CN117019217A - Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation - Google Patents

Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation Download PDF

Info

Publication number
CN117019217A
CN117019217A CN202310837777.2A CN202310837777A CN117019217A CN 117019217 A CN117019217 A CN 117019217A CN 202310837777 A CN202310837777 A CN 202310837777A CN 117019217 A CN117019217 A CN 117019217A
Authority
CN
China
Prior art keywords
catalyst
molecular sieve
composite catalyst
metal
carbon dioxide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310837777.2A
Other languages
Chinese (zh)
Inventor
葛庆杰
孙剑
位健
孙德越
高翔
孔维超
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhuhai Fuyi Energy Technology Co ltd
Original Assignee
Zhuhai Fuyi Energy Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhuhai Fuyi Energy Technology Co ltd filed Critical Zhuhai Fuyi Energy Technology Co ltd
Priority to CN202310837777.2A priority Critical patent/CN117019217A/en
Publication of CN117019217A publication Critical patent/CN117019217A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/82—Phosphates
    • B01J29/84—Aluminophosphates containing other elements, e.g. metals, boron
    • B01J29/85—Silicoaluminophosphates [SAPO compounds]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/80—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with zinc, cadmium or mercury
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
    • B01J29/42—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing iron group metals, noble metals or copper
    • B01J29/44—Noble metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
    • B01J29/42—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing iron group metals, noble metals or copper
    • B01J29/46—Iron group metals or copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0201—Impregnation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/30—Ion-exchange
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
    • C07C1/02—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon
    • C07C1/12—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon dioxide with hydrogen
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

The invention belongs to the technical field of synthesis of hydrocarbon compounds, and discloses a composite catalyst and application thereof in carbon dioxideA method for synthesizing saturated hydrocarbon by hydrogenation. The composite catalyst comprises a methanol synthesis catalyst and a metal modified molecular sieve, wherein: the modified metal of the molecular sieve comprises Pd and/or Cu, and the modified metal is loaded on the molecular sieve; the methanol synthesis catalyst comprises a copper-based catalyst. The invention takes carbon dioxide and hydrogen as raw materials, adopts a composite catalyst formed by compounding a methanol synthesis catalyst and a metal modified molecular sieve, and directly synthesizes C under certain reaction conditions 2+ Saturated hydrocarbons, the reaction route of which mainly goes through CO 2 Hydrogenation synthesis of methanol, dehydration synthesis of low-carbon olefin by methanol, polymerization of low-carbon olefin, hydrogenation synthesis of C 2+ Saturated hydrocarbon four steps, not only greatly improves the conversion efficiency of carbon dioxide, but also C 2+ The selectivity to saturated hydrocarbons is high and the selectivity to methane is low.

