, this ratio can also be Referred to as the refining ratio) can be 1: (0.03-0.3), preferably 1: (0.05-0.3), if the C4 hydrocarbons and/or C5 hydrocarbons of this device are used to prepare oligomeric olefins, the first reaction product and The yield of C4 hydrocarbons and/or C5 hydrocarbons in the second reaction product is adjusted according to the unit time feed amount of oligomerized olefins. Generally, the higher the yield of C4 hydrocarbons and/or C5 hydrocarbons, the higher the yield of oligomerized olefins per unit time. The larger the feed amount.

根据本发明，为了避免从第一反应段出来的催化剂和油气由于惯性直接冲出，达不到催化剂密度要求，可以在第一反应段出口处设置各种形式的出口分布器，例如如图1所示，第一反应段的所述第一反应段的上部可以从所述第二反应段的底部伸入所述第二反应段中；所述第一反应段的顶部可以封口，所述第一反应段上部的侧壁可以设置有多个通过反应油剂的开口，从而使来自第一反应段的油剂通过该开口可以在第二反应段中具有更好的分布效果，提高第二反应段中催化剂密度。第一反应段26上部的长度可以根据需要进行设置，例如占第一反应段总高度的0.05-0.2。According to the present invention, in order to prevent the catalyst and oil and gas from the first reaction section from directly flushing out due to inertia and failing to meet the catalyst density requirement, various forms of outlet distributors can be provided at the outlet of the first reaction section, for example, as shown in Figure 1 As shown, the upper part of the first reaction section of the first reaction section can extend into the second reaction section from the bottom of the second reaction section; the top of the first reaction section can be sealed, and the first reaction section can be sealed. The side wall of the upper part of the first reaction section can be provided with a plurality of openings for passing the reaction oil, so that the oil from the first reaction section can pass through the openings and have a better distribution effect in the second reaction section, improving the second reaction section. The catalyst density in the segment. The length of the upper part of thefirst reaction section 26 can be set as required, for example, it accounts for 0.05-0.2 of the total height of the first reaction section.

本发明中，还可以将汽油产物进行进一步的处理和分离，以得到轻芳烃，例如所述方法还可以包括：将所得汽油产物或汽油产物的部分馏分进行加氢精制处理，得到加氢精制汽油；其中，所述汽油产物的部分馏分的初馏点可以为70-85℃，终馏点为140-150℃；所述加氢精制处理的条件可以包括：氢分压为2-15兆帕，反应温度为200-400℃，氢油体积比为100-1000，体积空速为0.5-5小时^-1；将所得加氢精制汽油进行溶剂抽提，得到苯、甲苯和二甲苯；其中，所述溶剂抽提的条件可以包括：温度为80-120℃，抽提溶剂可以选自环丁砜、N-甲基吡咯烷酮、二乙二醇醚、三乙二醇醚、四乙二醇、二甲基亚砜和N-甲酰基吗啉醚中的一种或多种，溶剂与加氢精制汽油的体积比可以为2-6；具体操作还可以参照专利CN01119818、CN1393507A、CN1258717A公开的方法。抽提出BTX的汽油(抽余油)可以用于调和汽油、作为蒸汽裂解原料或者返回第一提升管反应器进行催化裂化反应。通过加氢精制，可使汽油馏分中的烯烃、二烯烃和炔烃饱和，同时可脱除硫、氮等杂质。所用加氢催化剂应具备高选择性加氢饱和活性以及脱氮、脱硫活性，加氢催化剂可以为负载在氧化铝和/或无定型硅铝上的VIB和/或VIII族非贵金属催化剂，所述VIB非贵金属选自Mo或/和W，VIII族非贵金属选自Co或/和Ni。优选的加氢催化剂由0-10重量％添加剂、1-9重量％的一种或多种第VIII族金属、12-39重量％的一种或多种第VIB族金属和余量氧化铝和/或无定型硅铝载体构成，其中所述添加剂可以选自氟、磷、钛等非金属元素和金属元素，具体可参考中国专利CN94102955、CN200310121166、CN200310121167和CN200310121168。In the present invention, the gasoline product can also be further processed and separated to obtain light aromatic hydrocarbons. For example, the method can also include: subjecting the obtained gasoline product or a partial fraction of the gasoline product to hydrorefining to obtain hydrorefined gasoline. ; wherein, the initial boiling point of the partial fraction of the gasoline product may be 70-85 ° C, and the final boiling point may be 140-150 ° C; , the reaction temperature is 200-400 ℃, the hydrogen oil volume ratio is 100-1000, and the volume space velocity is 0.5-5 hours^-1 ; The gained hydrorefined gasoline is subjected to solvent extraction to obtain benzene, toluene and xylene; The conditions for the solvent extraction may include: the temperature is 80-120° C., and the extraction solvent may be selected from sulfolane, N-methylpyrrolidone, diethylene glycol ether, triethylene glycol ether, tetraethylene glycol, dimethyl ether For one or more of sulfoxide and N-formyl morpholine ether, the volume ratio of solvent to hydrorefined gasoline can be 2-6; the specific operation can also refer to the methods disclosed in patents CN01119818, CN1393507A and CN1258717A. The gasoline from which BTX is extracted (raffinate) can be used to blend gasoline, as a feedstock for steam cracking, or returned to the first riser reactor for catalytic cracking reactions. Through hydrorefining, olefins, diolefins and alkynes in gasoline fractions can be saturated, and impurities such as sulfur and nitrogen can be removed at the same time. The hydrogenation catalyst used should have highly selective hydrogenation saturation activity and denitrification and desulfurization activities, and the hydrogenation catalyst can be a VIB and/or VIII group non-precious metal catalyst supported on alumina and/or amorphous silica-alumina. The VIB non-noble metal is selected from Mo or/and W, and the Group VIII non-noble metal is selected from Co or/and Ni. Preferred hydrogenation catalysts consist of 0-10 wt% additives, 1-9 wt% one or more Group VIII metals, 12-39 wt% one or more Group VIB metals and the balance alumina and /or an amorphous silicon-alumina support, wherein the additive can be selected from non-metallic elements and metal elements such as fluorine, phosphorus, titanium, etc., for details, please refer to Chinese patents CN94102955, CN200310121166, CN200310121167 and CN200310121168.

