CN112691701A

CN112691701A - Forming method of catalyst composition and application of catalyst composition in production of low-carbon olefins

Info

Publication number: CN112691701A
Application number: CN201911009086.3A
Authority: CN
Inventors: 周海波; 刘苏; 王仰东; 苏俊杰; 焦文千; 张琳; 刘畅
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2019-10-23
Filing date: 2019-10-23
Publication date: 2021-04-23

Abstract

The invention belongs to the technical field of chemistry and chemical engineering, and relates to a forming method of a catalyst composition and application of the catalyst composition in production of low-carbon olefins. The catalyst composition comprises a molecular sieve and a metal oxide, and the synthesis gas is reacted by a catalyst group bed layer to obtain the low-carbon olefin. When the catalyst composition is used as a catalyst for producing low-carbon olefins by taking synthesis gas as a raw material, the catalyst composition has the advantages of high low-carbon olefin selectivity and the like; solves the problems of low selectivity of low-carbon olefin, long separation process route and serious pollution in the prior art, and has the characteristics of simple process and low cost. Can efficiently, continuously and stably prepare low-carbon olefin products, and can be used in industrial production for directly preparing low-carbon olefin from synthesis gas.

Description

Forming method of catalyst composition and application of catalyst composition in production of low-carbon olefins

Technical Field

The invention belongs to the technical field of chemistry and chemical engineering, and relates to a forming method of a catalyst composition and application of the catalyst composition in production of low-carbon olefins.

Background

The energy characteristics of China are 'rich coal, lack of oil and little gas'. The dependence of petroleum consumption on the outside is high, the economic development is severely restricted, and clean and efficient utilization of coal, natural gas, biomass and the like is always an important issue of sustainable development. In principle, coal, natural gas and biomass are directly converted into chemicals with a poor industrialization prospect, so that the selection of a proper conversion medium as a platform for coal chemical industry and natural gas chemical industry to realize chemical synthesis is particularly necessary. In recent years, with the increasing maturity of coal gasification, natural gas reforming, and biomass gasification technologies, syngas chemistry has been considered the most feasible alternative to petroleum-based production of oil and bulk chemicals.

The low-carbon olefin, which is C2-C4 olefin, is a very important chemical raw material. Ethylene production is a measure of the state of the chemical industry. At present, the outstanding problems in the production of ethylene and propylene in China are low consumption self-sufficiency and outstanding supply-demand contradiction. The conventional process for producing ethylene mainly by steam cracking technology is completely dependent on and consumes a large amount of non-renewable petroleum resources. The development of the low-carbon hydrocarbon synthesis technology of a non-petroleum route can not only supplement the existing production technology, but also provide reference for the utilization of new energy in the future.

The catalyst and the process technology for preparing the low-carbon olefin by directly converting the synthesis gas integrate the conversion of the synthesis gas and the generation of the olefin in the same reaction system, can reduce the steps of water gas conversion, save the step of methanol synthesis and the like, show potential technical and economic advantages in the aspects of device investment, operation and the like, and have important strategic significance in developing related technologies.

Patent document CN109289910A provides a catalyst for preparing low carbon olefins by direct conversion of synthesis gas, a preparation method and an application thereof, the catalyst is composed of two parts, including a metal oxide catalyst MOx-ZnO-NOy for preparing methanol by conversion of synthesis gas and an SAPO-34 molecular sieve catalyst for preparing low carbon olefins by conversion of methanol, wherein the metal oxide catalyst comprises the following components by mass ratio: MOx 29-85%, ZnO 14-64% and auxiliary agent NOy0.2-7%; the mass ratio of the MOx-ZnO-NOy to the SAPO-34 is 0.3-5. Compared with the synthesis of low-carbon olefin by two-step series synthesis of synthesis gas (namely, methanol is synthesized from the synthesis gas firstly and then the methanol is converted into the low-carbon olefin), the catalyst can be directly converted into the low-carbon olefin from the synthesis gas in high selectivity by one-step reaction, so that the energy consumption and the equipment investment cost can be obviously reduced; meanwhile, the catalyst provided by the invention has good stability, and is beneficial to large-scale industrial application.

