CN109701630B

CN109701630B - Coupling catalyst system for directly preparing low-carbon olefin from synthesis gas

Info

Publication number: CN109701630B
Application number: CN201711010816.2A
Authority: CN
Inventors: 周海波; 刘苏; 刘畅; 苏俊杰; 王仰东
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: 2017-10-26
Filing date: 2017-10-26
Publication date: 2021-10-01
Anticipated expiration: 2037-10-26
Also published as: CN109701630A

Abstract

The invention belongs to the technical field of chemistry and chemical engineering, in particular to a coupling catalyst system for directly preparing low-carbon olefin from synthesis gas, which mainly solves the problem that the low-carbon olefin selectivity of the existing catalyst for preparing olefin from synthesis gas is not high. The catalyst couples the catalyst for preparing alcohol from the synthesis gas with the catalyst for preparing olefin from alcohol, so that the direct preparation of olefin from the synthesis gas by one-step method is realized. The catalyst for preparing alcohol from synthesis gas is an improved molybdenum-based catalyst with a molecular general formula of MoT_t‑X_aY_bZ_cWherein T is selected from at least one of S, O or C, X is one or more of Fe, Co, Ni, Ru, Rh and Pd metal, Y is one or more of Cr, Mn, Zn, La and Ce metal, and Z is one or more of alkali metal; the catalyst for preparing olefin from alcohol is a molecular sieve with CHA framework structure. The catalyst can solve the problems and prepare C efficiently, continuously and stably_2‑4The olefin product can be used in the industrial production of preparing low-carbon olefin from synthesis gas.

Description

Coupling catalyst system for directly preparing low-carbon olefin from synthesis gas

Technical Field

The invention belongs to the technical field of chemistry and chemical engineering, particularly relates to a coupling catalyst system for directly preparing low-carbon olefin from synthesis gas, and particularly relates to a coupling catalyst system for efficiently and directly preparing ethylene and propylene from synthesis gas.

Background

Light olefins (such as ethylene and propylene) are important chemical raw materials, and the consumption demand of the light olefins is increasing along with the increase of national economy. Although the production of ethylene and propylene in China has a considerable scale, the consumption self-sufficiency is low, and the contradiction between supply and demand is still outstanding. With the gradual decrease of petroleum resources, coal and natural gas will gradually replace petroleum to become new fuel and chemical raw material sources, and in recent years, various major petroleum companies in the world compete to develop research on the process of preparing olefins from synthesis gas of clean fuels, so as to occupy the market of low-carbon olefins.

Due to the natural resources of rich coal, oil and gas, coal and biomass are vigorously developed to prepare olefin through synthesis gas/methanol, and a petrochemical raw material-to-olefin route is replaced, so that the method has important strategic significance; from the technical point of view, the clean coal gasification technology is developing vigorously, the biomass gasification technology is mature continuously, and both catalysts and technological processes are improved, so that the economy of a synthetic gas olefin preparation route is believed to be more remarkable along with the continuous development of the gasification technology.

There are two main processes for preparing low-carbon olefin by using synthesis gas: one is that the synthesis gas is directly used for preparing low-carbon olefin; one is the indirect preparation of low carbon olefin (MTO/MTP) from synthetic gas through methanol or dimethyl ether. However, in the long run, the process for directly producing low carbon olefins from synthesis gas is more economical than the indirect process.

At present, synthesis gas is used for directly preparing low-carbon olefin, an F-T catalyst is mainly used as a basis, and the prior art discloses catalytic systems such as FeMnK, Fe/C, FeAl-ZSM-5 and the like, which can be used as catalysts for directly preparing low-carbon olefin from synthesis gas.

