Preparation method of acidity-adjustable catalyst for preparing aviation kerosene from synthesis gas through one-step method

Abstract

The invention relates to the field of preparing aviation kerosene from synthesis gas through a one-step method. The invention relates to a preparation method of an acidity-adjustable catalyst for preparing aviation kerosene from synthesis gas by a one-step method, which comprises the following steps of: dissolving ethylenediamine tetraacetic acid (EDTA), an aluminum source and a cobalt source in deionized water to form a complex which is marked as a solution A; the preparation method comprises the following steps: sequentially adding a silicon source, an alkali source, a solution A, a template agent, a pore forming agent and a seed crystal into deionized water, stirring to form uniform gel, transferring into a high-pressure reaction kettle, sealing, putting into a homogeneous reactor, and reacting at 140-200 DEG C under self-generated pressure for 20-72 hours; a solid product is separated out, washed with deionized water, filtered, dried and roasted for 10-40 h at the temperature of 400-600 DEG C, and the acidity-adjustable catalyst for preparing the aviation kerosene through the synthesis gas one-step method is obtained. According to the invention, the pore-forming agent is introduced to construct hierarchical pores, so that active sites are increased, mass transfer is accelerated, and the selectivity of C9-C16 is improved.

Description

Technical Field

[0001] The invention relates to the field of preparing aviation kerosene by one-step method using synthesis gas. Background Art

[0002] Jet fuel (jet kerosene) is mainly used as fuel for aviation turbine engines. It has a boiling range of 180-310℃ and is a mixture of C9-C16 hydrocarbons. In recent years, the world's air transport industry has developed rapidly. As far as the civil aviation industry is concerned, the average annual growth rates of air transport of personnel and material transport are 4.9% and 5.3% respectively. In 2017, the annual consumption of global aviation fuel was about 300 million tons. It is expected that by 2050, this figure will more than double.

[0003] As petroleum resources become increasingly depleted, the production routes of non-oil-based jet fuel are gaining more and more attention. 2 ) is one of the most promising industrial alternative fuel production routes. Traditional synthesis gas to aviation kerosene catalysts use iron-based and cobalt-based catalysts, which are complex and costly. The new metal-zeolite bifunctional catalyst can directly produce aviation kerosene from synthesis gas (CO and H2) with high selectivity in one step. This new catalytic process route greatly simplifies the process flow, reduces the process cost, and provides a new idea for the industrial production of aviation kerosene.

[0004] Invention patent CN 107573967 reported that diesel fraction raw oil was subjected to hydrocracking catalyst reaction, and the product was cooled, separated and fractionated to obtain aviation kerosene fraction. This method still uses petroleum-based products as raw materials. CN103801295A, CN102482595A, CN102719317A, etc. disclosed methods for biomass to produce aviation kerosene, but the waste oil components are complex and the content of colloid components is relatively high, which easily leads to catalyst coking and is difficult to scale up industrially. Summary of the invention

[0005] The technical problem to be solved by the present invention is: how to provide a method for preparing a catalyst for directly producing aviation kerosene by converting synthesis gas, wherein the aviation kerosene prepared by this method does not contain sulfur and nitrogen, has a high proportion of isomerized hydrocarbons and has excellent performance.

[0006] The technical solution adopted by the present invention is: a method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step, which is carried out according to the following steps: Step 1, dissolving ethylenediaminetetraacetic acid (EDTA), aluminum source, and cobalt source in deionized water to form a complex, which is referred to as solution A; Step 2: Add silicon source, alkali source, solution A, template, pore-forming agent and seed crystal to deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal and place in a homogeneous reactor, and react at 140-200° C. and autogenous pressure for 20-72 hours; Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry, and calcine at 400-600° C. for 10-40 h to obtain an acid-adjustable catalyst for one-step synthesis of aviation kerosene from synthesis gas.

[0007] In step 1, the molar number of ethylenediaminetetraacetic acid (EDTA) is 1.1-2 times the sum of the molar numbers of the aluminum source and the cobalt source, so that Al 3+ and Co 2+ All form complexes with ethylenediaminetetraacetic acid (EDTA).

[0008] In step 1, the aluminum source is Al(NO 3 ) 3 9H 2 O, the cobalt source is Co(NO 3 ) 2 6H 2 O.