Patent document CN 105107523a provides a cobalt-based catalyst for directly converting synthesis gas into low-carbon olefins, and a preparation method and use thereof, the cobalt-based catalyst comprises cobalt, manganese, a carrier and an auxiliary agent, and is prepared by a coprecipitation method, wherein the molar ratio of cobalt to manganese is 1: 30-30: 1. the cobalt-based catalyst obtained by the invention has low-temperature high activity and low methane selectivity, and the cobalt-based catalyst has low preparation cost, simple and convenient preparation method and easy industrial amplification; the cobalt-based catalyst obtained by the invention is used for the reaction of directly converting synthesis gas into low-carbon olefin, the reaction can reach a single-pass conversion rate of 20% below 250 ℃, the content of methane can be controlled below 10% in alkane distribution, the content of the low-carbon olefin can reach more than 50%, and the low-carbon olefin/alkane ratio is higher than 20.

In summary, in the existing technology for preparing low-carbon olefins by one-step conversion of synthesis gas, although the conversion rate of CO is high, the selectivity of olefins, especially low-carbon olefins, is low, and has a great gap from the ideal target of industrial application; some olefins have high selectivity, but the conversion rate of CO is low, and the energy consumption is high. The catalyst has the advantages of high single-pass CO conversion rate, high selectivity of low-carbon olefin in the product and the like, and has strong market competitiveness.

Disclosure of Invention

The invention aims to solve the problems of low selectivity of low-carbon olefin, long separation process route and serious pollution in the existing olefin production technology, and provides a forming method of a catalyst composition and application thereof in the production of the low-carbon olefin. When the catalyst composition is used for preparing low-carbon olefin from synthesis gas, the catalyst composition has the advantages of high selectivity of the low-carbon olefin and the like, and has the characteristics of simple process and low cost.

In the technical scheme, the synthesis gas is reacted and contacted through the catalyst bed layer to obtain a product containing the low-carbon olefin.

In the technical scheme, the olefin content in the organic component of the reaction product exceeds 60 percent in percentage by weight of the organic component of the reaction product; preferably more than 70%; more preferably 80%.

The molding method of the catalyst composition comprises the following steps:

1) mechanically mixing a molecular sieve and a metal oxide to obtain a mixture;

2) tabletting and molding the mixture to obtain a catalyst finished product;

the method is characterized in that the size of the molecular sieve is 0.16-2.0 mm, and the size of the metal oxide is 0.15-1.6 mm.

In the technical scheme, the size of the molecular sieve is preferably 0.2-0.8 mm, and the size of the metal oxide is preferably 0.35-1.4 mm.

In the technical scheme, the ratio of the diameter to the thickness of the finished catalyst product obtained by tabletting is 0.8-2.0; preferably 1.0 to 1.2.

In the above technical scheme, the molecular sieve is selected from a phosphorus aluminum molecular sieve and/or a silicon phosphorus aluminum molecular sieve.

In the technical scheme, the molecular sieve is selected from SAPO-14, SAPO-17, SAPO-18, SAPO-31, SAPO-34, SAPO-35, SAPO-44, SAPO-56 and AlPO₄-14、AlPO₄-17、AlPO₄-18、AlPO₄-31、AlPO₄-34、AlPO₄-35、AlPO₄-44、AlPO₄-56, preferably selected from SAPO-17, SAPO-18, SAPO-34, SAPO-35, AlPO₄-17、AlPO₄-18、AlPO₄-34、AlPO₄At least one of-35, preferably selected from SAPO-18, SAPO-34, AlPO₄-18 and AlPO₄-34.