Patent document [ CN103157489A]Relates to a catalyst for directly preparing low-carbon olefin from synthesis gas, a preparation method and application thereof. The invention adopts the cocurrent flow precipitation method to highly disperse Fe and the auxiliary agent on the surface of the self-made alkaline carrier, the loading capacity of the catalyst is low, the preparation process is simple, and the cost is lower than that of the same type of products. The catalyst is used for directly preparing low-carbon olefin from the synthesis gas, the CO conversion rate can reach 75-85 percent under the condition of single-pass catalysis of the synthesis gas, the alkene-alkane ratio in a gas organic product reaches 4.5-6.0, the weight of the olefin reaches 50-60 percent,more than 98% of the liquid product is water. The catalyst has good abrasion resistance and pressure resistance, and can be used for slurry beds and fixed beds. The catalyst reaction process conditions related by the invention are as follows: the temperature is 200 ℃ and the pressure is 0-5MPa, and the space velocity of the synthesis gas is 600 ℃ and 2400h^-1。

Patent document [ CN103331171A ] mentions a preparation method and application of a catalyst for preparing low-carbon olefin and co-producing gasoline by directly converting synthesis gas. The method takes iron salt as a precursor, and synthesizes the catalyst which takes an iron-containing compound as an active center and can directly convert synthesis gas into low-carbon olefin and co-produce gasoline through a simple and feasible preparation method comprising the steps of carbon source pretreatment, dispersive mixing, modified vapor deposition and the like, wherein the activity and the economic cost of the catalyst both have industrialization possibility.

Patent document [ CN1083415A]Reports on synthesis gas (CO + H)₂) The catalyst for preparing low-carbon olefin such as ethylene, propylene and the like with high selectivity is an iron-manganese catalyst system carried by alkaline earth metal oxides of families IIA such as MgO and the like or high-silicon zeolite molecular sieve (or phosphorus-aluminum zeolite), has good performance for synthesizing the low-carbon olefin under the action of strong alkali (IA family metal) K or Cs ion auxiliary agent, and can prepare the low-carbon olefin from synthesis gas with high activity (the CO conversion rate reaches more than 90 percent) and high selectivity (the olefin selectivity reaches more than 66 percent) by utilizing the catalyst under the reaction conditions of the pressure of 1.0-5.0MPa and the temperature of 300-400 ℃. The process flow of the invention can directly separate CO from the reaction tail gas through water absorption₂And absorbing and separating C3 and C4 components by medium-pressure oil, and then reacting benzene with ethylene with the alkene concentration in the tail gas to produce ethylbenzene. The operation process is simple and is suitable for popularization and application.

Patent document [ CN1279131A ] relates to a ZSM-5 zeolite and porous metal composite material containing a porous metal support and ZSM-5 zeolite directly crystallized on the support, wherein the porous metal support contains at least one porous nickel-aluminum, iron-aluminum or copper-aluminum alloy, and the pore volume of the porous metal support is 0.02 to 0.5mL/g based on the porous nickel-aluminum, iron-aluminum or copper-aluminum alloy. The combination of zeolite and porous metal carrier in the composite material is firmer, the zeolite has higher thermal and hydrothermal stability, and the copper-containing catalyst prepared by the composite material has unique catalytic performance.

In the prior art, the FT reaction with Fe as the main catalytic active component is mainly used as the basis, the distribution of the synthesized products is limited by the Anderson-Schulz-Flory rule (the molar distribution of chain growth decreasing according to the index), and the strong heat release of the reaction easily causes the generation of methane and low-carbon alkane, and promotes the synthesized low-carbon olefin to have secondary reaction, so that the selectivity of the low-carbon olefin is reduced.

The literature science.2016,351,1065-8 reports that the novel OX-ZEO process can obviously improve the selectivity of low-carbon olefins, and the core of the OX-ZEO process is a bifunctional composite catalyst ZnCrOx/SAPO: ZnCrOx and mesoporous SAPO zeolites of spinel structure. The catalyst has two active sites, and can separate CO activation and C-C coupling. In one aspect, partially oxidized ZnCrOx (zinc chromium oxide) activates CO and H₂(ii) a In another aspect, the C-C coupling is carried out within the acid-restricted channels of the zeolite. The catalyst has an ultra-high selectivity (80% olefins, 14% alkanes) up to 94% for the direct conversion of syngas to (C2-C4), with only 2% methane, with a CO conversion of 17%.

The document Angew.chem.int.Ed.2016,55,1-5 reports a bifunctional catalyst, which couples a methanol synthesis reaction with a C-C coupling (methanol to olefin) reaction, successfully designs a Zr-Zn/SAPO-34 bifunctional catalyst, and makes a breakthrough in the aspect of low-carbon olefin selectivity. Under the milder condition (1MPa/400 ℃/H)₂CO 2:1), the selectivity of the low-carbon olefin reaches 74 percent, and the conversion rate of CO is 11 percent.

