High-temperature-resistant sulfur-reducing additive and method for reducing sulfur and upgrading coking propylene

Abstract

The present application belongs to the technical field of propylene desulfurization, and particularly relates to a high-temperature-resistant sulfur-reducing additive and a method for reducing and upgrading the sulfur content of coking propylene by using the sulfur-reducing additive. The high-temperature-resistant sulfur-reducing additive comprises acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve and USY molecular sieve as effective components. The method for reducing and upgrading the sulfur content of coking propylene relies on the mature catalytic cracking process to reduce the sulfur content of coking propylene. By compounding the high-temperature-resistant sulfur-reducing additive with the catalytic cracking catalyst, carbonyl sulfur can be transferred to hydrogen sulfide under the condition that the state of propylene remains unchanged. The hydrogen sulfide can be absorbed by lean amine liquid, so as to achieve the purpose of reducing and upgrading the sulfur content of coking propylene.

Description

Technical Field

[0001] This invention belongs to the field of propylene desulfurization technology, specifically relating to a high-temperature resistant desulfurization aid and a method for desulfurizing and upgrading coking propylene using the aforementioned desulfurization aid. Background Technology

[0002] Propylene is an important organic compound, a colorless, odorless gas with a slightly sweet taste at room temperature. It has a rich downstream industrial chain and is used industrially to prepare acrylonitrile, propylene oxide, isopropanol, phenol, acetone, butanol, octanol, acrylic acid and its esters, propylene glycol, epichlorohydrin, and to synthesize glycerol, among many other compounds. It is an important chemical intermediate.

[0003] Currently, there are four main processes for the production and preparation of propylene: crude oil catalytic cracking, naphtha steam cracking, methanol (coal) to olefins, and propane dehydrogenation. (1) Refinery gas recovery: a certain amount of propylene is produced in the refinery gas by-products of catalytic cracking and delayed coking processes in oil refineries. (2) The process of producing propylene by naphtha steam cracking is relatively widely used. Naphtha undergoes molecular chain breakage and dehydrogenation reaction in a tubular heater under high temperature and steam environment to produce light hydrocarbons such as ethylene and propylene. Although the ethylene yield is relatively high in the naphtha steam cracking process, the propylene yield will also increase positively as the molecular weight of naphtha increases. (3) The methanol (coal) to olefins process is in line with China's resource structure of abundant coal and scarce oil. The technology selection is diversified, and China's production technology is relatively mature. The mainstream of the methanol (coal) to olefins process is to rely on coal resources to form an integrated construction from raw coal to olefins and even downstream polyolefins. (4) The propane dehydrogenation process is to produce propylene by dehydrogenation catalytic reaction of propane.

[0004] Qilu Petrochemical's butanol and octanol unit utilizes a low-pressure carbonyl synthesis process using syngas and propylene as feedstock. The process employs a catalyst liquid-phase circulation (LPO) method, where a carbonyl synthesis reaction occurs in the presence of a rhodium catalyst at 85-115℃ to produce mixed butyraldehyde. In this process, the propylene feedstock primarily consists of olefin plant cracking and polymerization grade propylene, chemical grade propylene, and a small amount of refinery catalytic propylene. The purity of coking propylene from the refinery can reach over 99.5%, exceeding the ≥95% purity requirement for chemical grade propylene used in the butanol and octanol unit. However, due to the high sulfur content in coking propylene, the activity of the rhodium catalyst in the carbonyl synthesis is affected, making it difficult to apply to butanol and octanol production. Instead, the company can only sell it to other companies at low prices, preventing direct downstream applications. Therefore, developing a process that can reduce the sulfur content and improve the quality of coking propylene is of significant importance for the direct downstream applications of propylene.

