Catalyst for producing monocyclic aromatic hydrocarbon and production method of monocyclic aromatic hydrocarbon

Abstract

The catalyst for producing aromatic hydrocarbon is for producing monocyclic aromatic hydrocarbon having 6 to 8 carbon number from oil feedstock having a 10 volume % distillation temperature of 140° C. or higher and a 90 volume % distillation temperature of 380° C. or lower and contains crystalline aluminosilicate and phosphorus. A molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate is from 0.1 to 1.0. The production method of monocyclic aromatic hydrocarbon is a method of bringing oil feedstock having a 10 volume % distillation temperature of 140° C. or higher and a 90 volume % distillation temperature of 380° C. or lower into contact with the catalyst for producing monocyclic aromatic hydrocarbon.

Claims

1. A production method of monocyclic aromatic hydrocarbon having 6 to 8 carbon number, comprising bringing oil feedstock having a 10 volume % distillation temperature of 140° C. or higher and a 90 volume % distillation temperature of 380° C. or lower into contact with a catalyst for producing monocyclic aromatic hydrocarbon, wherein the catalyst consists of a medium pore size zeolite crystalline aluminosilicate and phosphorus, wherein a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate is from 0.5 to 1.0, and wherein the oil feedstock comprises at least one of light cycle oil generated by fluidized catalytic cracking, coal-liquified oil, hydrocracked and refined heavy oil, straight-run kerosene, coker kerosene, and hydrocracked and refined sand oil.

2. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 1, further comprising bringing the oil feedstock into contact with the catalyst for producing monocyclic aromatic hydrocarbon by using a fluidized-bed reaction equipment.

3. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 1, wherein the phosphorus content is 0.1 to 10 mass % based on the catalyst weight.

4. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 1, wherein the crystalline aluminosilicate is MFI-type zeolite.

5. A production method of monocyclic aromatic hydrocarbon having 6 to 8 carbon number, comprising bringing oil feedstock having a 10 volume % distillation temperature of 140° C. or higher and a 90 volume % distillation temperature of 380° C. or lower into contact with a catalyst for producing monocyclic aromatic hydrocarbon, wherein the catalyst consists of a medium pore size zeolite crystalline aluminosilicate, phosphorus, and an inactive oxide, wherein a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate is from 0.5 to 1.0, and wherein the oil feedstock comprises at least one of light cycle oil generated by fluidized catalytic cracking, coal-liquified oil, hydrocracked and refined heavy oil, straight-run kerosene, coker kerosene, and hydrocracked and refined sand oil.

6. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 5, further comprising bringing the oil feedstock into contact with the catalyst for producing monocyclic aromatic hydrocarbon by using a fluidized-bed reaction equipment.

7. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 5, wherein the phosphorus content is 0.1 to 10 mass % based on the catalyst weight.

8. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 5, wherein the crystalline aluminosilicate is MFI-type zeolite.

9. The production method of a monocyclic aromatic hydrocarbon having 6 to 8 carbon number according to claim 5, wherein the inactive oxide consists of silica, alumina, zirconia, titania, and a mixture thereof.

Description

EXAMPLE

(1) Hereinafter, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to these examples.

Example 1

(2) A solution (A) containing 1706.1 g of sodium silicate (J sodium silicate No. 3, SiO.sub.2: 28 to 30 mass %, Na: 9 to 10 mass %, balance: water, manufactured by Nippon chemical industrial Co., LTD.) and 2227.5 g of water and a solution (B) containing 64.2 g of Al.sub.2(SO.sub.4).sub.3.14 to 18H.sub.2O (special grade chemical, manufactured by Wako Pure Chemical Industries, Ltd.), 369.2 g of tetrapropylammonium bromide, 152.1 g of H.sub.2SO.sub.4 (97 mass %), 326.6 g of NaCl, and 2975.7 g of water were prepared respectively.

