Process and system for improving light olefin yields

Abstract

To provide a process and system for enhancing the yield of light olefins.SOLUTION: The present disclosure provides a process for high conversion residue cracking in a circulating fluidized bed reactor while integrating it with dehydration of ethanol. More specifically, the present disclosure relates to an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of hydrocarbon feedstock. By integrating a cracking reactor with an ethanol dehydration reactor, more Conradson carbon residue feedstock can be processed in the cracking reactor while limiting a coke combustor temperature.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates generally to the field of petroleum and petroleum refining, and more particularly to a process and system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock to produce light olefins. The present disclosure is intended to further improve the yield of light olefins. [Background technology]

[0002] Maximizing the production of light olefins such as ethylene, propylene, and butylene in fluid catalytic cracking (FCC) units requires higher reaction temperatures, higher catalyst-to-oil ratios, and appropriate catalyst systems. Due to the high demand for light olefins, researchers worldwide are currently focusing on expanding the range of feedstocks that can be processed in catalytic crackers. However, upgrading residual hydrocarbon feedstocks to light olefins is challenging due to high concentrations of contaminants such as Conradson carbon content (CCR), which leads to high coke deposition on the catalyst. High coke content increases the temperature in the regenerator (coke burner), leading to reduced catalyst circulation or a lower catalyst-to-oil ratio, thereby reducing the conversion of hydrocarbon feedstock to light olefins.

[0003] To address the above problems, US5209287A discloses the use of a catalyst cooler to cool the catalyst in the FCC regenerator. US4412914, US4425259, US4450241, US6585884, US7699975, US7767075, US7932204 and US8518334 disclose the use of a coke gasifier to consume excess heat to maintain a low regenerator temperature and further increase the catalyst-to-oil ratio. However, the large amount of coke and steam produced in the regenerator limits the overall production of light olefins.

[0004] US8273930B2 discloses a process for converting ethanol to ethylene by contacting it with a cooled regenerated catalyst in a first reactor. A drawback of this process is that a large portion of the spent catalyst from the second reactor enters the regenerator directly, along with the coked catalyst from the first reactor, causing the regenerator to operate at a high temperature, resulting in overshoot of the regenerator temperature. Higher regenerator temperatures result in a lower catalyst-to-oil ratio and a lower conversion rate. Furthermore, higher regenerator temperatures result in significant catalyst deactivation and a lower conversion rate. Furthermore, the hot catalyst leaving the regenerator must be cooled to 200-450°C using a direct heat exchanger before entering the dehydration reactor. The direct heat exchanger uses cold air to contact the hot regenerated catalyst, resulting in excess heat loss in this process. Furthermore, the feed CCR that can be converted by this process is limited. Furthermore, the use of coked catalyst in the second reactor also reduces hydrocarbon conversion.

[0005] To increase ethylene production, US Pat. No. 7,867,378 B2 discloses a fluid catalytic cracking process in which ethanol is first dehydrated in a reactor in the presence of a regenerated high-temperature zeolite catalyst, and the output of this reactor, which contains ethylene product, water as a by-product, and unconverted ethanol, is fed to a subsequent reactor together with a deactivated catalyst, where hydrocarbons are fed and cracked to obtain products. This combination reduces the conversion rate in the main hydrocarbon cracking reactor due to the use of deactivated catalyst from the dehydration reactor. Furthermore, this process is intended for the processing of lighter feedstocks.

[0006] US8373013B2 discloses a process for combining catalytic conversion of organic oxyacid salts such as ethanol to ethylene with catalytic cracking of hydrocarbons in the presence of a Y zeolite catalyst. The coked catalyst from the dehydration reactor and the spent catalyst from the catalytic cracking reactor are mixed and fed to a regenerator for decoking, and the regenerated catalyst is sent back to the reactor.

[0007] Previous prior art has described using a catalyst cooler or placing an ethanol dehydrator upstream of a cracking reactor to remove excess heat. Placing an ethanol dehydrator upstream of a cracking reactor leads to catalyst deactivation entering the hydrocarbon cracking reactor. Furthermore, because ethanol dehydration is promoted at low temperatures, i.e., in the range of 350-550°C, it is necessary to lower the temperature of the regenerated catalyst entering the ethanol dehydration reactor. Therefore, a process is needed to integrate a hydrocarbon residue cracking reactor and a dehydration reactor, limiting the regenerator temperature to below 700°C while avoiding excessive deactivation and ensuring high conversion in the cracking reactor. To address the problems in the art, the present disclosure provides an integration of endothermic ethanol dehydration with residual hydrocarbon processing, thereby utilizing excess heat from the hydrocarbon residue and achieving higher conversion while increasing the yield of light olefins in the catalytic cracking unit.