[0005] In existing technologies, to remove carboxyl sulfur from propylene, sulfur reduction is mainly achieved stepwise in a fixed-bed reactor using hydrolysants and desulfurizing agents. This method is effective when the hydrocarbon material to be refined contains a high content of carbonyl sulfur, but deep desulfurization is often difficult to achieve, and trace amounts of carbonyl sulfur are hard to remove. For example, the scheme disclosed in Chinese patent CN103539612A utilizes a desulfurizing agent for the desulfurization and upgrading of propylene, but this method suffers from problems such as a complex desulfurization process, the need for desulfurization equipment, and high desulfurization costs. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to provide a high-temperature resistant sulfur-reducing agent, which, when used in combination with a catalytic cracking catalyst, can effectively reduce the sulfur content of coking propylene and achieve the purpose of quality improvement.

[0007] The second technical problem to be solved by the present invention is to provide a method for reducing the carbonyl sulfur content of coking propylene, improving the quality of coking propylene, and ensuring that the yield of coking propylene does not decrease.

[0008] To solve the above-mentioned technical problems, the present invention provides a high-temperature resistant desulfurization agent, wherein the desulfurization agent comprises the following components in parts by weight: acidified kaolin 36-44 wt%, ammonium metavanadate 4-6 wt%, zinc oxide 22-28 wt%, nickel oxide 3-5 wt%, REY molecular sieve 21-26 wt%, and USY molecular sieve 2-4 wt%.

[0009] The desulfurization aid described in this invention can decompose at a temperature of ≥700℃, with the aim of preventing the desulfurization catalyst from decomposing inside the riser.

[0010] The present invention also discloses a method for preparing the high-temperature resistant sulfur-reducing additive, comprising the following steps: taking selected amounts of the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve, mixing and pulping them, and collecting the reactants, filtering them, and then drying, calcining, and grinding them.

[0011] Specifically, the preparation method of the high-temperature resistant desulfurization agent is as follows:

[0012] The temperature of the drying step is 100-150℃, and the preferred drying time is 2-4 hours.

[0013] The temperature of the roasting step is 400-600℃, and the roasting time is preferably 2-4 hours.

[0014] The grinding step controls the particle size to be 60-100 micrometers.

[0015] The present invention also discloses a method for reducing sulfur and improving the quality of coking propylene, comprising the step of contacting coking propylene and catalytic cracking feedstock with a catalyst and carrying out a catalytic cracking reaction;

[0016] The catalyst comprises a mixture of a catalytic cracking catalyst and the sulfur reduction aid.

[0017] Preferably, the catalytic cracking feedstock comprises a mixture of Shengli crude oil vacuum residue, VRDS atmospheric residue, and hydrotreated coking wax oil, and the density (20°C) of the feedstock is approximately 0.9100-0.9200 g / cm³. 3 .

[0018] The method for desulfurization and upgrading of coking propylene described in this invention involves the transfer of carbonyl sulfur in the coking propylene during the reaction process under the action of a catalytic cracking catalyst and a desulfurization aid, resulting in a significant reduction in sulfur content without a noticeable decrease in propylene yield.

[0019] Specifically, the amount of the desulfurization aid accounts for 3-8 wt% of the total amount of the catalyst, with a preferred proportion of 5 wt%.

[0020] Specifically, in the method for reducing sulfur and improving the quality of coking propylene, the mass ratio of the catalyst to the feedstock oil is 1:6-10.

[0021] Specifically, the catalytic cracking catalyst is preferably the catalytic cracking catalyst used in the three catalytic units of Qilu Petrochemical, such as a mixture of COCK-1 and HCRI.

[0022] Specifically, in the method for reducing sulfur and upgrading the quality of coking propylene, the reaction temperature of the catalytic cracking reaction step is 500-550℃.

[0023] Specifically, the method for reducing sulfur and upgrading the quality of coking propylene uses a RU-II type continuous riser catalytic cracking unit for the reaction.

[0024] Specifically, the method for reducing sulfur and improving the quality of coking propylene includes the step of feeding the coking propylene and feedstock oil into the riser reactor from the terminator inlet of the catalytic cracking unit for reaction.

[0025] Specifically, in the method for reducing sulfur and improving the quality of coking propylene, the temperature at the inlet of the terminator is controlled at 455-475℃, and the input flow rate of the coking propylene is controlled at 80-120ml / min.

[0026] Specifically, the method for reducing sulfur and upgrading the quality of coking propylene also includes a step of regenerating the catalyst;

[0027] Preferably, the temperature of the regeneration step is controlled at 620-680°C.

