CN105618051B - Catalyst for CO hydrogenation to synthesize high-carbon alcohols for co-production of naphtha and diesel, its preparation method and application - Google Patents

Abstract

A catalyst for the hydrogenation of CO to synthesize high-carbon alcohols for the co-production of naphtha and diesel, as well as its preparation method and application. The catalyst uses Co as an active component, Si as an auxiliary agent and activated carbon as a carrier, the active component is 5-30 wt% of the catalyst weight, and the auxiliary agent is 0.1-5 wt% of the catalyst weight. According to the catalyst prepared by adding Si additives according to the present invention, the conversion rate of CO is increased, the selectivity of C ₁ -C ₄ gaseous hydrocarbons is reduced, and the selectivity of synthetic alcohols, naphtha and diesel oil is increased, especially the high value-added C ₆ -C The selectivity of ₁₈ higher carbon alcohols has been significantly improved.

Description

A kind of catalyst that is used for CO hydrogenation to synthesize high-carbon alcohol to co-produce naphtha and diesel oil and its Preparation method and application

technical field

The invention belongs to the technical field of chemical catalysts, and in particular relates to a catalyst for CO hydrogenation to synthesize high-carbon alcohols for co-production of naphtha and diesel and its preparation method and application. More specifically, it relates to an activated carbon-supported catalyst Cobalt-based catalyst, the performance of the catalyst is modulated by the Si promoter.

Background technique

Alcohols above C ₆ are called high-carbon alcohols, which have high added value and are widely used. At present, their demand is about 13 million tons. my country is a big consumer of high-carbon alcohol, and there is a broad consumer market for plastic products, detergents, surfactants and other fine chemical products. At present, there are two industrial processes for synthesizing higher alcohols by chemical method. The first is to use triethylaluminum catalyst, that is, the ethylene raw material undergoes triethylaluminum chain growth reaction and oxidation, hydrolysis and rectification to produce detergent alcohol, but this method consumes a lot of triethylaluminum catalyst, and the cost is high. Less secure. The second is to use a homogeneous cobalt-phosphine metal organic compound as a catalyst, and high-carbon olefins, carbon monoxide and hydrogen generate straight-chain and branched high-carbon aldehydes under the action of the catalyst, and then generate high-carbon alcohols through hydrogenation, but the process Complex, poor selectivity of the target product.

The direct synthesis of mixed alcohols from synthesis gas through Fischer-Tropsch synthesis has high economic benefits and resource utilization advantages. The mixed alcohols synthesized by it have relatively low carbon numbers, generally C ₁ -C ₆ OH, and can be used as high-quality fuels, clean gasoline additives, chemicals and chemical raw materials. US 4513100 discloses a methanol synthesis catalyst Cu-ZnO/Al ₂ O ₃ modified by alkali metal and alkaline earth metal. The main product generated by the synthesis gas reaction is C ₁ -C ₆ straight chain and branched chain alcohol, and the by-product is Minor amounts of other oxygenates and hydrocarbons. The French Institute of Petroleum (IFP) has developed a Cu-Co-based CO hydrogenation catalyst for the synthesis of lower alcohols (US4122110 and US4291126). The general formula of the catalyst composition is _CuxCoyMzAw , wherein M _{= Cr} , _Fe , V, Mn and rare earth, and A is alkali metal. The Cu-Co-based catalyst modulated by Cr, Mn, Fe, La and K additives has higher activity and selectivity for synthesizing ethanol. In 1984, American Dow Chemical Company and Union Carbide Chemical Company respectively discovered that a new catalyst of MoS ₂ doped with alkali metals could catalyze the conversion of synthesis gas into low-carbon linear mixed alcohols. The addition of the base additive greatly inhibits the formation of hydrocarbons on the catalyst, promotes the formation of alcohol products, and greatly improves the selectivity of alcohol formation (WO 8503073 and US 4882360). CN01130481 discloses Mn-Ni-K-MoS ₂ catalyst, the introduction of Mn element in the preparation of MoS ₂ -based catalyst, so that the activity of the catalyst to catalyze the synthesis of alcohol is significantly improved, and at the same time, the selectivity of C ₂ ⁺ alcohol is improved, up to 62 %. CN 200610097869 provides a catalyst for synthesizing low-carbon alcohols from syngas and its preparation method. The main components of the catalyst are CuO, ZnO, Cr ₂ O ₃ , Al ₂ O ₃ and appropriate amount of other additives (V, Mo, Mn , Mg, Ce), with higher _CO conversion and higher selectivity for alcohols above C2. The carbon number of mixed alcohols produced by Fischer-Tropsch synthesis is relatively low, generally C ₁ ~ C ₆ , basically no high-value-added C ₆₊ high-carbon alcohols can be obtained, and the proportion of low-value-added methanol is relatively large, reaching more than 40% , restricting the economy of the process.