In the above technical solution, the metal oxide is selected from at least one metal oxide of group iib metals, group vib metals, and gallium oxides of the periodic table of elements (preferably at least one metal oxide selected from zinc oxide, chromium oxide, and gallium oxide, more preferably at least one metal oxide selected from zinc oxide and chromium oxide, and still more preferably a composite metal oxide of zinc oxide and chromium oxide).

In the above-mentioned aspect, the method for forming the catalyst composition is characterized in that the weight ratio of the molecular sieve to the metal oxide is (1:3) to (3:1), more preferably (1:1.5) to (1.5: 1).

In the above technical solution, the strength of the catalyst composition may exceed 80N/cm.

In the technical scheme, the catalyst contains CO and H₂The raw materials are contacted with each other through a bed layer of the catalyst composition to obtain a product containing ethylene and/or propylene.

In the above technical scheme, the reaction temperature is preferably 320-,

in the technical scheme, the preferable reaction pressure is 0.5-8 MPa.

In the above technical scheme, preferably, the volume space velocity is 800-10000h^-1。

In the above technical scheme, preferably, the reaction temperature is 360-440 ℃; more preferably, the reaction temperature is 370-; most preferably, the reaction temperature is 380-410 ℃.

In the technical scheme, the reaction pressure is preferably 1-6 MPa; more preferably, the reaction pressure is from 2 to 5 MPa.

In the above technical scheme, the volume space velocity is preferably 1,000-8,000h^-1(ii) a More preferably, the volume space velocity is 2,000-^-1。

In the above technical solution, preferably, CO and H₂The volume ratio of (A) is 0.3-3.5; preferably 0.5 to 3; more preferably 0.7 to 2.5.

Wherein, C₂-C₄The olefin selectivity was calculated as: (2 moles of ethylene product +3 moles of propylene product + moles of butene product +4 moles of butene product)/moles of total carbon in the organic product.

The strength of the catalyst particles was measured using an intelligent particle strength tester, and the average strength of 10 catalyst particles was taken as the index of the catalyst strength of the batch.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

30 g of 0.15-0.18 mm ZnO/Cr₂O₃Catalyst and 30 g of AlPO with the particle size of 0.7-1.2 mm₄-17 mechanical mixing, tabletting to form (cylinder 4 x diameter 2mm thick), loading into quartz reaction tube, (n) mixing_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 2 ]

30 g of 0.6-1.0 mm ZnIn_0.2Catalyst and 30 g of AlPO with the particle size of 0.12-0.18 mm₄-18 mechanical mixing, tabletting to form (4 × 4mm diameter cylinder), loading into quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 3 ]

5 g of ZnGa with the thickness of 0.25-0.38 mm_2.2Oxide catalyst, 25 g of 0.25-0.38 mm Zn_1.5Cr oxide catalyst and 30 g of AlPO with the thickness of 0.15-0.25 mm₄-34 mechanical mixing, tabletting to form (cylinder 4 x thick 5mm in diameter), loading into a quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 DEG CThe pressure of the reaction system is 4MPa, and the space velocity of the gas volume is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 4 ]

28 g of ZnCr with the thickness of 0.16-0.27 mm_0.8In_0.232 g of catalyst and AlPO with the particle size of 0.30-0.88 mm₄-35 mechanical mixing, tabletting to form (3 × 3mm diameter cylinder), loading into quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 5 ]

30 g of 0.25-0.70 mm Zn_0.7Mechanically mixing Cr catalyst with 30 g of 0.30-0.88 mm SAPO-34, tabletting to form (column with diameter of 5X and thickness of 5 mm), placing into a quartz reaction tube, and adding (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 6 ]

30 g of 0.18-0.88 mm Zn_0.2/ZnCr₂Mechanically mixing the catalyst with 30 g of SAPO-18 with the thickness of 0.15-1.0 mm, tabletting and forming (a cylinder with the diameter of 4X and the thickness of 3.6 mm), filling the mixture into a quartz reaction tube, and adding (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 7 ]

