Catalyst used for producing dimethyl ether through methanol dehydration, and preparation method thereof

A technology of methanol dehydration and catalyst, which is applied in the direction of ether preparation, dehydration of hydroxyl-containing compounds to prepare ether, chemical instruments and methods, etc. It can solve the problems of easy carbon deposition, many by-products, high reaction temperature, etc., and achieve strong anti-carbon deposition ability, High activity and good selectivity at low temperature

Active Publication Date: 2015-05-06
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, the catalyst used for methanol dehydration is generally Al 2 o 3 Or molecular sieves, among which the commonly used molecular sieves include aluminum phosphate, HZSM-5, HY, SAPO, etc., and they all have their own shortcomings: for example, although alumina has high stability, the reaction temperature is high, and the requirements for reaction equipment are very high, resulting in cost High; molecular sieve catalysts have strong acidity and low initial temperature, but they also have the disadvantages of many by-products, easy carbon deposition, and easy deactivation
The above-mentioned catalysts have high catalytic activity and selectivity in the reaction, and the optimal load of silicotungstic acid is 10wt%~16wt%. Under normal pressure, when used to treat pure methanol raw materials, its selectivity is high, but Its low-temperature activity is not good, and when it is used as a methanol raw material containing water, its stability is not good, and the selectivity and activity also decrease.

Method used

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  • Catalyst used for producing dimethyl ether through methanol dehydration, and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] (1) Preparation of carrier:

[0035] Weigh 145.8g of cetyltrimethylammonium bromide and 205g of citric acid to make a mixed solution, add 302mL tetraethyl orthosilicate to the mixed solution, stir for 2 h, and then stir at 70°C until coagulation The gel was aged at room temperature for 12 h, then dried at 110 °C for 8 h, and calcined at 600 °C for 3 h to obtain a silica support, in which the molar ratio of cetyltrimethylammonium bromide to silica was 0.3, and the molar ratio of citric acid to silicon oxide is 0.8. The nature of the carrier is: the specific surface area is 533 m 2 / g, the pore volume is 0.65 mL / g, and the average pore diameter is 4.9 nm.

[0036] (2) Preparation of catalyst:

[0037]Add the prepared silica carrier into a C6 alkane solvent, soak for 10min, then filter, and dry at room temperature until there is no liquid phase on the surface of the carrier; then add it into an aqueous solution containing 25.6g of citric acid, and stir at 70°C until the...

Embodiment 2

[0043] (1) Preparation of carrier:

[0044] Weigh 200g of cetyltrimethylammonium bromide and 105.7g of citric acid to make a mixed solution, add 250mL tetraethyl orthosilicate into the mixed solution, stir for 2 h, and then stir at 70°C until coagulation The gel was aged at room temperature for 12 h, then dried at 110 °C for 8 h, and calcined at 600 °C for 3 h to obtain a silica support, in which the molar ratio of cetyltrimethylammonium bromide to silica was 0.5, the molar ratio of citric acid to silicon oxide is 0.5. The nature of the carrier is: the specific surface area is 570 m 2 / g, the pore volume is 0.72 mL / g, and the average pore diameter is 5.1 nm.

[0045] (2) Preparation of catalyst:

[0046] Add the prepared silica carrier into a C6 alkane solvent, soak it for 10min, then filter it, and dry it at room temperature until there is no liquid phase on the surface of the carrier; then add it into an aqueous solution containing 42.3g of citric acid, and stir at 70°C u...

Embodiment 3

[0049] (1) Preparation of carrier:

[0050] Weigh 316g of cetyltrimethylammonium bromide and 62.4g of citric acid to form a mixed solution, add 246mL tetraethyl orthosilicate into the mixed solution, stir for 2 h, and then stir at 70°C until coagulation The gel was aged at room temperature for 12 h, then dried at 110 °C for 8 h, and calcined at 600 °C for 3 h to obtain a silica support, in which the molar ratio of cetyltrimethylammonium bromide to silica was 0.8, and the molar ratio of citric acid to silicon oxide is 0.3. The nature of the carrier is: the specific surface area is 612 m 2 / g, the pore volume is 0.76 mL / g, and the average pore diameter is 5.0 nm.

[0051] (2) Preparation of catalyst:

[0052] Add the prepared silica carrier into a C6 alkane solvent, soak it for 10min, then filter, and dry at room temperature until there is no liquid phase on the surface of the carrier; then add it into an aqueous solution containing 62.4g of citric acid, and stir at 70°C unti...

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Abstract

The invention discloses a catalyst used for producing dimethyl ether through methanol dehydration, and a preparation method thereof. The catalyst comprises an active component, an auxiliary agent and a carrier. The active component is heteropoly acid ammonium salt. The auxiliary agent is lanthanum oxide and/or cerium oxide. The carrier is silicon oxide. The preparation method comprises the following steps: alkane, an organic acid, and an ammonium-containing alkaline solution or ammonia gas are sequentially loaded on the silicon oxide carrier; heteropoly acid and the auxiliary agent are loaded on the carrier; and drying and roasting are carried out, such that the catalyst is obtained. The catalyst provided by the invention has relatively high low-temperature activity, selectivity and coking resistance. Also, the stability of the catalyst is improved. The catalyst provided by the invention is especially suitable for a reaction for producing dimethyl ether with a methanol raw material with relatively high water content.

Description

technical field [0001] The invention relates to a catalyst for methanol dehydration to produce dimethyl ether and a preparation method thereof, in particular to a loaded heteropolyacid ammonium salt catalyst for methanol dehydration to produce dimethyl ether and a preparation method thereof. Background technique [0002] Dimethyl ether (Dimethy Ether, abbreviated as DME) is a colorless, non-toxic gas at normal temperature and pressure, which can be compressed into a liquid. Dimethyl ether is an important organic chemical raw material and chemical intermediate, which can be used in aerosols, refrigerants, alkylating agents, pharmaceuticals, cosmetics, fuels and other industries. [0003] Dimethyl ether was first produced by rectification of by-products in high-pressure methanol production, and soon developed into two processes of methanol dehydration and direct synthesis of synthesis gas. The liquid-phase method of methanol dehydration to produce dimethyl ether, the reaction...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J31/26C07C43/04C07C41/09
Inventor 金浩孙素华朱慧红刘杰杨光
Owner CHINA PETROLEUM & CHEM CORP
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