(3) Subsequently, while the solution (A) was being stirred at room temperature, the solution (B) was slowly added to the solution (A).

(4) The obtained mixture was vigorously stirred with a mixer for 15 minutes to crack the gel, whereby the mixture was put in the state of a homogenous fine emulsion.

(5) Thereafter, the mixture was put in a stainless steel autoclave and subjected to crystallization operation under a self-pressure in natural course of events, a temperature of 160° C. and a stirring speed of 100 rpm for 72 hours. After the crystallization operation ended, the product was filtered to collect a solid product, and the operation in which the solid product was washed with about 5 L of deionized water and filtered was repeated 5 times. The solid content separated and obtained by filtration was dried at 120° C. and baked for 3 hours at 550° C. under an air flow.

(6) X-ray diffraction analysis (name of instrument: Rigaku RINT-2500V) was performed on the obtained baked product, and as a result, it was confirmed that the product has an MFI structure. Moreover, a SiO.sub.2/Al.sub.2O.sub.3 ratio (molar ratio) confirmed by X-ray fluorescence analysis (name of instrument: Rigaku ZSX101e) was 64.8. In addition, the content of aluminum element contained in the lattice skeleton that was calculated from the above result was 1.32 mass %.

(7) A 30 mass % aqueous ammonium nitrate solution was added to the obtained baked product in such a ratio that 5 mL of the solution was added to 1 g of the product. The mixture was heated for 2 hours at 100° C. and stirred, followed by filtration and washing with water. This operation was repeated 4 times, and then the resultant was dried for 3 hours at 120° C., thereby obtaining ammonium-type crystalline aluminosilicate. Thereafter, baking was performed for 3 hours at 780° C., thereby obtaining proton-type crystalline aluminosilicate.

(8) Subsequently, the obtained proton-type crystalline aluminosilicate is impregnated with 30 g of an aqueous diammonium hydrogen phosphate solution such that 0.2 mass % (value calculated when the total weight of the catalyst is regarded as being 100 mass %) of phosphorus was contained in 30 g of the proton-type crystalline aluminosilicate, followed by drying at 120° C. Thereafter, the resultant was baked for 3 hours at 780° C. under an air flow, thereby obtaining a catalyst containing crystalline aluminosilicate and phosphorus.

(9) In the obtained catalyst, a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate was 0.14, and the content of phosphorus based on the total weight of the catalyst was 0.2 mass %.

(10) A pressure of 39.2 MPa (400 kgf) was applied to the obtained catalyst to form tablets, and the resultant was coarsely pulverized to have a size of 20 to 28 mesh, thereby obtaining a granular catalyst 1 (hereinafter, called a “granulated catalyst 1”).

Example 2

(11) A granular catalyst 2 (hereinafter, called a “granulated catalyst 2”) was obtained in the same manner as in Example 1, except that the concentration of an aqueous diammonium hydrogen phosphate solution was adjusted such that 0.7 mass % (value calculated when the total weight of the catalyst is regarded as being 100 mass %) of phosphorus was contained in 30 g of proton-type crystalline aluminosilicate, and the proton-type crystalline aluminosilicate was impregnated with 30 g of the aqueous solution.

(12) In the obtained catalyst, a molar ratio (P/Al ratio) between phosphorus contained in crystalline aluminosilicate and aluminum of crystalline aluminosilicate was 0.50, and the content of phosphorus based on the total weight of the catalyst was 0.7 mass %.

Example 3

(13) A granular catalyst 3 (hereinafter, called a “granulated catalyst 3”) was obtained in the same manner as in Example 1, except that the concentration of an aqueous phosphoric acid solution was adjusted such that 1.2 mass % (value calculated when the total weight of the catalyst is regarded as being 100 mass %) of phosphorus is added to 30 g of proton-type crystalline aluminosilicate, and the proton-type crystalline aluminosilicate is impregnated with 30 g of the aqueous solution.

