A novel ethylene cracking antifouling agent, its preparation method and application

Abstract

The application discloses a novel ethylene cracking coking inhibitor, a preparation method and application thereof. The ethylene cracking coking inhibitor is composed of the following components and monomers according to mass percentage: 45-50% of a supported iron passivator, 5-10% of an oil-soluble nickel passivator, 8-15% of a soluble chromium passivator, 2-5% of an anionic surfactant, 20-35% of an olefin recovery agent, 1-5% of a high-temperature antioxidant, 1-5% of a high-temperature polymerization inhibitor and 1-5% of a coking scale dispersant. The supported iron passivator is formed by loading a sulfur-phosphorus compound on an active nano-carrier. The olefin recovery agent is at least one of diesel oil, gasoline, naphtha, liquid paraffin and Fischer-Tropsch synthetic wax oil. The coking inhibitor can passivate the furnace tube at high temperature, prevent coking scale from corroding the inner wall of the furnace tube, and various organic active components can rapidly vaporize under cracking conditions, are uniformly dispersed on the inner wall surface of the cracking furnace tube and improve the coking inhibition effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coking inhibitors, in particular to a novel ethylene cracking coking inhibitor, a preparation method and application thereof. BACKGROUND

[0002] The ethylene cracking furnace is the core of the ethylene production device, and the production capacity directly affects the production scale and capacity of the device. The running cycle directly plays a decisive role. In the production of ethylene and cracking hydrocarbons, polymerization and condensation reactions often occur, and coking also occurs. The coke layer can corrode the furnace tube, form carburization, affect the strength of the tube material, reduce the performance of the furnace tube material, change the material organization, and reduce the service life of the furnace tube. Chemical coking inhibitors are usually used to achieve the purpose of inhibiting the coking of the furnace tube and prolonging the running cycle of the cracking furnace.

[0003] Currently, the following three methods are mainly used to inhibit the coking of the cracking furnace tube: (1) coating the inner surface of the cracking furnace tube with a metallurgical coating to prevent coking; (2) using a chemical coking inhibitor; (3) cracking furnace standby period online pretreatment technology.

[0004] The method of using a chemical coking inhibitor has the advantages of simple operation, no need to change the production process, and low cost. It is widely used at present, and the main patent technologies are US6497809, US4900426, US4551227, US4680421, CN1247887, CN1367225 and CN101318872A. The above patent technologies are based on the principles of inhibiting catalytic coking and changing the progress of free radicals to selectively select substances containing sulfur, phosphorus, alkali metals, alkaline earth metals, borides, etc. to inhibit coking and prolong the running cycle of the furnace tube. However, such coking inhibitors have single structure and function, and have good effect on gas phase furnaces (light hydrocarbon raw materials such as ethane), but limited effect on liquid phase furnaces. The main reason is that liquid phase furnaces use naphtha and other materials as raw materials, which have large composition differences, many coking components, less hydrogen content, and are corrosive and polluting.

[0005] The furnace tube coating metallurgical coating is to cover and isolate the surface of the furnace tube with inorganic inert metal materials such as silicon, aluminum, chromium, manganese oxides, etc. to reduce the catalytic activity of Fe and Ni, and at the same time reduce the friction coefficient of the furnace tube surface, which can effectively prevent the adhesion of coking precursors. The representative patent technologies include US6585864, US6579628, US6537388, US4297246A, CN1580316, CN1546609, CN112708444 and CN101294100A, etc. The above patent technologies all involve coating an oxide layer on the furnace tube to inhibit coking, which can prolong the running cycle to a certain extent. However, the process is complex, the cost is high, the service life of the coating is limited, the coating technology requires high technical requirements, and even requires technical transformation of the cracking furnace and the use of reinforced twisted sheets, which greatly limits the popularization and application.

[0006] The online pre-treatment of the standby cracking furnace is a method of adding a film forming agent, forming an anti-coking coating layer online, and updating the coating layer online, and through the action of water vapor, Si, B, S, P, Cr, Ca, Al and other compounds are decomposed to form oxides and deposited on the inner wall of the furnace tube, but the coating layer cannot withstand the action of airflow scouring, and the coating particles are large and numerous, which brings great negative impact to the downstream device system. SUMMARY

[0007] In view of the technical problems that the existing chemical coking inhibitors have single structure and function, the inhibition effect of the gas / phase cracking furnace is limited, the odor is large at normal temperature and pressure, it belongs to low flash point dangerous chemicals, and the storage and use cost is high, the application provides a novel ethylene cracking coking inhibitor, a preparation method and application thereof.

[0008] The technical scheme adopted by the application is:

[0009] A novel ethylene cracking coking inhibitor is composed of the following component monomers in percentage by mass:

[0010]

[0011] The supported passivator is formed by loading sulfur and phosphorus compounds on active nanocarriers.