[0028] The method for reducing sulfur and improving the quality of coking propylene described in this invention preferably uses a RU-II type continuous riser catalytic cracking evaluation test device. Coking propylene is introduced into the riser reactor of the catalytic cracking unit. A suitable position for the coking propylene to enter the riser reactor is selected so that the coking propylene comes into contact with the catalyst in the riser reactor. Carbonyl sulfur in the coking propylene is transferred, the sulfur content is greatly reduced, and the propylene yield is not significantly reduced.

[0029] The high-temperature resistant desulfurization aid of this invention uses acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve as effective components. The desulfurization agent has a decomposition temperature of ≥700℃ and can be regenerated and recycled, effectively ensuring that the desulfurization aid will not decompose within the riser. When used in combination with a catalytic cracking catalyst, the high-temperature resistant desulfurization aid of this invention effectively overcomes the problem of decomposition and deactivation of the desulfurization agent caused by adding it alone in traditional processes at high temperatures within the riser.

[0030] The method for desulfurizing and upgrading coking propylene described in this invention relies on a mature catalytic cracking process to reduce the sulfur content of coking propylene. By using a high-temperature resistant desulfurization aid in combination with a catalytic cracking catalyst, carbonyl sulfur can be transferred to hydrogen sulfide while the propylene remains in its original state. This hydrogen sulfide can then be absorbed by the lean amine solution, thereby achieving the goal of desulfurizing and upgrading coking propylene. This effectively solves the problems of complex desulfurization processes and difficulty in removing trace amounts of sulfur in existing technologies. Using this method, the carbonyl sulfur content of the desulfurized coking propylene is reduced from 4 ppm to below 0.5 ppm, and propylene loss is reduced by more than 1%, effectively overcoming the difficulty of existing adsorption desulfurization methods in reducing the sulfur content of coking propylene to below 0.5 ppm.

[0031] The present invention describes a method for reducing sulfur content and improving the quality of coking propylene. This method relies on a mature catalytic cracking process to reduce the sulfur content of coking propylene. In the later stages, it can be combined with the characteristics of Qilu Petrochemical Refining and Chemical Enterprise, and take advantage of the existing conditions of using catalytic propylene as feedstock for butanol and octanol. After the coking propylene is upgraded in the catalytic cracking riser reactor, it can provide feedstock for butanol and octanol. This method has the characteristics of low investment, simple process, and significant sulfur reduction effect. Attached Figure Description

[0032] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0033] Figure 1 This is a schematic diagram of the process flow of the RU-II type riser catalytic cracking test apparatus;

[0034] The reference numerals in the figure are: 1-regenerator, 2-retransmission line, 3-riser reactor, 4-terminant inlet, 5-separator settling tank, 6-fractionation system, 7-stripper, 8-line to be transported. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0036] The following embodiments of the present invention are based on... Figure 1 The evaluation test was completed on the RU-II type continuous riser catalytic cracking evaluation test apparatus shown.

[0037] like Figure 1 The structure and process shown indicate that the regenerated catalyst (including catalytic cracking catalyst and desulfurization additive) is transported from regenerator 1 to the bottom of riser reactor 3 via refeed line 2. Pre-lifted and preheated catalytic cracking feedstock oil and atomized steam enter riser reactor 3 from the bottom of the riser, while coking propylene enters riser reactor 3 from terminator inlet 4. The coking propylene and atomized catalytic cracking feedstock oil contact the catalyst and undergo a cracking reaction. After the reaction is complete, the oil, gas, and catalyst are lifted together to separator settling tank 5. After settling and filtration, the catalyst enters the post-distillation system 6 from the top of the settling tank. The coked catalyst falls into stripper 7, is stripped with steam, and then transported to the top of regenerator via feed line 8. In the regenerator, the coked catalyst is regenerated by air burning.

[0038] In the following embodiments and comparative examples of the present invention, the catalytic cracking feedstock used is a feedstock used in conventional processes, including a mixture of Shengli crude oil vacuum residue, VRDS atmospheric residue, and hydrotreated coking wax oil. The density (20°C) of the feedstock is approximately 0.9100-0.9200 g / cm³. 3 .