Dalian Institute of Chemical Physics has developed an activated carbon-supported cobalt-based catalyst (Co/AC) for CO hydrogenation to synthesize mixed primary alcohols (C ₂ -C ₁₈ OH) and co-production of liquid fuel (US 7670985 and CN101310865). The mass ratio of hydrocarbon products (mainly naphtha and diesel oil) to mixed primary alcohols in its synthetic liquid products is about 1:1, and the distribution of high-value-added high-carbon primary alcohols (carbon number ≥ 6) in alcohol products Reach around 50%. However, there is still a need in the art to provide a catalyst for further improving the performance of CO hydrogenation to synthesize higher alcohols, as well as its preparation method and application.

Contents of the invention

The object of the present invention is to address the above-mentioned shortcomings in the prior art, and to provide a catalyst with excellent performance for CO hydrogenation to synthesize high-carbon alcohols for co-production of naphtha and diesel and a preparation method thereof. On the basis of the research of activated carbon-supported cobalt-based (metal Co and Co ₂ C) catalysts, the present invention further improves the activity and selectivity of the catalyst by introducing Si additives to adjust the performance of the catalyst, and reduces the concentration of C ₁ -C ₄ gaseous hydrocarbons. Selectivity to improve the selectivity of synthetic alcohols and naphtha and diesel, especially to improve the selectivity of C ₆ -C ₁₈ higher alcohols, to further improve the economical efficiency of CO hydrogenation synthesis of higher alcohols, and promote the catalytic process industrial applications. The catalyst of the present invention is used for the one-step method of CO hydrogenation to synthesize high _- carbon alcohols and co _- produce naphtha and diesel oil. Alcohol co-production of naphtha and diesel selectivity (C ₁ -C ₁₈ alcohol and C ₅₊ hydrocarbon selectivity), especially high selectivity for the synthesis of C ₆ -C ₁₈ higher alcohols.

In order to realize the above-mentioned purpose of the present invention, the present invention provides following technical scheme:

A catalyst for the hydrogenation of CO to synthesize high-carbon alcohols for the co-production of naphtha and diesel. The catalyst uses Co as the active component, Si as the auxiliary agent, and activated carbon as the carrier.

According to the catalyst, the activated carbon is almond shell carbon or coconut shell carbon, the specific surface area of the activated carbon is 500-1500m ² /g, the average pore diameter is 1-10nm, and the pore volume is 0.3-1.0ml/g.

According to the catalyst, the Co active component is cobalt nitrate, cobalt oxalate or cobalt citrate, which is 5-30 wt% of the weight of the catalyst.

According to the catalyst, wherein the Si promoter is 0.1-5 wt% of the weight of the catalyst.

According to the catalyst, the Co active component is 10-20 wt% of the catalyst weight.

According to the catalyst, the CO conversion rate of the catalyst is 60%, the selectivity of C ₁ -C ₄ gaseous hydrocarbons is 17%, the selectivity of synthesizing high-carbon alcohols for co-production of naphtha and diesel oil is 82%, and the selectivity of C ₆ -C ₁₈ The distribution of straight-chain mixed alcohols in alcohol products is 60%, and the distribution of methanol in the alcohols generated by CO hydrogenation is 2-8%.

The present invention also provides a method for preparing a catalyst for the hydrogenation of CO to synthesize high-carbon alcohols and co-produce naphtha and diesel oil. Washing treatment, then boiling with deionized water, drying in air atmosphere at 383-403K for 4-8 hours, and then impregnating and supporting catalyst components to prepare catalyst precursors; Co nitrate solution and ethyl orthosilicate The ethanol solution impregnated on the activated carbon carrier, during impregnation, the active component of the catalyst is impregnated first, and then the catalyst auxiliary component is impregnated, or the catalyst auxiliary component is impregnated first, and then the catalyst active component is impregnated, or co-impregnated at the same time; Dry in the shade at room temperature, dry in air atmosphere at 323-353K for 8-24 hours, dry the dried samples at 373-393K in nitrogen atmosphere for 2-10 hours, the pressure of nitrogen is normal pressure, and the space velocity is 300h ^-1 ～ 1000h ^-1 , roasted at 473-773K for 4-20 hours under a nitrogen atmosphere, the pressure is normal pressure, and the space velocity is 300h ^-1 -1000h ^-1 , and finally reduced and activated in a hydrogen-containing mixed gas; hydrogen in a hydrogen-containing mixed gas The content is 30-100%, the gas other than hydrogen in the hydrogen-containing mixed gas is nitrogen, the reduction activation temperature is 573-773K, the pressure is 0.1-1MPa, the space velocity is 300-2000h ^-1 , and the time is 2-50 hours .