[0008] In the present disclosure, the coke-containing catalyst from the hydrocarbon cracking reactor is first sent to an ethanol dehydration reactor for producing ethylene. The temperature of the coke-containing catalyst in the dehydration reactor is reduced by the endothermic dehydration process. The low-temperature catalyst from the dehydration reactor is sent to a coke combustor (regenerator) for coke combustion. Due to the lower temperature of the incoming deactivated catalyst, the temperature of the coke combustor in the present disclosure is lower than or in a similar range to that of prior art systems with a catalyst cooler. The lower coke combustor temperature in the present disclosure allows for a higher catalyst-to-oil ratio for a given residue content in the feed, promoting the conversion of hydrocarbons to light olefins. Because a high catalyst-to-oil ratio is ensured in hydrocarbon cracking, the coke level on the coke-containing catalyst is relatively low, and the catalyst maintains sufficient activity for the ethanol dehydration reaction. Furthermore, the present disclosure allows for the desired catalyst-to-oil ratio to be maintained regardless of the residue content in the feed by varying the ethanol / hydrocarbon ratio. Since the fully regenerated catalyst is used for hydrocarbon cracking, the yield of light olefins from hydrocarbons is maximized due to the presence of more active sites on the regenerated catalyst. Furthermore, in the present disclosure, compared to the prior art, the excess heat is fully utilized for dehydrating ethanol without the need for an additional heat sink such as a catalyst cooler, resulting in a higher ethylene yield. Summary of the Invention

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description of the Invention.

[0010] In a first aspect of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, comprising: feeding a hydrocarbon feedstock (1) having a Conradson carbon content (CCR) of at least 4 wt. % and a regenerated catalyst (2) obtained from a coke combustor (a) into a fluidized bed cracking reactor (b); cracking the hydrocarbon feedstock at a temperature in the range of 490-680°C while depositing coke on the catalyst to obtain a reaction mixture comprising hydrocarbon vapor products and the coke-containing catalyst; separating the hydrocarbon vapor product from the coke-containing catalyst at the end of the fluidized bed cracking reactor (b) and fractionating the hydrocarbon vapor product (3); stripping the coke-containing catalyst to remove unseparated contained hydrocarbon vapor products; conducting the coke-containing catalyst and ethanol (5) obtained from the stripping step (4) to a dehydration reactor (c) for dehydrating the ethanol to ethylene to obtain a product mixture and a deactivated catalyst, the dehydration reactor (c) being maintained at a temperature in the range of 300 to 600°C, and the product mixture (6) being conducted to a fluidized bed cracking reactor (b) for fractionation; a step of introducing the deactivated catalyst (7) obtained from the dehydration step into a coke combustor (a) and burning the coke on the deactivated catalyst at a temperature in the range of 600 to 700°C in the presence of air or an oxygen-containing gas (8) to obtain a regenerated catalyst and an exhaust gas (9); and circulating the regenerated catalyst (2) to a fluidized bed cracking reactor (b) for cracking the hydrocarbon feedstock (1); A process for simultaneously increasing the cracking of hydrocarbon feedstocks and the dehydration of ethanol is provided.

[0011] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of hydrocarbon feedstocks is provided, wherein the catalyst is a multifunctional microspherical catalyst.

[0012] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock, comprising a multifunctional microspherical catalyst comprising: 1-6 wt% ultra-stable Y zeolite, 8-25 wt% shape-selective pentasil zeolite, 0-8 wt% of basal-selective active material; 0-1 wt% rare earth component, and 91 to 60 wt% of non-acidic components and binders; The wt% is based on the total weight of the catalyst.

[0013] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks, wherein the ultrastable Y zeolite has a pore size in the range of 8-11 Å, the shape-selective pentasil zeolite has a pore size in the range of 5-6 Å, and the bottom-selective active material has a pore size in the range of 50-1000 Å.

[0014] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, wherein the cracking of the hydrocarbon feedstock (1) is carried out at a temperature in the range of 550-650°C for 40-120 hours. -1 Weight hourly space velocity in the range of 0.9 to 5 kg / cm, catalyst to hydrocarbon ratio in the range of 3 to 25 (wt / wt), 2 (g) and the steam to hydrocarbon ratio is in the range of 0.1 to 1.0 wt / wt.

[0015] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, wherein the dehydration of ethanol is carried out at a temperature in the range of 350-550°C for 1-10 hours. -1 Weight hourly space velocity in the range of 0.9~5Kg / cm 2 (g) pressure range.

[0016] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, in which a dehydration reactor (c) is located downstream of a fluidized bed cracking reactor (b) and upstream of a coke combustor (a).

[0017] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks is provided, which process does not include a separate catalyst cooler or heat exchanger for cooling the catalyst.

[0018] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks is provided, in which hydrocarbon feedstocks with higher CCRs can be processed by increasing the ethanol to hydrocarbon ratio while maintaining a desired catalyst to oil ratio.