[0009] In step 1, the cobalt source is expressed as CoO and the aluminum source is expressed as Al 2 O 3 In step 2, the silicon source is SiO 2 The alkali source is OH - The molar ratio of silicon source, aluminum source, cobalt source, template, alkali source and deionized water is 1:0-0.5: 0.005-0.03:0.2-0.5:0.1-0.4:20-65.

[0010] In step 2, the silicon source is one or a mixture of silica sol, white carbon black, and ethyl orthosilicate, the alkali source is one or two of KOH and NaOH, and the template agent is one or a mixture of 1-ethylpyridinium bromide, 1,6-hexanediamine, and diethylamine.

[0011] In step 2, the pore-forming agent is one or a mixture of ethyl cellulose, carbon black, and PEG-6000, and the proportion of the pore-forming agent is 2 wt.%-10 wt.% of the silicon source.

[0012] The seed crystal is all-silicon ZSM-22, and its mass accounts for 1wt.%-8wt.% of the silicon source.

[0013] The beneficial effects of the present invention are as follows: the catalyst prepared by the present invention is highly dispersed on a ZSM-22 carrier by in-situ introduction of Co and EDTA into a molecular sieve by complexing, and the acidity of the carrier is adjusted by changing the silicon-aluminum ratio, a pore-forming agent is introduced to construct multi-level pores, active sites are increased, and mass transfer is accelerated, which is beneficial to improving the selectivity of C9-C16. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 XRD spectrum of the catalyst prepared in Example 1; Figure 2 This is the XRD spectrum of the catalyst prepared in Example 2. Example 1

[0015] A method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step is carried out according to the following steps: Step 1, dissolving ethylenediaminetetraacetic acid (EDTA) and cobalt nitrate (cobalt source) in deionized water to form a complex, where cobalt nitrate is calculated as CoO, and the mass ratio of (EDTA) to cobalt nitrate is 1:1.7, recorded as solution A; Step 2: Add silicon source (ethyl orthosilicate), alkali source (KOH), solution A, template (diethylamine), pore-forming agent (ethyl cellulose), and seed crystals into deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal it, and place it in a homogeneous reactor, and crystallize it at 140°C and autogenous pressure for 72 hours; Cobalt source is expressed as CoO, aluminum source is expressed as Al 2 O 3 In step 2, the silicon source is SiO 2 The alkali source is OH - The molar ratio of silicon source, cobalt source, template, alkali source and deionized water is 1:0.05:0.5:0.1:20. The amount of ethyl cellulose is 2wt.% of the silicon source, and the amount of seed added is 1wt.% of the silicon source.

[0016] Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry (normal temperature, the drying temperature not specified in the present invention is normal temperature), and calcine at 400°C for 40h to obtain the acidity adjustable catalyst 5Co / ZSM-22 for one-step synthesis of aviation kerosene from syngas, which is denoted as CZ1. Example 2

[0017] A method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step is carried out according to the following steps: Step 1: Dissolve ethylenediaminetetraacetic acid (EDTA), cobalt nitrate (cobalt source), and aluminum nitrate (aluminum source) in deionized water to form a complex, where cobalt nitrate is expressed as CoO and aluminum source is expressed as Al. 2 O 3The mass ratio of (EDTA), cobalt nitrate and aluminum nitrate is 1: 1.5:0.15, recorded as solution A; Step 2: Add silicon source (silica sol), alkali source (NaOH), solution A, template (1,6-hexanediamine), pore-forming agent (PEG-6000), and seed crystals into deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal and place in a homogeneous reactor, and crystallize at 200°C and autogenous pressure for 20 hours; Cobalt source is expressed as CoO, aluminum source is expressed as Al 2 O 3 In step 2, the silicon source is SiO 2 The alkali source is OH - The molar ratio of silicon source, aluminum source, cobalt source, template, alkali source and deionized water is 1: 0.03: 0.3: 0.2: 0.4: 65. Ethyl cellulose is 6wt.% of the silicon source, PEG-6000 is 4wt.% of the silicon source, and the seed addition amount is 8wt.% of the silicon source (based on SiO 2 count).