根据本发明，催化裂化催化剂是本领域技术人员所熟知的，本发明还优选提供合适的催化剂以达到增产低碳烯烃和轻芳烃的目的，第二提升管反应器中所使用的第二催化裂化催化剂可以与第一提升管所用第一催化裂化催化剂相同，也可以不同，优选第一提升管反应器和第二提升管反应器使用相同的催化剂。具体地，所述第一催化裂化催化剂和第二催化裂化催化剂各自独立地含有沸石、无机氧化物和任选的粘土，优选含有：5-50重量％沸石、5-95重量％无机氧化物、0-70重量％粘土，所述沸石优选包括平均孔径小于0.7纳米的择形沸石和任选的大孔沸石，平均孔径小于0.7纳米的择形沸石可以占活性组分的25-100重量％，优选50-100重量％，大孔沸石可以占活性组分的0-75重量％，优选0-50重量％。平均孔径小于0.7纳米的择形沸石可以选自ZSM系列沸石、ZRP沸石、镁碱沸石、菱沸石、环晶石、毛沸石、A沸石、柱沸石、浊沸石，以及经物理和/或化学方法处理后得到的上述沸石之中的一种或多种的混合物。ZSM系列沸石可以选自ZSM-5、ZSM-8、ZSM-11、ZSM-12、ZSM-22、ZSM-23、ZSM-35、ZSM-38ZSM-48和其它类似结构的沸石中的一种或多种的混合物。有关ZSM-5更为详尽的描述可以参见USP3702886，有关ZRP更为详尽的描述可以参见USP5232675、CN1211470A、CN1611299A。含有平均孔径小于0.7纳米的择形沸石催化剂可以是由现有技术提供的催化剂的一种或几种的组合，可以商购或按照现有方法制备。所述大孔沸石为具有至少0.7纳米环开口的孔状结构的沸石，例如选自Y型沸石、β型沸石、L型沸石、稀土Y型沸石(REY)、稀土氢Y型沸石(REHY)、超稳Y型沸石(USY)、稀土超稳Y型沸石(REUSY)中的一种或多种。所述无机氧化物作为粘接剂，可以选自二氧化硅(SiO₂)和/或三氧化二铝(Al₂O₃)。所述粘土作为基质，即载体，可以选自高岭土和/或多水高岭土。According to the present invention, catalytic cracking catalysts are well known to those skilled in the art. The present invention also preferably provides suitable catalysts to achieve the purpose of increasing the production of light olefins and light aromatics. The second catalytic cracking catalyst used in the second riser reactor The catalyst may be the same as the first catalytic cracking catalyst used in the first riser, or it may be different, preferably the first riser reactor and the second riser reactor use the same catalyst. Specifically, the first catalytic cracking catalyst and the second catalytic cracking catalyst each independently contain zeolite, inorganic oxide and optional clay, preferably: 5-50 wt% zeolite, 5-95 wt% inorganic oxide, 0-70 wt % clay, the zeolite preferably includes a shape-selective zeolite with an average pore size of less than 0.7 nm and an optional large-pore zeolite, and the shape-selective zeolite with an average pore size of less than 0.7 nm can account for 25-100 wt % of the active component, Preferably 50-100% by weight, the large pore zeolite may comprise 0-75% by weight of the active ingredient, preferably 0-50% by weight. The shape-selective zeolite with an average pore size of less than 0.7 nanometers can be selected from ZSM series zeolite, ZRP zeolite, ferrierite, chabazite, ring spar, erionite, A zeolite, pillar zeolite, turbidite, and zeolite through physical and/or chemical methods A mixture of one or more of the above-mentioned zeolites obtained after treatment. ZSM series zeolites can be selected from one of ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other similar structure zeolites or Various mixtures. More detailed descriptions of ZSM-5 can be found in USP3702886, and more detailed descriptions of ZRP can be found in USP5232675, CN1211470A, CN1611299A. The shape-selective zeolite catalyst with an average pore diameter of less than 0.7 nanometers can be one or a combination of catalysts provided in the prior art, which can be purchased commercially or prepared according to existing methods. The large-pore zeolite is a zeolite having a pore structure with at least 0.7 nanometer ring openings, for example, selected from Y-type zeolite, beta-type zeolite, L-type zeolite, rare earth Y-type zeolite (REY), rare earth hydrogen Y-type zeolite (REHY) , one or more of ultra-stable Y-type zeolite (USY) and rare earth ultra-stable Y-type zeolite (REUSY). The inorganic oxide, as a binder, can be selected from silicon dioxide (SiO₂ ) and/or aluminum oxide (Al₂ O₃ ). Said clay as matrix, ie carrier, can be selected from kaolin and/or halloysite.