[0019] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, wherein the product mixture from the dehydration reactor (c) comprises ethylene, steam, and trace amounts of unconverted ethanol, hydrogen, methane, ethane, propane, and propylene, and the ethylene is recovered in the range of 40-60 wt% based on ethanol.

[0020] In another aspect of the present disclosure, there is provided an integrated system for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock, comprising: a catalytic cracking unit comprising a fluidized bed cracking reactor (b) for receiving a hydrocarbon feedstock (1) and a regenerated catalyst (2) and for cracking the hydrocarbon feedstock to obtain a reaction mixture comprising hydrocarbon products and coke-containing catalyst; a dehydration unit comprising a dehydration reactor (c) for receiving the coke-containing catalyst and ethanol (5) from the fluidized bed cracking (b) and for dehydrating the ethanol to ethylene to obtain a product mixture and a deactivated catalyst; and a coke combustor apparatus comprising a coke combustor (a) for receiving the deactivated catalyst (7) from the dehydration reactor (c) and combusting it in the presence of air or an oxygen-containing gas (8) to regenerate the deactivated catalyst.

[0021] In one embodiment of the present disclosure, an integrated system for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein a dehydration reactor (c) is located downstream of a fluidized bed cracking reactor (b) and upstream of a coke combustor (a).

[0022] In one embodiment of the present disclosure, an integrated system for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock is provided, in which regenerated catalyst obtained from a coke combustor (a) is recycled to a fluidized bed cracking reactor (b).

[0023] In one embodiment of the present disclosure, an integrated system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock is provided, which does not include a separate catalyst cooler for cooling the coked catalyst.

[0024] In one embodiment of the present disclosure, there is provided an integrated system for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, wherein the fluidized bed cracking reactor (b) is a circulating fluidized bed cracking reactor.

[0025] In one embodiment of the present disclosure, there is provided an integrated system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock, the fluidized bed cracking reactor (b) being operated at a temperature in the range of 490 to 680°C for 40 to 120 hours. -1 Weight hourly space velocity in the range of 0.9~5Kg / cm 2 An integrated system is provided that operates at a pressure in the range of (g).

[0026] In one embodiment of the present disclosure, there is provided an integrated system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock, the dehydration reactor (c) being operated at a temperature in the range of 300 to 600°C for 1 to 10 hours. -1 Weight hourly space velocity in the range of 0.9~5Kg / cm 2 An integrated system is provided that operates at a pressure in the range of (g).

[0027] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. This Summary is provided to introduce some concepts in a simplified form. It is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. [Brief explanation of the drawings]

[0028] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure, which may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

[0029] [Figure 1] Schematic flow diagram of a catalytic cracking unit according to one embodiment of the present disclosure, including a fluidized bed cracking reactor (b), a coke combustor (a), a hydrocarbon feedstock (1), a dehydration reactor (c), and an ethanol (5). [Figure 2] FIG. 1 shows the variation of hydrocarbon to ethanol ratio and dehydration temperature with respect to feed CCR.

[0030] In addition, persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not necessarily be drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0031] Those skilled in the art should understand that the present disclosure is subject to variations and modifications other than those specifically described. The present disclosure is to be understood to include all such variations and modifications. Also, the present disclosure includes all such steps of processes, features of the present invention, and any and all combinations of any or more of such steps or features, individually or collectively referred to or indicated herein.

[0032] (definition) Before further description of the present disclosure, for convenience, certain terms used herein and examples are collected here. These definitions should be understood in light of the remainder of the disclosure and should be understood by those skilled in the art. Although the terms used herein have meanings that are recognized and known to those skilled in the art, for convenience and completeness, certain terms and their meanings are provided below.

[0033] The articles "a," "an," and "the" are used to refer to one or to more than one (i.e., at least one) of the grammatical object of the article. The terms "comprise" and "include" are used in an inclusive, open sense, meaning that additional elements may be included. They are not intended to be interpreted as "consisting only of." Throughout this specification, unless the context clearly indicates otherwise, the word "comprise" and variations such as "include" and "comprises" will be understood to mean the inclusion of a stated element or step or group of elements or steps, but not the exclusion of other elements or steps or groups of elements or steps.

[0034] As used in this disclosure, "hydrocarbon feedstock" refers to heavy oil remaining from petroleum distillation that can be further refined in a catalytic cracker. Examples of hydrocarbon feedstocks are vacuum gas oil, coker gas oil, deasphalted oil, hydrogenation bottoms, atmospheric residue, vacuum residue, and mixtures thereof.

[0035] As used in this disclosure, "feed Conradson carbon content (CCR)" refers to the carbonaceous residue formed after thermal breakdown of hydrocarbons, which is a direct indication of the coke-forming tendency of the hydrocarbon feedstock.