[0012] The olefin recovery agent is at least one of diesel oil, gasoline, naphtha, liquid paraffin and Fischer-Tropsch synthesis wax oil.

[0013] As preferred, the active nanocarriers load 15-30wt% of sulfur and phosphorus compounds by the equal volume impregnation method, and the molar ratio of sulfides and phosphides in the sulfur and phosphorus compounds is (5-10):1 in terms of sulfur and phosphorus elements.

[0014] As preferred, the active nanocarriers are at least one of kaolin, alumina, ZSM-5 molecular sieve and SSZ-13 molecular sieve; the sulfides are at least one of t-butyl polysulfide, H2S, diethyl polysulfide and sulfophenol; and the phosphides are at least one of thiophosphate, dihexyl phosphite, dioctyl phosphite, diphenyl phosphite and 2-hydroxyethyl methyl acrylate phosphorus. More preferably, the activation index of the kaolin is 93%-99.5%, the pore size of the alumina is 0.5-2nm, and the Si / Al of the ZSM-5 molecular sieve and the SSZ-13 molecular sieve is 50-100.

[0015] As preferably, the oil-soluble nickel passivator is at least one of antimony-based, bismuth-based and cerium-based metal passivators. The antimony-based passivator is NS-69 (di-antimony trioxide-tartaric acid-hexamethylene tetramine complex); the bismuth-based passivator is NS-65 (bismuth oxide-glucose acid-triethanolamine complex); the cerium-based passivator is NS-61 (cerium carbonate-sodium citrate-monoethanolamine complex); the water-soluble chromium passivator is trivalent chromium passivator.

[0016] As preferably, the anionic surfactant is at least one of sodium petroleum sulfonate, sodium dodecyl benzene sulfonate, sulfated castor oil and potassium fatty alcohol polyoxyethylene ether phosphate.

[0017] As preferably, the high-temperature antioxidant is at least one of hindered phenol, amine and phosphite antioxidant. More preferably, the high-temperature antioxidant is at least one of commercial brands S9228, 3114, T534 and L57.

[0018] As preferably, the high-temperature polymerization inhibitor is at least one of polyphenol, aromatic nitro compound and inhibitor-like compound. More preferably, the high-temperature polymerization inhibitor is at least one of commercial brands ZJ-705, 510, ZM-701, DNBP and TH-02 ethylene polymerization inhibitor.

[0019] As preferably, the coke dispersant is at least one of mono-olefin succinimide, Mannich amine, polyisobutylene bis-succinimide, polyisobutylene amine, polyether amine, sodium alkyl phenol phenyl ester disulfonate and polyisobutylene pentaerythritol succinate. More preferably, the mono-olefin succinimide is of type T151, the Mannich amine has a molecular weight Mw=1500-2000, the polyisobutylene bis-succinimide is of type T154, the polyether amine has a molecular weight Mw=1000-1500, the polyisobutylene amine has a molecular weight Mw=1000-1500, the polyisobutylene pentaerythritol succinate is of type T151, the Mannich amine has a molecular weight Mw=1500-2000, the polyisobutylene bis-succinimide is of type T154, the polyether amine has a molecular weight Mw=1000-1500 and the polyisobutylene amine has a molecular weight Mw=1000-1500.

[0020] The preparation method of any one of the novel ethylene cracking coke inhibitors above comprises the following steps:

[0021] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor are sequentially added into the reaction kettle, and the temperature is raised to 60-80℃, and the stirring is continued for 1-2h;

[0022] 2) After the end of stirring, the temperature is lowered to 25-35 DEG C, water-soluble chromium passivator, anionic surfactant, coke deposit dispersant are added, and stirring is continued for 0.5-1 h, and then natural sedimentation is carried out for 0.5-1 h, after which the bottom is removed, and the product is obtained.

[0023] The application method of any one of the novel ethylene cracking anti-coking agents is as follows: 100-300 ppm of the novel ethylene cracking anti-coking agent is injected into a cracking furnace to form an anti-coking coating in the furnace tube.

[0024] The present application has the following advantages:

[0025] 1. The supported iron passivator is formed by loading sulfur-phosphorus compounds on active nanocarriers, and the active nanocarriers contain silicon and aluminum compounds. The silicon and aluminum compounds form an oxide layer with trace elements (Mn and Cr) on the surface of the furnace tube at high temperature, which has a spinel structure, and coats the furnace tube to improve the anti-coking and anti-carburizing performance of the furnace tube. The active nanocarriers have a specific pore structure (nanometer confinement) and have catalytic activity at high temperature, and have a certain catalytic cracking synergistic effect. The sulfur-phosphorus compounds loaded on the active nanocarriers are desorbed and decomposed at high temperature to release sulfur and phosphorus free radicals, which cooperate with the nickel passivator to passivate Fe and Ni, and form a protective layer on the furnace tube to inhibit catalytic coking.

[0026] 2. The high-temperature antioxidant can fully capture alkyl radicals and quench singlet oxygen, and break the chain reaction of free radical oxidation. The high-temperature polymerization inhibitor is oxidized at high temperature and cooperates with the antioxidant to capture and quench olefin free radicals, thereby terminating the free radical polymerization reaction and slowing down the rate of olefin polymerization coking. The coke deposit dispersant can effectively disperse a small amount of coke deposit on the surface of the furnace tube. The anionic surfactant can dissolve the water-oil components into a homogeneous suspension liquid by emulsification and solubilization, and additionally supplement sulfur and phosphorus elements. The water-soluble chromium passivator can also play a synergistic role under the action of high-temperature water vapor to inhibit Cr-catalyzed coking on the furnace tube (the activity is weaker than that of Fe and Ni), and can effectively avoid the release of irritating odors from the anti-coking agent and meet the conditions for general transportation. The olefin yield enhancer can further crack olefins at high temperature, and cooperates with the antioxidant and the polymerization inhibitor to effectively avoid olefin polymerization and increase the yield of olefins; and the content of aromatic hydrocarbons in the yield enhancer is low, which can further slow down the gas phase coking caused by the dehydrogenation of aromatic hydrocarbons into rings and carbon.

[0027] 3. When the novel cracking anti-coking agent is used to inhibit coking on the cracking furnace tube, the injection amount is adjusted to be within the range of 100-300 ppm according to the S and P content in the cracking raw material, which can improve the anti-coking performance of the ethylene cracking furnace tube, prolong the operation cycle of the cracking furnace, increase the liquid phase furnace cycle by about 20%, and increase the gas phase furnace cycle by about 40%. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1The temperature change of the cracking furnace tube during the trial of the additive. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with the drawings and a preferred embodiment.

[0030] The raw materials used in the following examples are commercially available, except for special instructions.

[0031] The performance evaluation method of the coking inhibitor is as follows: a simulated cracking furnace experiment is conducted, the temperature of the cracking furnace is set to 900℃, the metered coking inhibitor and raw materials are rapidly injected into the cracking furnace by a pump, the ethylene and propylene content yield, the CO and CO2 content in the cracking gas are detected online by gas chromatography, and the coking rate is detected by weighing method.

[0032] Example 1

[0033] A new ethylene cracking coking inhibitor A, the monomers and mass percentage of each component are as follows:

[0034] The supported iron passivator is 45%, the oil-soluble nickel passivator is 10%, the water-soluble chromium passivator is 8%, the anionic surfactant is 5%, the olefin recovery agent is 20%, the high-temperature antioxidant is 3%, the high-temperature polymerization inhibitor is 4%, and the coke scale dispersant is 5%.

[0035] The supported iron passivator is made of kaolin with an activation index of 93% to 99.5% by adsorbing active components such as tertiary butyl polysulfide and phosphite diester through an equal volume impregnation method, which is a prior art. The molar ratio of tertiary butyl polysulfide and phosphite diester is n(S):n(P) = 5:1, and the loading amount of the active component is 15%.

[0036] The oil-soluble nickel passivator is an antimony-based passivator NS-69, which is made of 25wt% antimony trioxide, 5wt% tartaric acid, 15wt% amine and 55wt% solvent;

[0037] The water-soluble chromium passivator is a trivalent chromium passivator ALODINE 5992 from Hanse Metal Surface Treatment in Germany;

[0038] The anionic surfactant is sodium petroleum sulfonate;

[0039] The olefin recovery agent is diesel oil;

[0040] The high-temperature antioxidant is composed of 1% of 9228 and 2% of 3114;

[0041] The high-temperature polymerization inhibitor is composed of 2% of 705 and 2% of DNBP;

[0042] The coke scale dispersant is 3448N polyisobutylene amine.

[0043] The preparation method of the novel ethylene cracking anti-coking agent A comprises the following steps:

[0044] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor are sequentially added to the reaction kettle, and the temperature is raised to 60 DEG C, and the stirring is continued for 2 h;

[0045] 2) After the stirring is finished, the temperature is lowered to 35 DEG C, the water-soluble chromium passivator, the anionic surfactant and the coke scale dispersant are added, and the stirring is continued for 1 h, and then the natural sedimentation is carried out for 1 h, and then the obvious large particles of insoluble substances at the bottom are removed, and then the finished product is sealed.

[0046] The performance evaluation results of the obtained novel ethylene cracking anti-coking agent A are shown in Table 1.

[0047] Example 2

[0048] A novel ethylene cracking anti-coking agent B, the monomers and the mass percentage of each component of which are as follows:

[0049] The supported iron passivator is 50%, the oil-soluble nickel passivator is 5%, the water-soluble chromium passivator is 8%, the anionic surfactant is 5%, the olefin recovery agent is 20%, the high-temperature antioxidant is 3%, the high-temperature polymerization inhibitor is 4% and the coke scale dispersant is 5%.

[0050] The supported iron passivator is prepared by adsorbing H2S and thiophosphate on ZSM-5 with Si / Al=50 through an equal-volume impregnation method. The molar ratio n(S):n(P) of H2S and thiophosphate is 8:1, and the loading amount of the active component is 20%.

[0051] The oil-soluble nickel passivator is a cerium-based passivator NS-61, which is prepared by compounding cerium carbonate 30 wt%, sodium citrate 12 wt% and monoethanolamine 45 wt%;

[0052] The water-soluble chromium passivator is a trivalent chromium passivator ALODINE 5992 from Hanseatic Metal Surface Treatment, Germany;

[0053] The anionic surfactant is sodium dodecyl benzene sulfonate;

[0054] The olefin recovery agent is naphtha;

[0055] The high-temperature antioxidant is composed of 1% T534 and 2% L57;

[0056] The high-temperature polymerization inhibitor is composed of 2% 510 and 2% TH-02;

[0057] The coke scale dispersant is a Mannich amine with Mw=1500-2000.

[0058] The preparation method of the novel ethylene cracking anti-coking agent A comprises the following steps:

[0059] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor are sequentially added to the reaction kettle, heated to 80℃, and continuously stirred for 1h;

[0060] 2) After stirring, the temperature is lowered to 25℃, the water-soluble chromium passivator, the anionic surfactant, the coke fouling dispersant are added, and the stirring is continued for 0.5h, and then the product is obtained by natural sedimentation for 1h after removing the obvious large particle insoluble matter at the bottom.

[0061] The performance evaluation results of the obtained new ethylene cracking anti-coking agent B are shown in Table 1.

[0062] Example 3

[0063] A new type of ethylene cracking anti-coking agent each component monomer C, each component monomer and mass percentage are as follows:

[0064] The supported iron passivator is 45%, the oil-soluble nickel passivator is 5%, the water-soluble chromium passivator is 10%, the anionic surfactant is 2%, the olefin recovery agent is 35%, the high-temperature antioxidant is 1%, the high-temperature polymerization inhibitor is 1% and the coke fouling dispersant is 1%.

[0065] The supported iron passivator is prepared by adsorbing active components sulfophenol and 2-hydroxyethyl methacrylate phosphorus on alumina with a pore size of 0.5-2nm by equal volume impregnation method, and the equal volume impregnation method is prior art. The molar ratio of sulfophenol and 2-hydroxyethyl methacrylate phosphorus is n(S):n(P)=5:1, and the loading amount of active components is 30%.

[0066] The oil-soluble nickel passivator is a bimetallic passivator composed of 2% antimony-based passivator NS-69 and 3% cerium-based passivator NS-61;

[0067] The water-soluble chromium passivator is a trivalent chromium passivator ALODINE 5992 from Han Guo Metal Surface Treatment in Germany;

[0068] The anionic surfactant is sulfated castor oil;

[0069] The olefin recovery agent is naphtha;

[0070] The high-temperature antioxidant is T534;

[0071] The high-temperature polymerization inhibitor is 701;

[0072] The coke fouling dispersant is a polyether amine with Mw=1000-1500.

[0073] The preparation method of the new ethylene cracking anti-coking agent C comprises the following steps:

[0074] 1) According to the proportion, the supported iron passivator, oil-soluble nickel passivator, olefin recovery agent, high-temperature antioxidant and high-temperature polymerization inhibitor were added to the reaction kettle in turn, heated to 65℃, and stirred for 1.2h;

[0075] 2) After stirring, the temperature was lowered to 30℃, the water-soluble chromium passivator, anionic surfactant, and coke scale dispersant were added, and the stirring was continued for 0.8h, and then the mixture was naturally settled for 0.5h. After removing the obvious large particles of insoluble matter from the bottom, the product was obtained.

[0076] The performance evaluation results of the obtained new ethylene cracking anti-coking agent C are shown in Table 1.

[0077] Example 4

[0078] A new type of ethylene cracking anti-coking agent D, the monomers and mass percentages of each component are as follows:

[0079] The supported iron passivator is 45%, the oil-soluble nickel passivator is 5%, the water-soluble chromium passivator is 15%, the anionic surfactant is 2%, the olefin recovery agent is 30%, the high-temperature antioxidant is 1%, the high-temperature polymerization inhibitor is 1%, and the coke scale dispersant is 1%.

[0080] The supported iron passivator is prepared by adsorbing diethyl polysulfide and phosphite diester on SSZ-13 with Si / Al = 50-100 by equal volume impregnation method, which is a prior art. The molar ratio of diethyl polysulfide and phosphite diester is n(S):n(P) = 5:1, and the loading of active components is 25%.