As described in the preparation method of the catalyst for the CO hydrogenation synthesis of high-carbon alcohol co-production of naphtha and diesel oil, the CO hydrogenation reaction is carried out after reduction and activation, using a conventional fixed-bed reactor, or using a slurry-bed reactor, The reaction temperature is 473～513K, the reaction pressure is 1.5～4.0MPa, the space velocity is 300～3000h ^-1 , the mixed gas of _H2 and CO, the synthesis gas with the molar ratio of _H2 and CO of 1～3 is continuously fed, and the catalyst bed The CO hydrogenation reaction is carried out in the layer, and the reaction tail gas and products are continuously discharged. The heavy components are collected by the hot tank, and the light components are collected by the cold trap. The temperature of the hot tank is maintained at 373-403K, and the temperature of the cold trap is maintained at 273～293K.

The present invention also provides the application of the above-mentioned catalyst of the present invention in CO hydrogenation to synthesize high-carbon alcohols and co-produce naphtha and diesel oil, for CO hydrogenation to directly synthesize C2 _{- C18} straight-chain mixed primary alcohols and co-produce naphtha oil and diesel.

The catalyst prepared by the present invention has higher CO conversion rate, lower C ₁ -C ₄ gaseous hydrocarbon selectivity, higher selectivity of synthesizing high-carbon alcohol co-production naphtha and diesel oil (C ₁ -C ₁₈ Alcohol and C ₅₊ hydrocarbon selectivity), especially high selectivity for the synthesis of C ₆ -C ₁₈ higher carbon alcohols. According to the catalyst of the present invention, among the alcohols generated by CO hydrogenation, the distribution of methanol is low (2-8%), and the selectivity of synthesizing high-carbon alcohols for co-production of naphtha and diesel oil is high, about 82%, C ₆ -C ₁₈ The distribution of linear mixed primary alcohols (including C ₆ -C ₁₁ alcohols and C ₁₂ -C ₁₈ higher alcohols) in alcohols is as high as about 60%;

The present invention modifies the activated carbon-supported cobalt-based catalyst with Si auxiliary agent, improves the activity of the catalyst, reduces the selectivity of C ₁ -C ₄ gaseous hydrocarbons, so as to improve the selectivity of synthesizing high-carbon alcohols for co-production of naphtha and diesel oil, and improve the synthesis The selectivity of C ₆ -C ₁₈ higher alcohols further improves the economical efficiency of CO hydrogenation to synthesize higher alcohols. Under the action of this catalyst, the CO conversion rate increases, the selectivity of C ₁ -C ₄ gaseous hydrocarbons decreases, and the selectivity of synthesizing high-carbon alcohols to co-produce naphtha and diesel oil (C ₁ -C ₁₈ alcohols and C ₅₊ hydrocarbons Selectivity) increases, and the selectivity of C ₆ -C ₁₈ higher carbon alcohols increases.

Content of the present invention can be described in more detail as:

In the catalyst provided by the invention, the active component is metal Co, and the cobalt-containing compound is one of cobalt nitrate, cobalt oxalate and cobalt citrate, preferably cobalt nitrate. Its weight is 5-30% of the weight of the catalyst, preferably the cobalt element weight content is 10-20%. The additive component is Si, the raw material is ethyl orthosilicate, and the weight of the additive is 0.1-5% of the weight of the catalyst. The catalyst carrier is activated carbon, which can be apricot core charcoal or coconut shell charcoal. The specific surface area of the activated carbon carrier is 500-1500m ² /g, the average pore diameter is 1-10nm, and the pore volume is 0.3-1mL/g. The preferred specific surface area of activated carbon is It is 700-1200m ² /g, the average pore diameter is 3-8nm, and the pore volume is 0.5-0.8mL/g. The impregnation method is used to load the catalyst components on the carrier; the components contained in the impregnation liquid include catalyst active components and auxiliary components.