[0036] As used in this disclosure, "light olefins" refers to C2 to C4 olefins, such as ethylene, propylene, and butylene.

[0037] As used in this disclosure, "catalyst" refers to any substance that increases the rate of a particular chemical reaction. The catalysts described in this disclosure can be utilized to promote various reactions, such as, but not limited to, cracking (including aromatic cracking), demetallization, desulfurization, and denitrification. As used in this disclosure, "cracking" generally refers to a chemical reaction in which a molecule having a carbon-carbon bond is broken down into one or more molecules by breaking one or more of the carbon-carbon bonds, or a compound containing a cyclic moiety, such as a cycloalkane, cycloalkane, naphthalene, or aromatic, is converted into a compound that does not contain the cyclic moiety or contains fewer cyclic moieties than before the cracking.

[0038] As used in this disclosure, "regenerated catalyst" refers to a catalyst that has been introduced into a cracking reaction zone and then regenerated in a regenerator (coke burner) to remove at least a portion of the coke from the catalyst and / or restore at least a portion of the catalytic activity of the catalyst.

[0039] As used in this disclosure, "multifunctional catalyst" refers to a catalyst that is capable of catalyzing both cracking and dehydration reactions.

[0040] As used in this disclosure, "coke-containing catalyst" refers to a catalyst that has been introduced into and passed through a cracking reaction zone to crack hydrocarbon materials, resulting in the deposition of coke on its surface, and that has not been regenerated in a coke combustor after introduction into the cracking reaction zone.

[0041] As used in this disclosure, "deactivated catalyst" refers to a catalyst that has been introduced into and passed through a dehydration reaction zone, resulting in further coke deposition on its surface and not being regenerated in a coke burner, thus resulting in temporary deactivation of the catalyst. As used in this disclosure, "reactor" refers to a vessel in which one or more chemical reactions can occur, optionally between one or more reactants, in the presence of one or more catalysts.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any processes and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, the preferred processes and materials are described herein. All publications mentioned herein are incorporated by reference. The present disclosure is not limited in scope by the specific embodiments described herein, which are for illustrative purposes only. Functionally equivalent products and processes, as described herein, are clearly within the scope of the present disclosure.

[0043] In a first aspect of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, comprising: feeding a hydrocarbon feedstock (1) having a Conradson carbon content (CCR) of at least 4 wt. % and a regenerated catalyst (2) obtained from a coke combustor (a) into a fluidized bed cracking reactor (b); cracking the hydrocarbon feedstock at a temperature in the range of 490-680°C while depositing coke on the catalyst to obtain a reaction mixture comprising hydrocarbon vapor products and the coke-laden catalyst; separating the hydrocarbon vapor product from the coke-containing catalyst at the end of the fluidized bed cracking reactor (b) and fractionating the hydrocarbon vapor product (3); stripping the coke-containing catalyst to remove unseparated hydrocarbon vapor products; conducting the coke-containing catalyst and ethanol (5) obtained from the stripping step (4) to a dehydration reactor (c) for dehydrating the ethanol to ethylene and obtaining a product mixture and a deactivated catalyst, the dehydration reactor (c) being maintained at a temperature in the range of 300 to 600°C, and the product mixture (6) being conducted to a fluidized bed cracking reactor (b) for fractionation; a step of introducing the deactivated catalyst (7) obtained from the dehydration step into a coke combustor (a) and burning the coke on the deactivated catalyst at a temperature in the range of 600 to 700°C in the presence of air or an oxygen-containing gas (8) to obtain a regenerated catalyst and an exhaust gas (9); circulating the regenerated catalyst (2) to a fluidized bed cracking reactor (b) for cracking the hydrocarbon feedstock (1); A process for simultaneously increasing the cracking of hydrocarbon feedstocks and the dehydration of ethanol is provided.

[0044] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein the hydrocarbon feedstock is selected from the group consisting of vacuum gas oil, coker gas oil, deasphalted oil, hydrogenation bottoms, atmospheric residue, vacuum residue, and mixtures thereof.

[0045] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein the hydrocarbon vapor products obtained from the cracking step include propylene, ethylene, butylene, hydrogen, ethane, propane, butane, isobutene, light cracked naphtha, heavy cracked naphtha, light cycle oil, heavy cycle oil, clarified oil, etc.

[0046] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of hydrocarbon feedstock, wherein the product mixture obtained from the dehydration reactor (c) is introduced downstream of the fluidized bed cracking reactor (b) for fractionation to obtain a light olefin fraction, the light olefin fraction mainly comprising ethylene obtained from the ethanol dehydration and hydrocarbon cracking and C3-C4 olefins obtained from the hydrocarbon cracking.