In summary, in the prior art, although the FT catalyst has high activity, the product selectivity is limited by ASF distribution (58%), which also prevents the syngas from being directly used to prepare light olefins. The novel coupling catalyst system can break through ASF distribution and realize the high-selectivity preparation of low-carbon olefin by synthesis gas. The catalyst has the advantages of strong raw material adaptability, high CO conversion rate, high ethylene propylene selectivity and adjustable ethylene propylene proportion.

Disclosure of Invention

The invention aims to solve the problems of poor sulfur resistance of a catalyst, low selectivity of low-carbon olefin in a product and non-adjustable ethylene/propylene ratio in the prior art, and provides a novel coupling catalytic system for preparing low-carbon olefin from synthesis gas.

In order to solve the technical problems, the technical scheme of the invention is as follows: a coupled catalyst system for directly preparing low-carbon olefin from synthetic gas is characterized by comprising a molybdenum-based catalyst and a molecular sieve with CHA framework structure.

In the above-described aspect, preferably, the molybdenum-based catalyst contains at least one component selected from the group consisting of molybdenum sulfide, molybdenum oxide, and molybdenum carbide.

In the above-described aspect, it is more preferable that the molybdenum-based catalyst contains one component selected from the group consisting of molybdenum sulfide, molybdenum oxide, and molybdenum carbide; most preferably, the molybdenum-based catalyst comprises molybdenum sulfide.

In the above technical solution, preferably, the general molecular formula of the molybdenum-based catalyst is MoT_t-X_aY_bZ_cWherein T is selected from at least one of S, O or C, X is one or more of Fe, Co, Ni, Ru, Rh and Pd metal, Y is one or more of Cr, Mn, Zn, La and Ce metal, and Z is one or more of alkali metal;

the value range of a is 0-4, the value range of b is 0-2, the value range of c is 0.1-2.5, and t is the number of atoms required by the valence of each element.

In the above technical solution, preferably, T is selected from S, O or C; more preferably, T is selected from S.

In the above technical scheme, preferably, the value range of a is 0.1-3.3; more preferably, the value range of a is 0.3-3.

In the above technical scheme, preferably, the value range of b is 0.1-1.8; more preferably, the value range of a is 0.2-1.6.

In the above technical scheme, preferably, the value range of c is 0.15-2.2; more preferably, the value range of a is 0.2-2.

In the above technical solution, X is preferably at least one of Ni and Co; x is preferably one of Ni and Co; more preferably a mixture of Ni and Co.

In the above-mentioned embodiment, the ratio of Ni to Co is preferably (1:2) to (2: 1).

In the above embodiment, Y is preferably Mn.

In the technical scheme, Z is preferably a mixture of Na and K, and the ratio of Na to K is preferably (2:1) - (8: 1); more preferably, the ratio of Na to K is (1:1) to (6: 1).

In the above technical scheme, preferably, an oxygen-containing compound can be further added into the raw material; more preferably, methanol or carbon dioxide may also be added to the feedstock.

In the above technical scheme, (MoT)_t-X_aY_bZ_cThe use of the + CHA) catalyst is as follows:

at the reaction temperature of 320-^-1In syngas, CO and H₂The volume ratio of the catalyst is 0.3-3.5, and the synthesis gas contacts and reacts with the catalyst to obtain a product containing low-carbon olefin.

In the above technical scheme, preferably, the reaction temperature is 360-440 ℃; more preferably, the reaction temperature is 380-430 ℃; most preferably, the reaction temperature is 390-420 ℃.

In the technical scheme, the reaction pressure is preferably 1-6 MPa.

In the above technical scheme, the volume space velocity is preferably 1,000-8,000h^-1。

Wherein, the selectivity of the C2-C4 olefin is calculated by the following steps: (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