(14) In the obtained catalyst, a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate was 0.86, and the content of phosphorus based on the total weight of the catalyst was 1.2 mass %.

Example 4

(15) Fumed silica was impregnated with 30 g of an aqueous diammonium hydrogen phosphate solution such that 16.2 mass % of phosphorus was contained in 18 g of the fumed silica, followed by drying at 120° C. Thereafter, the resultant was baked for 3 hours at 780° C. under an air flow, thereby obtaining phosphorus-containing fumed silica. 18 g of the phosphorus-containing fumed silica was mixed with 12 g of the catalyst 2 prepared in Example 2, and a pressure of 39.2 MPa (400 Kgf) was applied to the obtained catalyst to form tablets. The resultant was coarsely pulverized to have a size of 20 to 28 mesh, thereby obtaining a granular catalyst 4 (hereinafter, called a “granulated catalyst 4”).

(16) In the obtained catalyst, a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate was 0.50, and the content of phosphorus based on the total weight of the catalyst was 10 mass %.

Example 5

(17) A mixed solution containing 106 g of sodium silicate (J sodium silicate No. 3, SiO.sub.2: 28 to 30 mass %, Na: 9 to 10 mass %, balance: water, manufactured by Nippon chemical industrial Co., LTD.) and pure water was added dropwise to diluted sulfuric acid, thereby preparing an aqueous silica sol solution (SiO.sub.2 concentration of 10.2%). In addition, distilled water was added to 20.4 g of the catalyst 2 that was prepared in Example 2 and contained crystalline aluminosilicate and phosphorus, thereby preparing zeolite slurry. The zeolite slurry was mixed with 300 g of the aqueous silica sol solution, and the thus prepared slurry was spray-dried at 250° C., thereby obtaining a spherical catalyst. Thereafter, the catalyst was baked for 3 hours at 600° C., thereby obtaining a catalyst 5 having a powder shape (hereinafter, called a “powdery catalyst 5”) that had an average particle size of 84 pun and a bulk density of 0.74 g/cc.

(18) In the obtained catalyst, a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate was 0.50, and the content of phosphorus based on the total weight of the catalyst was 0.28 mass %.

Comparative Example 1

(19) A granular catalyst 6 (hereinafter, called a “granulated catalyst 6”) was obtained in the same manner as in Example 1, except that the concentration of an aqueous diammonium hydrogen phosphate solution was adjusted such that 2.0 mass % (value calculated when the total weight of the catalyst is regarded as being 100 mass %) of phosphorus was contained in 30 g of proton-type crystalline aluminosilicate, and the crystalline aluminosilicate was impregnated with 30 g of the aqueous solution.

(20) In the obtained catalyst, a molar ratio (P/Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate was 1.43, and the content of phosphorus based on the total weight of the catalyst was 2.0 mass %.

Comparative Example 2

(21) A granular catalyst 7 (hereinafter, called a “granulated catalyst 7”) was obtained in the same manner as in Example 1, except that proton-type crystalline aluminosilicate was used as it was.

(22) The catalytic activity of the obtained granulated catalyst at the initial stage of reaction and after hydrothermal deterioration was evaluated as below.

(23) [Evaluation of Catalytic Activity at the Initial Stage of Reaction: Evaluation 1]

(24) By using a circulation-type reaction device including a reactor filled with the granulated catalysts 1 to 4, 6, and 7 (10 ml) respectively, the oil feedstock having properties shown in Table 1 was brought into contact with the granulated catalyst and reacted, at a reaction temperature of 550° C. and a reaction pressure of 0 MPaG. At this time, nitrogen as a diluent was introduced into the device such that oil feedstock came into contact with the granulated catalyst for 7 seconds.

(25) The reaction was caused for 30 minutes under the above conditions, thereby producing monocyclic aromatic hydrocarbon having 6 to 8 carbon number. By using an FID gas chromatograph directly connected to the reaction device, the composition of the product was analyzed to evaluate the catalytic activity at the initial stage of the reaction. The evaluation results are shown in Table 2A to 2C.

