A kind of preparation method of methanol system p-xylene catalyst

Abstract

The invention discloses a catalyst method for producing paraxylene from methanol, using dioxane, mesitylene, glacial acetic acid, COF‑1 nanomaterials, FeSO 4 ·7H 2 O.KBH 4 As the main raw material, a unique process and technical parameters are adopted. Thermal expansion-amino modification-nano-iron reaction generates a load. After thermal expansion treatment, the surface adhesion performance of COF‑1 is improved, which provides the basis for subsequent amino modification. After amino modification , the surface properties are improved, which is conducive to the nano-iron generated by the reaction being fully and evenly loaded on the porous carrier. The present invention obtains paraxylene through the methanol alkylation reaction, eliminating the isomerization and other steps in the traditional process. Process route shortened, and the single-pass yield of paraxylene was greatly increased.

Description

technical field

[0001] The invention relates to a catalyst for producing p-xylene from methanol and a preparation method thereof, belonging to the technical field of catalysts. Background technique

[0002] P-xylene is an extremely important bulk chemical raw material, mainly used in the production of terephthalic acid and dimethyl terephthalate. Due to the rapid development of my country's polyester industry, the consumption of p-xylene has also increased rapidly. In industry, p-xylene is generally produced by separating aromatics from petroleum cracking products, disproportionating toluene, or transalkylating heavy aromatics. Because these methods produce a large amount of benzene by-product, and the economic value of benzene is low, it affects p-xylene to a certain extent. Economics of the toluene production process. The traditional method mostly adopts fixed bed technology, the bed temperature is not uniform, the catalyst is poor in stability, easy to deactivate and di...

Examples

Embodiment 1

[0016] A method for preparing a catalyst for producing p-xylene from methanol, comprising the following steps:

[0017] Step 1. Freeze-dry 100g of COF-1 nanomaterials and pulverize them, place them in a tube furnace, blow nitrogen gas for 10min, flow rate is 0.5L / min, and rapidly raise the temperature to 350°C and keep the constant temperature for 5h to obtain a thermally expandable porous material;

[0018] Step 2, put the above COF-1 nanomaterials in 1mol / L dilute hydrochloric acid, stir at constant temperature, and filter to obtain a solid; take 100g of the solid, add a mixed solution of 50ml concentrated sulfuric acid and 50ml concentrated nitric acid in a volume ratio, and then mechanically stir for 4 hours , suction filtration,

[0019] wash and dry;

[0020] Step 3. Add the above-mentioned dried product into 25ml of ammonia water, mechanically stir for 15 minutes, add 25g of sodium dithionite, stir at a constant speed for 24 hours, filter with suction, wash and dry to ...

Embodiment 2

[0027] Step 4. Take 20g of amino-modified COF-1 nanomaterials, add 160ml of alcohol-water mixed system containing 15gFeSO4•7H2O and 5g of PEG-4000, wherein the volume ratio of water and absolute ethanol is 1:2, and inject high-purity nitrogen, While stirring at a constant speed, 30 ml of KBH4 solution with a concentration of 0.5 mol / L was added dropwise, then continued to stir for 20 min, and vacuum freeze-dried to obtain nano-iron-loaded amino-modified COF-1 catalyst. All the other steps are the same as in Example 1.

Embodiment 3

[0029] Step 4. Take 10g of amino-modified COF-1 nanomaterials, add 160ml of alcohol-water mixed system containing 15gFeSO4•7H2O and 5g of PEG-4000, wherein the volume ratio of water and absolute ethanol is 1:2, and inject high-purity nitrogen, While stirring at a constant speed, 30 ml of KBH4 solution with a concentration of 0.5 mol / L was added dropwise, then continued to stir for 20 min, and vacuum freeze-dried to obtain nano-iron-loaded amino-modified COF-1 catalyst. All the other steps are the same as in Example 1.

technical field

[0001] The invention relates to a catalyst for producing p-xylene from methanol and a preparation method thereof, belonging to the technical field of catalysts. Background technique

[0002] P-xylene is an extremely important bulk chemical raw material, mainly used in the production of terephthalic acid and dimethyl terephthalate. Due to the rapid development of my country's polyester industry, the consumption of p-xylene has also increased rapidly. In industry, p-xylene is generally produced by separating aromatics from petroleum cracking products, disproportionating toluene, or transalkylating heavy aromatics. Because these methods produce a large amount of benzene by-product, and the economic value of benzene is low, it affects p-xylene to a certain extent. Economics of the toluene production process. The traditional method mostly adopts fixed bed technology, the bed temperature is not uniform, the catalyst is poor in stability, easy to deactivate and di...

Examples

Embodiment 1

[0016] A method for preparing a catalyst for producing p-xylene from methanol, comprising the following steps:

[0017] Step 1. Freeze-dry 100g of COF-1 nanomaterials and pulverize them, place them in a tube furnace, blow nitrogen gas for 10min, flow rate is 0.5L / min, and rapidly raise the temperature to 350°C and keep the constant temperature for 5h to obtain a thermally expandable porous material;

[0018] Step 2, put the above COF-1 nanomaterials in 1mol / L dilute hydrochloric acid, stir at constant temperature, and filter to obtain a solid; take 100g of the solid, add a mixed solution of 50ml concentrated sulfuric acid and 50ml concentrated nitric acid in a volume ratio, and then mechanically stir for 4 hours , suction filtration,

[0019] wash and dry;

[0020] Step 3. Add the above-mentioned dried product into 25ml of ammonia water, mechanically stir for 15 minutes, add 25g of sodium dithionite, stir at a constant speed for 24 hours, filter with suction, wash and dry to ...

Embodiment 2

[0027] Step 4. Take 20g of amino-modified COF-1 nanomaterials, add 160ml of alcohol-water mixed system containing 15gFeSO4•7H2O and 5g of PEG-4000, wherein the volume ratio of water and absolute ethanol is 1:2, and inject high-purity nitrogen, While stirring at a constant speed, 30 ml of KBH4 solution with a concentration of 0.5 mol / L was added dropwise, then continued to stir for 20 min, and vacuum freeze-dried to obtain nano-iron-loaded amino-modified COF-1 catalyst. All the other steps are the same as in Example 1.

Embodiment 3

[0029] Step 4. Take 10g of amino-modified COF-1 nanomaterials, add 160ml of alcohol-water mixed system containing 15gFeSO4•7H2O and 5g of PEG-4000, wherein the volume ratio of water and absolute ethanol is 1:2, and inject high-purity nitrogen, While stirring at a constant speed, 30 ml of KBH4 solution with a concentration of 0.5 mol / L was added dropwise, then continued to stir for 20 min, and vacuum freeze-dried to obtain nano-iron-loaded amino-modified COF-1 catalyst. All the other steps are the same as in Example 1.

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