Compared with the existing catalyst, the technical scheme adopts the coupling of the alcohol preparation catalyst and the alcohol-to-olefin catalyst. Wherein, the catalyst for preparing alcohol from synthesis gas takes a molybdenum-based catalyst as a main body; the chain growth auxiliary agent component adopts Fe, Co, Ni, Ru, Rh, Pd and other metals, so that the chain growth capacity of the alcohol preparation catalyst is effectively improved; the structural auxiliary agent component adopts metals such as Cr, Mn, Zn, La, Ce and the like, so that the specific surface of the catalyst is effectively improved, and the dispersion of active sites is promoted; the addition of alkali metal effectively regulates the acid-base property and electronic property of the surface of the catalyst, moderately weakens the hydrogenation capacity of the active center and reduces the content of alkane in the product; the selection of molecular sieves with different CHA framework structures is beneficial to realizing the adjustment of the ethylene/propylene ratio, and the E/P can be adjusted to be 0.3-3.6 according to the prices of ethylene and propylene so as to obtain good economic benefit.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.03mol of ferric nitrate and 0.01mol of zinc nitrate are weighed and dissolved in water, the two aqueous solutions are co-current and co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 hours. 0.02mol of Cs loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Fe_0.6Zn_0.2Cs_0.8A sulfide catalyst.

The SAPO-34 catalyst is prepared by the following steps: phosphoric acid, pseudo-boehmite, ethyl orthosilicate and morpholine are respectively used as a phosphorus source, an aluminum source, a silicon source and a template agent, and the molar ratio of Al is₂O₃∶P₂O₅∶SiO₂∶R∶H₂Adding O1: 0.6: 3: 100 into a reaction kettle, aging for 2 hours, stirring and crystallizing for 24 hours at 200 ℃, washing the obtained solid to be neutral by deionized water, separating to obtain the solid, drying, and roasting for 6 hours at 550 ℃ in a muffle furnace to obtain the SAPO-34 molecular sieve.

0.75 g of prepared Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1Under the condition of making low grade synthetic gasAnd (3) reacting carbon olefin. The reaction results are shown in Table 1.

[ example 2 ]

Mo-Fe_0.8Cs_0.8The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.04mol of ferric nitrate is weighed and dissolved in water, the two aqueous solutions are co-current co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 h. 0.02mol of Cs loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Fe_0.8Cs_0.8A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Fe_0.8Cs_0.8The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 3 ]

Mo-Zn_0.8Cs_0.8The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.04mol of zinc nitrate is weighed and dissolved in water, the two aqueous solutions are co-current co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 h. 0.02mol of Cs loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Zn_0.8Cs_0.8A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Zn_0.8Cs_0.8The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 4 ]

The Mo-Na sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.10mol of acetic acid is weighed and dissolved in water, the two aqueous solutions are co-current co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight, and roasted at 500 ℃ for 4 h. The sulfide intermediate is loaded with 0.025mol of Na₂CO₃And drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain the Mo-Na sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of the prepared Mo-Na sulfide catalyst and 0.75 g of the prepared SAPO-34 were mixed, and packed in a quartz reaction tube having an inner diameter of 6 mm, and (n) was added_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 5 ]

Mo-Na_0.6K_0.4The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.10mol of acetic acid is weighed and dissolved in water, the two aqueous solutions are co-current co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight, and roasted at 500 ℃ for 4 h. 0.015mol of Na is loaded on the sulfide intermediate₂CO₃And 0.01mol of K₂CO₃Drying at 80 deg.C overnight, and calcining at 400 deg.C for 1h to obtain Mo-Na_0.6K_0.4A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Na_0.6K_0.4Sulfide catalyst and 0.75 gThe prepared SAPO-34 is mixed and filled into a quartz reaction tube with the inner diameter of 6 mm, and (n) is added_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 6 ]

The Mo-K sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.10mol of acetic acid is weighed and dissolved in water, the two aqueous solutions are co-current co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight, and roasted at 500 ℃ for 4 h. Sulfide intermediate load 0.025mol of K₂CO₃And drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain the Mo-K sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of the prepared Mo-K sulfide catalyst and 0.75 g of the prepared SAPO-34 were mixed, and the mixture was charged into a quartz reaction tube having an inner diameter of 6 mm, and (n) was added_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 7 ]

Mo-Ni_0.5Mn_0.1K_0.6The oxide catalyst is prepared by the following steps:

0.05mol of ammonium molybdate, 0.025mol of nickel nitrate and 0.01mol of manganese nitrate are weighed, stirred, mixed, dried at 100 ℃ overnight and roasted at 500 ℃ for 6 h. After completion of calcination, the catalyst intermediate was loaded with 0.015mol of K₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Ni_0.5Mn_0.1K_0.6An oxide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g ofPrepared Mo-Ni_0.5Mn_0.1K_0.6The oxide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged in a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 8 ]