如图1所示，本发明还提供一种生产低碳烯烃的催化裂化装置，该装置包括第一提升管反应器1、第二提升管反应器2、沉降器3、汽提器4和再生器5；所述第一提升管反应器1的底部设置有催化剂入口，下部设置有第一重质原料入口，顶部设置有油剂出口；所述第二提升管反应器2由下至上依次包括流体连通的预提升段25、第一反应段26、第二反应段27和出口段28，所述第二反应段27的内径大于第一反应段26的内径，所述预提升段25的底部设置有催化剂入口，所述第一反应段26的下部设置有第二重质原料入口，所述第二反应段27的下部设置有齐聚烯烃入口，所述出口段28的顶部设置有油剂出口；所述沉降器3位于所述汽提器4上方且二者流体连通，所述沉降器3侧面设置有油剂入口、顶部设置有油气出口，所述汽提器4的底部设置有催化剂出口，所述再生器5设置有催化剂入口和催化剂出口；所述第一提升管反应器1的油剂出口和所述出口段28的油剂出口与所述沉降器3的油剂入口连通，所述再生器5的催化剂入口与所述汽提器4的催化剂出口连通，所述再生器5的催化剂出口与所述第一提升管反应器1的催化剂入口和预提升段25的催化剂入口连通。As shown in Figure 1, the present invention also provides a catalytic cracking device for producing light olefins, the device comprising a first riser reactor 1, a second riser reactor 2, a settler 3, a stripper 4 and a regeneration 5; the bottom of the first riser reactor 1 is provided with a catalyst inlet, the lower part is provided with a first heavy raw material inlet, and the top is provided with an oil outlet; the second riser reactor 2 sequentially includes from bottom to top A pre-lift section 25, a first reaction section 26, a second reaction section 27 and an outlet section 28 in fluid communication, the inner diameter of the second reaction section 27 being larger than the inner diameter of the first reaction section 26, the bottom of the pre-lift section 25 A catalyst inlet is provided, the lower part of the first reaction section 26 is provided with a second heavy raw material inlet, the lower part of the second reaction section 27 is provided with an oligomeric olefin inlet, and the top of the outlet section 28 is provided with an oil agent outlet; the settler 3 is located above the stripper 4 and the two are in fluid communication, the settler 3 is provided with an oil inlet on the side, an oil and gas outlet on the top, and a catalyst is provided at the bottom of the stripper 4 The regenerator 5 is provided with a catalyst inlet and a catalyst outlet; the oil outlet of the first riser reactor 1 and the oil outlet of the outlet section 28 communicate with the oil inlet of the settler 3, The catalyst inlet of the regenerator 5 is communicated with the catalyst outlet of the stripper 4, and the catalyst outlet of the regenerator 5 is communicated with the catalyst inlet of the first riser reactor 1 and the catalyst inlet of the pre-lifting section 25. .

本发明的装置结构简单，工艺灵活度高，可以实现重质原料与齐聚烯烃的催化裂化反应，以多产低碳烯烃和轻芳烃，另外，该装置将第一提升管反应器和第二提升管反应器的产物直接引入沉降器，避免了反应后的油气继续反应，降低了干气和焦炭的生成，同时也能避免两个提升管的油气产物互相影响。The device of the invention has simple structure and high process flexibility, and can realize the catalytic cracking reaction of heavy raw materials and oligomeric olefins to produce more low-carbon olefins and light aromatics. In addition, the device combines the first riser reactor and the second The product of the riser reactor is directly introduced into the settler, which avoids the continued reaction of the oil and gas after the reaction, reduces the generation of dry gas and coke, and also avoids the mutual influence of the oil and gas products of the two risers.

根据本发明，为了避免从第一反应段出来的催化剂和油气由于惯性直接冲出，达不到催化剂密度要求，可以在第一反应段出口处设置各种形式的出口分布器，例如如图1所示，所述第一反应段26的上部从所述第二反应段27的底部伸入所述第二反应段27中；所述第一反应段26的顶部封口，所述第一反应段26上部的侧壁设置有多个通过反应油剂的开口24。从而使来自第一反应段的油剂通过该开口可以在第二反应段中具有更好的分布效果，提高第二反应段中催化剂密度。第一反应段26上部的长度可以根据需要进行设置，例如占第一反应段总高度的0.05-0.2。According to the present invention, in order to prevent the catalyst and oil and gas from the first reaction section from directly flushing out due to inertia and failing to meet the catalyst density requirement, various forms of outlet distributors can be provided at the outlet of the first reaction section, for example, as shown in Figure 1 As shown, the upper part of thefirst reaction section 26 extends into thesecond reaction section 27 from the bottom of thesecond reaction section 27; the top of thefirst reaction section 26 is sealed, and the first reaction section The upper side wall of 26 is provided with a plurality ofopenings 24 for passing the reaction oil. Therefore, the oil from the first reaction section can pass through the opening to have a better distribution effect in the second reaction section, thereby increasing the catalyst density in the second reaction section. The length of the upper part of thefirst reaction section 26 can be set as required, for example, it accounts for 0.05-0.2 of the total height of the first reaction section.

根据本发明，所述装置还可以包括齐聚反应器和气液分离器，所述齐聚反应器可以设置有C4烃和/或C5烃入口以及齐聚产物出口，所述气液分离器可以设置有进料口、气体产物出口和齐聚烯烃出口，所述齐聚反应器的齐聚产物出口可以与所述气液分离器的进料口连通，所述气液分离器的齐聚烯烃出口可以与所述第二反应段27的齐聚烯烃入口连通。齐聚反应器用于将C4烃和/或C5烃进行齐聚反应生成齐聚烯烃并送入第二反应段中。According to the present invention, the device may further comprise an oligomerization reactor and a gas-liquid separator, the oligomerization reactor may be provided with a C4 hydrocarbon and/or C5 hydrocarbon inlet and an oligomerization product outlet, and the gas-liquid separator may be provided with There are a feed port, a gas product outlet and an oligomerization olefin outlet, the oligomerization product outlet of the oligomerization reactor can be communicated with the feed port of the gas-liquid separator, and the oligomerization olefin outlet of the gas-liquid separator It can be in communication with the oligomeric olefin inlet of thesecond reaction section 27 . The oligomerization reactor is used to oligomerize C4 hydrocarbons and/or C5 hydrocarbons to form oligomeric olefins and send them to the second reaction section.

根据本发明，所述装置还可以包括用于分离油气的分离系统，所述沉降器的油气出口可以与分离系统连通，以将装置的反应产物分离为干气、液化气、汽油、柴油和重油等产物，重油产物可以作为第二重质原料返回第一反应段回炼，若有必要也可以分离出C4烃和/或C5烃，以返回齐聚反应器进行齐聚反应。因此，分离系统可以设置有油气入口、干气出口、液化气出口、汽油出口、柴油出口、重油出口、以及C4烃和/或C5烃出口，所述重油出口可以与第一反应段26的第二重质原料入口连通，所述C4烃和/或C5烃出口可以与齐聚反应器的C4烃和/或C5烃入口连通。According to the present invention, the device may further comprise a separation system for separating oil and gas, and the oil and gas outlet of the settler may be communicated with the separation system to separate the reaction products of the device into dry gas, liquefied gas, gasoline, diesel oil and heavy oil and other products, the heavy oil product can be used as the second heavy raw material to return to the first reaction stage for refining, and if necessary, C4 hydrocarbons and/or C5 hydrocarbons can be separated to return to the oligomerization reactor for oligomerization. Therefore, the separation system may be provided with an oil and gas inlet, a dry gas outlet, a liquefied gas outlet, a gasoline outlet, a diesel oil outlet, a heavy oil outlet, and a C4 hydrocarbon and/or C5 hydrocarbon outlet, the heavy oil outlet may be connected with thefirst reaction section 26 The duplex feedstock inlet is in communication, and the C4 hydrocarbon and/or C5 hydrocarbon outlet may be in communication with the C4 hydrocarbon and/or C5 hydrocarbon inlet of the oligomerization reactor.