(26) In Table 2A to 2C a heavy fraction in the product refers to hydrocarbon that is not included in monocyclic aromatic hydrocarbon having 6 to 8 carbon number and has 6 or more carbon number, light naphtha refers to hydrocarbon having 5 to 6 carbon number, liquefied petroleum gas refers to hydrocarbon having 3 to 4 carbon number, and cracked gas refers to hydrocarbon having 2 or less carbon number.

(27) [Evaluation of Catalytic Activity after Hydrothermal Deterioration: Evaluation 2]

(28) Each of the granulated catalysts 1 to 4 and 7 was subjected to hydrothermal treatment at a treatment temperature of 650° C. for a treatment time of 6 hours in an environment of 100 mass % of water vapor, thereby preparing pseudo-deteriorated catalysts 1 to 4 and 7 that were caused to undergo pseudo-hydrothermal deterioration.

(29) The oil feedstock was reacted in the same manner as in Evaluation 1, except that the pseudo-deteriorated catalysts 1 to 4 and 7 were used respectively instead of the granulated catalysts 1 to 4 and 7. The composition of the thus obtained products was analyzed to evaluate the catalytic activity after hydrothermal deterioration. The evaluation results are shown in Table 2A to 2C.

(30) [Evaluation of Yield of Monocyclic Aromatic Hydrocarbon at the Initial Stage of Reaction: Evaluation 3]

(31) By using a circulation-type reaction device including a reactor filled with the powdery catalyst 5 (400 g), the oil feedstock having properties shown in Table 1 was brought into contact with the powdery catalyst 5 and reacted, at a reaction temperature of 550° C. and a reaction pressure of 0.1 MPaG. At this time, the powdery catalyst was filled in a reaction tube having a diameter of 60 mm. As a diluent, nitrogen was introduced into the device such that the oil feedstock came into contact with the powdery catalyst for 10 seconds.

(32) The reaction was caused for 10 minutes under the above condition, thereby producing monocyclic aromatic hydrocarbon having 6 to 8 carbon number. By using an FID gas chromatograph directly connected to the reaction device, the composition of the product was analyzed to evaluate the catalytic activity at the initial stage of the reaction. The evaluation results are shown in Table 2B.

(33) In Table 2B, a heavy fraction in the product refers to hydrocarbon that is not included in monocyclic aromatic hydrocarbon having 6 to 8 carbon number and has 6 or more carbon number, light naphtha refers to hydrocarbon having 5 to 6 carbon number, liquefied petroleum gas refers to hydrocarbon having 3 to 4 carbon number, and cracked gas refers to hydrocarbon having 2 or less carbon number.

(34) [Evaluation of Catalytic Activity After Hydrothermal Deterioration: Evaluation 4]

(35) The powdery catalyst 5 was subjected to hydrothermal treatment at a treatment temperature of 650° C. for a treatment time of 6 hours in an environment of 100 mass % of water vapor, thereby preparing pseudo-deteriorated catalyst 5 that was caused to undergo pseudo-hydrothermal deterioration.

(36) The oil feedstock was reacted in the same manner as in Evaluation 3, except that the pseudo-deteriorated catalyst 5 was used instead of the powdery catalyst 5. The composition of the thus obtained product was analyzed to evaluate the catalytic activity after hydrothermal deterioration. The evaluation results are shown in Table 2B.

(37) [Catalyst Deterioration]

(38) A value of the amount (mass %) of monocyclic aromatic hydrocarbon having 6 to 8 carbon number in the evaluation (Evaluation 2 or 4) of catalytic activity after hydrothermal deterioration with respect to a value of the amount (mass %) of monocyclic aromatic hydrocarbon having 6 to 8 carbon number in the evaluation (Evaluation 1 or 3) of catalytic activity at the initial stage of the reaction ([amount (mass %) of monocyclic aromatic hydrocarbon having 6 to 8 carbon number in Evaluation 2 (or 4)]/[amount (mass %) of monocyclic aromatic hydrocarbon having 6 to 8 carbon number in Evaluation 1 (or 3)]) was calculated to determine the degree of catalyst deterioration. The results are also shown in Table 2A to 2C. The larger value means that the catalyst hard to deteriorate. In addition, the amount of monocyclic aromatic hydrocarbon having 6 to 8 carbon number will be abbreviated to the amount of monocyclic aromatic hydrocarbon in some cases.