The invention provides a catalyst for CO hydrogenation to synthesize high-carbon alcohols and co-produce naphtha and diesel oil. The specific method of preparing the catalyst is as follows: using activated carbon as the carrier, the activated carbon is first boiled and washed with a hydrochloric acid solution with a concentration of 5-15%, then boiled with deionized water, and dried in an air atmosphere at a temperature of 383-403K for 4-8 hours , and then impregnating the loaded catalyst component to prepare the catalyst precursor; impregnating the nitrate solution of Co and the ethanol solution of tetraethyl orthosilicate on the activated carbon carrier, the active component of the catalyst can be impregnated first and then the catalyst auxiliary agent group Divide, or impregnate the catalyst auxiliary component first and then impregnate the catalyst active component, or co-impregnation; after impregnation, the catalyst is dried in the shade at room temperature, and dried in an air atmosphere at a temperature of 323-353K for 8-24 hours. Dry the dried sample at ^373-393K for ^2-10 hours under a nitrogen atmosphere. At normal pressure, the space velocity is 300h ^-1 ~ 1000h ^-1 , and finally reduced and activated in hydrogen-containing mixed gas. The hydrogen content in the hydrogen-containing mixed gas is 30-100%, the gas other than hydrogen in the hydrogen-containing mixed gas is nitrogen, the reduction activation temperature is 573-773K, the pressure is 0.1-1MPa, and the space velocity is 300-2000h ^-1 , The time is 2 to 50 hours.

The reaction of the present invention can adopt conventional fixed-bed reactor, also can adopt slurry-state reactor. Reaction temperature: 473～500K, reaction pressure: 1.5～4.0MPa, space velocity 300～3000h ^-1 . The heavy components are collected in a hot tank, and the light components are collected in a cold trap. The temperature of the hot tank is maintained at 373-403K, and the temperature of the cold trap is maintained at 273-293K.

Using the catalyst of the present invention or the catalyst prepared by the preparation method of the present invention, the conversion rate of CO is about 60%, the selectivity of C ₁ -C ₄ gaseous hydrocarbons is about 17%, and the synthesis of high-carbon alcohol co-produces naphtha and diesel oil. The selectivity is high, about 82%, and the distribution of C ₆ -C ₁₈ linear mixed alcohols in alcohol products is about 60%. _The catalyst can be used for CO hydrogenation to directly synthesize C ₂ -C ₁₈ linear mixed primary alcohols to co _- produce naphtha and diesel oil. High selectivity of synthesizing high-carbon alcohols for co-production of naphtha and diesel (C ₁ -C ₁₈ alcohols and C ₅₊ hydrocarbon selectivity), especially those with high synthesis of C ₆ -C ₁₈ linear mixed primary alcohols selective.

Description of drawings

Fig. 1 is the XRD spectrogram after catalyst reaction.

detailed description

The present invention will be further described through specific embodiments below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

Example 1

The specific surface area and pore size distribution of coconut shell activated carbon were measured on the AS-1 adsorption instrument of QUANTACHROME Company. The sample was first degassed at 573K for 3 hours, and nitrogen adsorption test was carried out at the temperature of liquid nitrogen. The cross-sectional area of N ₂ molecules was 0.162nm ² . The BET method was used to calculate the specific surface area of the samples, and the BJH method was used to calculate the pore distribution. The measured specific surface area of the coconut shell activated carbon is 912m ² /g, the average pore diameter is 3.5nm, and the pore volume is 0.43mL/g.

1000 grams of coconut shell activated carbon carrier was treated once by boiling and washing with 10% hydrochloric acid solution, then nine times by boiling and washing with deionized water, and then dried at 393K for 8 hours. It was marked as AC1 for later use. The specific method is: take 1000 grams of coconut shell activated carbon, add 5000 grams of hydrochloric acid solution containing 10% mass concentration, heat to boiling and boil for 0.5 hours in a boiling state, then pour out the hot acid solution, add 5000 grams of deionized water, Heat to boiling and boil for 0.5 hours in a boiling state, pour out the hot deionized water, add deionized water again for the next boiling wash. Boil and wash with deionized water for a total of 9 times. The washed activated carbon was dried at a temperature of 393K for 8 hours, and was marked as AC1 for later use. The specific surface area of AC1 activated carbon measured by the above method was 956m ² /g, the average pore diameter was 3.6nm, and the pore volume was 0.49mL/g.

The composition of catalyst A is 15Co0.1Si/AC1. The activated carbon treated with 20-40 mesh is used as the carrier, and the catalyst is prepared according to the following steps. Weigh 10 grams of processed activated carbon, weigh 0.09 grams of tetraethyl orthosilicate and dissolve it in 5 mL of absolute ethanol, weigh 8.71 grams of Co(NO ₃ ) ₂ ·6H ₂ O and dissolve it in 12 mL of deionized water. Mix and stir until homogeneous, then load the mixed solution on activated carbon by conventional impregnation method. Dry in the shade at room temperature, then dry in an air atmosphere at 333K for 24 hours, then dry at 393K in a nitrogen atmosphere for 4 hours; finally bake at 623K in a nitrogen atmosphere for 8 hours to obtain a Co weight content of 15%, Si weight Catalyst oxide precursor at 0.1%. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Example 2

