Catalyst used for synthesizing diethyl carbonate from urea and ethanol, preparation method and application thereof

Abstract

The invention relates to a catalyst used for synthesizing diethyl carbonate from urea and ethanol. The catalyst is a solid alkaline catalyst and is prepared through a precipitation method or a coprecipitation method. A preparation method includes following steps: preparing an aqueous solution from soluble metal salt of alkaline-earth metals, transition metals and other metals; adding dropwisely a certain amount of a precipitating agent with a pH value being adjusted to between 8-12 to obtain a precursor; drying the precursor at 50-150 DEG C for 2-24 hours; and then calcining the precursor at 200-1000 DEG C for 2-10 hours. The catalyst is simple in preparation, is high in activity, is environmental-friendly, is easy to separate and recycle and is good in stability.

Description

[0001] technology field,

[0002] The invention relates to a catalyst and its preparation method and application, in particular to a solid base catalyst for synthesizing diethyl carbonate from urea and ethanol, its preparation method and application. technical background

[0003] Diethyl carbonate, referred to as DEC, contains carbonyl, ethoxy, and ethyl groups in the molecule, which have good reactivity. A series of important organic chemical products are derived from the reaction. DEC itself is a low-toxic substance, which will slowly hydrolyze when released into the environment to generate ethanol and carbon dioxide, and will not pollute the environment. Therefore, it is an environmentally friendly chemical. It is used in solvents, electrolytes, organic synthesis, pharmaceuticals and engineering plastics, etc. Fields are widely used. The oxygen content of 40.6% of diethyl carbonate is much higher than that of methyl tert-butyl ether (MTBE) (18.2%). As an oxygen-containing...

Examples

Embodiment 1

[0024] Take 25.981g La(NO 3 ) 3 In a beaker, add 400mL deionized water, stir and heat to 60°C, add ammonia water dropwise until the pH value is 9-10, continue to stir for 3 hours, age, filter and wash until neutral, dry at 80°C, and calcine at 500°C for 4 hours . Prepared solid base La 2 o 3 .

Embodiment 2

[0026] In the autoclave, add 2.060g urea, 20mL absolute ethanol, the catalyst prepared in 0.350g example 1, exhaust the air in the kettle with nitrogen, stir and heat up, control the reaction temperature to be 210°C, the pressure is 2.2MPa, and the rotating speed is 550r / min, reacted for 3 hours, the obtained results are shown in Table 1.

Embodiment 3

[0028] Take 50mL of deionized water and heat it to 65°C, slowly add 0.15mol of Mg(NO 3 ) 2 and 0.05mol of AL(NO 3 ) 3 The mixed solution of 150mL, 2.0mol / L (NH 4 ) 2 CO 3 Solution 150mL, adjust the pH value between 9-10 with 25% ammonia water after the dropwise addition, stir and react at 65°C for 3 hours, filter, wash until neutral, dry at 100°C for 12 hours, and then calcined at 450°C for 3 hours . Prepared solid base Mg x AL y o x+3y / 2 (x:y=1:1‐3:1).

[0001] technology field,

[0002] The invention relates to a catalyst and its preparation method and application, in particular to a solid base catalyst for synthesizing diethyl carbonate from urea and ethanol, its preparation method and application. technical background

[0003] Diethyl carbonate, referred to as DEC, contains carbonyl, ethoxy, and ethyl groups in the molecule, which have good reactivity. A series of important organic chemical products are derived from the reaction. DEC itself is a low-toxic substance, which will slowly hydrolyze when released into the environment to generate ethanol and carbon dioxide, and will not pollute the environment. Therefore, it is an environmentally friendly chemical. It is used in solvents, electrolytes, organic synthesis, pharmaceuticals and engineering plastics, etc. Fields are widely used. The oxygen content of 40.6% of diethyl carbonate is much higher than that of methyl tert-butyl ether (MTBE) (18.2%). As an oxygen-containing...

Examples

Embodiment 1

[0024] Take 25.981g La(NO 3 ) 3 In a beaker, add 400mL deionized water, stir and heat to 60°C, add ammonia water dropwise until the pH value is 9-10, continue to stir for 3 hours, age, filter and wash until neutral, dry at 80°C, and calcine at 500°C for 4 hours . Prepared solid base La 2 o 3 .

Embodiment 2

[0026] In the autoclave, add 2.060g urea, 20mL absolute ethanol, the catalyst prepared in 0.350g example 1, exhaust the air in the kettle with nitrogen, stir and heat up, control the reaction temperature to be 210°C, the pressure is 2.2MPa, and the rotating speed is 550r / min, reacted for 3 hours, the obtained results are shown in Table 1.

Embodiment 3

[0028] Take 50mL of deionized water and heat it to 65°C, slowly add 0.15mol of Mg(NO 3 ) 2 and 0.05mol of AL(NO 3 ) 3 The mixed solution of 150mL, 2.0mol / L (NH 4 ) 2 CO 3 Solution 150mL, adjust the pH value between 9-10 with 25% ammonia water after the dropwise addition, stir and react at 65°C for 3 hours, filter, wash until neutral, dry at 100°C for 12 hours, and then calcined at 450°C for 3 hours . Prepared solid base Mg x AL y o x+3y / 2 (x:y=1:1‐3:1).