[0081] The oil-soluble nickel passivator is bismuth-based passivator NS-65, which is prepared by compounding bismuth oxide 10wt%, gluconic acid 15wt% and triethanolamine 27wt%;

[0082] The water-soluble chromium passivator is trivalent chromium passivator ALODINE 5992 from Hanseatic Metal Surface Treatment, Germany;

[0083] The anionic surfactant is potassium fatty alcohol polyoxyethylene ether phosphate;

[0084] The olefin recovery agent is Fischer-Tropsch synthesis wax oil;

[0085] The high-temperature antioxidant is T534;

[0086] The high-temperature polymerization inhibitor is 701;

[0087] The coke scale dispersant is 3448N.

[0088] The preparation method of the new ethylene cracking anti-coking agent D comprises the following steps:

[0089] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor are sequentially added to the reaction kettle, heated to 62℃, and continuously stirred for 1.5h;

[0090] 2) After stirring, the temperature is lowered to 30℃, the water-soluble chromium passivator, the anionic surfactant, the coke deposit dispersant are added, and the stirring is continued for 1h, and then the product is obtained by natural sedimentation for 1h after removing the obvious large particle insoluble matter at the bottom.

[0091] The performance evaluation results of the obtained new ethylene cracking anti-coking agent D are shown in Table 1

[0092] Example 5

[0093] A new type of ethylene cracking anti-coking agent E, the monomer components and mass percentage are as follows:

[0094] The supported iron passivator is 45%, the oil-soluble nickel passivator is 10%, the water-soluble chromium passivator is 8%, the anionic surfactant is 2%, the olefin recovery agent is 32%, the high-temperature antioxidant is 1%, the high-temperature polymerization inhibitor is 1% and the coke deposit dispersant is 1%.

[0095] The supported iron passivator is made of kaolin with an activation index of 93% to 99.5% by adsorbing active components such as tertiary butyl polysulfide and thiophosphate through equal volume impregnation method, which is a prior art. The molar ratio of tertiary butyl polysulfide and thiophosphate is n(S):n(P)=10:1, and the loading amount of active components is 30%.

[0096] The oil-soluble nickel passivator is composed of 5% antimony-based passivator NS-69 and 5% bismuth-based passivator NS-65;

[0097] The water-soluble chromium passivator is ALODINE 5992 trivalent chromium passivator from Han Guo Metal Surface Treatment in Germany;

[0098] The anionic surfactant is composed of 1% petroleum sulfonate sodium and 1% dodecyl benzene sulfonate sodium;

[0099] The olefin recovery agent is composed of 20% diesel and 12% gasoline;

[0100] The high-temperature antioxidant is L57;

[0101] The high-temperature polymerization inhibitor is DNBP;

[0102] The coke deposit dispersant is T151.

[0103] The preparation method of the new ethylene cracking anti-coking agent E includes the following steps:

[0104] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor were sequentially added to the reaction kettle, and the temperature was raised to 70 DEG C, and the stirring was continued for 2h;

[0105] 2) After stirring, the temperature was lowered to 35 DEG C, the water-soluble chromium passivator, the anionic surfactant, the coke fouling dispersant were added, and the stirring was continued for 1h, and the natural sedimentation was 1h, and the obvious large particles of insoluble matter at the bottom were removed, and the finished product was sealed.

[0106] The performance evaluation results of the obtained new ethylene cracking anti-coking agent E are shown in Table 1

[0107] Example 6

[0108] A new type of ethylene cracking anti-coking agent F, the monomer and mass percentage of each component are as follows:

[0109] The supported iron passivator is 48%, the oil-soluble nickel passivator is 5%, the water-soluble chromium passivator is 8%, the anionic surfactant is 5%, the olefin recovery agent is 25%, the high-temperature antioxidant is 2%, the high-temperature polymerization inhibitor is 2% and the coke fouling dispersant is 5%.

[0110] The supported iron passivator is prepared by adsorbing H2S and phosphite diester on 50% ZSM-5 and 50% SSZ-13 by equal volume impregnation method, and the equal volume impregnation method is prior art. The molar ratio of H2S and phosphite diester is n(S):n(P) = 10:1, and the loading of active components is 28%.

[0111] The oil-soluble nickel passivator is cerium-based passivator NS-61;

[0112] The water-soluble chromium passivator is trivalent chromium passivator ALODINE 5992 from Hanseatic Metal Surface Treatment, Germany;

[0113] The anionic surfactant is composed of 3% sodium petroleum sulfonate and 2% sulfated castor oil;

[0114] The olefin recovery agent is naphtha;

[0115] The high-temperature antioxidant is composed of 1% T534 and 1% 9228;

[0116] The high-temperature polymerization inhibitor is composed of 1% 701 and 2% TH-02;

[0117] The coke fouling dispersant is composed of 2% polyether amine and 3% 3448N.