Mo-Ni_0.5Mn_0.1K_0.6The carbide catalyst is prepared by the following steps:

0.05mol of ammonium molybdate, 0.025mol of nickel nitrate and 0.01mol of manganese nitrate are weighed, stirred, mixed, dried at 100 ℃ overnight and roasted at 500 ℃ for 6 h. After completion of calcination, in CH₄Carbonizing for 4 hours at 500 ℃ in atmosphere to obtain carbide, wherein 0.015mol of K is loaded on the carbide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Ni_0.5Mn_0.1K_0.6A carbide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Ni_0.5Mn_0.1K_0.6The carbide catalyst was mixed with 0.75 g of the prepared SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to obtain (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 9 ]

Mo-Ni_0.5Mn_0.1K_0.6The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.025mol of nickel acetate and 0.005mol of manganese nitrate are weighed and dissolved in water, the two aqueous solutions are cocurrently co-precipitated, filtered and washed, dried at 100 ℃ overnight, and then the mixture is driedRoasting at 500 deg.c for 4 hr. 0.015mol of K is loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Ni_0.5Mn_0.1K_0.6A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Ni_0.5Mn_0.1K_0.6The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 10 ]

Mo-Ni_0.2Co_0.3Mn_0.1K_0.6The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.01mol of nickel acetate, 0.015mol of cobalt acetate and 0.005mol of manganese nitrate are weighed and dissolved in water, the two aqueous solutions are co-current precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 hours. 0.015mol of K is loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Ni_0.2Co_0.3Mn_0.1K_0.6A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Ni_0.2Co_0.3Mn_0.1K_0.6The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 11 ]

Mo-Ni_0.1Co_0.4Mn_0.1K_0.6The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.005mol of nickel acetate, 0.02mol of cobalt acetate and 0.005mol of manganese nitrate are weighed and dissolved in water, the two aqueous solutions are co-current precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 hours. 0.015mol of K is loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Ni_0.1Co_0.4Mn_0.1K_0.6A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Ni_0.1Co_0.4Mn_0.1K_0.6The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 12 ]

Mo-Co_0.5Mn_0.1K_0.6The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.025mol of cobalt acetate and 0.005mol of manganese nitrate are weighed and dissolved in water, the two aqueous solutions are co-current and co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 h. 0.015mol of K is loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Co_0.5Mn_0.1K_0.6A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Co_0.5Mn_0.1K_0.6VulcanizationThe catalyst was mixed with 0.75 g of the prepared SAPO-34, and the mixture was packed in a quartz reaction tube having an inner diameter of 6 mm, and (n) was added_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 13 ]

Mo-Ru_0.08Ce_0.1Na_0.4The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.004mol of ruthenium chloride and 0.005mol of cerium nitrate are weighed and dissolved in water, the two aqueous solutions are co-current and co-precipitated, filtered and washed after precipitation, dried overnight at 100 ℃, and roasted for 4 hours at 500 ℃. 0.01mol of Na is loaded on the sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Ru_0.08Ce_0.1Na_0.4A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Ru_0.08Ce_0.1Na_0.4The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 14 ]

Mo-Rh_0.04La_0.6Cs_0.2The sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.002mol of rhodium nitrate and 0.03mol of lanthanum nitrate are weighed and dissolved in water, the two aqueous solutions are co-current and co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 hours. 0.005mol of Cs loaded on sulfide intermediate₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Rh_0.04La_0.6Cs_0.2A sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Rh_0.04La_0.6Cs_0.2The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 15 ]

Mo-Pd_0.1Cr_0.2The K sulfide catalyst is prepared by the following steps:

0.05mol of ammonium thiomolybdate is weighed and dissolved in water, 0.005mol of palladium chloride and 0.01mol of chromium nitrate are weighed and dissolved in water, the two aqueous solutions are co-current and co-precipitated, filtered and washed after precipitation, dried at 100 ℃ overnight and roasted at 500 ℃ for 4 h. Sulfide intermediate load 0.025mol of K₂CO₃Drying at 80 ℃ overnight, and roasting at 400 ℃ for 1h to obtain Mo-Pd_0.1Cr_0.2K sulfide catalyst.