Description

Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation
Technical Field
The invention belongs to the technical field of synthesis of hydrocarbon compounds, in particular to a composite catalyst for synthesizing hydrocarbon by hydrogenation of carbon dioxide and a method for synthesizing saturated hydrocarbon by hydrogenation of carbon dioxide by using the composite catalyst.
Background
Ethylene and propylene in the low-carbon olefin play a significant role in modern petrochemical industry. Along with the rapid increase of the demands of the market on ethylene and propylene and the increasing reduction of cheap and easy-to-collect petroleum resources, the new technology for producing the low-carbon olefin is actively developed in various countries of the world, and the raw material sources for producing the olefin are expanded. At present, ethylene and propylene mainly come from the pyrolysis of naphtha and light diesel oil, and the disadvantage of the route is that the method relies on petroleum excessively, and the raw material cost accounts for about 70-75% of the production cost of the ethylene and the propylene. The light alkane cracking process has high target product yield, less side product, low investment and low power consumption. Therefore, how to optimize the raw materials of ethylene and propylene and reduce the production cost of ethylene and propylene becomes a very important technical and economic problem. With the increasing shortage of petroleum resources, natural gas and coal resources are continuously discovered, C 2+ The saturated alkane with the carbon number more than or equal to 2 becomes a potential cheap raw material for preparing ethylene and propylene.
With the increasing development of petrochemical resources and the development of society, environmental problems facing humans due to carbon dioxide emissions are becoming serious, carbon dioxide emission is reduced andresource utilization has become a focus of attention in various countries worldwide. Such as feed C for converting carbon dioxide to ethylene and propylene 2+ Saturated alkane has important significance for reducing carbon dioxide emission, converting and utilizing and solving the problems of olefin raw materials.
Currently, carbon dioxide is used for hydrogenation synthesis of C 2+ The saturated alkane has the technical problems of low conversion rate and low selectivity. Thus, a high conversion rate and high selectivity for producing C by hydrogenation of carbon dioxide are sought 2+ The saturated alkane technology for producing the low-carbon alkane has important significance for recycling the carbon dioxide, and can relieve the C existing in the production of the low-carbon olefin such as ethylene, propylene and the like caused by the reduction of petroleum resources 2+ A shortage of saturated alkane feedstock.
Disclosure of Invention
Synthesizing C by aiming at the existing carbon dioxide hydrogenation 2+ Low yield of saturated hydrocarbons, C 2+ The invention provides a composite catalyst and a method for synthesizing saturated hydrocarbon by hydrogenation of carbon dioxide by using the composite catalyst, wherein the synthetic method has the advantages of low selectivity of saturated hydrocarbon and high methane selectivity 2 High conversion rate, C 2+ High selectivity of saturated hydrocarbon and low selectivity of methane.
The invention is characterized in that: the method takes carbon dioxide and hydrogen as raw materials, adopts a composite catalyst formed by compounding a methanol synthesis catalyst and a metal modified molecular sieve, and directly synthesizes C under certain reaction conditions 2+ Saturated hydrocarbons. The reaction route mainly goes through CO 2 Hydrogenation synthesis of methanol, dehydration synthesis of low-carbon olefin by methanol, polymerization of low-carbon olefin, hydrogenation synthesis of C 2+ Saturated hydrocarbon four steps, not only greatly improves the conversion efficiency of carbon dioxide, but also C 2+ The selectivity to saturated hydrocarbons is high and the selectivity to methane is low.
To solve the above technical problems, a first aspect of the present invention provides a composite catalyst, including a methanol synthesis catalyst and a metal-modified molecular sieve, wherein a modified metal of the molecular sieve includes Pd and/or Cu, and the modified metal is supported on the molecular sieve; the methanol synthesis catalyst comprises a copper-based catalyst.
Specifically, the catalyst of the invention is formed by compounding a methanol synthesis catalyst and a metal modified molecular sieve, wherein: the methanol synthesis catalyst comprises a copper-based catalyst, and compared with other methanol synthesis catalysts, the copper-based catalyst has higher performance for synthesizing methanol by hydrogenating carbon dioxide; the molecular sieve is modified by metal Pd and/or Cu, so that the olefin hydrogenation function of the molecular sieve can be greatly improved, and the combined action of the two catalysts ensures that the product of the hydrogenation synthesis of carbon dioxide is C 2+ Saturated alkanes, not lower alkenes.
As a further improvement of the scheme, the modified metal accounts for 0.01-20% of the mass of the molecular sieve.
Preferably, when the modified metal is Pd, the active component Pd accounts for 0.01-5% of the mass of the molecular sieve.
Preferably, when the modified metal is Cu, the active component Cu accounts for 2-20% of the mass of the molecular sieve.
Preferably, the molecular sieve is selected from SAPO-34 and/or ZSM-5.
As a further improvement of the scheme, the copper-based catalyst comprises the components of Cu/ZnO/Al 2 O 3 、Cu/ZrO 2 Or Cu/ZnO/CeO 2 /ZrO 2 。
Preferably, when the copper-based catalyst has a composition of Cu/ZnO/Al 2 O 3 When the molar ratio of Cu to ZnO is 1:2-3:1, al 2 O 3 The molar ratio of Cu+ZnO is 0.01-0.1.
Preferably, when the copper-based catalyst has a composition of Cu/ZrO 2 When the Cu is in the alloy, the mass percentage of Cu is 10-70%.
Preferably, when the copper-based catalyst has a composition of Cu/ZnO/CeO 2 /ZrO 2 When CeO 2 +ZrO 2 The molar ratio of the catalyst to Cu+ZnO is 0.01-0.1, and CeO 2 With ZrO 2 The molar ratio of (2) to (5) to (2) to (1).
As a further improvement of the scheme, the mass ratio of the methanol synthesis catalyst to the metal modified molecular sieve is 1:1-4.
The second aspect of the present invention provides a preparation method of the above composite catalyst, comprising the steps of:
(1) Loading the modified metal on the molecular sieve by adopting an ion exchange method or an isovolumetric impregnation method to obtain a metal modified molecular sieve;
(2) And (3) mixing the methanol synthesis catalyst with the metal modified molecular sieve prepared in the step (1) to obtain the composite catalyst.