The composition of catalyst B is 6Co0.1Si/AC1. The activated carbon treated with 20-40 mesh is used as the carrier, and the catalyst is prepared according to the following steps. Weigh 10 grams of processed activated carbon, weigh 0.08 grams of tetraethyl orthosilicate and dissolve it in 3 mL of absolute ethanol, weigh 3.15 grams of Co(NO ₃ ) ₂ ·6H ₂ O and dissolve it in 10 mL of deionized water. Mix and stir until homogeneous, then load the mixed solution on activated carbon by conventional impregnation method. Dry in the shade at room temperature, then dry at 343K in air atmosphere for 20 hours, then dry at 383K in nitrogen atmosphere for 6 hours; finally bake at 603K in nitrogen atmosphere for 6 hours to obtain a Co weight content of 6%, Si weight Catalyst oxide precursor at 0.1%. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Example 3

The composition of catalyst C is 15Co0.5Si/AC1. Using the coconut shell activated carbon treated in Example 1 as a carrier, the catalyst was prepared according to the following steps. Weigh 10 grams of processed activated carbon, weigh 0.44 grams of tetraethyl orthosilicate and dissolve in 5 mL of absolute ethanol, weigh 8.76 grams of Co(NO ₃ ) ₂ 6H ₂ O in 12 mL of deionized water, and mix the two solutions And stir until uniform, and then use the conventional impregnation method to load the mixed solution on the activated carbon. Dry in the shade at room temperature, then dry at a temperature of 353K in an air atmosphere for 12 hours, then dry at a temperature of 383K in a nitrogen atmosphere for 8 hours; finally bake at a temperature of 603K in a nitrogen atmosphere for 8 hours to obtain a Co weight content of 15%, a Si weight Catalyst oxide precursor at 0.5%. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Example 4

The composition of catalyst D is 15Co1Si/AC1. Using the coconut shell activated carbon treated in Example 1 as a carrier, the catalyst was prepared according to the following steps. Weigh 10 grams of AC1 activated carbon, weigh 0.89 grams of tetraethyl orthosilicate and dissolve in 5 mL of absolute ethanol, weigh 8.81 grams of Co(NO ₃ ) ₂ 6H ₂ O in 12 mL of deionized water, mix the two solutions and Stir until uniform, and then load the mixed solution on activated carbon by conventional impregnation method. Dry in the shade at room temperature, then dry at a temperature of 343K in an air atmosphere for 24 hours, then dry at a temperature of 383K in a nitrogen atmosphere for 4 hours; finally bake at a temperature of 623K in a nitrogen atmosphere for 4 hours to obtain a Co weight content of 15%, Si weight 1% catalyst oxide precursor. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Example 5

The composition of catalyst E is 15Co2Si/AC1. Using the coconut shell activated carbon treated in Example 1 as a carrier, the catalyst was prepared according to the following steps. Weigh 10 grams of processed activated carbon, weigh 1.79 grams of tetraethyl orthosilicate and dissolve in 8 mL of absolute ethanol, weigh 4.50 grams of cobalt oxalate CoC ₂ O ₄ in 10 mL of deionized water, and dissolve them after the two components are completely dissolved Mix and load the resulting solution on activated carbon by a conventional impregnation method. Dry in the shade at room temperature, then dry at 333K in an air atmosphere for 24 hours, then dry at 393K in a nitrogen atmosphere for 2 hours; finally bake at 623K in a nitrogen atmosphere for 6 hours to obtain a Co weight content of 15%, Si weight Catalyst at 2%. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Example 6

The specific surface area and pore size distribution of apricot shell activated carbon were measured on the AS-1 adsorption instrument of QUANTACHROME Company. The sample was first degassed at 573K for 3 hours, and nitrogen adsorption test was carried out at the temperature of liquid nitrogen. The cross-sectional area of N ₂ molecules was 0.162nm ² . The BET method was used to calculate the specific surface area of the samples, and the BJH method was used to calculate the pore distribution. The measured specific surface area of apricot shell activated carbon is 856m ² /g, the average pore diameter is 3.5nm, and the pore volume is 0.58mL/g.

1000 grams of apricot shell activated carbon carrier was treated once by boiling and washing with 7% hydrochloric acid solution, then 12 times by boiling and washing with deionized water, and then dried at 393K for 8 hours. It was reserved and marked as AC1. The specific method is: take 1000 grams of apricot shell activated carbon, add 5000 grams of hydrochloric acid solution containing 7% mass concentration, heat to boiling and boil for 0.5 hour in a boiling state, then pour out the hot acid solution, add 5000 grams of deionized water, Heat to boiling and boil for 0.5 hours in a boiling state, pour out the hot deionized water, add deionized water again for the next boiling wash. Boil and wash with deionized water 12 times in total. The washed apricot shell activated carbon was dried at a temperature of 393K for 12 hours, and was set aside, marked as AC2. The specific surface area of AC2 activated carbon measured by the above method is 956m ² /g, the average pore diameter is 3.8nm, and the pore volume is 0.62mL/g.