(39) TABLE-US-00001 TABLE 1 Method of Properties of raw material analysis Density (measured at 15° C.) g/cm.sup.3 0.908 JIS K 2249 Kinetic viscosity (measured mm.sup.2/s 3.645 JIS K 2283 at 30° C.) Distilla- Initial boiling point ° C. 177.5 JIS K 2254 tion 10 volume % distillation ° C. 226.5 properties temperature 50 volume % distillation ° C. 276.0 temperature 90 volume % distillation ° C. 350.0 temperature Final point ° C. 377.0 Com- Saturated fraction volume % 34 JPI-5S-49 position Olefin fraction volume % 8 analysis Total aromatic fraction volume % 58 Monocyclic aromatic volume % 23 fraction Bicyclic aromatic volume % 26 fraction Aromatic fraction volume % 9 having 3 or more rings

(40) TABLE-US-00002 TABLE 2A Method of preparing granular catalyst Example 1 Example 2 Example 3 Phosphorus contained in 0.14 0.5 0.86 crystalline aluminosilicate/aluminum of crystalline aluminosilicate (P/Al ratio) (molar ratio) Content of phosphorus 0.2  0.7 1.2  based on weight of catalyst (mass %) Evaluation 1 Evaluation 2 Evaluation 1 Evaluation 2 Evaluation 1 Evaluation 2 Catalyst Granulated Pseudo- Granulated Pseudo- Granulated Pseudo- catalyst 1 deteriorated catalyst 2 deteriorated catalyst 3 deteriorated catalyst 1 catalyst 2 catalyst 3 Generated Heavy 46 53 47 50 52 52 amount fraction (mass %) Monocyclic 39 27 34 30 22 23 aromatic hydrocarbon having 6 to 8 carbon number Light 1 1 1 1 2 1 naphtha Liquefied 4 9 8 8 14 13 petroleum gas Cracked gas 8 9 9 9 11 11 Hydrogen 1 1 1 1 0 0 Amount (mass %) of 0.69 0.9 1.06 monocyclic aromatic hydrocarbon in Evaluation 2 (or 4)/ amount (mass %) of monocyclic aromatic hydrocarbon in Evaluation 1 (or 3) (mass %)

(41) TABLE-US-00003 TABLE 2B Method of preparing granular catalyst Example 4 Example 5 Phosphorus contained in 0.5 0.5 crystalline aluminosilicate/aluminum of crystalline aluminosilicate (P/Al ratio) (molar ratio) Content of phosphorus 10 0.28 based on weight of catalyst (mass %) Evaluation 1 Evaluation 2 Evaluation 3 Evaluation 4 Catalyst Granulated Pseudo-deteriorated Powdered Pseudo-deteriorated catalyst 4 catalyst 4 catalyst 5 catalyst 5 Generated Heavy 50 53 48 50 amount fraction (mass %) Monocyclic 23 22 31 28 aromatic hydrocarbon having 6 to 8 carbon number Light 1 1 1 1 naphtha Liquefied 15 14 9 10 petroleum gas Cracked gas 11 10 11 11 Hydrogen 1 1 1 1 Amount (mass %) of 0.96 0.9 monocyclic aromatic hydrocarbon in Evaluation 2 (or 4)/ amount (mass %) of monocyclic aromatic hydrocarbon in Evaluation 1 (or 3) (mass %)

