CN110368949A - A kind of CO adds hydrogen low-carbon alcohols GaFe base catalyst and preparation method and application - Google Patents

Abstract

The invention discloses a kind of CO to add hydrogen low-carbon alcohols GaFe base catalyst, belongs to chemical technology field.Catalyst not metallic components Cu, using Ga and Fe as active component, mass percent accounts for 20 ~ 60%；Auxiliary agent is one or more of K, La, Zn, Mn, In, and mass percent accounts for 30 ~ 60%；Carrier is by CeO₂、ZrO₂、SiO₂、Al₂O₃In any one or it is two or more compound and obtain, calculating by mass percentage is 5 ~ 20%.Catalyst preparation is using sol-gal process, coprecipitation, precipitating sedimentation or Complete Liquid-phast process.Catalyst preparation process of the present invention is simple, is applicable to a variety of reaction bed-type, good catalyst activity, C under relatively mild reaction condition₂₊Alcohol selectivity is high.

Description

A kind of CO hydrogenation to produce low carbon alcohol GaFe-based catalyst and preparation method and application

technical field

The invention belongs to the technical field of chemical industry, and in particular relates to a GaFe-based catalyst for producing low-carbon alcohol by hydrogenation of CO, a preparation method and application thereof.

Background technique

Low-carbon alcohols mainly produced by hydrogenation of CO to ethanol are one of the important ways for the clean and efficient utilization of coal. Low-carbon alcohols can not only be used as fuel for direct combustion, but also can be used as a fuel additive instead of methyl tertiary butyl ether (MTBE). It can improve the octane number of gasoline, and has broad application prospects as a chemical product and a bulk chemical raw material. In recent years, the development of synthetic ethanol fuel and high value-added low carbon alcohol fuel technology has gradually attracted widespread attention, which is in line with the strategic development of my country's coal chemical industry.

At present, the large-scale production of industrial ethanol in the world is mainly through the ethylene hydration method of grain fermentation. Due to the large population in my country and less per capita arable land, the cost and energy consumption of the fermentation method are too high, and a large amount of crops need to be consumed as raw materials. It will inevitably lead to the problem of "competing with others for food". Based on the resource status of “rich coal, lean oil and little gas” in my country, the development of a technical route for preparing low-carbon alcohols with coal as raw material from synthesis gas can not only give full play to the resource advantages of rich coal resources in my country, but also reduce the extensive utilization zones such as direct coal combustion. It can also reduce the dependence on oil and relieve the pressure of excessive food consumption in my country. Therefore, this research has great practical significance.

The production of low-carbon alcohols from synthesis gas has not yet been industrialized, which is mainly limited by the lack of catalysts. The currently used catalysts mainly include two categories: I: precious metal Rh-based catalysts; II: non-precious metal catalysts. US Patent US4377643 discloses a catalyst containing Rh, but its activity is low and a large amount of CH ₄ is generated, and various additives are added subsequently, but the effect is inadvertently obvious. There are also many domestic patents reporting related precious metal Rh catalysts, such as CN102029173A, CN102268045A, CN101428229A. Non-precious metal catalysts are mainly composed of molybdenum-based catalysts, modified methanol synthesis catalysts and modified Fischer-Tropsch synthesis catalysts. This type of catalyst mainly includes the following components: Cu, Co, Mo, Fe, Mn, Zn, etc., such as patents CN105944723 A, CN101804354 A, CN107890872A, etc. However, due to the addition of metallic Cu to this type of catalyst, although Cu is an excellent catalytic active center for alcohol synthesis, it also easily promotes the water-gas shift reaction and generates more CO ₂ , which is a great waste of raw gas. , the economy is not high. From the current situation, Rh catalysts are expensive and difficult to achieve the purpose of industrialization. Cu-modified FT synthesis catalysts generate more _CO2 , Mo-based catalysts have low activity, and the products contain trace amounts of sulfur, making subsequent separation difficult. , In order to achieve a breakthrough in low-carbon alcohol catalysts, the development of new and efficient catalysts is urgently needed.