29.5 g of ZnCr with the thickness of 0.50-1.7 mm_0.9Al_0.3Catalyst and 30.5 g of AlPO with the particle size of 0.15-0.35 mm₄44 mechanical mixing, tabletting to shape (4X diameter 4mm thick cylinder), loading into quartz reaction tube,will (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 8 ]

28 g of ZnCr with the thickness of 0.23-0.60 mm_0.9Al_0.332 g of AlPO of 0.18-0.50 and catalyst₄-56 mechanical mixing, tabletting to shape (4 × 4mm diameter cylinder), loading into quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 9 ]

30 g of ZnCr with the thickness of 0.16-0.60 mm_0.9Al_0.3Catalyst, 18 g of AlPO with the particle size of 0.18-0.60 mm₄-18, and 12 g AlPO 0.18-1.0 mm₄-34 mechanical mixing, tabletting to shape (4 × 4mm diameter cylinder), loading into quartz reaction tube, (n) mixing_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 10 ]

29 g of ZnCr with the thickness of 0.25-0.70 mm_0.9Al_0.3Catalyst, 30 g of AlPO with the particle size of 0.30-0.70 mm₄-18/AlPO₄Mechanically mixing-34 eutectic molecular sieve and 1 g graphite powder, tabletting to form (diameter 3.3X thickness 3mm cylinder), loading into quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 11 ]

29 g of ZnCr with the thickness of 0.25-0.70 mm_0.9Al_0.3Catalyst, 30 g of AlPO with the particle size of 0.30-0.70 mm₄-18/AlPO₄Mechanically mixing-34 eutectic molecular sieve and 1 g graphite powder, tabletting to form (cylinder with diameter of 5X and thickness of 3 mm), loading into quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

[ example 12 ]

29 g of ZnCr with the thickness of 0.25-0.70 mm_0.9Al_0.3Catalyst, 30 g of AlPO with the particle size of 0.30-0.70 mm₄-18/AlPO₄Mechanically mixing-34 eutectic molecular sieve and 1 g graphite powder, tabletting to form (cylinder with diameter of 3.3X and thickness of 4 mm), loading into quartz reaction tube, and mixing (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 1.

Comparative example 1

According to the document [ Science,2016,351,1065-]Preparation method of (1), Synthesis of Zn_3.5CrAl and SAPO-34.

30 g of Zn_3.5CrAl and 30 g SAPO-34 were each tableted (4X 4mm cylinders) and mechanically mixed, placed in a quartz reaction tube, and the synthesis gas (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 2.

Comparative example 2

According to the literature [ Angewandte Chemie,2016,128,4803-]Preparation method of (1), Synthesis of ZnZr₂And SAPO-34.

30 g of ZnZr₂And 30 g of SAPO-34 were each tableted (4X 4mm cylinder), mechanically mixed, placed in a quartz reaction tube, and the synthesis gas (n)_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube and enters a catalyst bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume space velocity is 4,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The results of the activity evaluation are shown in Table 2.

TABLE 1

	Catalyst and process for preparing same	Strength N/cm	CO conversion/%	Olefin selectivity/%
					Example 1	ZnO/Cr₂O₃/AlPO₄-17	85.8	43.6	81.5
Example 2	ZnIn_0.2/AlPO₄-18	100.8	49.1	81.7
					Example 3	ZnGa_2.2+Zn_1.5Cr/AlPO₄-17	116.9	52.4	80.1
Example 4	ZnCr_0.8In_0.2/AlPO₄-35	130.8	52.0	82.6
					Example 5	Zn_0.7Cr/SAPO-34	122.7	53.4	83.3
Example 6	Zn_0.2/ZnCr₂/SAPO-18	103.0	52.5	80.6
					Example 7	ZnCr_0.9Al_0.3/AlPO₄-44	113.6	53.2	84.6
Example 8	ZnCr_0.9Al_0.3/AlPO₄-56	110.2	48.7	81.4
					Example 9	ZnCr_0.9Al_0.3/AlPO₄-18+AlPO₄-34	112.0	54.0	82.9
Example 10	ZnCr_0.9Al_0.3/AlPO₄-18～AlPO₄-34	171.4	54.3	83.8
					Example 11	ZnCr_0.9Al_0.3/AlPO4-18～AlPO4-34	164.9	51.4	81.9
Example 12	ZnCr_0.9Al_0.3/AlPO4-18～AlPO4-34	163.8	52.5	80.5