The composition of catalyst F is 20Co3Si/AC2. With the treated apricot shell activated carbon AC2 as the carrier, the catalyst was prepared according to the following steps. Weigh 10 grams of AC2 activated carbon, weigh 2.90 grams of tetraethyl orthosilicate and dissolve in 10 mL of absolute ethanol, weigh 12.81 grams of Co(NO ₃ ) ₂ 6H ₂ O in 8 mL of deionized water, mix the two solutions and Stir until uniform, and load the prepared solution on activated carbon by conventional impregnation method. Dry in the shade at room temperature, then dry at 353K in an air atmosphere for 36 hours, then dry at 383K in a nitrogen atmosphere for 10 hours; finally bake at 623K in a nitrogen atmosphere for 2 hours to obtain a Co weight content of 20%, Si weight Catalyst at 3%.

Example 7

The composition of catalyst G is 25Co4Si/AC2. With the apricot shell activated carbon AC2 processed in Example 6 as the carrier, the catalyst was prepared according to the following steps. Weigh 10 grams of activated carbon AC2, weigh 4.19 grams of ethyl orthosilicate and dissolve it in 12 ml of absolute ethanol, weigh 17.36 grams of Co(NO ₃ ) ₂ 6H ₂ O in 12 mL of deionized water, mix the two solutions and Stir until uniform, and load the prepared solution on activated carbon by conventional impregnation method. Dry in the shade at room temperature, then dry at 343K in an air atmosphere for 20 hours, then dry at 393K in a nitrogen atmosphere for 4 hours; finally bake at 603K in a nitrogen atmosphere for 6 hours to obtain a Co weight content of 25%, Si weight Catalyst at 4%. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Comparative example 1

The composition of catalyst H is 15Co/AC1. With 20-40 mesh treated AC1 activated carbon as the carrier, the catalyst is prepared according to the following steps. Weigh 10 g of treated activated carbon, weigh 8.7 g of Co(NO ₃ ) ₂ ·6H ₂ O and dissolve it in 10 mL of deionized water, and then load the prepared solution on the activated carbon by conventional impregnation method. Dry in the shade at room temperature, then dry in an air atmosphere at 333K for 24 hours, then dry at 393K in a nitrogen atmosphere for 4 hours; finally bake at 623K in a nitrogen atmosphere for 8 hours to obtain a catalyst with a Co weight content of 15%. precursors. The crystal phase of Co in the catalyst after the reaction was determined by XRD, and the XRD test was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Company. Cu k _α1 radiation source, tube pressure 40KV, tube current 40mA, scanning range 2θ=5°-75°, scanning speed 0.2°/s. The XRD pattern of the catalyst after the reaction is shown in Figure 1.

Comparative example 2

The composition of catalyst I is 15Co2Zr/AC2. With 20-40 mesh treated apricot shell charcoal AC2 as the carrier, the catalyst is prepared according to the following steps. Weigh 10 grams of processed activated carbon, weigh 8.9 grams of Co(NO ₃ ) ₂ 6H ₂ O and dissolve it in 10 mL of deionized water, weigh 1.13 grams of Zr(NO ₃ ) ₄ 5H ₂ O and dissolve it in 5 mL of 373K temperature In deionized water, the two solutions were thoroughly mixed until uniform, and then the prepared solution was loaded on activated carbon by a conventional impregnation method. Dry in the shade at room temperature, then dry at 333K in an air atmosphere for 24 hours, then dry at 383K in a nitrogen atmosphere for 6 hours; finally bake at 623K in a nitrogen atmosphere for 4 hours to obtain a Co weight content of 15%, a Zr content of 2% catalyst oxide precursor.

Catalyst AI reaction evaluation was carried out in a fixed bed reactor. 4 mL of each catalyst was taken and packed in a fixed bed reactor, the diameter of the fixed bed reactor was 10 mm, and the length was 40 mm. The catalyst is reductively activated before the reaction, and the conditions for reductively activating are pure hydrogen atmosphere, normal pressure, space velocity 1000h ^-1 , temperature 703K, and time 10 hours. That is, the catalyst whose main active component is metal cobalt is obtained. After activation, the temperature of the catalyst bed dropped to below 373K, and the synthesis gas (containing 66.6 vol% H ₂ , 33.4 vol% CO) was switched, at a temperature of 493K, a reaction pressure of 3.0MPa, and a space velocity of 500h ^-1 for continuous feed conditions The next reaction. The early stage of reaction (TOS=48 hours) is the pretreatment period and the stabilization period. Samples were collected for 48 hours after the stabilization period for analysis and calculation. The reaction tail gas and gas phase products are continuously discharged, and the heavy components are collected by a hot tank, and the liquid phase products are collected by a cold trap. The temperature of the hot tank is 373K, and the temperature of the cold trap is 278K. The tail gas of the reaction is analyzed online by HP-6890 gas chromatograph (Porapark QS packed column, TCD detector). The oil phase and water phase products were analyzed, and the water phase product was analyzed with sec-butanol as the internal standard. According to the analysis results, the conversion rate of CO and the selectivity of products were calculated. The composition and evaluation results of catalyst AH are listed in Table 1.