As a further improvement of the above scheme, the modification process of the ion exchange method is as follows: mixing water-soluble Pd salt or Cu salt with molecular sieve, ion-exchanging at 50-70 deg.C for 6-10 hr, suction filtering, washing, baking, and calcining at 500-800 deg.C for 4-6 hr to obtain the target product (metal modified molecular sieve).
As a further improvement of the above scheme, the modification process of the isovolumetric impregnation method is as follows: the water-soluble Pd salt or Cu salt and the molecular sieve are immersed in equal volume, dried and baked for 4-6 hours at 400-800 ℃ to prepare the target product (metal modified molecular sieve).
As a further improvement of the above scheme, the methanol synthesis catalyst and the metal modified molecular sieve are mixed by adopting a particle mixing or powder mixing mode.
Preferably, the particle mixing process is as follows: the methanol synthesis catalyst and the metal modified molecular sieve are respectively pressed into tablets, then respectively crushed into 20-40 meshes, and then mixed according to the mass ratio.
Preferably, the powder mixing process is as follows: mixing the powder of the two metal modified molecular sieves, grinding, tabletting, crushing into 20-40 meshes, and then mixing with the methanol synthesis catalyst particles.
The third aspect of the invention provides a method for synthesizing saturated hydrocarbon, wherein the saturated hydrocarbon is formed by converting carbon dioxide and hydrogen serving as reaction gases under the action of a catalyst, and the catalyst is the composite catalyst.
Preferably, the molar ratio of the hydrogen to the carbon dioxide is 1-5:1; more preferably, the molar ratio of hydrogen to carbon dioxide is 2.5-4.
As a further improvement of the above scheme, the method for synthesizing saturated hydrocarbons comprises the following steps:
placing the composite catalyst in a reactor, introducing hydrogen, and heating; and then introducing the reaction gas, boosting pressure, and reacting to obtain the saturated hydrocarbon.
Specifically, during the synthesis process, the purpose of passing hydrogen gas is mainly to reduce the active metal component in the methanol synthesis catalyst and the active metal component of the metal modified molecular sieve.
Preferably, the temperature is raised to 260-380 ℃; more preferably, the temperature is raised to 290-360 ℃.
Preferably, the flow rate of the reaction gas is 500-6000h -1 The method comprises the steps of carrying out a first treatment on the surface of the More preferably, the flow rate of the reaction gas is 1000 to 2000 hours -1 。
Preferably, the pressure is increased to 1.0-6.0MPa; more preferably, the pressure is increased to 3.0-5.0MPa.
Compared with the prior art, the technical scheme of the invention has at least the following technical effects or advantages:
(1) The catalyst is formed by compounding a methanol synthesis catalyst and a metal modified molecular sieve, wherein the methanol synthesis catalyst comprises a copper-based catalyst, and has higher performance for synthesizing methanol by hydrogenating carbon dioxide compared with other methanol synthesis catalysts; the molecular sieve is modified by metal Pd and/or Cu, so that the olefin hydrogenation function of the molecular sieve is greatly improved, the combined action of the two catalysts greatly improves the conversion efficiency of carbon dioxide, and the catalyst C 2+ The selectivity to saturated hydrocarbons is high and the selectivity to methane is low.
(2) When the composite catalyst of the invention is applied to the hydrogenation of carbon dioxide to synthesize saturated hydrocarbon, CO 2 The conversion rate of (C) can reach more than 50 percent 2+ The total selectivity of saturated alkane in hydrocarbon can be up to above 90%, and the selectivity of methane in hydrocarbon is lower than 10%. The product gas is used in the production of ethylene and propylene by cracking, can reduce equipment investment, energy consumption and operation cost, has few byproducts and obvious economic benefit.
Detailed Description
The present invention is described in detail below with reference to examples to facilitate understanding of the present invention by those skilled in the art. It is specifically pointed out that the examples are given solely for the purpose of illustration of the invention and are not to be construed as limiting the scope of the invention, since numerous insubstantial modifications and variations of the invention will be within the scope of the invention, as described above, will become apparent to those skilled in the art. Meanwhile, the raw materials mentioned below are not specified, and are all commercial products; the process steps or preparation methods not mentioned in detail are those known to the person skilled in the art.
The reaction products of the examples and comparative examples of the present invention were each introduced in gaseous form into a chromatograph for on-line analysis, wherein: CO 2 、CO、N 2 And CH (CH) 4 Methanol, dimethyl ether (DME) and hydrocarbons were detected by FID detection by TCD.
Example 1
A composite catalyst comprising a methanol synthesis catalyst and a metal modified molecular sieve, wherein: the modified metal of the molecular sieve is Pd, and the metal Pd is loaded on the molecular sieve SAPO-34 (with the loading amount of 0.5%) and ZSM-5 (with the loading amount of 0.5%). The catalyst for synthesizing methanol is Cu/ZnO/Al 2 O 3 And the mol ratio of Cu to ZnO is 2:1, al 2 O 3 The mol ratio of Cu to ZnO is 0.05:1; cu/ZnO/Al 2 O 3 The mass ratio of 0.5% Pd/SAPO-34 to 0.5% Pd/ZSM-5 is 1:2:1.
A method for preparing a composite catalyst, comprising the steps of:
(1) Respectively weighing 30g of molecular sieves SAPO-34 and ZSM-5, and respectively dissolving in an conical flask filled with 500ml of deionized water; 7mL of PdCl is then added 2 The solution (metal Pd content 20 mg/mL) is slowly dripped into an conical flask respectively, exchanged for 8 hours in water bath at 60 ℃, filtered and washed again, dried at 120 ℃ and baked at 500 ℃ for 6 hours to prepare 0.5% Pd/SAPO-34 and 0.5% Pd/ZSM-5;
(2) Catalyst Cu-ZnO-Al for synthesizing methanol 2 O 3 Respectively tabletting with 0.5Pd%SAPO-34 and 0.5 Pd/ZSM-5 prepared in the step (1), crushing into 20-40 meshes, and mixing granules according to the mass ratioThe composite catalyst of this example was obtained.
A method for synthesizing saturated hydrocarbons, comprising the steps of:
1.0g of the composite catalyst of this example was weighed and placed in a stainless steel fixed bed reactor, and was stirred in H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to 300-375 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising the pressure to 4.0MPa, and the total flow rate of the gas is 1500mL/min and H 2 With CO 2 The molar ratio of (2) was 4:1.