[0047] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of hydrocarbon feedstocks is provided, wherein the catalyst is a multifunctional microspherical catalyst.

[0048] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock, comprising a multifunctional microspherical catalyst comprising: 1-6 wt% ultra-stable Y zeolite, 8-25 wt% shape-selective pentasil zeolite, 0-8 wt% of basal-selective active material; 0-1 wt% rare earth component, and 91 to 60 wt % of non-acidic components and binders; The wt% is based on the total weight of the catalyst.

[0049] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of hydrocarbon feedstocks is provided, wherein the bottom selective active material is alumina or peptized alumina.

[0050] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein the rare earth component comprises an oxide of lanthanum or cerium.

[0051] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein the non-acidic component comprises silica, alumina, or a natural clay such as kaolin or kaolinite.

[0052] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks is provided, wherein the ultrastable Y zeolite has a pore size in the range of 8-11 Å, the shape-selective pentasil zeolite has a pore size in the range of 5-6 Å, and the bottom-selective active material has a pore size in the range of 50-1000 Å.

[0053] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, wherein the cracking of the hydrocarbon feedstock (1) is carried out at a temperature in the range of 550-650°C for 40-120 hours. -1 Weight hourly space velocity in the range of 0.9 to 5 kg / cm, catalyst to hydrocarbon ratio in the range of 3 to 25 (wt / wt), 2 (g) and the steam to hydrocarbon ratio is in the range of 0.1 to 1.0 wt / wt.

[0054] In one embodiment of the present disclosure, there is provided an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock, wherein the dehydration of ethanol is carried out at a temperature in the range of 350-550°C for 1-10 hours. -1 Weight hourly space velocity in the range of 0.9~5Kg / cm 2 (g) pressure range.

[0055] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, in which a dehydration reactor (c) is located downstream of a fluidized bed cracking reactor (b) and upstream of a coke combustor (a).

[0056] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock is provided, which process does not include a separate catalyst cooler or heat exchanger for cooling the catalyst.

[0057] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks is provided, in which hydrocarbon feedstocks with higher CCRs can be processed by increasing the ethanol to hydrocarbon ratio while maintaining a desired catalyst to oil ratio.

[0058] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks is provided, wherein the desired catalyst to oil ratio is in the range of 5-20.

[0059] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of hydrocarbon feedstocks is provided, wherein the ethanol to hydrocarbon ratio ranges from 0 to 2 wt / wt.

[0060] In one embodiment of the present disclosure, an integrated circulating fluidized bed process for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein the product mixture comprises ethylene, water vapor, and trace amounts of unconverted ethanol, hydrogen, methane, ethane, propane, and propylene, and ethylene is recovered in the range of 40-60 wt% based on ethanol.

[0061] In another aspect of the present disclosure, there is provided an integrated system for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock, comprising: a catalytic cracking unit comprising a fluidized bed cracking reactor (b) for receiving a hydrocarbon feedstock (1) and a regenerated catalyst (2) and for cracking the hydrocarbon feedstock to obtain a reaction mixture comprising hydrocarbon products and coke-containing catalyst; a dehydration unit comprising a dehydration reactor (c) for receiving the coke-containing catalyst and ethanol (5) from the fluidized bed cracking (b) and for dehydrating the ethanol to ethylene to obtain a product mixture and a deactivated catalyst; and a coke combustor apparatus including a coke combustor (a) for receiving the deactivated catalyst (7) from the dehydration reactor (c) and combusting it in the presence of air or an oxygen-containing gas (8) to regenerate the deactivated catalyst.

[0062] In one embodiment of the present disclosure, an integrated system for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein a dehydration reactor (c) is located downstream of a fluidized bed cracking reactor (b) and upstream of a coke combustor (a).

[0063] In one embodiment of the present disclosure, an integrated system for simultaneous ethanol dehydration and cracking of hydrocarbon feedstock is provided, in which regenerated catalyst obtained from a coke combustor (a) is recycled to a fluidized bed cracking reactor (b).

[0064] In one embodiment of the present disclosure, an integrated system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock is provided, the system not including a separate catalyst cooling device for cooling the catalyst.

[0065] In one embodiment of the present disclosure, an integrated system for simultaneous dehydration of ethanol and cracking of a hydrocarbon feedstock is provided, wherein the fluidized bed cracking reactor (a) is a circulating fluidized bed cracking reactor.

[0066] In one embodiment of the present disclosure, there is provided an integrated system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock, the fluidized bed cracking reactor (b) being operated at a temperature in the range of 490 to 680°C for 40 to 120 hours. -1 Weight hourly space velocity in the range of 0.9 to 5 kg / cm 2 (g) is a pressure range of the system.