TABLE 2

	Catalyst and process for preparing same	Strength N/cm	CO conversion/%	Olefin selectivity/%
					Example 5	Zn_0.7Cr/SAPO-34	122.7	53.4	83.3
Comparative example 1	Zn_3.5CrAl/SAPO-34	89.0	31.3	68.4
					Comparative example 2	ZnZr₂/SAPO-34	85.0	28.9	66.1

Claims

1. A method of forming a catalyst composition comprising the steps of:

1) mechanically mixing a molecular sieve and a metal oxide to obtain a mixture;

2) tabletting and molding the mixture to obtain a catalyst finished product;

the method is characterized in that the size of the molecular sieve is 0.16-2 mm, and the size of the metal oxide is 0.15-1.6 mm.

2. The process for forming a catalyst composition according to claim 1, wherein the molecular sieve has a size of 0.2 to 0.8 mm; and/or the size of the metal oxide is 0.35-1.4 mm.

3. The method for molding the catalyst composition according to claim 1, wherein the ratio of the diameter to the thickness of the finished catalyst product obtained by tableting is 0.8 to 2.0; preferably 1.0 to 1.2.

4. The method of claim 1, wherein the molecular sieve is selected from the group consisting of aluminophosphate molecular sieves and silicoaluminophosphate molecular sieves.

5. The method of claim 4, wherein the molecular sieve is selected from the group consisting of SAPO-14, SAPO-17, SAPO-18, SAPO-31, SAPO-34, SAPO-35, SAPO-44, SAPO-56, AlPO₄-14、AlPO₄-17、AlPO₄-18、AlPO₄-31、AlPO₄-34、AlPO₄-35、AlPO₄-44、AlPO₄-56, preferably selected from SAPO-17, SAPO-18, SAPO-34, SAPO-35, AlPO₄-17、AlPO₄-18、AlPO₄-34、AlPO₄At least one of-35, preferably selected from SAPO-18, SAPO-34, AlPO₄-18 and AlPO₄-34.

6. The method of claim 1, wherein the metal oxide is at least one metal oxide selected from the group consisting of an oxide of a metal belonging to group IIB, an oxide of a metal belonging to group VIB, and a gallium oxide (preferably at least one metal oxide selected from the group consisting of zinc oxide, chromium oxide, and gallium oxide, more preferably at least one metal oxide selected from the group consisting of zinc oxide and chromium oxide, and still more preferably a composite metal oxide of zinc oxide and chromium oxide).

7. The process of claim 1, wherein the weight ratio of molecular sieve to metal oxide is (1:3) - (3:1), more preferably (1:1.5) - (1.5: 1).

8. A catalyst composition shaped by the shaping method according to any one of claims 1 to 7.

9. The catalyst composition of claim 8, wherein the catalyst composition has a strength in excess of 80N/cm.

10. Method for preparing low-carbon olefin containing CO and H₂The raw material (A) is contacted with a bed layer containing the catalyst composition of any one of claims 7 to 9 to obtain a product containing ethylene and/or propylene.

11. The method for preparing lower olefins according to claim 10, wherein the reaction temperature is 480 ℃ (preferably 360-^-1(preferably 1,000-8,000 h)^-1More preferably 2,000-7,000h^-1) CO and H in the synthesis gas₂Is 0.3 to 3.5 (preferably 0.5 to 3, more preferably 0.7 to 2.5).