The reaction temperature was varied to examine the changes in catalyst activity and product selectivity at the same pressure at different temperatures, and the test results are shown in table 1, in which: c (C) 2+ ＝ Represents an olefin product having 2 to 7 carbon atoms; c (C) 2+ 0 Represents an alkane product having 2 to 7 carbon atoms.
Table 1: comparative table of the influence of different reaction temperatures on the reaction properties
As is clear from Table 1, CO as the reaction temperature increases 2 The conversion rate is gradually increased and then decreased. This is because the dehydration ability of molecular sieve is gradually enhanced with the increase of temperature, which promotes dehydration of methanol and dimethyl ether to hydrocarbon, breaks the thermodynamic equilibrium of methanol synthesis reaction, C 2+ The saturated hydrocarbon synthesis process involves reactions that are mostly exothermic, with increasing temperature, the chemical equilibrium shifts to the left, so the CO conversion begins to decrease as the temperature increases further. The temperature is increased from 300 ℃ to 375 ℃, C 2+ Saturated hydrocarbon selectivity reaches a maximum at 325 ℃ and then decreases, while DME selectivity gradually decreases, CO 2 The selective influence of (2) gradually increases.
Example 2
The composite catalyst of example 2 and the method for preparing the catalyst were the same as in example 1.
A method for synthesizing saturated hydrocarbons, comprising the steps of:
1.0g of the composite catalyst of this example was weighed and placed in a stainless steel fixed bed reactor, and was stirred in H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to the reaction temperature of 325 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising pressure to 1.0-4.0MPa, and making total gas flow rate be 1500mL/min and H 2 With CO 2 The molar ratio of (2) was 5:1.
The reaction pressure was varied to examine the changes in catalyst activity and product selectivity at the same temperature at different pressures, and the test results are shown in table 2.
Table 2: comparative table of the influence of different reaction pressures on the reaction properties
As can be seen from Table 2, C 2+ The synthesis reaction of saturated hydrocarbons is a process of decreasing volume, increasing pressure favors the forward reaction, so CO 2 The conversion increases gradually with increasing reaction pressure. As the CO conversion increases, the molecular sieves in the catalyst gradually fail to meet the dehydration requirements, so the overall selectivity of the hydrocarbon products increases and decreases, C in the hydrocarbon products 2+ Saturated hydrocarbons gradually increase.
Example 3
Example 3 differs from example 1 in that the Cu/ZnO/Al in the composite catalyst of example 3 2 O 3 The mass ratios of 0.5% Pd/SAPO-34 and 0.5% Pd/ZSM-5 are 1:1:2, 1:1.5:1.5 and 1:2:1, respectively.
The catalyst of example 3 was prepared in the same manner as in example 1.
A method for synthesizing saturated hydrocarbons, comprising the steps of:
1.0g of the composite catalyst of this example was weighed and placed in a stainless steel fixed bed reactor, and was stirred in H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to the reaction temperature of 325 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising pressure to 1.0MPa, and making gas total flowSpeed 1500mL/min, H 2 With CO 2 The molar ratio of (2) was 5:1.
The catalyst ratio was varied to examine the variation of catalyst activity and product selectivity at the same pressure and the same temperature, and the test results are shown in table 3.
Table 3: comparative table of the effect of different catalyst ratios on the reactivity
As can be seen from Table 3, the different structural characteristics and acidity of the two molecular sieves, namely SAPO-34 and ZSM-5, affect CO 2 Conversion of (c) and distribution of the product.
Example 4
Example 4 differs from example 1 in that the composite catalyst of example 4 is Cu/ZnO/Al 2 O 3 And 0.5% Pd/SAPO-34, in a mass ratio of 1:3.
The catalyst of example 4 was prepared in the same manner as in example 1.
A method for synthesizing saturated hydrocarbons, comprising the steps of:
1.0g of the composite catalyst of this example was weighed and placed in a stainless steel fixed bed reactor, and was stirred in H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to the reaction temperature of 325 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising the pressure to 6.0MPa, and the total gas flow rate is 2000mL/min and H 2 With CO 2 The molar ratio of (2) to (6) to (1).
Change H 2 With CO 2 The changes in catalyst activity and product selectivity at the same pressure and the same temperature were examined and the test results are shown in table 4.
Table 4: different H 2 With CO 2 Comparative table of the effect of molar ratio on the reactivity
As can be seen from Table 4, the height H 2 With CO 2 Molar ratio (hydrogen to carbon ratio) of (c) is more favorable for CO 2 Is also lower in CO selectivity and C 2+ The saturated hydrocarbon selectivity is higher.
Example 5
Example 5 differs from example 1 in that the composite catalyst of example 5 is Cu/ZnO/Al 2 O 3 And 0.03-3% Pd/SAPO-34, the mass ratio of the two being 1:3.
The catalyst of example 5 was prepared in the same manner as in example 1.
A method for synthesizing saturated hydrocarbons, comprising the steps of:
1.0g of the composite catalyst of this example was weighed and placed in a stainless steel fixed bed reactor, and was stirred in H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to the reaction temperature of 325 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising the pressure to 5.0MPa, and the total flow rate of the gas is 1000mL/min and H 2 With CO 2 The molar ratio of (2) was 4:1.
The loading of the molecular sieve SAPO-34 with Pd of different metals was changed, the changes of the catalyst activity and the product selectivity under the same pressure and the same temperature were examined, and the test results are shown in Table 5.
Table 5: comparative table of the effect of the loadings of different metallic Pd on the reactivity
As can be seen from Table 5, the Pd content of the supported metal on the molecular sieve SAPO-34 is changed from 0.03 to 3%, and CO 2 The conversion rate can reach more than 50 percent, C 2+ The selectivity of saturated hydrocarbon can reach more than 90 percent.
Example 6
A composite catalyst comprises a methanol synthesis catalyst and a metal modified componentSub-sieves, wherein: the modified metal of the molecular sieve is Cu, and the metal Cu is loaded on the molecular sieve SAPO-34 (the loading capacity is 5-15 percent); the catalyst for synthesizing methanol is Cu/ZnO/Al 2 O 3 And the mol ratio of Cu to ZnO is 3:1, al 2 O 3 The molar ratio of Cu to ZnO is 0.01:1; cu/ZnO/Al 2 O 3 And 5-15% Pd/ZSM-5 in a mass ratio of 1:3.