[0018] Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry (normal temperature, the drying temperature not specified in the present invention is normal temperature), and calcine at 600°C for 10 hours to obtain the acidity adjustable catalyst 30Co / ZSM-22 for one-step synthesis of aviation kerosene from syngas, which is denoted as CZ2. Example 3

[0019] A method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step is carried out according to the following steps: Step 1: Dissolve ethylenediaminetetraacetic acid (EDTA), cobalt nitrate (cobalt source), and aluminum nitrate (aluminum source) in deionized water to form a complex, where cobalt nitrate is expressed as CoO and aluminum source is expressed as Al. 2 O 3 The mass ratio of (EDTA), cobalt nitrate and aluminum nitrate is 1:1:0.25, recorded as solution A; Step 2: Add silicon source (silica sol), alkali source (NaOH), solution A, template (1-ethylpyridinium bromide), pore-forming agent (PEG-6000) and seed crystals into deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal and place in a homogeneous reactor, and crystallize at 160°C and autogenous pressure for 40 hours; Cobalt source is expressed as CoO, aluminum source is expressed as Al 2 O 3 In step 2, the silicon source is SiO 2 The alkali source is OH -The molar ratio of silicon source, aluminum source, cobalt source, template, alkali source and deionized water is 1: 0.03: 0.3: 0.2: 0.4: 65. Ethyl cellulose is 2wt.% of the silicon source, PEG-6000 is 8wt.% of the silicon source, and the seed addition amount is 2wt.% of the silicon source (based on SiO 2 count).

[0020] Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry (normal temperature, the drying temperature not specified in the present invention is normal temperature), and calcine at 500°C for 20h to obtain the acidity adjustable catalyst 20Co / ZSM-22 for one-step synthesis of aviation kerosene from syngas, which is denoted as CZ3. Example 4

[0021] A method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step is carried out according to the following steps: Step 1: Dissolve ethylenediaminetetraacetic acid (EDTA), cobalt nitrate (cobalt source), and aluminum nitrate (aluminum source) in deionized water to form a complex, where cobalt nitrate is expressed as CoO and aluminum source is expressed as Al. 2 O 3 The mass ratio of (EDTA), cobalt nitrate and aluminum nitrate is 1:0.67:0.06, recorded as solution A; Step 2: Add silicon source (silica sol), alkali source (NaOH), solution A, 1,6-hexanediamine (template), diethylamine (template), pore-forming agent (carbon black), and seed crystals into deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal it, and place it in a homogeneous reactor, and crystallize it at 160° C. and autogenous pressure for 40 hours; Cobalt source is expressed as CoO, aluminum source is expressed as Al 2 O 3 In step 2, the silicon source is SiO 2 The alkali source is OH - The molar ratio of silicon source, aluminum source, cobalt source, 1,6-hexanediamine, diethylamine, alkali source and deionized water is 1: 0.017: 0.2: 0.2: 0.1: 0.3: 45, carbon black is 5wt.% of the silicon source, and the amount of seed added is 2wt.% of the silicon source (based on SiO 2 count).

[0022] Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry (normal temperature, the drying temperature not specified in the present invention is normal temperature), and calcine at 500°C for 20h to obtain the acidity adjustable catalyst 20Co / ZSM-22 for one-step synthesis of aviation kerosene from syngas, which is denoted as CZ4. Example 5

[0023] A method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step is carried out according to the following steps: Step 1: Dissolve ethylenediaminetetraacetic acid (EDTA), cobalt nitrate (cobalt source), and aluminum nitrate (aluminum source) in deionized water to form a complex, where cobalt nitrate is expressed as CoO and aluminum source is expressed as Al. 2 O 3 The mass ratio of (EDTA), cobalt nitrate and aluminum nitrate is 1:0.8:0.08, recorded as solution A; Step 2: Add silicon source (silica sol), alkali source (NaOH), solution A, 1,6-hexanediamine (template), pore-forming agent (carbon black), and seed crystals into deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal it, and place it in a homogeneous reactor, and crystallize it at 160°C and autogenous pressure for 40 hours; Cobalt source is expressed as CoO, aluminum source is expressed as Al 2 O 3 In step 2, the silicon source is SiO 2 The alkali source is OH - The molar ratio of silicon source, aluminum source, cobalt source, 1,6-hexanediamine (template), alkali source, and deionized water is 1: 0.017: 0.2: 0.2: 0.3: 45, carbon black is 5wt.% of the silicon source, and the amount of seed added is 2wt.% of the silicon source (based on SiO 2 count).