SUMMARY OF THE INVENTION

The present invention provides a _GaFe -based catalyst for CO hydrogenation to produce low-carbon alcohols, a preparation method and application thereof. OH selectivity.

A GaFe-based catalyst for CO hydrogenation to low-carbon alcohol, which does not contain metal component Cu, uses Ga and Fe as active components, and the auxiliary agent includes one or more of K, La, Zn, Mn, and In. The carrier is one or a combination of CeO ₂ , ZrO ₂ , SiO ₂ and Al ₂ O ₃ .

Described GaFe-based catalyst, by total weight percentage: active component accounts for 10~60%, preferably 30~50%; auxiliary agent accounts for 5~30%, preferably 10~20%; carrier accounts for 5~20%, preferably 10~15%.

The GaFe-based catalyst preparation method includes: (a) preparing a catalyst precursor by a sol-gel method, a precipitation method, and a precipitation deposition method; (b) drying and calcining the prepared precursor, or uniformly distributing the precursor. Disperse in liquid paraffin and heat under inert atmosphere to obtain GaFe-based catalyst.

The sol-gel method described in the step (a) is to use citric acid as a complexing agent and ethylene glycol as a dispersant to obtain a precursor sol by hydrolysis at a temperature of 50 to 95 °C; the precipitation method is to mix KOH, K ₂ CO ₃ , urea and catalyst constituent elements (Fe, Ga, K, La, Zn, Mn, In, Zr, Al, Ce, Si) were prepared into solutions of corresponding concentrations and then co-precipitated in co-current flow; the precipitation deposition The method is to deposit KOH, K ₂ CO ₃ , urea, active metal elements and auxiliary elements in the catalyst on the carrier in co-current flow.

The precursor described in step (b) is dried at 80-120°C for 12-24h, and the dried sample is calcined at 300-500°C for 4-12h; or the precursor is directly dispersed in liquid paraffin without drying and calcination Heating at 260~320℃ for 6~12h.

The hydrolysis temperature of the GaFe-based catalyst is 50-95°C; the active components, auxiliary agents and carrier elements in the catalyst are from nitrate, citrate and acetate; the precipitating agent is K ₂ CO ₃ , KOH or urea one or more of.

The reaction conditions when any of the described GaFe-based catalysts are applied in CO hydrogenation to produce low-carbon alcohol are: pressure 1-6MPa, temperature 200-400°C, GHSV=1000-8000 h ^-1 , H ₂ /CO=0.5 ~4.

The GaFe-based catalyst of the present invention does not contain metal component Cu; the provided method for hydrogenating CO to produce low-carbon alcohols can be used in different reaction bed types according to different heat treatment methods, and can effectively avoid traditional The Cu-based catalyst has serious problems in the water-gas shift reaction, and can greatly improve the C2 ₊ alcohol selectivity, and has a good industrial application prospect.

Detailed ways

The following specific embodiments further describe the preparation and application of the above-mentioned CO hydrogenation to lower alcohol GaFe-based catalyst of the present invention.

Embodiment 1

Weigh 1.2 g of zirconium nitrate, 13.6 g of ferric nitrate and 7.2 g of gallium nitrate, respectively, and dissolve them in 150 mL of deionized water, dissolve them completely under magnetic stirring, and heat them to 40°C in a water bath; then weigh 16.5 g of potassium carbonate to dissolve In 150 mL of deionized water, potassium carbonate solution was added dropwise to the GaFeZr salt solution at a rate of 3 mL/min until a uniform and stable precipitate was formed. After aging at room temperature for 2 h, suction filtration, and drying at 100 °C for 12 h. calcined at 400 °C for 5 h. The obtained solid was ground, tableted, crushed and sieved to obtain a catalyst of 40-60 meshes, which was reduced at 300 °C under H ₂ atmosphere, 250 ° C, 4MPa, H ₂ /CO=1, GHSV=2000 h ^-1 The activity evaluation was carried out under the same conditions, and the results showed that the CO conversion was 8.9 (C-mol %), and the C ₂₊ alcohol selectivity was 20.9 (C-mol %).