Take 10 mL each of catalyst E and F oxide precursors prepared in Examples 5 and 6 above, grind them to powders below 150 mesh, and place them in fluidized bed reactors respectively. The diameter of the fluidized bed reactor is 20 mm, and the volume 100mL, hydrogen gas was passed through to perform reduction activation in a fluidized state, and the activation was performed for 12 hours at a temperature of 703K, normal pressure, and a space velocity of 1000h ^-1 . Catalyst evaluation was performed in a slurry bed reactor. After the temperature of the catalyst dropped to 333K, the activated catalyst was transferred to a 1-liter stainless steel high-pressure back-stirred reaction kettle pre-installed with 300 mL of liquid paraffin by purging. The purge gas is H ₂ , the volume space velocity is 2000h ^-1 , and the purge time is 2 hours. After the transfer was completed, a mixed gas of H ₂ and CO (containing 66.6 vol% H ₂ and 33.4 vol% CO) was introduced into the autoclave for reaction. The reaction temperature was 493K, the reaction pressure was 3.0 MPa, and the space velocity was 500 h ^-1 . The early stage of reaction (TOS=48 hours) is the pretreatment period and the stabilization period. Samples were collected for 48 hours after the stabilization period for analysis and calculation. The reaction tail gas and gas phase products are continuously discharged, and the heavy components are collected by the hot tank, and the light components are collected by the cold trap. The temperature of the hot tank is 373K, and the temperature of the cold trap is 278K. The tail gas of the reaction is analyzed online by HP-6890 gas chromatograph (Porapark QS packed column, TCD detector). The oil phase and water phase products were analyzed, and the water phase product was analyzed with sec-butanol as the internal standard. According to the analysis results, the conversion rate of CO and the selectivity of products were calculated. The composition and evaluation results of catalyst AH are listed in Table 1.

It can be seen from Table 1 that the catalysts modulated by Si additives in the examples show good alcohol synthesis performance. Compared with the 15Co/AC catalyst without additives (Comparative Example 1), the activity and selectivity of the catalyst with Si additives were significantly improved for synthesizing alcohols, with higher CO conversion and lower _C1 -C ₄ gaseous hydrocarbon selectivity, higher selectivity for synthesizing C ₅₊ hydrocarbons and alcohol liquid organic products, especially the selectivity for synthesizing C ₆ -C ₁₈ higher carbon alcohols is significantly improved, in the alcohol components Distribution increased from 50% to around 60%. Among them, the CO conversion rate of 15Co1Si/AC catalyst is as high as 52.75%, the selectivity of C ₁ -C ₄ gaseous hydrocarbons is as low as 16.5%, and the selectivity of C ₅₊ hydrocarbons and alcohol liquid organic products is 82.4% (C ₅₊ hydrocarbon selectivity and Alcohol selectivity), the distribution of C ₆ -C ₁₈ higher alcohols in alcohols is as high as 58.6%, and the selectivity and space-time yield of synthetic C ₆ -C ₁₈ higher alcohols are 4.0g/kg*h. , has excellent synthetic alcohol properties. Patents US 7670985 and CN101310856 disclose the activity and selectivity of activated carbon-supported catalysts modulated by Zr and other additives in the synthesis of C ₁ -C ₁₈ alcohols, but do not give the distribution of C ₆ -C ₁₈ higher alcohols. The comparative example 2 of the present application develops the catalyst 15Co2Zr/AC2 with the representative Zr auxiliary agent in the patent US 7670985 and CN101310856. Table 1 shows that the indicators of the 15Co2Zr/AC2 catalyst for synthesizing alcohol are lower than those of the above-mentioned 15Co1Si/AC catalyst for synthesizing alcohol. index.