[0039] In the following Examples 1-5 and Comparative Examples 1-2 of the present invention, the sulfur reduction effect and propylene loss of the method were investigated separately without the addition of feedstock oil.

[0040] Example 1

[0041] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0042] The catalyst loading in the riser reactor is 7000g, including 6650g of catalyst from Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0043] The catalyst used in the Qilu Petrochemical No. 3 catalytic converter is COCK-1 catalyst produced by Sinopec Catalyst Qilu Branch, with a specific surface area of ​​≥240 m². 2 / g, microreactive activity ≥74, sieve composition ≥89 for 0-149μm and ≤18 for 0-40μm.

[0044] The sulfur-reducing additive comprises the following components in parts by weight: 44 parts acidified kaolin, 5 parts ammonium metavanadate, 22 parts zinc oxide, 3 parts nickel oxide, 23 parts REY molecular sieve, and 3 parts USY molecular sieve.

[0045] According to the selected components mentioned above, the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve are mixed and pulped. The reactants are collected, filtered, dried at 120°C for 3 hours, calcined at 500°C for 3 hours, and ground to a particle size of 60-100 micrometers to obtain the final product.

[0046] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment involves coking propylene entering the riser reactor from the inlet of the terminator in the riser device, controlling the inlet temperature of the terminator at 455°C, the flow rate of coking propylene at 100 ml / min, controlling the reaction temperature inside the reactor at 510°C, and controlling the regeneration temperature of the catalyst at 650°C.

[0047] Example 2

[0048] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0049] The catalyst loading in the riser reactor is 7000g, including 6650g of catalyst from Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0050] The catalyst used in the Qilu Petrochemical No. 3 catalytic converter is COCK-1 catalyst produced by Sinopec Catalyst Qilu Branch, with a specific surface area of ​​≥240 m². 2 / g, microreactive activity ≥74, sieve composition ≥89 for 0-149μm and ≤18 for 0-40μm.

[0051] The sulfur-reducing additive comprises the following components in parts by weight: 36 parts acidified kaolin, 4 parts ammonium metavanadate, 28 parts zinc oxide, 5 parts nickel oxide, 24 parts REY molecular sieve, and 3 parts USY molecular sieve.

[0052] According to the selected components mentioned above, the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve are mixed and pulped. The reactants are collected, filtered, dried at 120°C for 3 hours, calcined at 500°C for 3 hours, and ground to a particle size of 60-100 micrometers to obtain the final product.

[0053] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment involves coking propylene entering the riser reactor from the terminator inlet of the riser device, controlling the terminator inlet temperature at 460°C, the coking propylene flow rate at 100 ml / min, controlling the reaction temperature inside the reactor at 510°C, and the catalyst regeneration temperature at 650°C.

[0054] Example 3

[0055] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0056] The catalyst loading in the riser reactor is 7000g, including 6650g of catalyst from Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0057] The catalyst used in the Qilu Petrochemical No. 3 catalytic converter is COCK-1 catalyst produced by Sinopec Catalyst Qilu Branch, with a specific surface area of ​​≥240 m². 2 / g, microreactive activity ≥74, sieve composition ≥89 for 0-149μm and ≤18 for 0-40μm.

[0058] The sulfur-reducing additive comprises the following components in parts by weight: 38 parts acidified kaolin, 6 parts ammonium metavanadate, 26 parts zinc oxide, 4 parts nickel oxide, 22 parts REY molecular sieve, and 4 parts USY molecular sieve.

[0059] According to the selected components mentioned above, the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve are mixed and pulped. The reactants are collected, filtered, dried at 120°C for 3 hours, calcined at 500°C for 3 hours, and ground to a particle size of 60-100 micrometers to obtain the final product.

[0060] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment involves coking propylene entering the riser reactor from the inlet of the riser device's terminator. The inlet temperature of the terminator is controlled at 465°C, the flow rate of coking propylene is 100 ml / min, the reaction temperature inside the reactor is controlled at 510°C, and the regeneration temperature of the catalyst is 650°C.