Embodiment 2

Weigh 0.6 g of zirconium nitrate, 13.6 g of ferric nitrate, 3.5 g of zinc nitrate and 14.4 g of gallium nitrate, respectively, and dissolve them in 150 mL of deionized water, and then weigh 18.5 g of potassium carbonate and dissolve them in 150 mL of deionized water. It was added dropwise to the beaker at a rate of 3 mL/min until a uniform and stable precipitate was formed, aged at room temperature for 2 h, filtered with suction, dried at 100 °C for 12 h, and calcined at 400 °C for 5 h to obtain a solid. The obtained solid was ground, tableted, crushed and sieved to obtain a catalyst of 40-60 meshes, which was reduced at 300°C under a CO atmosphere, 280°C, 3MPa, H ₂ /CO=1, GHSV=2000 h ^-1 The activity evaluation was carried out under the conditions, and the results showed that the CO conversion was 10.6 (C-mol %), and the C ₂₊ alcohol selectivity was 35.5 (C-mol %).

Embodiment 3

Weigh 6.0 g of cerium nitrate, 2.4 g of lanthanum nitrate, 3.6 g of ferric nitrate and 14.4 g of gallium nitrate and dissolve them in 150 mL of deionized water, and then weigh 20.5 g of potassium carbonate and dissolve them in 150 mL of deionized water. It was added dropwise to the beaker at a rate of /min until a uniform and stable precipitate was formed. After aging at room temperature for 2 h, suction filtration, drying at 100 °C for 12 h, and calcination at 500 °C for 12 h to obtain a solid. The obtained solid was ground, tableted, crushed and sieved to obtain a catalyst of 40-60 meshes. The catalyst was reduced at 300°C under CO atmosphere, 300°C, 6 MPa, H ₂ /CO=2, GHSV=8000 h ^-1 The activity evaluation was carried out under the conditions of , and the results showed that the CO conversion was 8.9 (C-mol %), and the C ₂₊ alcohol selectivity was 27.5 (C-mol %).

Embodiment 4

Weigh 3.5 g of aluminum nitrate, 6.2 g of manganese nitrate, 5.0 g of ferric nitrate and 7.2 g of gallium nitrate and dissolve them in 150 mL of deionized water, and then weigh 26.6 g of potassium hydroxide and dissolve them in 150 mL of deionized water. It was added dropwise to the beaker at a rate of 3 mL/min until a uniform and stable precipitate was formed, aged at room temperature for 2 h, filtered with suction, dried at 100 °C for 24 h, and calcined at 300 °C for 8 h to obtain a solid. The obtained solid was ground, tableted, crushed and sieved to obtain a catalyst of 40-60 meshes. The catalyst was reduced at 300°C in a syngas atmosphere, 250°C, 6 MPa, H ₂ /CO=0.5, GHSV=8000 h ⁻ Activity evaluation was carried out under the conditions of ¹ , and the results: CO conversion was 12.9 (C-mol %), and C ₂₊ alcohol selectivity was 23.6 (C-mol %).