下面结合附图对本发明所提供的方法进行进一步的说明，但并不因此限制本发明。本示意图为简化流程，但这并不影响本领域普通技术人员对本发明的理解。The method provided by the present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not thereby limited. This schematic diagram is a simplified process, but this does not affect the understanding of the present invention by those of ordinary skill in the art.

如图1所示，第一重质原料经过预热至180-400℃后，与水蒸汽一起通过喷嘴11喷入第一提升管反应器11，在温度450-550℃(优选480-540℃)、压力0.1-0.3兆帕(优选0.15-0.35兆帕)、剂油重量比为4-15、停留时间为0.1-5秒(优选1-4秒)的条件下，与来自管线12经流量控制阀13控制流量的热再生催化剂接触进行第一催化裂化反应，生成的富含低碳烯烃、芳烃的第一反应产物以及携带的第一待生催化剂在反应器出口处进入沉降器3的一级旋风分离器31和二级旋风分离器32中。分离出的第一反应产物离开反应装置引入后续分离系统进行分离，得到气体产物(包括干气和液化气)、轻汽油产物、富含轻芳烃重汽油产物、柴油产物和重油产物。气体通过本领域技术人员熟知的分离技术，分离得到丙烯等低碳烯烃。第一待生催化剂进入汽提器4中经过挡板41与来自下方的汽提蒸汽进行汽提。As shown in Figure 1, after the first heavy raw material is preheated to 180-400°C, it is sprayed into the first riser reactor 11 through the nozzle 11 together with water vapor, and the temperature is 450-550°C (preferably 480-540°C). ), the pressure is 0.1-0.3 MPa (preferably 0.15-0.35 MPa), the weight ratio of agent to oil is 4-15, and the residence time is 0.1-5 seconds (preferably 1-4 seconds). The thermally regenerated catalyst whose flow is controlled by thecontrol valve 13 contacts to carry out the first catalytic cracking reaction, and the generated first reaction product rich in light olefins and aromatic hydrocarbons and the carried first catalyst to be produced enter the first stage of the settler 3 at the outlet of the reactor. In the first stage cyclone separator 31 and the second stage cyclone separator 32. The separated first reaction product leaves the reaction unit and is introduced into a subsequent separation system for separation to obtain gas products (including dry gas and liquefied gas), light gasoline products, light aromatic-rich heavy gasoline products, diesel products and heavy oil products. The gas is separated to obtain light olefins such as propylene through separation techniques well known to those skilled in the art. The first to-be-grown catalyst enters thestripper 4 and passes through thebaffle plate 41 for stripping with the stripping steam from below.

分离系统得到的重油产物，经喷嘴21与水蒸汽一起喷入第二提升管反应器2下方的第一反应段26，在反应温度为520-640℃(优选540-620℃)、剂油重量比为4-15、停留时间为0.1-2秒(优选0.5-1.2秒)、催化剂密度为50-100千克/米³的条件下与来自管线22并经流量控制阀23控制流量的进入预提升段25提升的热再生催化剂接触进行第二催化裂化反应，反应油剂通过开口24离开第一反应段26后进入第二反应段27中。The heavy oil product obtained by the separation system is sprayed into thefirst reaction section 26 below thesecond riser reactor 2 through thenozzle 21 together with water vapor, and the reaction temperature is 520-640 ° C (preferably 540-620 ° C), and the weight of the agent oil is The ratio is 4-15, the residence time is 0.1-2 seconds (preferably 0.5-1.2 seconds), and the catalyst density is 50-100 kg/^m3 with the incoming pre-lift fromline 22 and controlled flow throughflow control valve 23 The thermally regenerated catalyst lifted in thesection 25 is contacted to carry out the second catalytic cracking reaction, and the reaction oil leaves thefirst reaction section 26 through theopening 24 and then enters thesecond reaction section 27 .

分离系统得到的C4烃和/或C5烃进入齐聚反应器进行齐聚反应，反应后的产物经过简单的冷凝分离出含有C4-C5烃的气体产物和液态的齐聚烯烃，齐聚烯烃经喷嘴29进入第二反应段27，在反应温度为510-630℃(优选530-610℃)、剂油重量比5-25、停留时间为0.1-5秒(优选1-4秒)、催化剂密度100-300千克/米³的条件下，与来自第一反应段26的油剂接触进行第三催化裂化反应，反应后的第二反应产物和第二待生催化剂经出口段28进入沉降器3的一级旋风分离器31和二级旋风分离器32分离第二反应产物和积碳的第二待生催化剂，反应产物离开反应系统引入后续分离系统进行分离，第二待生催化剂进入汽提器4中经过挡板41与来自下方的汽提蒸汽进行汽提，汽提后的催化剂经管线42和流量控制阀43进入再生器5中进行烧焦再生。The C4 hydrocarbons and/or C5 hydrocarbons obtained by the separation system enter the oligomerization reactor for oligomerization reaction, and the reacted products are simply condensed to separate gas products containing C4-C5 hydrocarbons and liquid oligomeric olefins. Thenozzle 29 enters thesecond reaction section 27, and the reaction temperature is 510-630°C (preferably 530-610°C), the weight ratio of the agent to oil is 5-25, the residence time is 0.1-5 seconds (preferably 1-4 seconds), and the catalyst density is Under the condition of 100-300 kg/^m3 , the third catalytic cracking reaction is carried out in contact with the oil from thefirst reaction section 26, and the second reaction product after the reaction and the second catalyst to be grown enter the settler 3 through theoutlet section 28. The first stage cyclone 31 and the second stage cyclone 32 separate the second reaction product and the carbon deposited second catalyst, the reaction product leaves the reaction system and is introduced into the subsequent separation system for separation, and the second catalyst enters thestripper 4 is stripped with the stripping steam from below through thebaffle 41, and the stripped catalyst enters the regenerator 5 through thepipeline 42 and theflow control valve 43 for coke regeneration.