A method for preparing a composite catalyst, comprising the steps of:
(1) 0.95g Cu (NO) was weighed out 3 ) 2 ·H 2 O is dissolved in 4mL of deionized water to prepare Cu (NO 3 ) 2 The solution is then treated with Cu (NO) 3 ) 2 Dropwise adding the solution into a beaker filled with 5g of SAPO-34 molecular sieve, continuously stirring with a glass rod, uniformly mixing, and standing for 20 hours; baking at 120 ℃ and roasting at 400 ℃ for 4 hours to obtain 5% Cu/SAPO-34; modification of Cu (NO) 3 ) 2 ·H 2 O content, 15% Cu/SAPO-34 is prepared by the same method;
(2) Catalyst Cu-ZnO-Al for synthesizing methanol 2 O 3 And (3) mixing with 5% Cu/SAPO-34 (or 15% Cu/SAPO-34) prepared in the step (1) according to a mass ratio, and obtaining the composite catalyst of the embodiment.
A method for synthesizing saturated hydrocarbons, comprising the steps of:
0.8g of the composite catalyst of the example was weighed and placed in a stainless steel fixed bed reactor, and the catalyst was put in H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to 350 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising the pressure to 4.0MPa, and the total flow rate of the gas is 1000mL/min and H 2 With CO 2 The molar ratio of (2) was 4:1.
The loading of the molecular sieve SAPO-34 with Cu of different metals was changed, the changes of the catalyst activity and the product selectivity under the same pressure and the same temperature were examined, and the test results are shown in Table 6.
Table 6: comparative table of the effect of the loading of Cu of different metals on the reactivity
As can be seen from Table 6, the Pd content of the supported metal on the molecular sieve SAPO-34 is changed from 5 to 15%, and CO 2 The conversion rate is not greatly changed, and C is seen from hydrocarbon distribution 2+ The selectivity of saturated hydrocarbon can be up to 95%, and the methane content is about 5%, which is lower than that of Pd.
Comparative example 1
A composite catalyst comprising a methanol synthesis catalyst and a molecular sieve, wherein: the molecular sieves are SAPO-34 and ZSM-5; the catalyst for synthesizing methanol is Cu/ZnO/Al 2 O 3 And the mol ratio of Cu to ZnO is 2:1, al 2 O 3 The mol ratio of Cu to ZnO is 0.05:1; cu/ZnO/Al 2 O 3 The mass ratio of SAPO-34 to ZSM-5 is 1:2:1.
A method for preparing a composite catalyst, comprising the steps of:
catalyst Cu-ZnO-Al for synthesizing methanol 2 O 3 And respectively tabletting with SAPO-34 and ZSM-5, crushing into 20-40 meshes, and mixing the granules according to the mass ratio to obtain the composite catalyst of the comparative example.
The method for synthesizing the saturated hydrocarbon of comparative example 1 is the same as in example 1.
The reaction temperature was varied to examine the variation of catalyst activity and product selectivity using unmodified molecular sieves at different temperatures and the same pressures, and the test results are shown in table 7.
Table 7: comparison table of influence of unmodified molecular sieves at different reaction temperatures on reaction performance
As can be seen by comparing the results of Table 7 and Table 1, the catalyst composition using the molecular sieve which has not been subjected to metal modification, CO 2 Hydrogenation of CO 2 Conversion and C 2+ The selectivity of saturated alkane is obviously reduced compared with the composite catalyst formed by adopting the metal modified molecular sieve.
Meanwhile, the invention also examines the stability of the composite catalyst prepared in the example 1 and the comparative example 1 in different reaction times in the synthetic process of saturated hydrocarbon. The specific experimental process is as follows:
1.0g of the composite catalyst of example 1 and comparative example 1 was weighed into a stainless steel fixed bed reactor, respectively, and was put into a reactor vessel of H 2 Reducing for 5 hours after the air flow is increased to 250 ℃ at the speed of 1.5 ℃/min, H 2 The flow is 10mL/min, and the temperature is raised to 350 ℃; then introducing carbon dioxide and hydrogen raw material gas, raising pressure to 4.0MPa, reacting for 2-100 hr, total gas flow rate being 1500mL/min, and H 2 With CO 2 The molar ratio of (2) was 4.
The reaction time was varied to examine the CO2 conversion of the catalysts of example 1 and comparative example 1 at the same temperature and the same pressure, and the test results are shown in table 8.
Table 8: comparison of the effect of different reaction times on the stability of the catalyst
As can be seen from table 8, example 1 has significantly superior catalytic stability than the catalyst of comparative example 1.
Comparative example 2
A composite catalyst comprising a methanol synthesis catalyst and a molecular sieve, wherein: the molecular sieves are SAPO-34 and ZSM-5; the catalyst for synthesizing methanol is ZnO-ZrO 2 And ZnO and ZrO 2 The molar ratio of ZnO-ZrO is 1:1 2 The mass ratio of SAPO-34 to ZSM-5 is 1:2:1.
A method for preparing a composite catalyst, comprising the steps of:
catalyst ZnO-ZrO for synthesizing methanol 2 And respectively tabletting with SAPO-34 and ZSM-5, crushing into 20-40 meshes, and mixing the granules according to the mass ratio to obtain the composite catalyst of the comparative example.
The method for synthesizing the saturated hydrocarbon of comparative example 2 was the same as in example 1.
Changing reaction temperature, examining different temperatures, and under the same pressure, adopting ZnO-ZrO 2 The composite catalyst activity and product selectivity of the methanol synthesis catalyst were varied and the test results are shown in table 9.
Table 9: znO-ZrO at different reaction temperatures 2 Reaction Performance of the SAPO-34-ZSM-5 catalyst
As can be seen by comparing the results of Table 9 and Table 1, znO-ZrO was used 2 Catalyst for synthesizing methanol and composite catalyst formed by non-metal modified molecular sieve, and CO thereof 2 Hydrogenation of CO 2 Conversion and C 2+ The selectivity of saturated alkane is obviously reduced compared with the composite catalyst formed by adopting a copper-based methanol synthesis catalyst and a metal modified molecular sieve, and CO 2 The conversion rate is reduced to below 20 percent, C 2+ The saturated alkane selectivity is reduced to below 30 percent.
It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the inventive concept. Accordingly, it is intended that all such modifications as would be within the scope of this invention be included within the scope of this invention. The above embodiments are preferred embodiments of the present invention, and all similar processes and equivalent modifications are intended to fall within the scope of the present invention.