[0061] Example 4

[0062] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0063] The catalyst loading in the riser reactor is 7000g, including 6650g of catalyst from Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0064] The catalyst used in the Qilu Petrochemical No. 3 catalytic converter is COCK-1 catalyst produced by Sinopec Catalyst Qilu Branch, with a specific surface area of ​​≥240 m². 2 / g, microreactive activity ≥74, sieve composition ≥89 for 0-149μm and ≤18 for 0-40μm.

[0065] The sulfur-reducing additive comprises the following components in parts by weight: 42 parts acidified kaolin, 4 parts ammonium metavanadate, 24 parts zinc oxide, 3 parts nickel oxide, 25 parts REY molecular sieve, and 2 parts USY molecular sieve.

[0066] According to the selected components mentioned above, the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve are mixed and pulped. The reactants are collected, filtered, dried at 120°C for 3 hours, calcined at 500°C for 3 hours, and ground to a particle size of 60-100 micrometers to obtain the final product.

[0067] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment involves coking propylene entering the riser reactor from the terminator inlet of the riser device, controlling the terminator inlet temperature at 470°C, the coking propylene flow rate at 100 ml / min, controlling the reaction temperature inside the reactor at 510°C, and controlling the catalyst regeneration temperature at 650°C.

[0068] Example 5

[0069] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0070] The catalyst loading in the riser reactor is 7000g, including 6650g of catalyst from Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0071] The catalyst used in the Qilu Petrochemical No. 3 catalytic converter is COCK-1 catalyst produced by Sinopec Catalyst Qilu Branch, with a specific surface area of ​​≥240 m². 2 / g, microreactive activity ≥74, sieve composition ≥89 for 0-149μm and ≤18 for 0-40μm.

[0072] The sulfur-reducing additive comprises the following components in parts by weight: 44 parts acidified kaolin, 5 parts ammonium metavanadate, 22 parts zinc oxide, 3 parts nickel oxide, 23 parts REY molecular sieve, and 3 parts USY molecular sieve.

[0073] According to the selected components mentioned above, the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve, and USY molecular sieve are mixed and pulped. The reactants are collected, filtered, dried at 120°C for 3 hours, calcined at 500°C for 3 hours, and ground to a particle size of 60-100 micrometers to obtain the final product.

[0074] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment involves coking propylene entering the riser reactor from the terminator inlet of the riser device, controlling the terminator inlet temperature at 475°C, the coking propylene flow rate at 100 ml / min, controlling the reaction temperature inside the reactor at 510°C, and controlling the catalyst regeneration temperature at 650°C.

[0075] Comparative Example 1

[0076] The method for desulfurization and quality improvement of coking propylene described in this comparative example is the same as that in Example 4, except that the coking propylene enters the riser reactor from the inlet of the pre-lifter, the inlet temperature of the pre-lifter is 545°C, and the flow rate of coking propylene is 100 ml / min.

[0077] Comparative Example 2

[0078] The method for desulfurization and quality improvement of coking propylene described in this comparative example is the same as that in Example 2, except that the catalyst loading amount is 7000g, and all the catalysts are the in-use catalysts of Qilu Petrochemical's three-catalyst unit, without the desulfurization aids.

[0079] The compositional properties and carbonyl sulfur content of the coking ethylene feedstock and the samples after reaction under various experimental conditions in Examples 1-5 and Comparative Examples 1-2 are shown in Table 1 below.

[0080] Table 1. Results of property analysis of propylene coking before and after reaction.

[0081]

[0082] As can be seen from the data in Table 1, the method of the present invention for upgrading and desulfurizing coking propylene can significantly reduce the carbonyl sulfur content to below 0.5 ppm. Compared with the phase change scheme in Comparative Example 2, it reduces propylene loss by more than 1%, thus providing a guarantee for the production of butanol and octanol. In contrast, in the scheme of Comparative Example 1, the sulfur content is significantly reduced, but the propylene loss rate is too high. The desulfurization effect of Comparative Example 2 is too poor and the propylene loss is higher than that of the schemes in Examples 1-5.