下面的实施例将对本发明予以进一步的说明，但并不因此限制本发明。The following examples will further illustrate the present invention, but do not limit the present invention accordingly.

实施例在中型试验装置上进行，其中第一提升管反应器的内径是18毫米，高度6米，第二提升管反应器高度5米，第一反应段的高度为1.2米、内径16毫米。第二反应段的高度为2.8米、内径34毫米。第一提升管反应器和第二提升管反应器中催化剂的装量为60千克。其流程如图1所示。The examples were carried out on a medium-scale test device, wherein the inner diameter of the first riser reactor was 18 mm and the height was 6 meters, the height of the second riser reactor was 5 meters, and the height of the first reaction section was 1.2 meters and the inner diameter was 16 mm. The height of the second reaction section was 2.8 meters and the inner diameter was 34 mm. The catalyst loading in the first riser reactor and the second riser reactor was 60 kg. Its process is shown in Figure 1.

本发明实施例和对比例所用重质原料的性质见表1；所用的催化裂化催化剂为中国石化催化剂齐鲁分公司生产的MMC-2催化剂，其具体性质见表2，该催化剂含平均孔径小于0.7nm的择形沸石。所用齐聚催化剂为自制的Fe-ZSM-5催化剂，制备方法如下：取氢型的Fe-ZSM-5分子筛20克(SiO₂/Fe₂O₃摩尔比为90)，加入6克白碳黑及3克田菁粉，用25克SiO₂(40％重量)硅溶胶作为粘结剂，挤条成型，切粒，120℃干燥12小时，在550℃下焙烧3小时，制得齐聚催化剂。The properties of the heavy raw materials used in the examples of the present invention and the comparative examples are shown in Table 1; the catalytic cracking catalyst used is the MMC-2 catalyst produced by Sinopec Catalyst Qilu Branch, and its specific properties are shown in Table 2. The catalyst contains an average pore size of less than 0.7 nm shape-selective zeolite. The oligomerization catalyst used is a self-made Fe-ZSM-5 catalyst, and the preparation method is as follows: take 20 grams of hydrogen-type Fe-ZSM-5 molecular sieves (SiO₂ /Fe₂ O₃ molar ratio is 90), add 6 grams of white carbon black And 3 grams of succulent powder, using 25 grams of SiO₂ (40% by weight) silica sol as a binder, extruded into strips, cut into pellets, dried at 120 ° C for 12 hours, and calcined at 550 ° C for 3 hours to obtain an oligomerization catalyst .

实施例1Example 1

按照图1所示流程进行反应。The reaction was carried out according to the scheme shown in Figure 1.

性质如表1所示的重质原料通过第一提升管反应器1下部的喷嘴11进入第一提升管反应器中与来自管线12的再生催化剂接触并进行第一催化裂化反应，所得第一反应产物和第一待生催化剂进入沉降器3的一级和二级旋风分离器分离，分离的第一待生催化剂进入汽提器4汽提，分离的第一反应产物引入后续分离系统进行分离。分离系统得到的重油产物(馏程为330-550℃)引入第二提升管反应器2的第一反应段26，与来自管线22的再生催化剂接触并进行第二催化裂化反应，反应后油剂继续进入第二反应段中。分离系统得到的C4-C5混合烃进入固定床齐聚反应器进行齐聚反应，齐聚反应的条件为：反应温度为300℃，反应压力为4.5兆帕，液时体积空速为1.8小时^-1，反应后的齐聚产物在40℃下分离出其中的含有C4烃和C5烃的气体产物，液态的齐聚烯烃进入第二反应段下部，与第一反应段经开口24分布的油剂一起接触并进行第三催化裂化反应，反应后的第二反应产物和第二待生催化剂进入沉降器3的一级和二级旋风分离器分离。引入第二反应段的齐聚烯烃中C8-C10烯烃的含量占齐聚烯烃的89.2重量％。The heavy raw materials whose properties are shown in Table 1 enter the first riser reactor through the nozzle 11 at the lower part of the first riser reactor 1 and contact the regenerated catalyst from thepipeline 12 to conduct the first catalytic cracking reaction, and the obtained first reaction The product and the first to-be-grown catalyst enter the primary and secondary cyclones of the settler 3 for separation, the separated first to-be-grown catalyst enters thestripper 4 for stripping, and the separated first reaction product is introduced into the subsequent separation system for separation. The heavy oil product obtained by the separation system (with a distillation range of 330-550° C.) is introduced into thefirst reaction section 26 of thesecond riser reactor 2, and is contacted with the regenerated catalyst from thepipeline 22 to carry out the second catalytic cracking reaction. After the reaction, the oil Continue into the second reaction section. The C4-C5 mixed hydrocarbons obtained by the separation system enter the fixed bed oligomerization reactor for oligomerization reaction. The conditions of the oligomerization reaction are: the reaction temperature is 300°C, the reaction pressure is 4.5 MPa, and the liquid hourly volume space velocity is 1.8^{hours- 1.} The gaseous products containing C4 hydrocarbons and C5 hydrocarbons are separated from the reacted oligomerization product at 40° C. The liquid oligomerization olefin enters the lower part of the second reaction section, and the oil agent distributed through theopening 24 in the first reaction section is separated. Contact and carry out the third catalytic cracking reaction together, the second reaction product after the reaction and the second to-be-grown catalyst enter the primary and secondary cyclones of the settler 3 for separation. The content of C8-C10 olefins in the oligomerized olefins introduced into the second reaction stage accounted for 89.2% by weight of the oligomerized olefins.

第一提升管反应器和第二提升管反应器的具体反应条件及结果见表3。The specific reaction conditions and results of the first riser reactor and the second riser reactor are shown in Table 3.