Claims (10)

1. A composite catalyst, characterized by comprising a methanol synthesis catalyst and a metal modified molecular sieve, wherein the modified metal of the molecular sieve comprises Pd and/or Cu, and the modified metal is supported on the molecular sieve; the methanol synthesis catalyst comprises a copper-based catalyst.
2. The composite catalyst according to claim 1, wherein the modified metal accounts for 0.01-20% of the mass of the molecular sieve; and/or the molecular sieve is selected from SAPO-34 and/or ZSM-5.
3. The composite catalyst according to claim 1, wherein the copper-based catalyst has a composition of Cu/ZnO/Al 2 O 3 、Cu/ZrO 2 Or Cu/ZnO/CeO 2 /ZrO 2 。
4. The composite catalyst of claim 1, wherein the mass ratio of the methanol synthesis catalyst to the metal modified molecular sieve is 1:1-4.
5. A method for preparing the composite catalyst according to any one of claims 1 to 4, comprising the steps of:
(1) Loading the modified metal on the molecular sieve by adopting an ion exchange method or an isovolumetric impregnation method to obtain a metal modified molecular sieve;
(2) And (3) mixing the methanol synthesis catalyst with the metal modified molecular sieve prepared in the step (1) to obtain the composite catalyst.
6. The method for preparing a composite catalyst according to claim 5, wherein the modification process of the ion exchange method is as follows: mixing water-soluble Pd salt or Cu salt with a molecular sieve, performing ion exchange at 50-70 ℃ for 6-10 hours, performing suction filtration, washing and drying, and roasting at 500-800 ℃ for 4-6 hours to obtain the catalyst;
and/or, the modification process of the isovolumetric impregnation method comprises the following steps: soaking water soluble Pd salt or Cu salt and molecular sieve in equal volume, drying, and roasting at 400-800 deg.c for 4-6 hr.
7. A method for synthesizing saturated hydrocarbon, wherein the saturated hydrocarbon is converted by using carbon dioxide and hydrogen as reaction gases under the action of a catalyst, and the catalyst is the composite catalyst as claimed in any one of claims 1 to 4.
8. The method for synthesizing saturated hydrocarbons according to claim 7, wherein the molar ratio of hydrogen to carbon dioxide is 1 to 5:1.
9. The method for synthesizing saturated hydrocarbons according to claim 7, comprising the steps of:
placing the composite catalyst in a reactor, introducing hydrogen, and heating; and then introducing the reaction gas, boosting pressure, and reacting to obtain the saturated hydrocarbon.
10. The method for synthesizing saturated hydrocarbons according to claim 9, wherein the temperature is raised to 260 to 380 ℃; and/or the flow rate of the reaction gas is 500-6000h -1 The method comprises the steps of carrying out a first treatment on the surface of the And/or, the pressure is increased to 1.0-6.0MPa.
CN202310837777.2A 2023-07-10 2023-07-10 Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation Pending CN117019217A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310837777.2A CN117019217A (en) 2023-07-10 2023-07-10 Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310837777.2A CN117019217A (en) 2023-07-10 2023-07-10 Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation

Publications (1)

Publication Number Publication Date
CN117019217A true CN117019217A (en) 2023-11-10

Family

ID=88601280

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310837777.2A Pending CN117019217A (en) 2023-07-10 2023-07-10 Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation

Country Status (1)

Country Link
CN (1) CN117019217A (en)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6376562B1 (en) * 1998-12-24 2002-04-23 Korea Advanced Institute Of Science And Technology Hybrid catalyst for hydrocarbon synthesis via hydrogenation of carbon dioxide
CN101983765A (en) * 2010-11-15 2011-03-09 大连理工大学 Catalyst for preparing methyl alcohol by catalytic hydrogenation on assistant modified carbon dioxide and preparation method thereof
CN102580753A (en) * 2012-03-05 2012-07-18 昆明理工大学 Catalyst for synthesizing methanol by taking multi-carbon sources in metallurgical fume as raw materials and preparation method of catalyst
CN103508828A (en) * 2012-06-30 2014-01-15 中国科学院大连化学物理研究所 Method used for preparing ethane and propane from synthetic gas
CN105562009A (en) * 2016-01-28 2016-05-11 中国科学院上海高等研究院 Layer-structured copper-based catalyst and preparation method and application thereof
CN106423263A (en) * 2016-09-12 2017-02-22 中国科学院大连化学物理研究所 Catalyst for preparing low-carbon olefins by carbon dioxide hydrogenation and synthesis of low-carbon olefins
CN106660894A (en) * 2014-07-11 2017-05-10 陶氏环球技术有限责任公司 Conversion of carbon monoxide, carbon dioxide, or a combination thereof over hybrid catalyst
CN109317192A (en) * 2018-09-30 2019-02-12 宁夏大学 A kind of CO2The nucleocapsid catalyst of hydrogenation coupled preparing low-carbon olefins and its preparation
CN114130398A (en) * 2021-12-15 2022-03-04 大连理工大学 Zn-based coordination polymer derived CO2Preparation method and application of catalyst for preparing methanol by hydrogenation
CN115770612A (en) * 2022-12-06 2023-03-10 中国科学院青岛生物能源与过程研究所 Catalyst for preparing methanol by carbon dioxide hydrogenation and preparation method and application thereof