[0067] In one embodiment of the present disclosure, there is provided an integrated system for simultaneously dehydrating ethanol and cracking a hydrocarbon feedstock, the dehydration reactor (c) being operated at a temperature in the range of 300 to 600°C for 1 to 10 hours. -1 Weight hourly space velocity in the range of 0.9~5Kg / cm 2 (g) is a pressure range of the system.

[0068] The following description provides a detailed description of the process and system according to the present disclosure.

[0069] Figure 1 shows a catalytic cracking unit equipped with a fluidized-bed cracking reactor (1) for processing a heavy hydrocarbon feedstock (1) having a CCR of at least 4 wt%. A catalyst (2) regenerated from a coke burner at a temperature of 600-700°C enters the fluidized-bed cracking reactor (b) where it contacts the hydrocarbon feedstock (1). The hydrocarbon feedstock is instantly vaporized and cracked in the presence of the catalyst in the fluidized-bed cracking reactor (b). The reactor outlet temperature is maintained in the range of 550-650°C by adjusting the catalyst-to-oil ratio. During cracking, the catalyst is deactivated by the deposition of coke and other feed impurities. Separation of the coke-laden catalyst from the hydrocarbon product vapor occurs at the end of the fluidized-bed cracking reactor (b). After stripping the coke-laden catalyst from the hydrocarbons (unseparated hydrocarbon vapor product), it is sent to the dehydration reactor (c). Ethanol (5) is introduced into the dehydration reactor, where it is dehydrated to ethylene in the presence of the coke-containing catalyst. The temperature of the ethanol dehydration reactor is maintained in the range of 350–550 °C depending on the CCR of the feed hydrocarbon. Because the dehydration reaction is highly endothermic, a catalyst cooler is not required to reduce the catalyst temperature. As the CCR of the feed hydrocarbon increases, the temperature of the dehydration reactor is reduced by increasing the hydrocarbon-to-ethanol ratio so that the temperature of the coke burner is maintained below 700 °C. The dehydration reactor output mixture, consisting of ethylene, steam, and trace amounts of hydrocarbons such as hydrogen, methane, ethane, propane, and propylene, is sent downstream to a fluidized-bed cracking reactor (b) for fractionation. The product mixture from the dehydration reactor contains 40–60 wt% ethylene. In addition to coke deposition during cracking, 0.1–0.25 wt% coke is also deposited on the catalyst during ethanol dehydration.

[0070] Here, the coke deposited on the catalyst is burned with air or oxygen-containing gas at temperatures ranging from 600 to 700°C to restore the catalyst activity. After coke combustion, the regenerated catalyst is recycled to the fluidized bed cracking reactor (b).

[0071] The following description describes the conditions and catalysts employed in a process or system according to the present disclosure.

[0072] Residual hydrocarbon feedstock having a CCR of at least 4 wt% is cracked in a reactor in the presence of a multifunctional microspherical catalyst consisting of 1-6 wt% ultrastable Y-zeolite; 8-25 wt% shape-selective pentasil zeolite; 0-8 wt% bottom-selective active material; 0-1 wt% rare earth component; and 91-60 wt% non-acidic component and binder. The cracking of hydrocarbons is carried out at an operating temperature in the range of 490-680°C, preferably 550-650°C, and at a yield of 0.9-5 Kg / cm. 2 (g), preferably 1.0 to 1.5 kg / cm 2 The desired operating pressure ranges from 40 to 120 h (g). -1 The hydrocarbon to catalyst ratio is maintained in the range of 3 to 25 (wt / wt), preferably 5 to 22. The residence time of the feed to the cracking reactor is maintained in the range of 1 to 10 seconds, preferably 3 to 7 seconds. The dehydration reactor is maintained in the range of 0.9 to 5 kg / cm. 2 (g) range pressure and 1~10hr -1 The reactor is operated at a weight hourly space velocity (WHSV) of 1000 to 600°C. The temperature of the ethanol dehydration reactor is maintained in the range of 300 to 600°C, preferably 350 to 550°C. The resulting reaction mixture consists of cracked hydrocarbons with a total ethylene yield in the range of 40 to 60 wt%. Other gaseous products produced in the cracking and dehydration process include propylene, butylene, methane, hydrogen, propane, butane, etc. The liquid products produced in the process can be fractionated according to the desired cut range. The catalyst is deactivated during the cracking process due to the deposition of coke. The coke consists of carbon, hydrogen, sulfur, nitrogen, and metals (Ni, Na, V, Fe, and other trace metals present in the feedstock). Although the subject matter has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. [Example]

[0073] The present disclosure will now be described by way of examples, which are intended to illustrate the implementation of the present disclosure and are not intended to be limiting as meaning limitations on the scope of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. Although similar or equivalent processes and materials to those described herein can be used in the implementation of the disclosed processes, exemplary processes, devices, and materials are described herein. It should be understood that the present disclosure is not limited to the specific processes and experimental conditions described, as such processes and conditions may vary. Those skilled in the art will recognize that the present examples are further subject to variations and modifications specifically described herein based on the technical requirements of the experiments, and are not intended to be limiting to those specifically described.