实施例2Example 2

本实施例流程同实施例1，不同之处在于仅将C4烃进行齐聚反应，齐聚反应条件同实施例1，齐聚后的产物分离出含有C4烃的气体产物，液态的齐聚烯烃进入第二反应段反应，齐聚烯烃中C8烯烃占92.4重量％。The flow process of this example is the same as that of Example 1, except that only C4 hydrocarbons are subjected to the oligomerization reaction, and the oligomerization reaction conditions are the same as those of Example 1, and the products after oligomerization are separated into gaseous products containing C4 hydrocarbons, and the liquid oligomerization olefins In the second reaction stage, the C8 olefins in the oligomerized olefins accounted for 92.4% by weight.

第一提升管反应器和第二提升管反应器的具体反应条件及结果见表3。The specific reaction conditions and results of the first riser reactor and the second riser reactor are shown in Table 3.

对比例1Comparative Example 1

本对比例流程同实施例1，不同之处在于分离系统得到的C4-C5混合烃不经过齐聚反应，直接引入第二反应段进行反应。The process of this comparative example is the same as that of Example 1, except that the C4-C5 mixed hydrocarbons obtained by the separation system are directly introduced into the second reaction section for reaction without undergoing oligomerization.

第一提升管反应器和第二提升管反应器的具体反应条件及结果见表3。The specific reaction conditions and results of the first riser reactor and the second riser reactor are shown in Table 3.

对比例2Comparative Example 2

本对比例所用装置与实施例1装置不同之处为，第二提升管反应器为等直径提升管反应器，高5米，内径16毫米。齐聚烯烃直接进入第二提升管反应器的下部(从喷嘴21进入)，重油产物不回炼。The difference between the device used in this comparative example and the device in Example 1 is that the second riser reactor is an equal diameter riser reactor, with a height of 5 meters and an inner diameter of 16 mm. The oligomeric olefin directly enters the lower part of the second riser reactor (entered from the nozzle 21), and the heavy oil product is not refined.

第一提升管反应器和第二提升管反应器的具体反应条件及结果见表3。The specific reaction conditions and results of the first riser reactor and the second riser reactor are shown in Table 3.

对比例3Comparative Example 3

与实施例1基本相同，不同之处在于第二提升管反应器两个反应段同轴相连且等内径，即内径均为16毫米，喷嘴位置和进料量不变。It is basically the same as Example 1, except that the two reaction sections of the second riser reactor are coaxially connected and have equal inner diameters, that is, the inner diameters are both 16 mm, and the nozzle position and feed amount are unchanged.

第一提升管反应器和第二提升管反应器的具体反应条件及结果见表3。The specific reaction conditions and results of the first riser reactor and the second riser reactor are shown in Table 3.

对比例4Comparative Example 4

本实施例所用装置如图2所示，反应器形式为提升管加流化床。分离系统得到的C4-C5混合烃不回炼。重质原料通过喷嘴111进入提升管反应器101，与来自再生器105、管线112和流量控制阀113的再生催化剂接触反应，然后引入与提升管反应器101串联的流化床反应器114进行反应，反应油气经沉降器103中的一级旋风分离器131和二级旋风分离器132分离待生催化剂引入汽提器104经挡板141与来自下方的汽提蒸汽汽提后由管线142和流量控制阀143进入再生器105中烧焦再生。提升管反应器内径为18mm，高度为6m，流化床反应器的内径为64mm，高度600mm。具体反应条件及结果见表4。The device used in this example is shown in Figure 2, and the reactor is in the form of a riser plus a fluidized bed. The C4-C5 mixed hydrocarbons obtained by the separation system are not refined. The heavy feedstock enters theriser reactor 101 through thenozzle 111, contacts and reacts with the regenerated catalyst from theregenerator 105, theline 112 and theflow control valve 113, and is then introduced into thefluidized bed reactor 114 in series with theriser reactor 101 for reaction , the reaction oil and gas are separated by theprimary cyclone separator 131 and thesecondary cyclone separator 132 in thesettler 103 and the catalyst to be produced is introduced into thestripper 104 after being stripped by thebaffle 141 and the stripping steam from below.Control valve 143 entersregenerator 105 for char regeneration. The inner diameter of the riser reactor is 18 mm and the height is 6 m, and the inner diameter of the fluidized bed reactor is 64 mm and the height is 600 mm. The specific reaction conditions and results are shown in Table 4.

对比例5Comparative Example 5

与对比例4基本相同，不同之处在于将分离系统分离的C4-C5混合烃按照实施例1的方法进行齐聚反应，所得齐聚烯烃返回流化床反应器中。具体反应条件及结果见表4。It is basically the same as Comparative Example 4, except that the C4-C5 mixed hydrocarbons separated by the separation system are subjected to oligomerization reaction according to the method of Example 1, and the obtained oligomerized olefin is returned to the fluidized bed reactor. The specific reaction conditions and results are shown in Table 4.

由表3和表4可见，本发明提供的催化转化方法，具有更高的乙烯、丙烯产率和轻芳烃产率，并且干气和焦炭产率明显降低。It can be seen from Table 3 and Table 4 that the catalytic conversion method provided by the present invention has higher yields of ethylene, propylene and light aromatics, and the yields of dry gas and coke are obviously reduced.

以上详细描述了本发明的优选实施方式，但是，本发明并不限于上述实施方式中的具体细节，在本发明的技术构思范围内，可以对本发明的技术方案进行多种简单变型，这些简单变型均属于本发明的保护范围。The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

另外需要说明的是，在上述具体实施方式中所描述的各个具体技术特征，在不矛盾的情况下，可以通过任何合适的方式进行组合，为了避免不必要的重复，本发明对各种可能的组合方式不再另行说明。In addition, it should be noted that the specific technical features described in the above-mentioned specific embodiments can be combined in any suitable manner under the condition of no contradiction. In order to avoid unnecessary repetition, the present invention has The combination method will not be specified otherwise.

此外，本发明的各种不同的实施方式之间也可以进行任意组合，只要其不违背本发明的思想，其同样应当视为本发明所发明的内容。In addition, the various embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content of the present invention.