[0083] The following Examples 6-9 and Comparative Examples 3-4 of this invention investigate the effects of incorporating coking propylene into a catalytic cracking unit on product yield and product distribution.

[0084] Example 6

[0085] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0086] The riser reactor contains 7000g of catalyst, all of which is COKC-1 catalyst from the Qilu Petrochemical No. 3 Catalytic Cracking Unit. The feedstock is from the Qilu No. 3 Catalytic Cracking Unit, specifically a mixture of Shengli crude oil vacuum residue, VRDS atmospheric residue, and hydrotreated coking wax oil. The catalyst-to-feedstock ratio is controlled at 7. The reaction temperature is controlled at 510℃, the regeneration temperature at 650℃, and the terminator inlet temperature at 460℃.

[0087] Example 7

[0088] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0089] The catalyst loading in the riser reactor is 7000g, including 6650g of COCK-1 catalyst in use in Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0090] The sulfur-reducing additive comprises the following components in parts by weight: 42 parts acidified kaolin, 4 parts ammonium metavanadate, 24 parts zinc oxide, 3 parts nickel oxide, 25 parts REY molecular sieve, and 2 parts USY molecular sieve.

[0091] The feedstock is Qilu No. 3 Catalytic Oil, the catalyst-to-feedstock ratio is 7, the reaction temperature is 510℃, the regeneration temperature is 650℃, and the coking propylene enters the riser reactor from the terminator inlet of the riser unit. The terminator inlet temperature is 455℃, and the coking propylene flow rate is 100ml / min.

[0092] Example 8

[0093] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0094] The catalyst loading in the riser reactor is 7000g, including 6650g of COCK-1 catalyst in use in Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0095] The sulfur-reducing additive comprises the following components in parts by weight: 38 parts acidified kaolin, 6 parts ammonium metavanadate, 26 parts zinc oxide, 4 parts nickel oxide, 22 parts REY molecular sieve, and 4 parts USY molecular sieve.

[0096] The feedstock is Qilu No. 3 Catalytic Oil, the catalyst-to-feedstock ratio is 7, the reaction temperature is 510℃, the regeneration temperature is 650℃, and the coking propylene enters the riser reactor from the terminator inlet of the riser unit. The terminator inlet temperature is 460℃, and the coking propylene flow rate is 100ml / min.

[0097] Example 9

[0098] The method for reducing sulfur and improving the quality of coking propylene described in this embodiment is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0099] The catalyst loading in the riser reactor is 7000g, including 6650g of COCK-1 catalyst in use in Qilu Petrochemical's three-catalyst unit and 350g of desulfurization aid.

[0100] The sulfur-reducing additive comprises the following components in parts by weight: 36 parts acidified kaolin, 4 parts ammonium metavanadate, 28 parts zinc oxide, 5 parts nickel oxide, 24 parts REY molecular sieve, and 3 parts USY molecular sieve.

[0101] The feedstock is Qilu No. 3 Catalytic Oil, the catalyst-to-feedstock ratio is 7, the reaction temperature is 510℃, the regeneration temperature is 650℃, and the coking propylene enters the riser reactor from the terminator inlet of the riser unit. The terminator inlet temperature is 470℃, and the coking propylene flow rate is 100ml / min.

[0102] Comparative Example 3

[0103] The method for desulfurization and quality improvement of coking propylene described in this comparative example is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0104] The catalyst loading is 7000g, and all catalysts are COCK-1 catalysts produced by Sinopec Catalyst Qilu Branch. The feed oil is Qilu No. 3 Catalyst feed oil, the catalyst to feed oil ratio is 7, the reaction temperature is 510℃, the regeneration temperature is 650℃, and the coking propylene enters the riser reactor from the terminator inlet of the riser unit. The terminator inlet temperature is 465℃, and the coking propylene flow rate is 100ml / min.

[0105] Comparative Example 4

[0106] The method for desulfurization and quality improvement of coking propylene described in this comparative example is based on the appendix. Figure 1 The RU-II type continuous riser catalytic cracking unit shown has been completed.