Embodiment 5

Weigh 1.2 g of zirconium nitrate, 3.5 g of aluminum nitrate, 6.2 g of manganese nitrate, 5.0 g of ferric nitrate and 7.2 g of gallium nitrate, respectively, and dissolve them in 150 mL of deionized water, and then weigh 35.8 g of carbon urea and dissolve them in 150 mL of deionized water. The above two solutions were added dropwise to a beaker at a rate of 3 mL/min until a uniform and stable precipitate was formed. After aging at room temperature for 2 h, suction filtration was performed, dried at 120 °C for 18 h, and then calcined at 500 °C for 6 h to obtain a solid. The obtained solid was ground, tableted, crushed and sieved to obtain a catalyst of 40-60 meshes. The catalyst was reduced at 300°C under a synthesis gas atmosphere, 220°C, 1 MPa, H ₂ /CO=4, GHSV=1000 h ⁻ Activity evaluation was carried out under the conditions of ¹ , and the results showed that the CO conversion was 14.6 (C-mol %), and the C ₂₊ alcohol selectivity was 38.3 (C-mol %).

Embodiment 6

Weigh 5.6 g of ethyl orthosilicate and dissolve it in deionized water with a certain amount of citric acid, then add 10.8 g of ferric nitrate, 3.4 g of zinc nitrate and 5.2 g of gallium nitrate ethylene glycol solution, and stir under magnetic stirring. 1h; the obtained mixed solution was heated and hydrolyzed in a water bath at 80°C until a uniform and stable sol was formed, the obtained sol was baked at 80°C for 24h, and after calcined at 500°C for 10h, pressed into tablets and sieved to obtain 40-60 mesh catalyst particles. The catalyst was loaded into a fixed bed reactor and fixed with packing, and the catalyst was reduced at atmospheric pressure of 400°C in a syngas atmosphere, and the catalyst was heated at 250°C, 3MPa, H ₂ /CO=2, GHSV=5000 h ^-1 Activity evaluation was carried out under the following conditions: CO conversion was 18.0 (C-mol %), and C ₂₊ alcohol selectivity was 30.6 (C-mol %).

Embodiment 7

The sol obtained in Embodiment 6 was dispersed in 300 mL of liquid paraffin, and gradually heated from room temperature to 300 °C under N ₂ atmosphere and maintained for 8 h to obtain the catalyst. The catalyst was put into a slurry bed reactor and reduced at atmospheric pressure at 280°C in a syngas atmosphere, and the activity was evaluated under the conditions of 250°C, 3MPa, H ₂ /CO=2, GHSV=2000 h ^-1 . : CO conversion is 15.5 (C-mol %), C ₂₊ alcohol selectivity is 35.2 (C-mol %).

Embodiment 8

Disperse 3.0 g of commercial alumina in deionized water, then add the solution containing 10.8 g of ferric nitrate, 3.4 g of zinc nitrate and 5.2 g of gallium nitrate and 30.8 g of potassium hydroxide solution into the above-mentioned oxide solution. In the aluminum suspension, after the precipitation is completed, suction filtration, the filter cake is directly dispersed in liquid paraffin, and heat-treated to 320 ° C under nitrogen atmosphere for 12 hours to obtain a slurry catalyst, which is loaded into a slurry bed reactor The reduction was carried out at atmospheric pressure at 280°C in a syngas atmosphere, and the activity was evaluated under the conditions of 250°C, 5MPa, H ₂ /CO=4, GHSV=4000 h ^-1 , the result: CO conversion was 13.4 (C-mol %), the C ₂₊ alcohol selectivity was 29.0 (C-mol %).

Embodiment 9

Weigh 10.6 g of aluminum isopropoxide and dissolve it in deionized water with a certain amount of citric acid dissolved, and then add ethyl acetate dissolved in 12.2 g of ferric citrate, 4.3 g of zinc citrate, 5.2 g of manganese citrate and 6.4 g of gallium citrate. The glycol solution was stirred under magnetic stirring for 1 h; the resulting mixed solution was continuously heated and hydrolyzed in a 95°C water bath until a homogeneous and stable sol was formed. sieve to get 40~60 mesh catalyst particles, put this catalyst into a fixed bed reactor and reduce it at normal pressure 450 ℃ in a synthesis gas atmosphere, and at 250 ℃, 2MPa, H ₂ /CO=2, GHSV=4000 h ^-1 The activity evaluation was carried out under the same conditions, and the results showed that the CO conversion was 12.1 (C-mol %), and the C ₂₊ alcohol selectivity was 36.3 (C-mol %).