表1Table 1

表2Table 2

催化剂名称catalyst nameMMC-2MMC-2化学性质，重量％Chemical Properties, wt%Al₂O₃Al₂O₃49.249.2Na₂ONa₂O0.0720.072RE₂O₃RE₂O₃0.610.61物理性质physical properties总孔体积，毫升/克Total pore volume, ml/g0.2080.208微孔体积，毫升/克Micropore volume, ml/g0.0240.024比表面，米²/克Specific surface, m²/g155155分子筛比表面，米²/克Molecular sieve specific surface, m²/g5050基质比表面，米²/克Substrate specific surface, m²/g105105堆积密度，克/毫升Bulk density, g/ml0.720.72粒度分析，V％Particle Size Analysis, V%0～20微米0～20 microns1.61.60～40微米0～40 microns14.214.20～80微米0～80 microns53.853.80～110微米0～110 microns72.672.60～149微米0～149 microns89.589.5裂解活性，重量％Lysis activity, wt%6666

表3table 3

表4Table 4

对比例4Comparative Example 4对比例5Comparative Example 5反应压力，MPaReaction pressure, MPa0.220.220.220.22提升管反应器riser reactor剂油重量比Agentoil weight ratio12121212出口温度,℃Outlet temperature, °C560560560560停留时间，秒dwell time, seconds2.22.22.22.2催化剂密度，千克/米³Catalyst density, kg/m³80808080流化床反应器fluidized bed reactor床层温度,℃Bed temperature, °C548548548548床层重时空速，小时^-1Bed weight hourly space velocity, hour ^-12.42.42.42.4注水量(占新鲜原料)，重量％Amount of water injected (accounting for fresh raw materials), % byweight25252525回炼比，重量％Refinement ratio, wt%//0.120.12物料平衡，重％Material balance, wt%干气dry gas3.33.33.63.6液化气liquefied gas25.525.525.725.7汽油gasoline35.535.535.135.1柴油diesel fuel18.818.818.918.9重油heavy oil12.312.31212焦炭coke4.14.14.34.3损失loss0.50.50.40.4总计total100.0100.0100100乙烯产率，重％Ethylene yield, wt%2.62.62.52.5丙烯产率，重％Propylene yield, wt%16.516.516.716.7轻芳烃产率，重％Light Aromatics Yield, wt%8.58.58.48.4

Claims (15)

1. A catalytic cracking process for producing lower olefins, the process comprising:

introducing a first heavy raw material into the lower part of a first riser reactor to contact with a first catalytic cracking catalyst from the bottom of the first riser reactor and carrying out a first catalytic cracking reaction to obtain a first reaction product and a first catalyst to be generated;

introducing a second heavy raw material into the lower part of the first reaction section of the second riser reactor to contact with a second catalytic cracking catalyst from the bottom of the first reaction section and perform a second catalytic cracking reaction; the second riser reactor comprises a first reaction section and a second reaction section which are communicated with each other from bottom to top, and the inner diameter of the first reaction section is smaller than that of the second reaction section;

feeding the reaction oil obtained in the first reaction section into the second reaction section, and carrying out a third catalytic cracking reaction in the second reaction section together with the oligomerized olefin from the lower part of the second reaction section to obtain a second reaction product and a second spent catalyst;

separating the obtained first reaction product, the first catalyst to be regenerated, the second reaction product and the second catalyst to be regenerated, and introducing the obtained first catalyst to be regenerated and the obtained second catalyst to be regenerated into a regenerator to obtain a regenerated catalyst;

returning the obtained regenerated catalyst serving as a first catalytic cracking catalyst and a second catalytic cracking catalyst to the first riser reactor and the second riser reactor;

separating the first reaction product from the second reaction product to obtain a dry gas product, a liquefied gas product, a gasoline product, a diesel oil product and a heavy oil product;

the preparation method of the oligomerization olefin comprises the following steps:

c4 hydrocarbon and/or C5 hydrocarbon contact with an oligomerization catalyst in an oligomerization reactor and carry out oligomerization reaction to obtain an oligomerization product; and carrying out gas-liquid separation on the oligomerization product at the temperature of 30-80 ℃ to obtain a gas product containing C4 hydrocarbon and/or C5 hydrocarbon and the liquid oligomerization olefin.

2. The process of claim 1 wherein the oligomerized olefin has a C8-C10 olefin content of no less than 60 weight percent, based on the weight of the oligomerized olefin.

3. The process of claim 1, wherein the oligomerization conditions comprise: the reaction temperature is 200 ℃ and 400 ℃, the reaction pressure is 2-5 MPa, and the liquid hourly space velocity is 0.5-4 h^-1(ii) a The oligomerization catalyst contains a molecular sieve with an MFI structure; the oligomerization reactor is a fixed bed reactor or a fluidized bed reactor.

4. The process of claim 1, wherein the C4 hydrocarbons and/or C5 hydrocarbons are from one or more processes of catalytic cracking, steam cracking, coking, and methanol to olefins.

5. The process of claim 1, wherein the C4 hydrocarbons and/or C5 hydrocarbons are separated from the first reaction product and/or the second reaction product.

6. The process of claim 1, wherein the first heavy feedstock is selected from one or more of a hydrotreated tail oil, a vacuum gas oil, a crude oil, a residual oil, a coal liquefied oil, an oil sand oil, a shale oil, and an animal or vegetable oil; the second heavy raw material is selected from one or more of hydrogenated tail oil, vacuum gas oil, crude oil, residual oil, coal liquefaction oil, oil sand oil, shale oil, animal and vegetable oil and fat and the heavy oil product; the distillation range of the heavy oil product is 330-550 ℃.