[0074] (Materials and Processes) Catalytic cracking experiments were carried out in a fixed-bed microreactor unit using a coked catalyst obtained from a commercial high-severity fluid catalytic cracking unit. The coke content on the catalyst was 0.65%. Analytical grade ethanol (purity 99.99%) was used in the experiments. WHSV: 5 hr -1 The commercial operating conditions of the dehydration reactor were estimated by maintaining the same temperature. The feed ethanol was contacted with the catalyst bed, and a reaction mixture was obtained downstream of the reactor. The product gas from the reactor was passed through a cooler to separate the liquid and gas, and the resulting liquid and gas samples were analyzed by gas chromatography. The deactivated catalyst was regenerated by passing air through the catalyst bed. The experiment was repeated using the regenerated catalyst to evaluate the effect of "coke on catalyst" on the dehydration reaction.

[0075] Example 1 To investigate the effect of catalyst deactivation on the ethylene yield obtained from ethanol dehydration, experimental data for ethanol dehydration were generated using a commercial coke-containing catalyst (0.65% coke on the spent catalyst) and a regenerated catalyst. [Table 1]

[0076] The data in Table 1 show that the coked catalyst does not significantly reduce the ethylene yield at 400°C compared to the regenerated catalyst.

[0077] Example 2 The effect of increasing temperature on ethanol dehydration is shown in Table 2. It has been verified that increasing the temperature above 400°C reduces the ethylene yield, and therefore the limitations of prior art US7867378 are addressed in the present disclosure.

[0078] [Table 2]

[0079] Example 3 To estimate the ethanol-to-hydrocarbon ratio required for a given feed CCR and corresponding dehydration temperature, a heat balance calculation for the system was performed at a cracking temperature of 600 °C and a coke burner temperature of 700 °C. The variation of ethanol-to-hydrocarbon ratio and dehydration temperature with feed CCR is shown in Figure 2.

[0080] It is observed that the ethanol to hydrocarbon ratio increases with increasing feed CCR, while the dehydration temperature decreases to control the combustor temperature, demonstrating that the present disclosure provides flexibility in the feed CCR that can be processed in the cracking reactor by varying the hydrocarbon to ethanol ratio.

[0081] Overall, the present disclosure provides an integrated circulating fluidized bed process and system for simultaneous ethanol dehydration and cracking of hydrocarbon feedstocks. The present disclosure provides high conversion of residual hydrocarbons while maintaining a desired catalyst-to-oil ratio, independent of feedstock weight. As a result, high yields of light olefins are achieved through the conversion of ethanol to ethylene in the dehydration reactor. The present disclosure expands the range of feedstocks that can be processed in catalytic cracking processes. The present disclosure prevents thermal deactivation of the catalyst by maintaining lower coke burner temperatures through the integration of the endothermic ethanol dehydration reaction.

[0082] It will therefore be understood that all matter contained in the above description is intended to be interpreted as illustrative and not in a limiting sense, since the above-described objectives, among those apparent from the preceding description, are efficiently attained and certain changes can be made in the described structure without departing from the spirit and scope of the present invention. The present invention has been described with reference to preferred and alternative embodiments. Changes and modifications will become apparent to those skilled in the art upon reading and understanding the detailed discussion of the invention provided herein. The present invention is intended to include all such changes and modifications insofar as they fall within the scope of the present invention. These and other modifications of the preferred embodiment, as well as other embodiments of the present invention, will be apparent from the disclosure herein, whereby the foregoing illustrative matter is intended to be merely illustrative of the present invention, and not limiting.

[0083] Finally, to the extent necessary to understand or complete the disclosure of the present invention, all publications, patents, and patent applications mentioned herein are expressly incorporated by reference to the same extent as if each were individually incorporated.