[0024] Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry (normal temperature, the drying temperature not specified in the present invention is normal temperature), and calcine at 500°C for 20h to obtain the acidity adjustable catalyst 10Co / ZSM-22 for one-step synthesis of aviation kerosene from syngas, which is denoted as CZ5.

[0025] The above catalyst was treated with 1 M NH 4 Cl was ion exchanged at 80°C for 3 h, filtered, washed to neutrality, calcined at 400°C for 10 h, and then used in synthesis gas conversion reaction. Catalyst evaluation conditions: CO / H 2 =2, P = 2MPa, GHSV = 2000ml g -1 ·h -1 , 280℃.

[0026] The CO conversion rate and the selectivity of hydrocarbon products can be calculated using the following formula: CO conversion rate:

[0027] Product selectivity: S i =

[0028] in, Nco,in is the mole number of CO in the feed gas; N co,out is the molar number of CO in the tail gas; i, j are the carbon numbers of different hydrocarbons in the product (j = 1, 2, 3, ...); W i is the mass of hydrocarbons.

[0029] Figure 1 This is the XRD spectrum of Example 1. There is no diffraction peak of Co oxide, indicating that the cobalt species is highly dispersed on the surface of the molecular sieve. Figure 2 The XRD spectrum of Example 2 shows Co 3 O 4 The characteristic diffraction peaks of zeolite indicate that the cobalt species are partially aggregated on the surface of the molecular sieve.

Claims

1. A method for preparing a catalyst with adjustable acidity for one-step synthesis of aviation kerosene from synthesis gas, characterized in that Proceed as follows: Step 1, dissolving ethylenediaminetetraacetic acid (EDTA), aluminum source, and cobalt source in deionized water to form a complex, which is referred to as solution A; Step 2: Add silicon source, alkali source, solution A, template, pore-forming agent and seed crystal to deionized water in sequence, stir to form a uniform gel, transfer to a high-pressure reactor, seal and place in a homogeneous reactor, and react at 140-200° C. and autogenous pressure for 20-72 hours; Step 3: Separate the solid product of step 2, wash with deionized water, filter, dry, and calcine at 400-600° C. for 10-40 h to obtain an acid-adjustable catalyst for one-step synthesis of aviation kerosene from synthesis gas.

2. The method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step according to claim 1, characterized in that: In step 1, the molar number of ethylenediaminetetraacetic acid (EDTA) is 1.1-2 times the sum of the molar numbers of the aluminum source and the cobalt source, so that Al 3+ and Co 2+ All form complexes with ethylenediaminetetraacetic acid (EDTA).

3. The method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step according to claim 1, characterized in that: In step 1, the aluminum source is Al(NO3)3·9H2O, and the cobalt source is Co(NO3)2·6H2O.

4. The method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step according to claim 1, characterized in that: In step 1, the cobalt source is calculated as CoO, the aluminum source is calculated as Al2O3, in step 2, the silicon source is calculated as SiO2, and the alkali source is calculated as OH - The molar ratio of silicon source, aluminum source, cobalt source, template, alkali source and deionized water is 1:0-0.5: 0.005-0.03:0.2-0.5:0.1-0.4:20-65.

5. The method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step according to claim 1, characterized in that: In step 2, the silicon source is one or a mixture of silica sol, white carbon black, and ethyl orthosilicate, the alkali source is one or two of KOH and NaOH, and the template agent is one or a mixture of 1-ethylpyridinium bromide, 1,6-hexanediamine, and diethylamine.

6. The method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step according to claim 1, characterized in that: In step 2, the pore-forming agent is one or a mixture of ethyl cellulose, carbon black, and PEG-6000, and the proportion of the pore-forming agent is 2 wt.%-10 wt.% of the silicon source.

7. The method for preparing a catalyst with adjustable acidity for preparing aviation kerosene from synthesis gas in one step according to claim 1, characterized in that: The seed crystal is all-silicon ZSM-22, and its mass accounts for 1wt.%-8wt.% of the silicon source.

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