[0118] The preparation method of the new ethylene cracking anti-coking agent F comprises the following steps:

[0119] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor were sequentially added to the reaction kettle, and the temperature was raised to 70 DEG C, and the stirring was continued for 2h;

[0120] 2) After the end of stirring, the temperature was lowered to 30°C, water-soluble chromium passivator, anionic surfactant, coke fouling dispersant were added, and then continuous stirring was carried out for 1 h, natural sedimentation was carried out for 1 h, and then the bottom obvious large particle insoluble was removed, and the product was sealed.

[0121] The performance evaluation results of the obtained new ethylene cracking antifouling agent F are shown in Table 1

[0122] Example 7

[0123] A new type of ethylene cracking antifouling agent G, the monomer components and mass percentage are as follows:

[0124] Supported iron passivator 48%, oil-soluble nickel passivator 8%, water-soluble chromium passivator 8%, anionic surfactant 5%, olefin recovery agent 25%, high-temperature antioxidant 2%, high-temperature polymerization inhibitor 2%, and coke fouling dispersant 5%.

[0125] The supported iron passivator is made of mesoporous alumina by adsorbing sulfenol and phosphite diester H2S through equal volume impregnation method, which is a prior art. The molar ratio of sulfenol and phosphite diester n(S):n(P) is 8:1, and the loading of active components is 28%.

[0126] The oil-soluble nickel passivator is antimony-based passivator NS-69;

[0127] The water-soluble chromium passivator is trivalent chromium passivator ALODINE 5992 from Hanse Metal Surface Treatment in Germany;

[0128] The anionic surfactant is composed of 3% petroleum sodium sulfonate and 2% sulfated castor oil;

[0129] The olefin recovery agent is diesel oil;

[0130] The high-temperature antioxidant is T534;

[0131] The high-temperature polymerization inhibitor is TH-02;

[0132] The coke fouling dispersant is composed of 1% T151 and 1% T154.

[0133] The preparation method of the new ethylene cracking antifouling agent G includes the following steps:

[0134] 1) According to the proportion, the supported iron passivator, oil-soluble nickel passivator, olefin recovery agent, high-temperature antioxidant and high-temperature polymerization inhibitor were added to the reaction kettle in turn, and the temperature was raised to 78°C, and the stirring was continued for 2 h;

[0135] 2) After the end of stirring, the temperature was lowered to 32°C, water-soluble chromium passivator, anionic surfactant, coke fouling dispersant were added, and then continuous stirring was carried out for 1 h, natural sedimentation was carried out for 1 h, and then the bottom obvious large particle insoluble was removed, and the product was sealed.

[0136] The performance evaluation results of the new ethylene cracking anti-coking agent G obtained are shown in Table 1

[0137] Example 8

[0138] A new ethylene cracking anti-coking agent H, the components and mass percentages of the monomers are as follows:

[0139] The supported iron passivator is made of 30% ZSM-5 and 70% SSZ-13 by adsorbing H2S and phosphorous diester through an equal volume impregnation method, which is a prior art. The molar ratio of H2S and phosphorous diester n(S):n(P) = 10:1, and the loading of active components is 18%.

[0140] The supported iron passivator is made of 30% ZSM-5 and 70% SSZ-13 by adsorbing H2S and phosphorous diester through an equal volume impregnation method, which is a prior art. The molar ratio of H2S and phosphorous diester n(S):n(P) = 10:1, and the loading of active components is 18%.

[0141] The oil-soluble nickel passivator is composed of 3% antimony-based passivator NS-69 and 2% cerium-based passivator NS-61;

[0142] The water-soluble chromium passivator is trivalent chromium passivator ALODINE 5992 from Hanse Metal Surface Treatment, Germany;

[0143] The anionic surfactant is sodium dodecyl benzene sulfonate;

[0144] The olefin recovery agent is composed of 20% diesel oil and 15% naphtha;

[0145] The high-temperature antioxidant is T534;

[0146] The high-temperature polymerization inhibitor is composed of 1% 701 and 2% TH-02;

[0147] The coke deposit dispersant is composed of 1% polyether amine, 1% Mannich amine, and 3% 3448N.

[0148] The preparation method of the new ethylene cracking anti-coking agent H includes the following steps:

[0149] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant, and the high-temperature polymerization inhibitor are sequentially added to the reaction kettle, and the temperature is raised to 73°C, and the stirring is continued for 1.8h;

[0150] 2) After the stirring is completed, the temperature is lowered to 32°C, the water-soluble chromium passivator, the anionic surfactant, the coke deposit dispersant are added, and the stirring is continued for 0.5h, and then the natural sedimentation is performed for 0.5h, and then the obvious large particle insoluble substances at the bottom are removed, and then the finished product is sealed.

[0151] The performance evaluation results of the new ethylene cracking anti-coking agent H are shown in Table 1

[0152] Example 9

[0153] A new ethylene cracking anti-coking agent I, the components and mass percentages of the monomers are as follows:

[0154] The supported iron passivator is made of kaolin with an activation index of 93% to 99.5% by adsorbing H2S and phosphite diester through an equal-volume impregnation method, which is a prior art. The molar ratio of H2S to phosphite diester n(S):n(P) is 10:1, and the loading of the active component is 30%.