Claims

1. 1. An integrated circulating fluidized bed process for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock, comprising: feeding a hydrocarbon feedstock (1) having a Conradson carbon content (CCR) of at least 4 wt. % and a regenerated catalyst (2) obtained from a coke combustor (a) into a fluidized bed cracking reactor (b); cracking the hydrocarbon feedstock at a temperature in the range of 490-680°C while depositing coke on the catalyst to obtain a reaction mixture comprising hydrocarbon vapor products and coke-containing catalyst; separating the hydrocarbon vapor product from the coke-containing catalyst at the end of the fluidized bed cracking reactor (b) and introducing the hydrocarbon vapor product for fractionation (3); stripping the coke-containing catalyst to remove unseparated hydrocarbon vapor products; conducting the coke-containing catalyst and ethanol (5) obtained from the stripping step (4) to a dehydration reactor (c) for dehydrating the ethanol to ethylene and obtaining a product mixture and a deactivated catalyst, the dehydration reactor (c) being maintained at a temperature in the range of 350 to 600°C, and the product mixture (6) being conducted to the fluidized bed cracking reactor (b) for fractionation; a step of introducing the deactivated catalyst (7) obtained from the dehydration step into the coke combustor (a) and combusting the coke on the deactivated catalyst at a temperature in the range of 600 to 700°C in the presence of air or an oxygen-containing gas (8) to obtain the regenerated catalyst and exhaust gas (9); circulating the regenerated catalyst (2) to the fluidized bed cracking reactor (b) for cracking the hydrocarbon feedstock (1); simultaneously increasing the cracking of the hydrocarbon feedstock and the dehydration of the ethanol; the catalyst is a multifunctional microspherical catalyst; The multifunctional microspherical catalyst comprises: 1-6 wt% ultrastable Y zeolite, 8-25 wt% of a shape-selective pentasil zeolite; 0-8 wt % of a basal-selective active material; 0-1 wt % rare earth component, and 91 to 60 wt % of non-acidic components and binders; wt% is based on the total weight of the catalyst; the ultrastable Y zeolite has a pore size in the range of 8-11 Å, the shape selective pentasil zeolite has a pore size in the range of 5-6 Å, and the basal selective active material has a pore size in the range of 50-1000 Å.

2. The decomposition of the hydrocarbon feedstock (1) is carried out at a temperature in the range of 550 to 650°C for 40 to 120 hours. －１ a weight hourly space velocity in the range of 0.9 to 5 kg / cm; a catalyst to hydrocarbon ratio in the range of 3 to 25 (wt / wt); ２ 10. The process of claim 1, wherein the process is carried out at a pressure in the range of (g) and a steam to hydrocarbon ratio in the range of 0.1 to 1.0 wt / wt.

3. The dehydration of the ethanol is carried out at a temperature in the range of 350 to 550°C for 1 to 10 hours. －１ and 0.9 to 5 Kg / cm ２ 10. The process of claim 1, wherein the process is carried out at a pressure in the range of (g).

4. 2. The process of claim 1, wherein the dehydration reactor (c) is located downstream of the fluidized bed cracking reactor (b) and upstream of the coke combustor (a).

5. 10. The process of claim 1, which does not include a separate catalyst cooler or heat exchanger for cooling the catalyst.

6. 10. The process of claim 1, wherein the product mixture comprises ethylene, steam, and trace amounts of unconverted ethanol, hydrogen, methane, ethane, propane, and propylene, and wherein ethylene is recovered in the range of 40 to 60 wt %, based on ethanol.

7. 1. An integrated system for simultaneous ethanol dehydration and cracking of a hydrocarbon feedstock, comprising: a catalytic cracking unit comprising a fluidized bed cracking reactor (b) for receiving the hydrocarbon feedstock (1) and the regenerated catalyst (2) and cracking the hydrocarbon feedstock to obtain a reaction mixture comprising hydrocarbon products and coke-containing catalyst; a dehydration reactor (c) for receiving the coke-containing catalyst and the ethanol (5) from the fluidized-bed cracking reactor (b) and for dehydrating the ethanol to ethylene to obtain a product mixture and a deactivated catalyst; and a coke burner (a) for receiving the deactivated catalyst (7) from the dehydration reactor (c) and burning it in the presence of air or an oxygen-containing gas (8) to regenerate the deactivated catalyst, wherein the fluidized bed cracking reactor (b) operates at a temperature in the range of 490 to 680°C, the dehydration reactor (c) operates at a temperature in the range of 350 to 600°C, and the coke burner operates at a pressure in the range of 0.9 to 5 kg / cm2 (g).

8. 8. The integrated system of claim 7, wherein the dehydration reactor (c) is located downstream of the fluidized bed cracking reactor (b) and upstream of the coke combustor (a).

9. 8. The integrated system of claim 7, wherein the regenerated catalyst obtained from the coke combustor (a) is recycled to the fluidized bed cracking reactor (b).

10. 8. The integrated system of claim 7, which does not include a separate catalyst cooling device for cooling the catalyst.

11. 8. The integrated system of claim 7, wherein the fluidized bed decomposition reactor (1b) is a circulating fluidized bed decomposition reactor.

12. The fluidized bed decomposition reactor (b) is operated for 40 to 120 hours. －１ 8. The integrated system of claim 7, wherein the integrated system is operated at a weight hourly space velocity in the range of

13. The dehydration reactor (c) is a reactor having a duration of 1 to 10 hours. －１ 8. The integrated system of claim 7, wherein the integrated system is operated at a weight hourly space velocity in the range of

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