SAPO-34 catalyst was prepared as in [ example 1 ].

1.36 g of prepared Mo-Pd_0.1Cr_0.2K sulfide catalyst was mixed with 0.17 g of the prepared SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to obtain (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 16 ]

Mo-Pd_0.1Cr_0.2K sulfide catalyst was prepared as in [ example 13 ].

SAPO-34 catalyst was prepared as in [ example 1 ].

1.14 g of prepared Mo-Pd_0.1Cr_0.2K sulfide catalyst was mixed with 0.38 g of the prepared SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to obtain (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 17 ]

Mo-Pd_0.1Cr_0.2K sulfide catalyst was prepared as in [ example 13 ].

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Pd_0.1Cr_0.2K sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to obtain (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 18 ]

Mo-Pd_0.1Cr_0.2K sulfide catalyst was prepared as in [ example 13 ].

SAPO-34 catalyst was prepared as in [ example 1 ].

0.38 g of prepared Mo-Pd_0.1Cr_0.2K sulfide catalyst was mixed with 1.14 g of the prepared SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to obtain (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 1.

[ example 19 ]

Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst was prepared as in [ example 1 ].

SAPO-34 catalyst was prepared as in [ example 1 ].

The SSZ-13 catalyst is prepared as follows: pseudo-boehmite, ethyl orthosilicate and N, N, N-trimethyl adamantane ammonium hydroxide are respectively used as an aluminum source, a silicon source and a template agent, and the molar ratio of Al₂O₃∶SiO₂∶R∶H₂Adding O1: 40: 5: 900 into a reaction kettle, aging for 2 hours, stirring and crystallizing at 150 ℃ for 48 hours, washing the obtained solid to be neutral by deionized water, separating to obtain the solid, drying, and roasting in a muffle furnace at 550 ℃ for 6 hours to obtain the SSZ-13 molecular sieve.

0.75 g of prepared Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst, 0.5 g of the prepared SAPO-34, and 0.25 g of the prepared SSZ-13 were mixed and packed into a quartz reaction tube having an inner diameter of 6 mm, and (n) was added_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 2.

[ example 20 ]

Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst was prepared as in [ example 1 ].

SAPO-34 catalyst was prepared as in [ example 1 ]. SSZ-13 catalyst was prepared as [ example 19 ].

0.75 g of prepared Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst, 0.25 g of the prepared SAPO-34, and 0.5 g of the prepared SSZ-13 were mixed and packed into a quartz reaction tube having an inner diameter of 6 mm, and (n) was added_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 2.

[ example 21 ]

Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst was prepared as in [ example 1 ].

SSZ-13 catalyst was prepared as [ example 19 ].

0.75 g of prepared Mo-Fe_0.6Zn_0.2Cs_0.8The sulfide catalyst and 0.75 g of the prepared SSZ-13 were mixed and charged into a quartz reaction tube having an inner diameter of 6 mm, and (n) was introduced_{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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 2.

[ examples 22 to 26 ]

The catalyst prepared in example 1 was used in the reaction of synthesis gas to produce light olefins, and the reaction conditions and evaluation results are shown in table 3.

[ example 27 ]

Mo-Ni_0.1Co_0.4Mn_0.1K_0.6The sulfide catalyst was prepared as in [ example 11 ].

SAPO-34 catalyst was prepared as in [ example 1 ].

0.71 g of prepared Mo-Ni_0.1Co_0.4Mn_0.1K_0.6The sulfide catalyst was mixed with 0.79 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (n)_{Hydrogen gas}:n_{Carbon monoxide}70:30) 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 3MPa, and the gas volume space velocity is 7,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 5.

[ example 28 ]

SAPO-34 catalyst was prepared as in [ example 1 ].

0.75 g of prepared Mo-Ni_0.1Co_0.4Mn_0.1K_0.6The sulfide catalyst was mixed with 0.75 g of the prepared SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (n)_{Hydrogen gas}:n_{Carbon monoxide}:n_{Hydrogen sulfide}49.99:50:0.01) is introduced into a reaction tube, 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 2,000h^-1The life test of preparing low carbon olefin by synthesis gas is carried out under the condition, and the reaction result at the 200 th hour is shown in the table 6.