[0155] The supported iron passivator is made of kaolin with an activation index of 93% to 99.5% by adsorbing H2S and phosphite diester through an equal-volume impregnation method, which is a prior art. The molar ratio of H2S to phosphite diester n(S):n(P) = 10:1, and the loading of the active component is 30%.

[0156] The oil-soluble nickel passivator is composed of 3% antimony-based passivator NS-69 and 2% cerium-based passivator NS-61;

[0157] The water-soluble chromium passivator is trivalent chromium passivator ALODINE 5992 from Hanse Metal Surface Treatment in Germany;

[0158] The anionic surfactant is sodium dodecyl benzene sulfonate;

[0159] The olefin recovery agent is composed of 25% diesel oil and 5% naphtha;

[0160] The high-temperature antioxidant is T534;

[0161] The high-temperature polymerization inhibitor is composed of 1% 701 and 1% TH-02;

[0162] The coke deposit dispersant is composed of 1% polyether amine, 1% Mannich amine, and 1% 3448N.

[0163] The preparation method of the new ethylene cracking anti-coking agent I includes the following steps:

[0164] 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant, and the high-temperature polymerization inhibitor are sequentially added to the reaction kettle, and the temperature is raised to 76°C, and the stirring is continued for 1.6h;

[0165] 2) After the stirring is completed, the temperature is lowered to 28°C, the water-soluble chromium passivator, the anionic surfactant, the coke deposit dispersant are added, and the stirring is continued for 1h, and then the natural sedimentation is performed for 1h, and then the obvious large particles of insoluble substances at the bottom are removed, and then the finished product is sealed.

[0166] The performance evaluation results of the new ethylene cracking anti-coking agent I are shown in Table 1

[0167] Example 10

[0168] A new ethylene cracking anti-coking agent J, each component monomer and mass percentage are as follows:

[0169] Supported iron passivator 50%, oil-soluble nickel passivator 10%, water-soluble chromium passivator 8%, anionic surfactant 2%, olefin recovery agent 25%, high-temperature antioxidant 2%, high-temperature polymerization inhibitor 1%, and coke deposit dispersant 2%.

[0170] The supported iron passivator is made of kaolin with an activation index of 93% to 99.5% by adsorbing H2S and phosphite diester through an equal-volume impregnation method, which is a prior art. The molar ratio of H2S to phosphite diester n(S):n(P) is 10:1, and the loading of active components is 20%.

[0171] The oil-soluble nickel passivator is composed of 5% antimony-based passivator NS-69 and 5% cerium-based passivator NS-61;

[0172] The water-soluble chromium passivator is trivalent chromium passivator ALODINE 5992 from Hanse Metal Surface Treatment in Germany;

[0173] The anionic surfactant is composed of 1% sodium petroleum sulfonate and 1% potassium fatty alcohol polyoxyethylene ether phosphate ester;

[0174] The olefin recovery agent is diesel oil;

[0175] The high-temperature antioxidant is T534;

[0176] The high-temperature polymerization inhibitor is DNBP;

[0177] The coke deposit dispersant is composed of 1% T151 and 1% 3448N.

[0178] The preparation method of the new ethylene cracking anti-coking agent J includes the following steps:

[0179] 1) According to the proportion, the supported iron passivator, oil-soluble nickel passivator, olefin recovery agent, high-temperature antioxidant, and high-temperature polymerization inhibitor are sequentially added to the reaction kettle, heated to 65°C, and continuously stirred for 1.2h;

[0180] 2) After stirring, the temperature is lowered to 30°C, the water-soluble chromium passivator, anionic surfactant, coke deposit dispersant are added, and the stirring is continued for 0.8h, and then the product is obtained by natural sedimentation for 0.5h, and removing the obvious large particles of insoluble matter at the bottom.

[0181] The performance evaluation results of the obtained new ethylene cracking anti-coking agent J are shown in Table 1

[0182] Table 1 Laboratory evaluation test results of Examples 1 to 10

[0183]

[0184] As can be seen from Table 1, the coking rate of the pyrolysis furnace with the novel ethylene cracking coking inhibitor of the present invention is much lower than that of the blank sample without the coking inhibitor, and the CO content in the cracked gas is lower, less than ≤0.2%, which meets the technical requirements of ethylene cracking.

[0185] Taking the novel ethylene cracking coking inhibitor I prepared in Example 9 as an example, it was promoted and tested in industrial ethylene cracking gas-phase and liquid-phase cracking furnaces. The inhibitory effect of the novel ethylene cracking coking inhibitor on furnace tube coking performance was examined by investigating indicators such as furnace operating cycle, average ethylene / propylene yield, furnace tube temperature rise, and CO content change. The results are as follows: Figure 1 As shown in Table 2.