Embodiment 10

Weigh 10.6 g of aluminum isopropoxide and 5.6 g of ethyl orthosilicate and dissolve them in deionized water with a certain amount of citric acid, and then add 10.8 g of ferric nitrate, 3.4 g of zinc nitrate, 4.8 g of manganese nitrate and 6.4 g of dissolved citric acid. The ethylene glycol solution of gallium nitrate was stirred under magnetic stirring for 1 h; the resulting mixed solution was continuously heated and hydrolyzed in a 95°C water bath until a homogeneous and stable sol was formed, and the obtained sol was directly dispersed in liquid paraffin, and was placed under a nitrogen atmosphere. Heat treatment to 280°C for 10h to obtain a slurry catalyst, which was put into a slurry bed reactor and reduced at atmospheric pressure at 280°C under a synthesis gas atmosphere, and was heated at 250°C, 4MPa, H ₂ /CO=2, GHSV=2000 The activity evaluation was carried out under the conditions of h ^-1 , and the results showed that the CO conversion was 15.9 (C-mol %), and the C ₂₊ alcohol selectivity was 40.2 (C-mol %).

Claims (10)

1. a kind of CO adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: using Ga and Fe as active component, auxiliary agent include K, One or more of La, Zn, Mn, In, carrier CeO₂、ZrO₂、SiO₂、Al₂O₃One of or any several combinations.

2. a kind of CO as described in claim 1 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: the GaFe base is urged Agent is by weight percentage: active component accounts for 10 ~ 60%；Auxiliary agent accounts for 5 ~ 30%；Carrier accounts for 5 ~ 20%.

3. a kind of CO as described in claim 1 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: the GaFe base is urged Agent is by weight percentage: active component accounts for 30 ~ 50%；Auxiliary agent accounts for 10 ~ 20%；Carrier accounts for 10 ~ 15%.

4. a kind of CO as described in claim 1 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that preparation method includes Following the description:

(a) catalyst precursor is prepared using sol-gal process, the precipitation method, precipitating sedimentation；

(b) by catalyst precursor dry 12 at 80 ~ 120 DEG C ~ for 24 hours, it is dry after sample roast 4 at 300 ~ 500 DEG C ~ 12h；Or catalyst precursor is dispersed in atoleine 6 ~ 12h of heat treatment under 260 ~ 320 DEG C of inert atmospheres.

5. a kind of CO as claimed in claim 4 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: the colloidal sol is solidifying Glue method is using citric acid as complexing agent, and ethylene glycol is dispersing agent, hydrolyzes at 50 ~ 95 DEG C and precursor sol is made.

6. a kind of CO as claimed in claim 4 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: the precipitation method For precipitating reagent and catalyst component are made into co-precipitation after the solution of respective concentration.

7. a kind of CO as claimed in claim 4 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: the precipitating is heavy Area method is that the active metallic element in precipitating reagent and catalyst, auxiliary element cocurrent are deposited on carrier.

8. a kind of CO as claimed in claim 4 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: active in catalyst Component, auxiliary agent and carrier element are from nitrate, citrate, acetate.

9. a kind of CO as claimed in claim 5 adds hydrogen low-carbon alcohols GaFe base catalyst, it is characterised in that: the precipitating reagent For K₂CO₃, KOH, one of urea or a variety of.

10. a kind of any CO adds hydrogen low-carbon alcohols GaFe base catalyst according to claim 1 ~ 9, it is characterised in that: GaFe Base catalyst adds in the reaction of hydrogen low-carbon alcohols in CO, use condition are as follows: 1 ~ 6MPa of pressure, 200 ~ 400 DEG C of temperature, GHSV=1000 ~ 8000h^-1, H₂/CO=0.5~4。