Figure 1 is the XRD pattern of the catalyst after the reaction. It can be seen from the figure that the catalyst after the reaction contains crystal phases of Co ₂ C and metal Co, indicating that part of the metal cobalt of the catalyst is in-situ carbonized to Co ₂ C during the reaction process. It can also be seen from the figure that after adding the Si promoter to the catalyst, the Co ₂ C and metal Co diffraction peaks of the Co species become weaker, indicating that the dispersion of the catalyst is improved. This may be the reason why the performance of synthesizing alcohol is improved after adding Si promoter to the catalyst. With the further increase of Co loading and Si addition, the XRD diffraction peak signal is enhanced, indicating that the crystal grains of Co species are enlarged, which is consistent with the 25Co4Si/AC2 catalyst in Table 1 (high loading of Co and high addition of Si ) is consistent with the decrease in performance of synthols.

Claims (6)

1. The catalyst for CO hydrogenation to synthesize high-carbon alcohol co-production naphtha and diesel oil is characterized in that the catalyst uses Co as an active component, Si as an auxiliary agent, and activated carbon as a carrier, and the activated carbon is apricot shell carbon or Coconut shell carbon, activated carbon has a specific surface area of 500-1500m ² /g, an average pore diameter of 1-10nm, and a pore volume of 0.3-1.0ml/g. The Co active component is cobalt nitrate, cobalt oxalate or cobalt citrate, and its weight It is 5-30wt% of the weight of the catalyst, and the weight of the Si promoter is 0.1-5wt% of the weight of the catalyst. 2. The catalyst according to claim 1, wherein the Co active component is 10-20 wt% of the catalyst weight. 3. according to the described catalyst of claim 1, it is characterized in that, this catalyst CO conversion rate is 60%, C ₁ -C ₄ gaseous hydrocarbon selectivity is 17%, the selection of synthesizing high carbon alcohol co-production naphtha and diesel oil The property is 82%, the distribution of C ₆ -C ₁₈ linear mixed alcohols in alcohol products is 60%, and the distribution of methanol in the alcohols produced by CO hydrogenation is 2-8%. 4. the preparation method of the catalyst that is used for the CO hydrogenation synthesis high-carbon alcohol coproduction naphtha and diesel oil described in claim 1, it is characterized in that, with activated carbon as carrier, activated carbon is the hydrochloric acid of 5～15% through concentration earlier The solution is boiled and washed, then boiled with deionized water, dried in an air atmosphere at a temperature of 383-403K for 4-8 hours, and then impregnated with a catalyst component to prepare a catalyst precursor; the nitrate solution of Co and orthosilicic acid The ethanol solution of ethyl ester is impregnated on the activated carbon carrier. When impregnating, the active component of the catalyst is impregnated first and then the catalyst auxiliary component is impregnated, or the catalyst auxiliary component is impregnated first and then the catalyst active component is impregnated, or co-impregnated at the same time; catalyst impregnation Then dry in the shade at room temperature, dry in air atmosphere at 323-353K for 8-24 hours, dry the dried samples at 373-393K in nitrogen atmosphere for 2-10 hours, the pressure of nitrogen is normal pressure, and the space velocity is 300h ^{- 1} ~ 1000h ^-1 , roasted at 473 ~ 773K for 4 ~ 20 hours under a nitrogen atmosphere, the pressure is normal pressure, and the space velocity is 300h ^-1 ~ 1000h ^-1 , and finally reduced and activated in a hydrogen-containing mixed gas; a hydrogen-containing mixed gas The hydrogen content in the medium is 30-100%, the gas other than hydrogen in the hydrogen-containing mixed gas is nitrogen, the reduction activation temperature is 573-773K, the pressure is 0.1-1MPa, the space velocity is 300-2000h ^-1 , and the time is 2-2 50 hours. 5. the preparation method of the catalyst that is used for CO hydrogenation to synthesize high-carbon alcohol co-production naphtha and diesel oil as claimed in claim 4, is characterized in that, after reduction activation, carry out CO hydrogenation reaction, with conventional fixed-bed reactor , or use a slurry bed reactor with a reaction temperature of 473-513K, a reaction pressure of 1.5-4.0MPa, a space velocity of 300-3000h ^-1 , a mixture of H ₂ and CO, and a molar ratio of H ₂ and CO of 1-3 The synthesis gas is continuously fed, and the CO hydrogenation reaction is carried out on the catalyst bed. The reaction tail gas and products are continuously discharged. The heavy components are collected by the hot tank, and the light components are collected by the cold trap. The temperature of the hot tank is maintained at 373 ~ 403K, the temperature of the cold trap is maintained at 273 ~ 293K. 6. The application of the catalyst as claimed in claim 1 in the CO hydrogenation synthesis of high-carbon alcohol co-production naphtha and diesel oil, characterized in that the catalyst is used for CO hydrogenation to directly synthesize C ₂ -C ₁₈ linear mixed primary alcohols Co-production of naphtha and diesel.