Comparative example 1

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

0.75 g of Zn_3.5CrAl was mixed with 0.75 g SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 4.

Comparative example 2

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

0.75 g of ZnZr₂Mixed with 0.75 g of SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to mix (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 4.

Comparative example 3

According to the preparation method of patent document [ CN103157489A ], the FeMnCuK catalyst is synthesized.

1.50 g of FeMnCuK catalyst was charged into a quartz reaction tube having an inner diameter of 6 mm, and (n) was introduced_{Hydrogen gas}:n_{Carbon monoxide}50:50) is introduced into a reaction tube, enters a catalytic bed for reaction, the reaction temperature is 400 ℃, the pressure of a reaction system is 4MPa, and the gas volume is emptyThe speed is 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 4.

Comparative example 4

According to the preparation method of patent document [ CN1279131A ], ZSM-5 zeolite directly crystallized on Fe-Al alloy is synthesized.

Loading 1.50 g of ZSM-5 zeolite catalyst crystallized directly on Fe-Al alloy into a quartz reaction tube with an internal diameter of 6 mm, and reacting (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 2,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 4.

Comparative example 5

0.71 g of Zn_3.5CrAl was mixed with 0.79 g of SAPO-34, and the mixture was charged into a quartz reaction tube having an inner diameter of 6 mm, and (n) was heated_{Hydrogen gas}:n_{Carbon monoxide}70:30) 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 3MPa, and the gas volume space velocity is 7,000h^-1The reaction for preparing the low-carbon olefin from the synthesis gas is carried out under the condition. The reaction results are shown in Table 5.

Comparative example 6

0.75 g of Zn_3.5CrAl was mixed with 0.75 g SAPO-34, and charged into a quartz reaction tube having an inner diameter of 6 mm to mix (n)_{Hydrogen gas}:n_{Carbon monoxide}:n_{Hydrogen sulfide}49.99:50:0.01) is introduced into a reaction tube, 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 2,000h^-1The life test of preparing low carbon olefin by synthesis gas is carried out under the condition, and the reaction result at the 200 th hour is shown in the table 6.

Comparative example 7

According to the literature [ Angewandte Chemie,2016,128,4803-4806]Preparation method of (1), Synthesis of ZnZr₂And SAPO-34.

0.75 g of ZnZr₂Mixed with 0.75 g of SAPO-34, and packed in a quartz reaction tube having an inner diameter of 6 mm to mix (n)_{Hydrogen gas}:n_{Carbon monoxide}:n_{Hydrogen sulfide}49.99:50:0.01) is introduced into a reaction tube, 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 2,000h^-1The life test of preparing low carbon olefin by synthesis gas is carried out under the condition, and the reaction result at the 200 th hour is shown in the table 6.

Comparative example 8

1.50 g of FeMnCuK catalyst was charged into a quartz reaction tube having an inner diameter of 6 mm, and (n) was introduced_{Hydrogen gas}:n_{Carbon monoxide}:n_{Hydrogen sulfide}49.99:50:0.01) is introduced into a reaction tube, 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 2,000h^-1The life test of preparing low carbon olefin by synthesis gas is carried out under the condition, and the reaction result at the 200 th hour is shown in the table 6.

Comparative example 9

Loading 1.50 g of ZSM-5 zeolite catalyst crystallized directly on Fe-Al alloy into a quartz reaction tube with an internal diameter of 6 mm, and reacting (n)_{Hydrogen gas}:n_{Carbon monoxide}:n_{Hydrogen sulfide}49.99:50:0.01) is introduced into a reaction tube, 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 2,000h^-1The life test of preparing low carbon olefin by synthesis gas is carried out under the condition, and the reaction result at the 200 th hour is shown in the table 6.

TABLE 1

TABLE 2

	CO hydrogenation catalyst	CHA molecular sieve and weight ratio	Ethylene selectivity/%)	Propylene selectivity/%)
					Example 1	Mo-Fe_0.6Zn_0.2Cs_0.8	SAPO-34	13.9	45.8
Example 19	Mo-Fe_0.6Zn_0.2Cs_0.8	SAPO-34:SSZ-13＝2:1	22.5	34.6
					Example 20	Mo-Fe_0.6Zn_0.2Cs_0.8	SAPO-34:SSZ-13＝1:2	36.1	20.3
Example 21	Mo-Fe_0.6Zn_0.2Cs_0.8	SSZ-13	45.0	12.4

TABLE 3

	Temperature/. degree.C	pressure/MPa	Space velocity/h^-1	Conversion rate/%	C2-4 olefin selectivity/%)
						Example 1	400	4	2000	28.3	74.8
Example 22	380	7	4000	21.1	72.2
						Example 23	390	6	3000	25.8	73.5
Example 24	410	3	6000	28.5	73.2
						Example 25	420	2	5000	30.4	71.0
Example 26	430	0.5	7000	34.5	69.1

TABLE 4

	Catalyst and process for preparing same	Conversion rate/%	C2-4 olefin selectivity/%)
				Example 11	Mo-Ni_0.1Co_0.4Mn_0.1K_0.6+ SAPO-34 (weight ratio 1:1)	31.5	80.3
Comparative example 1	Zn_3.5CrAl + SAPO-34 (weight ratio 1:1)	38.2	65.8
				Comparative example 2	ZnZr₂+ SAPO-34 (weight ratio 1:1)	35.7	62.1
Comparative example 3	FeMnCuK	55.0	49.5
				Comparative example 4	ZSM-5/FeAl	45.4	50.7

TABLE 5

	Catalyst and process for preparing same	Conversion rate/%	C2-4 olefin selectivity/%)
				Example 27	Mo-Ni_0.1Co_0.4Mn_0.1K_0.6+ SAPO-34 (weight ratio 1:1)	16.6	84.3
Comparative example 5	Zn_3.5CrAl + SAPO-34 (weight ratio 1:1)	17.2	78.8

TABLE 6

	Catalyst and process for preparing same	Conversion rate/%	C2-4 olefin selectivity/%)
				Example 28	Mo-Ni_0.1Co_0.4Mn_0.1K_0.6+ SAPO-34 (weight ratio 1:1)	29.2	77.6
Comparative example 6	Zn_3.5CrAl + SAPO-34 (weight ratio 1:1)	24.6	61.0
				Comparative example 7	ZnZr₂+ SAPO-34 (weight ratio 1:1)	21.5	58.8
Comparative example 8	FeMnCuK	47.5	46.7
				Comparative example 9	ZSM-5/FeAl	38.2	47.1

Claims

1. A coupling catalyst system for directly preparing low-carbon olefin from synthesis gas is characterized in that the coupling catalyst system comprises a molybdenum-based catalyst and a molecular sieve with CHA framework structure;

wherein the molecular general formula of the molybdenum-based catalyst is MoT_t-X_aY_bZ_cWherein T is selected from at least one of S, O or C, X is Co and Ni, Y is one or more of Cr, Mn, Zn, La and Ce metals, and Z is selected from at least one of Na, K and Cs; the value range of a is 0.1-3.3, the value range of b is 0-2, the value range of c is 0.1-2.5, and t is the number of atoms required by the valence of each element;

the molecular sieve with the CHA framework structure is SAPO-34 and/or SSZ-13;

the weight ratio of the molybdenum-based catalyst to the molecular sieve with the CHA framework structure is (1: 10) - (10: 1).

2. The coupled catalyst system for directly preparing the light olefins from the synthesis gas according to claim 1, wherein the value range of b is 0.1-1.8.

3. The coupled catalyst system for directly preparing the light olefins from the synthesis gas according to claim 1, wherein the value range of c is 0.1-2.2.

4. The coupled catalyst system for direct synthesis of light olefins according to claim 1, wherein the weight ratio of the molybdenum-based catalyst to the molecular sieve with CHA framework structure is (1: 6) - (6: 1).

5. The coupled catalyst system for direct synthesis of light olefins according to claim 1, wherein the weight ratio of the molybdenum-based catalyst to the molecular sieve with CHA framework structure is (1: 4) - (4: 1).

6. A method for preparing low-carbon olefin by using synthesis gas, wherein the reaction temperature is 320-480 ℃, the reaction pressure is 0.5-8MPa, and the volume space velocity800 + 10000 h^-1CO and H in syngas₂Under the condition that the volume ratio of (A) is 0.3-3.5, the synthesis gas contacts and reacts with the coupling catalyst system of any one of claims 1-5 to obtain a product containing low-carbon olefin.