7. The process of claim 1, wherein the conditions of the first catalytic cracking reaction comprise: the reaction temperature is 450-550 ℃, the residence time is 0.1-5 seconds, the catalyst-oil weight ratio is 4-15, and the catalyst density is 50-100 kg/m³；

The conditions of the second catalytic cracking reaction include: the reaction temperature is 520-640 ℃, the residence time is 0.1-2 seconds, the catalyst-oil weight ratio is 4-15, and the catalyst density is 50-100 kg/m³；

The reaction conditions of the third catalytic cracking reaction include: the reaction temperature is 510-630 ℃, the residence time is 0.1-5 seconds, the catalyst-oil weight ratio is 5-25, and the catalyst density is 100-300 kg/m³。

8. The process of claim 1, wherein the feed weight ratio of the first heavy feedstock to the second heavy feedstock per unit time is 1: (0.01-0.35), wherein the weight ratio of the first heavy raw material to the oligomerized olefin fed per unit time is 1: (0.03-0.3).

9. The process of claim 1 wherein the upper portion of the first reaction zone extends into the second reaction zone from the bottom of the second reaction zone;

the top of the first reaction section is sealed, and the side wall of the upper part of the first reaction section is provided with a plurality of openings for passing through reaction oil.

10. The method of claim 1, further comprising:

carrying out hydrofining treatment on the obtained gasoline product or partial fraction of the gasoline product to obtain hydrofined gasoline; wherein the initial boiling point of the partial fraction of the gasoline product is 70-85 ℃, and the final boiling point is 140-150 ℃; the conditions of the hydrofining treatment comprise: the hydrogen partial pressure is 2-15 MPa, the reaction temperature is 200-400 ℃, the hydrogen-oil volume ratio is 100-1000, and the volume space velocity is 0.5-5 hours^-1；

Carrying out solvent extraction on the obtained hydrofined gasoline to obtain benzene, toluene and xylene; wherein the solvent extraction conditions comprise: the temperature is 80-120 ℃, the extraction solvent is one or more of sulfolane, N-methyl pyrrolidone, diethylene glycol ether, triethylene glycol ether, tetraethylene glycol, dimethyl sulfoxide and N-formyl morpholine ether, and the volume ratio of the solvent to the hydrofined gasoline is 2-6.

11. The process of claim 1 wherein the first catalytic cracking catalyst comprises from 0 to 50 wt% zeolite, from 5 to 95 wt% inorganic oxide, and from 0 to 70 wt% clay, based on the weight of the first catalytic cracking catalyst;

the second catalytic cracking catalyst comprises 0 to 50 wt% zeolite, 5 to 95 wt% inorganic oxide, and 0 to 70 wt% clay, based on the weight of the second catalytic cracking catalyst.

12. The method of claim 11, wherein the zeolite comprises 25-100 wt% of shape selective zeolite having an average pore diameter of less than 0.7nm and 0-75 wt% of large pore zeolite based on the weight of the zeolite, the shape selective zeolite being selected from one or more of ZSM series zeolite, ZRP zeolite, ferrierite, chabazite, dachiardite, erionite, a zeolite, post zeolite and erionite, and the large pore zeolite being selected from one or more of Y-type zeolite, beta-type zeolite, L-type zeolite, rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultrastable Y-type zeolite and rare earth ultrastable Y-type zeolite;

the inorganic oxide is silicon dioxide and/or aluminum oxide, and the clay is kaolin and/or halloysite.

13. An apparatus suitable for the catalytic cracking process for producing lower olefins according to any of claims 1 to 12, comprising a first riser reactor (1), a second riser reactor (2), a settler (3), a stripper (4) and a regenerator (5);

the bottom of the first riser reactor (1) is provided with a catalyst inlet, the lower part of the first riser reactor is provided with a first heavy raw material inlet, and the top of the first riser reactor is provided with an oil agent outlet;

the second riser reactor (2) sequentially comprises a pre-lifting section (25), a first reaction section (26), a second reaction section (27) and an outlet section (28) from bottom to top, wherein the pre-lifting section (25), the first reaction section (26), the second reaction section (27) and the outlet section (28) are in fluid communication, the inner diameter of the second reaction section (27) is larger than that of the first reaction section (26), a catalyst inlet is formed in the bottom of the pre-lifting section (25), a second heavy raw material inlet is formed in the lower portion of the first reaction section (26), an oligomerization olefin inlet is formed in the lower portion of the second reaction section (27), and an oil agent outlet is formed in the top of the outlet section (28);

the settler (3) is positioned above the stripper (4) and is in fluid communication with the stripper (4), the side surface of the settler (3) is provided with an oil agent inlet, the top of the settler is provided with an oil gas outlet, the bottom of the stripper (4) is provided with a catalyst outlet, and the regenerator (5) is provided with a catalyst inlet and a catalyst outlet;

an oil agent outlet of the first riser reactor (1) and an oil agent outlet of the outlet section (28) are communicated with an oil agent inlet of the settler (3), a catalyst inlet of the regenerator (5) is communicated with a catalyst outlet of the stripper (4), and a catalyst outlet of the regenerator (5) is communicated with a catalyst inlet of the first riser reactor (1) and a catalyst inlet of the pre-lifting section (25).

14. The apparatus of claim 13, wherein the upper portion of the first reaction section (26) extends into the second reaction section (27) from the bottom of the second reaction section (27);

the top of the first reaction section (26) is sealed, and the side wall of the upper part of the first reaction section (26) is provided with a plurality of openings (24) for passing reaction oil.

15. The apparatus of claim 13, further comprising an oligomerization reactor provided with a C4 hydrocarbon and/or C5 hydrocarbon inlet and an oligomerization product outlet, and a gas-liquid separator provided with a feed inlet, a gas product outlet and an oligomerization olefin outlet, the oligomerization product outlet of the oligomerization reactor being in communication with the feed inlet of the gas-liquid separator, the oligomerization olefin outlet of the gas-liquid separator being in communication with the oligomerization olefin inlet of the second reaction stage (27);

the device also comprises a separation system for separating oil and gas, wherein the separation system is provided with an oil and gas inlet, a dry gas outlet, a liquefied gas outlet, a gasoline outlet, a diesel oil outlet, a heavy oil outlet and a C4 hydrocarbon and/or C5 hydrocarbon outlet, the heavy oil outlet is communicated with the second heavy raw material inlet of the first reaction section (26), and the C4 hydrocarbon and/or C5 hydrocarbon outlet is communicated with the C4 hydrocarbon and/or C5 hydrocarbon inlet of the oligomerization reactor.

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