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6376562B1 (en) * 1998-12-24 2002-04-23 Korea Advanced Institute Of Science And Technology Hybrid catalyst for hydrocarbon synthesis via hydrogenation of carbon dioxide
CN101983765A (en) * 2010-11-15 2011-03-09 大连理工大学 Catalyst for preparing methyl alcohol by catalytic hydrogenation on assistant modified carbon dioxide and preparation method thereof
CN102580753A (en) * 2012-03-05 2012-07-18 昆明理工大学 Catalyst for synthesizing methanol by taking multi-carbon sources in metallurgical fume as raw materials and preparation method of catalyst
CN103508828A (en) * 2012-06-30 2014-01-15 中国科学院大连化学物理研究所 Method used for preparing ethane and propane from synthetic gas
CN106660894A (en) * 2014-07-11 2017-05-10 陶氏环球技术有限责任公司 Conversion of carbon monoxide, carbon dioxide, or a combination thereof over hybrid catalyst
US20170210679A1 (en) * 2014-07-11 2017-07-27 Dow Global Technologies Llc Conversion of carbon monoxide, carbon dioxide, or a combination thereof over hybrid catalyst
CN105562009A (en) * 2016-01-28 2016-05-11 中国科学院上海高等研究院 Layer-structured copper-based catalyst and preparation method and application thereof
CN106423263A (en) * 2016-09-12 2017-02-22 中国科学院大连化学物理研究所 Catalyst for preparing low-carbon olefins by carbon dioxide hydrogenation and synthesis of low-carbon olefins
CN109317192A (en) * 2018-09-30 2019-02-12 宁夏大学 A kind of CO2The nucleocapsid catalyst of hydrogenation coupled preparing low-carbon olefins and its preparation
CN114130398A (en) * 2021-12-15 2022-03-04 大连理工大学 Zn-based coordination polymer derived CO2Preparation method and application of catalyst for preparing methanol by hydrogenation
CN115770612A (en) * 2022-12-06 2023-03-10 中国科学院青岛生物能源与过程研究所 Catalyst for preparing methanol by carbon dioxide hydrogenation and preparation method and application thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JONG-KI JEON等: "Selective synthesis of C3-C4 hydrocarbons through carbon dioxide hydrogenation on hybrid catalysts composed of a methanol synthesis catalyst and SAPO", APPLIED CATALYSIS A: GENERAL, vol. 124, 7 November 1994 (1994-11-07), pages 91 - 106 *

Similar Documents

Publication Publication Date Title
CN106423263A (en) Catalyst for preparing low-carbon olefins by carbon dioxide hydrogenation and synthesis of low-carbon olefins
CN108067235A (en) A kind of catalyst of synthesis gas alkene coproduction higher alcohols and its preparation and application
CN114588910B (en) Preparation method and application of Ni-Zn supported catalyst for lignin depolymerization
CN111036278B (en) Method for preparing low-carbon olefin from synthesis gas
WO2019183842A1 (en) Composite catalyst, preparation method therefor and method for preparing ethylene
CN109574798A (en) A kind of method that synthesis gas directly produces ethyl alcohol
CN109912372A (en) Synthesis gas methanation catalyst and its preparation method
CN107486226B (en) Catalyst, the preparation method and its usage of preparation of low carbon olefines by synthetic gas
JP2017521232A (en) Catalyst suitable for production of aircraft kerosene from synthetic oil obtained by biomass Fischer-Tropsch process and process for its preparation
CN108250010A (en) A kind of selection method of hydrotreating of methanol-to-olefins product
CN115770612A (en) Catalyst for preparing methanol by carbon dioxide hydrogenation and preparation method and application thereof
CN106890665A (en) A kind of catalyst of Dimethyl ether carbonylation production methyl acetate and its application
CN117019217A (en) Composite catalyst and method for synthesizing saturated hydrocarbon by using carbon dioxide hydrogenation
CN106607048B (en) The method of fixed bed production low-carbon alkene
CN108126701B (en) A kind of syngas catalytic conversion catalyst and preparation method thereof
CN107913718A (en) The ferrum-based catalyst of the direct synthesizing low-carbon alkene of synthesis gas
CN107617446B (en) Catalyst for preparing gasoline fraction hydrocarbon by directly converting synthesis gas and preparation and application thereof
CN111036284A (en) Catalyst, preparation method thereof and method for preparing low-carbon olefin from synthesis gas
CN109158107B (en) Method for preparing liquid hydrocarbon by directly hydrogenating carbon dioxide
CN114433059A (en) CO2Catalyst for synthesizing low-carbon olefin compound by hydrogenation, preparation and application thereof
CN1054202A (en) A kind of by the synthetic gas propane catalyst prepared selectively
CN111068770A (en) Supported catalyst for preparing low-carbon olefin by carbon monoxide hydrogenation, and preparation method and application thereof
KR101551399B1 (en) The method for preparation of catalysts for the production of oxygenated carbon compound and production method of oxygenated carbon compound using thereof
CN108927214A (en) A kind of multi-functional composite catalyst and its preparation method and application
KR101493398B1 (en) Mesoporous carbon nanoparticle based catalysts for the production of oxygenated carbon compound and production method of oxygenated carbon compound using thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination