CN109651035B

CN109651035B - Method for preparing low-carbon olefin by synthesis gas one-step method

Info

Publication number: CN109651035B
Application number: CN201710941299.4A
Authority: CN
Inventors: 陶跃武; 庞颖聪; 李剑锋; 宋卫林; 赵相武
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: 2017-10-10
Filing date: 2017-10-10
Publication date: 2021-09-03
Anticipated expiration: 2037-10-10
Also published as: CN109651035A

Abstract

The invention relates to a method for preparing low-carbon olefin by a synthesis gas one-step method, which mainly solves the problem of low selectivity of the low-carbon olefin in the prior art, and the method for preparing the low-carbon olefin by the synthesis gas one-step method comprises the step of reacting the synthesis gas to generate the low-carbon olefin in the presence of an iron-based catalyst, wherein the catalyst comprises a carrier and an active component, and the active component contains a composition which is calculated by atomic ratio and has the following chemical formula: fe₁₀₀Mn_aZn_bCu_cQ_fO_xThe technical scheme that Q comprises at least one element selected from lanthanide elements better solves the problem, and can be used for industrial production of synthesizing low-carbon olefin by fluidized bed synthesis gas.

Description

Method for preparing low-carbon olefin by synthesis gas one-step method

Technical Field

The invention relates to a method for preparing low-carbon olefin by synthesis gas in one step.

Background

The method for converting synthesis gas into hydrocarbons by the action of catalyst is invented by Frans Fischer and Hans Tropsch, German scientists, and is called F-T synthesis for short in 1923, namely the process that CO is subjected to heterogeneous catalytic hydrogenation reaction on a metal catalyst to generate a mixture mainly comprising straight-chain alkane and olefin. Research and development are carried out in the last 20 th century in germany, and industrialization is realized in 1936, and the two-war aftermath is closed because the economy cannot compete with the petroleum industry; south Africa has abundant coal resources, but oil resources are scarce, and are limited by international socioeconomic and political sanctions for a long time, so that the south Africa is forced to develop the coal-to-oil industrial technology, and a first coal-based F-T synthetic oil plant (Sasol-1) with the production capacity of 25-40 ten thousand tons of products per year is built in 1955.

The two global oil crises in 1973 and 1979 caused the price of crude oil in the world to fall and rise greatly, and the F-T synthesis technology re-aroused interest in industrialized countries based on the consideration of strategic technical reserves. In 1980 and 1982, Sasol company in south Africa built and produced two coal-based synthetic oil plants in succession. However, the great reduction of the oil price in the world in 1986 postpones the large-scale industrialization process of the F-T synthesis technology in other countries.

Since the 90 s of the twentieth century, petroleum resources have been in shortage and deterioration, and the exploratory reserves of coal and natural gas have been increasing, so that F-T synthesis technology has attracted much attention again. At present, the main raw materials of the low-carbon olefins in the world are petroleum hydrocarbons, wherein naphtha accounts for most of the raw materials, and alkane, hydrogenated diesel oil, part of heavy oil and the like are also used. Natural gas or light petroleum fractions are mostly used as raw materials at home and abroad, low-carbon olefin is produced by adopting a steam cracking process in an ethylene combination device, the steam cracking is a high-energy consumption device in petrochemical industry, and the steam cracking completely depends on non-renewable petroleum resources, so that alternative resources are urgently needed to be searched along with the gradual shortage of the petroleum resources. Therefore, the research work of preparing olefin by replacing petroleum with other resources is gradually emphasized, and some famous petroleum companies and scientific research institutes in the world perform the research and obtain good results.

Over the course of decades, fischer-tropsch catalysts have also developed in a great deal, and typically comprise the following components: active metals (transition metals of group VIII), oxide supports or structural assistants (SiO)₂,Al₂O₃Etc.), chemical assistants (alkali metal oxides, transition metals) and noble metal assistants (Ru, Re, etc.). Fe produces a large amount of olefins and oxygen-containing compounds, Ru and Co produce mainly long-chain saturated hydrocarbons, and Ni produces mainly methane. Because of the loss of carbonyl compounds easily formed during Ni pressurization reaction and serious methanation, and the expensive Ru and Rh equivalents, the currently commonly used catalysts are divided into two categories from the aspect of active components: iron-based catalysts and cobalt-based catalysts. The selectivity of the cocatalyst for the low-carbon olefin is greatly influenced, the improvement of the selectivity of the low-carbon olefin is mainly realized by the cocatalyst, and the selection and addition technology of the cocatalystThe technology is one of the key technologies for developing excellent catalysts.

The F-T synthesis reactors are further classified into fixed bed reactors, fluidized bed reactors and slurry bed reactors according to the difference in the catalysts used and the difference in the target products. The fixed bed reactor has complex structure, high price, difficult heat removal and lower productivity of the whole device. The slurry bed is characterized by low reaction temperature, easy control, low conversion rate, most of products of high carbon hydrocarbon and difficult liquid-solid separation of slurry in the reactor. The fluidized bed reactor has the characteristics of higher temperature, higher conversion rate, no difficulty of liquid-solid separation and mostly low-carbon hydrocarbon as a product; the lower construction and operating costs, while the lower pressure differential saves a lot of compression costs and facilitates the removal of the heat evolved during the reaction, while the longer run is possible due to the lower gas line speed and less wear problems.

The iron catalyst has many advantages, such as obtaining low-carbon olefin with high selectivity and preparing gasoline with high octane value, and the iron catalyst also has the characteristics of wide operating condition and large product adjustability. The preparation method of the iron-based catalyst mainly comprises three methods: the precipitation method (precipitation catalyst) comprises the steps of preparing a mixed solution according to a certain proportion by using Fe and auxiliary agents such as Mn, Zn, K and the like, heating to boil, adding a precipitator, stirring, filtering and washing. Adding water into the obtained filter cake for repulping, adding a certain amount of potassium silicate, drying, carrying out extrusion forming, then, grinding and screening; sintering process (sintering catalyst); oxide mixing method (molten iron catalyst) using mill scale or magnetite powder as raw material and adding Al as auxiliary agent₂O₃MgO, MnO, CuO and the like are fed into an electric arc furnace at 1500 ℃ for melting, and the outflow melt is subjected to casting, cooling and multistage crushing.

At present, the iron-based catalyst is used for directly synthesizing low-carbon olefin by F-T in a fixed bed, for example, the patent CN1040397C mentions an iron-based catalyst for Fischer-Tropsch synthesis of low-carbon olefin, and the selectivity of the low-carbon olefin can be as high as 69%. However, the fixed bed reactor has a complex structure, high price, difficult heat removal and low productivity of the whole device. The fluidized bed reactor has the characteristics of higher temperature, higher conversion rate, no difficulty of liquid-solid separation and mostly low-carbon hydrocarbon as a product; the lower construction and operating costs, while the lower pressure differential saves a lot of compression costs and facilitates the removal of the heat evolved during the reaction, while the longer run is possible due to the lower gas line speed and less wear problems. Most of the prior reports on the application of the catalyst to the fluidized bed F-T synthesis are molten iron type catalysts, for example, a molten iron type catalyst for the F-T synthesis is mentioned in patent CN 1704161A; however, the existing fluidized bed F-T synthesis has the problems of insufficiently concentrated products and insufficiently high selectivity of low-carbon olefins.

Disclosure of Invention

The invention aims to solve the technical problem of low selectivity of low-carbon olefin in the prior art, and provides a method for preparing low-carbon olefin by using synthesis gas in one step, which has the characteristic of high selectivity of low-carbon olefin.

In order to solve the technical problems, the technical scheme of the invention is as follows:

the method for preparing low-carbon olefin by using synthesis gas in one step comprises the step of reacting the synthesis gas to generate the low-carbon olefin in the presence of an iron-based catalyst, wherein the catalyst comprises a carrier and an active component, and the active component contains a composition with the following chemical formula in atomic ratio:

Fe₁₀₀Mn_aZn_bCu_c Q_fO_x；

q comprises at least one element selected from the lanthanide series;

the value range of a is 5.0-60.0;

the value range of b is 5.0-60.0;

the value range of c is 1.0-30.0;

the value range of f is 0.9-40.0;

x is the total number of oxygen atoms required to satisfy the valences of the elements in the catalyst.

In the above technical solution, the support is not particularly limited, and those commonly used in the art may be used, for example, but not limited to, including at least one of alumina, silica and titania.

In the above technical solution, the amount of the carrier is not particularly limited, and those skilled in the art can reasonably select the carrier without creative efforts, for example, but not limited to, the amount of the carrier is 30 to 70% by weight of the catalyst.

In the above technical solution, Q preferably further includes at least one of IA elements, and the presence of both lanthanide and alkali metal elements is beneficial to improving the selectivity of the low-carbon olefin. At this time, Fe₁₀₀Mn_aZn_bCu_cQ_fO_xMay be further expressed as Fe₁₀₀Mn_aZn_bCu_cA_dL_eO_xWherein A is at least one of IA elements, L is at least one of lanthanide elements, d ranges from 1.0 to 30.0, and e ranges from 0.1 to 10.0.

In the technical scheme, the value range of a is preferably 10.0-50.0. Such as, but not limited to, 15.0, 20.0, 25.0, 30.0, 35.0, 40.0, 45.0, and the like.

In the technical scheme, the value range of b is preferably 10.0-50.0. Such as, but not limited to, 15.0, 20.0, 25.0, 30.0, 35.0, 40.0, 45.0, and the like.

In the technical scheme, the value range of c is preferably 5.0-25.0. Such as, but not limited to, 10.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0, and the like.

In the technical scheme, the value range of d is preferably 2.0-25.0. Such as, but not limited to, 3.0, 4.0, 5.0, 8.0, 10.0, 15.0, 20.0, and the like.

In the technical scheme, the value range of e is preferably 1.0-8.0. Such as but not limited to 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, and so forth.

In the above technical solution, the IA element is selected from at least one of Li, Na, K and Cs; more preferably, the IA element includes at least two of Li, K and Cs at the same time, and when the two elements, such as Li and K, Li and Cs, K and Cs, have synergistic effect in improving the selectivity of the lower olefins. The atomic ratio between the two elements is not particularly limited, but is not limited to 0.1 to 10, wherein more specific atomic ratios may be 0.2, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, and the like.

In the above technical solution, the lanthanide element includes La.

The catalyst of the invention can be reduced or not reduced before being used for the reaction of preparing low-carbon olefin by one-step method with synthesis gas, but is preferably reduced. When reducing, the reducing conditions are not particularly limited and can be reasonably selected by the person skilled in the art, for example but not limited to the reducing conditions of the catalyst prepared according to the invention: the pressure is 0.05-5 MPa, preferably 0.1-4 MPa; the reducing gas can be hydrogen, carbon monoxide or synthesis gas, and when the reducing gas is synthesis gas, H thereof₂The mol ratio of/CO is 0.1-6.0, preferably 0.2-6.0; the load of reducing gas is 100-8000 hours^-1Preferably 500 to 6000 hours^-1(ii) a The reduction temperature is 200-600 ℃, preferably 220-500 ℃; the reduction time is 1 to 100 hours, preferably 6 to 72 hours.

For comparison, the reduction conditions used for the catalyst prepared in the embodiment of the present invention are:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

The reduction time was 24 hours.

The technical key of the invention is the selection of the catalyst, and the technical conditions for specific application can be reasonably selected by a person skilled in the art without creative labor.

As known to those skilled in the art, lower olefins are C2-C4 olefins, more specifically ethylene, propylene and butylene or mixtures thereof. The butene includes butene-1, butene-2, isobutene and butadiene.

The reaction temperature can be 200-600 ℃, preferably 220-500 ℃;

the pressure of the reaction can be 0.5-10 MPa, preferably 1-8 MPa; (ii) a

H in synthesis gas₂The mol ratio of/CO can be 0.1-5.0, preferably 0.5-3.0;

the volume space velocity of the synthetic gas can be 100-8000 hours^-1Preferably 500 to 6000 hours^-1More preferably 2000 to 6000 hours^-1。

For the sake of comparability, the evaluation conditions of the catalyst used in the embodiment of the present invention were as follows:

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The catalyst in the above technology can be prepared by a method comprising the following steps:

obtaining slurry comprising a catalyst carrier and active component elements, wherein the pH value of the slurry is 1-6;

feeding the slurry into a spray dryer for spray forming;

and (4) roasting.

When the active component contains both lanthanide and alkali metal elements, the preparation method of the catalyst preferably comprises the following process steps:

obtaining an aqueous solution comprising metallic elements other than alkali metals in the composition;

adding sol of a carrier with required amount into the aqueous solution, adding an alkali metal hydroxide solution, and adjusting the pH value to 1-6 by using an acid-base regulator to obtain slurry;

feeding the slurry into a spray dryer for spray forming;

and (4) roasting.

In the technical scheme, the roasting temperature is preferably 400-1000 ℃, and more preferably 450-800 ℃.

In the above technical scheme, the roasting time is preferably 0.15 to 10 hours, and more preferably 0.5 to 8 hours.

The process conditions for spray drying and shaping are not particularly limited and can be appropriately selected by those skilled in the art and can achieve comparable technical effects. For example, but not limited to, the inlet temperature of the spray can be 200-380 ℃, the outlet temperature can be 100-230 ℃, the spray drying is carried out to form microspheres, and finally the microspheres are roasted to prepare the catalyst.

In order to facilitate comparison, the spray drying conditions adopted by the specific embodiment of the invention are as follows:

the inlet temperature is 300 ℃,

the exit temperature was 200 ℃.

In the above technical scheme, the soluble ferric salt can be ferric nitrate or ferric sulfate.

In the above technical scheme, the soluble compounds of Mn, Zn, Cu and lanthanoid can be nitrates, salts decomposable into oxides.

In the above-mentioned embodiment, although the atmosphere for firing is not particularly limited, an oxidizing atmosphere or an inert atmosphere is preferable, and an air atmosphere is more preferable from the economical viewpoint.

In the present invention, unless otherwise specified, the pressure including the reaction pressure means a gauge pressure.

The method is used, the reaction temperature is 200-600 ℃, the reaction pressure is 0.5-10 MPa, and the catalyst load is 100-8000 hours^-1Raw material ratio (mol) H₂The F-T synthesis reaction is carried out under the condition that the ratio of/CO (0.1-5.0): 1, the CO conversion rate can reach 91.7%, the selectivity of low-carbon olefin in a reaction product can reach 71.5%, and a better technical effect is achieved.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

1. Catalyst preparation

343.00 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving in 500g of water to obtain a material I, and taking 12.20 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 119.10 g of 50% manganese nitrate (Mn (NO)₃)₂) 30.46 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 50.51 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Mixing the materials I and III, adding 312.50 g of 40 wt% of silica sol material under stirring, then adding 50g of aqueous solution containing 6.83 g of KOH, adjusting the pH value of the slurry by using 27 wt% of ammonia water to ensure that the pH value of the mixed slurry is 6.0, and carrying out microspherical molding on the slurry prepared after fully stirring in a spray dryer, wherein the specific spray drying conditions are that the inlet temperature of a sprayer is 300 ℃ and the outlet temperature is 200 ℃. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅K₁₂La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

Reduction was carried out and then the Fischer-Tropsch synthesis reaction was carried out under the following conditions:

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 2 ]

1. Catalyst preparation

352.10 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving with 500g of water to obtain a material I, and taking 12.60 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 122.20 g of 50% manganese nitrate (Mn (NO)₃)₂) 31.26 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 51.84 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Materials I and III were mixed, 312.50 g of a 40 wt% silica sol material was added under stirring, 50g of an aqueous solution containing 7.09 g of LiOH was then added, the pH of the slurry was adjusted with 27 wt% ammonia water so that the pH of the mixed slurry became 6.0, and the slurry was subjected to microspherical molding in a spray dryer under specific spray drying conditions of 300 ℃ at the inlet temperature and 200 ℃ at the outlet temperature of a sprayer. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅Li₁₂La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 3 ]

1. Catalyst preparation

319.10 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving in 500g of water to obtain a material I, and taking 11.40 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 110.80 g of 50% manganese nitrate (Mn (NO)₃)₂) 28.33 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 46.99 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Materials I and iii were mixed, 312.50 g of a 40 wt% silica sol material was added under stirring, 50g of an aqueous solution containing 1.98 g of CsOH was then added, the pH of the slurry was adjusted with 27 wt% ammonia water so that the pH of the mixed slurry became 6.0, and the slurry prepared after sufficient stirring was subjected to microspherical molding in a spray dryer under specific spray drying conditions of 300 ℃ at the inlet temperature and 200 ℃ at the outlet temperature of a sprayer. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅Cs₁₂La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 4 ]

1. Catalyst preparation

347.50 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving with 500g of water to obtain a material I, and taking 12.40 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 120.70 g of 50% manganese nitrate (Mn (NO)₃)₂) 30.85 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 51.17 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Mixing the materials I, II and III, adding 312.50 g of 40% (weight) silica sol material under stirring, then adding 50g of aqueous solution containing 4.10 g of NaOH, adjusting the pH value of the slurry with 27% (weight) ammonia water to make the pH value of the mixed slurry be 6.0, and carrying out microspherical molding on the slurry prepared after fully stirring in a spray dryer, wherein the specific spray drying conditions are that the inlet temperature of a sprayer is 300 ℃ and the outlet temperature is 200 ℃. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅Na₁₂La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 5 ]

1. Catalyst preparation

Mixing the materials I, II and III, adding 312.50 g of 40 wt% silica sol material under stirring, then adding 50g of aqueous solution containing 3.50 g of LiOH and 3.46 g of KOH, adjusting the pH value of the slurry with 27 wt% ammonia water to make the pH value of the mixed slurry equal to 6.0, and carrying out microspherical molding on the slurry prepared after fully stirring in a spray dryer, wherein the specific spray drying conditions are that the inlet temperature of a sprayer is 300 ℃ and the outlet temperature is 200 ℃. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅Li₆K₆La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 6 ]

1. Catalyst preparation

334.80 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving with 500g of water to obtain a material I, taking 11.90 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 116.20 g of 50% manganese nitrate (Mn (NO)₃)₂) 29.73 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 49.30 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Materials I and III were mixed, 312.50 g of a 40 wt% silica sol material was added under stirring, 50g of an aqueous solution containing 3.37 g of LiOH and 9.55 g of CsOH was added, the pH of the slurry was adjusted to 6.0 with 27 wt% aqueous ammonia, and the slurry obtained after sufficient stirring was subjected to microspherical molding in a spray dryer under conditions of 300 ℃ at the inlet and 200 ℃ at the outlet of a sprayer. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅Li₆Cs₆La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 7 ]

1. Catalyst preparation

330.60 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving in 500g of water to obtain a material I, and taking 11.80 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 114.80 g of 50% manganese nitrate (Mn (NO)₃)₂) 29.36 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 48.69 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Materials I, II and III were mixed, 312.50 g of a 40 wt% silica sol material was added under stirring, 50g of an aqueous solution containing 3.29 g of KOH and 9.43 g of CsOH was added, the pH of the slurry was adjusted to 6.0 with 27 wt% aqueous ammonia, and the slurry obtained after sufficient stirring was subjected to microspherical molding in a spray dryer under conditions of 300 ℃ at the inlet and 200 ℃ at the outlet of a sprayer. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅K₆Cs₆La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

[ example 8 ]

1. Catalyst preparation

337.50 g of ferric nitrate (Fe (NO)₃)₃·9H₂O), dissolving in 500g of water to obtain a material I, and taking 12.00 g of lanthanum nitrate (La (NO)₃)₃·6H₂O) was dissolved in 100g of water under heating to obtain a material II, 117.20 g of 50% manganese nitrate (Mn (NO)₃)₂) 29.97 g of copper nitrate (Cu (NO)₃)₂·3H₂O) and 49.70 g of zinc nitrate (Zn (NO)₃)₂·6H₂O) in the same container, adding 200g of water, stirring and dissolving to obtain a material III.

Materials I, II and III were mixed, 312.50 g of a 40 wt% silica sol material was added under stirring, 50g of an aqueous solution containing 2.24 g of KOH, 2.26 g of LiOH and 6.42 g of CsOH was added, the pH of the slurry was adjusted with 27 wt% aqueous ammonia so that the pH of the mixed slurry became 6.0, and the slurry obtained after sufficient stirring was subjected to microspherical molding in a spray dryer under conditions of an inlet temperature of 300 ℃ and an outlet temperature of 200 ℃ in a sprayer. Finally, the catalyst is calcined in a rotary calcining furnace with the inner diameter of 89 mm and the length of 1700 mm (phi 89 x 1700 mm) for 2.0 hours at 500 ℃ in an air atmosphere, and the prepared catalyst comprises the following components:

50% by weight Fe₁₀₀Mn₄₀Zn₂₀Cu₁₅Li₄K₄Cs₄La₅O_x+ 50% by weight of SiO₂

2. Reduction and evaluation of the catalyst

The prepared catalyst is carried out under the reduction conditions:

the temperature is 400 DEG C

Pressure 3.0MPa

Catalyst loading 100g

Catalyst loading 4000 hours^-1

Reducing gas H₂/CO＝2/1

Reduction time 24 hours

phi 38 mm fluidized bed reactor

The reaction temperature is 330 DEG C

The reaction pressure is 2.0MPa

Catalyst loading 100g

Catalyst loading 3000 hours^-1

Raw material ratio (mol) H₂/CO＝2/1。

The experimental results of the synthesis reaction are shown in table 1.

TABLE 1

Claims

1. The method for preparing low-carbon olefin by using synthesis gas in one step comprises the step of reacting the synthesis gas to generate the low-carbon olefin in the presence of an iron-based catalyst, wherein the catalyst comprises a carrier and an active component, and the active component contains a composition with the following chemical formula in atomic ratio:

Fe₁₀₀Mn_aZn_bCu_cA_dL_eO_x，

wherein A simultaneously comprises Li, K and Cs, and L is at least one of lanthanide elements;

the value range of a is 5.0-60.0;

the value range of b is 5.0-60.0;

the value range of c is 1.0-30.0;

the preferable value range of d is 1.0-30.0;

the value range of e is preferably 0.1-10.0;

2. The process according to claim 1, wherein the reaction temperature is 200 to 600 ℃.

3. The method according to claim 1, characterized in that H in the synthesis gas₂The mol ratio of/CO is 0.1-5.0.

4. The method of claim 1, wherein the volume space velocity of the synthesis gas is 100-8000 hours^-1。

5. The method as set forth in claim 1, wherein the support comprises at least one selected from the group consisting of silica, alumina and titania.

6. The method of claim 1, wherein a is in the range of 10.0 to 50.0.

7. The method of claim 1, wherein b is selected from the range of 10.0 to 50.0.

8. The method of claim 1, wherein c is selected from the range of 5.0 to 25.0.