(42) TABLE-US-00004 TABLE 2C Method of preparing granular catalyst Comparative example 1 Comparative example 2 Phosphorus contained in 1.43 0.0 crystalline aluminosilicate/aluminum of crystalline aluminosilicate (P/Al ratio) (molar ratio) Content of phosphorus 2.0 0.0 based on weight of catalyst (mass %) Evaluation 1 Evaluation 2 Evaluation 1 Evaluation 2 Catalyst Granulated — Granulated Pseudo-deteriorated catalyst 6 catalyst 7 catalyst 7 Generated Heavy 58 — 46 62 amount fraction (mass %) Monocyclic 5 — 38 10 aromatic hydrocarbon having 6 to 8 carbon number Light 6 — 1 4 naphtha Liquefied 21 — 5 15 petroleum gas Cracked gas 10 — 9 9 Hydrogen 0 — 1 0 Amount (mass %) of — 0.26 monocyclic aromatic hydrocarbon in Evaluation 2 (or 4)/ amount (mass %) of monocyclic aromatic hydrocarbon in Evaluation 1 (or 3) (mass %)

(43) [Result]

(44) In Examples 1 to 5 using the granulated catalysts 1 to 4 and powdery catalyst 5, the amount of monocyclic aromatic hydrocarbon having 6 to 8 carbon number generated at the initial stage of the reaction was 39 mass %, 34 mass %, 22 mass %, 23 mass %, and 31 mass % respectively, and the amount of monocyclic aromatic hydrocarbon having 6 to 8 carbon number generated after hydrothermal deterioration was 27 mass %, 30 mass %, 23 mass %, 22 mass %, and 28 mass % respectively. In addition, the degree of catalyst deterioration ([amount (mass %) of monocyclic aromatic hydrocarbon in Evaluation 2 (or 4)/amount (mass %) of monocyclic aromatic hydrocarbon in Evaluation 1 (or 3)]) was 0.69, 0.90, 1.06, 0.96, and 0.90 respectively.

(45) It was found that in Examples 1 to 5 using the granulated catalysts 1 to 4 and powdery catalyst 5, both the catalytic activity at the initial stage of the reaction and the catalytic activity after hydrothermal deterioration were excellent, and monocyclic aromatic hydrocarbon having 6 to 8 carbon was obtained with an excellent yield at the initial stage of the reaction and after hydrothermal deterioration, as the object of the present application.

(46) On the other hand, it was found that in Comparative example 1 using the granulated catalyst 6 having a high P/Al ratio, the amount of monocyclic aromatic hydrocarbon having 6 to 8 carbon number generated at the initial stage of the reaction was 5 mass %, and when a large amount of phosphorus was added, the yield of monocyclic aromatic hydrocarbon having 6 to 8 carbon number in the product markedly decreased even at the initial stage of the reaction.

(47) In Comparative example 2 using the granulated catalyst 7 having a P/Al ratio of 0, the amount of monocyclic aromatic hydrocarbon having 6 to 8 carbon number generated at the initial stage of the reaction was 38 mass %, the amount of monocyclic aromatic hydrocarbon having 6 to 8 carbon number generated after hydrothermal deterioration was 10 mass %, and the degree of catalyst deterioration ([amount (mass %) of monocyclic hydrocarbon in Evaluation 2/[amount (mass %) of monocyclic aromatic hydrocarbon in Evaluation 1]) was 0.26. Accordingly, it was found that when a catalyst not containing phosphorus is used, though the yield of monocyclic aromatic hydrocarbon having 6 to 8 carbon number at the initial stage of the reaction is excellent, the yield decreases after hydrothermal deterioration, and the catalyst deteriorates markedly, so the catalyst is not practical.

(48) So far, preferable embodiments of the present invention have been described, but the present invention is not limited to the above embodiments. Within a scope that is not extrinsic to the object of the present invention, the constitutional elements can be added, omitted, substituted, and modified in another way. The present invention is restricted not by the above description but only by the claims attached.