[0107] The catalyst loading is 7000g, including 6650g of the catalyst in use in Qilu Petrochemical's three-catalyst unit and 350g of sulfur-reducing additive.

[0108] The sulfur-reducing additive comprises the following components in parts by weight: 38 parts acidified kaolin, 6 parts ammonium metavanadate, 26 parts zinc oxide, 4 parts nickel oxide, 22 parts REY molecular sieve, and 4 parts USY molecular sieve.

[0109] The feedstock is Qilu No. 3 Catalytic Oil, the catalyst-to-feedstock ratio is 7, the reaction temperature is 510℃, the regeneration temperature is 650℃, and the coking propylene enters the riser reactor from the inlet of the pre-riser. The inlet temperature of the pre-riser is 545℃, and the coking propylene flow rate is 100ml / min.

[0110] The product distribution and carbonyl sulfide content analysis of the above-mentioned schemes in Examples 6-9 and Comparative Examples 3-4 under various experimental conditions are shown in Table 2 below.

[0111] Table 2. Distribution and property analysis of products after reaction.

[0112]

[0113] As can be seen from the data in Table 2, comparing Examples 7-9 with Example 6, it can be seen that the addition of desulfurizing agent and coking propylene to the riser device has little effect on the distribution of reaction products. At the same time, the addition of coking propylene plays a role in quenching the oil, improving the distribution of catalytic cracking products, increasing the yield of liquefied gas and gasoline, and playing a positive role.

[0114] Comparative Examples 3 and 4 show that, in order to ensure propylene yield, coking propylene was introduced into the terminator inlet, but no desulfurization catalyst was added, resulting in an unsatisfactory desulfurization effect; while introducing coking propylene into the pre-lifting inlet resulted in a significant desulfurization effect, but also a large loss of propylene.

[0115] In summary, as can be seen from the schemes in Examples 1-5 and 7-9 of this invention, coking propylene is converted into catalytic propylene by this invention, the carbonyl sulfur content is reduced to below 0.5 ppm, and propylene loss is reduced, with propylene loss controlled within 5%, achieving a good desulfurization effect, which is beneficial to the later utilization of coking propylene.

[0116] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for reducing sulfur content and improving the quality of coking propylene, characterized in that, This includes the step of contacting coking propylene, catalytic cracking feedstock oil with a catalyst and carrying out a catalytic cracking reaction; The catalyst comprises a mixture of a catalytic cracking catalyst and a sulfur-reducing agent; the sulfur-reducing agent is used in an amount of 3-8 wt% of the total catalyst. The sulfur-reducing agent comprises, by weight, the following components: 36-44 wt% acidified kaolin, 4-6 wt% ammonium metavanadate, 22-28 wt% zinc oxide, 3-5 wt% nickel oxide, 21-26 wt% REY molecular sieve, and 2-4 wt% USY molecular sieve; The reaction temperature of the catalytic cracking reaction step is 500-550℃; The method includes the step of feeding the coking propylene and feedstock oil into the riser reactor from the terminator inlet of the catalytic cracking unit for reaction; controlling the temperature at the terminator inlet to be 455-475℃ and controlling the input flow rate of the coking propylene to be 80-120ml / min; The preparation method of the desulfurization additive includes the following steps: taking a selected amount of the acidified kaolin, ammonium metavanadate, zinc oxide, nickel oxide, REY molecular sieve and USY molecular sieve, mixing and pulping them, and collecting the reactants, filtering them and drying, calcining and grinding them.

2. The method for desulfurization and upgrading of coking propylene according to claim 1, characterized in that, The method further includes a step of regenerating the catalyst; the temperature of the regeneration step is controlled at 620-680℃.

3. The method for desulfurization and upgrading of coking propylene according to claim 1, characterized in that, The mass ratio of the catalyst to the feedstock oil is 1:6-10.

4. The method for desulfurization and upgrading of coking propylene according to claim 2, characterized in that, The drying step is performed at a temperature of 100-150℃; the calcination step is performed at a temperature of 400-600℃; and the grinding step controls the particle size to be 60-100 micrometers.

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