[0186] Table 2 Comparison of operating indicators of gas-phase and liquid-phase furnaces during the adjuvant trial period.

[0187]

[0188] Note: The amount of coking inhibitor added is adjusted according to the S (main) and P elements in the raw materials. During the trial operation, the average amount of coking inhibitor added is approximately 50 ppm.

[0189] pass Figure 1 It can be seen that the ethylene cracking coking inhibitor in Example 9 can effectively suppress coking in the furnace tubes and enhance the heat transfer coefficient of the furnace tube metal. The temperature of the third group of furnace tubes rises slowly, from 960°C at start-up to 1050°C before shutdown, which can meet the cracking temperature of the cracking furnace.

[0190] As shown in Table 2, the ethylene cracking coking inhibitor formulated in Example 9 (with the best laboratory evaluation results) increased the operating cycle by 43% and 40% respectively in ethylene cracking gas-phase and liquid-phase furnaces. The olefin yield was significantly improved, with the ethylene / propylene yield increasing by 2.9% and 3.3% respectively. Moreover, the CO content at the methanation inlet decreased significantly, meeting the process requirement of CO content ≤0.2%. The novel ethylene cracking coking inhibitor of this invention can meet the requirements for coking suppression in chemical methods and can effectively improve the operating conditions of ethylene gas-phase and liquid-phase cracking furnaces.

[0191] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also within the protection scope of the present invention.

Claims

1. An ethylene scission focus inhibitor characterized by, Composed of the following components monomer according to the mass percentage: 45-50% of supported iron passivator; 5-10% of oil-soluble nickel passivator; 0-15% of water-soluble chromium passivator; 2-5% of anionic surfactant; 20-35% of olefin recovery agent; 1-5% of high-temperature antioxidant; 1-5% of high-temperature polymerization inhibitor; 1-5% of coke deposit dispersant; The supported iron passivator is formed by loading sulfur phosphorus compounds on active nanocarriers; The olefin recovery agent is at least one of diesel oil, gasoline, naphtha and liquid paraffin; The active nanocarriers load 15-30wt% of sulfur phosphorus compounds by equal volume impregnation, and the molar ratio of sulfides and phosphides in the sulfur phosphorus compounds is (5-10):1 in terms of sulfur and phosphorus elements; the active nanocarriers are at least one of kaolin, alumina, ZSM-5 molecular sieve and SSZ-13 molecular sieve.

2. The ethylene scorch retarder of claim 1, wherein, The olefin recovery agent is Fischer-Tropsch synthesis wax oil.

3. The ethylene scorch retarder of claim 1, wherein, The sulfides are at least one of t-butyl polysulfide, H2S, diethyl polysulfide and sulfophenol; and the phosphides are at least one of thiophosphate, dihexyl phosphite, dioctyl phosphite, diphenyl phosphite and 2-hydroxyethyl methyl acrylate phosphorus.

4. The ethylene scission focus inhibitor according to claim 1, wherein The oil-soluble nickel passivator is at least one of antimony-based, bismuth-based and cerium-based metal passivators.

5. The ethylene scorch retarder of claim 1 wherein, The anionic surfactant is at least one of petroleum sodium sulfonate, sodium dodecyl benzene sulfonate, sulfated castor oil and fatty alcohol polyoxyethylene ether phosphate potassium.

6. The ethylene scorch retarder of claim 1 wherein, The high-temperature antioxidant is at least one of hindered phenolic, amine and phosphite antioxidants.

7. The ethylene scission focus inhibitor according to claim 1, wherein The high-temperature polymerization inhibitor is at least one of polyphenol and aromatic nitro compound.

8. The ethylene scorch retarder of claim 1 wherein, The coke deposit dispersant is at least one of monoalkenyl succinimide, Mannich amine, polyisobutylene bis succinimide, polyisobutylene amine, polyether amine and polyisobutylene succinic acid pentaerythritol ester.

9. A process for the preparation of a fouling inhibitor for ethylene cracking according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: 1) According to the proportion, the supported iron passivator, the oil-soluble nickel passivator, the olefin recovery agent, the high-temperature antioxidant and the high-temperature polymerization inhibitor are sequentially added to the reaction kettle, heated to 60-80℃, and continuously stirred for 1-2h; 2) After stirring, the temperature is lowered to 25-35℃, the water-soluble chromium passivator, the anionic surfactant, the coke deposit dispersant are added, and the stirring is continuously performed for 0.5-1h, the natural sedimentation is performed for 0.5-1h, the obviously large particle insoluble substances at the bottom are removed, and the finished product is sealed.

10. The use of a focus depressant for ethylene cracking according to any one of claims 1 to 8, characterized in that, 100-300ppm of ethylene coking inhibitor is injected into the cracking furnace to form a coking-resistant coating in the furnace tube.

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