CN103121954B

CN103121954B - Method for preparing allyl acetate

Info

Publication number: CN103121954B
Application number: CN201110369544.1A
Authority: CN
Inventors: 刘军晓; 杨运信; 张丽斌
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2011-11-18
Filing date: 2011-11-18
Publication date: 2014-08-13
Anticipated expiration: 2031-11-18
Also published as: CN103121954A

Abstract

The invention relates to a method for preparing allyl acetate, and is mainly used for solving the problems that in the prior art, the space-time yield and the selectivity are lower. The preparation method of allyl acetate comprises the following steps of: contacting propylene, acetic acid, oxygen and water as raw materials with a catalyst to obtain a reaction product containing allyl acetate, wherein the catalyst comprises SiO2, Al2O3 or a mixture thereof as a carrier and the active components of 1-12g/L of palladium, 0.1-9g/L of gold and 10-90g/L of alkali metal acetate; and the average grain diameter of crystalline grains of palladium and gold is 4-9nm, and the crystalline grains in a range of +/-20% of the average grain diameter account for 60-81% of all crystalline grains. The problems are better solved by the technical scheme, and the method can be applied to industrial production of allyl acetate.

Description

Prepare the method for allyl acetate

Technical field

The present invention relates to a kind of method of preparing allyl acetate.

Background technology

Allyl acetate is important industrial chemicals, of many uses.The main method of producing allyl acetate in the world today is taking propylene, oxygen and acetic acid as raw material, synthesizes by gas phase catalytic reaction.For obtaining the catalyzer of high space time yield, highly selective, constantly improve at aspects such as active ingredient composition, preparation technology and even the shapes of catalyzer always.

The Chinese patent application (application number 200880011926.3) of Showa Denko K. K provides a kind of and prepares load and have the preparation method of the catalyzer of Primary Catalysts precious metal, promoter metal and basic metal or alkaline earth metal compound.Its concrete manufacturing processed is as follows: (1), in the steeping vat of rotation, adds the mixed solution of the precious metal configuring and promotor, passes into hot-air dry extremely; (2) get a certain amount of solution with alkaline matters such as water glass and make an addition in dried catalyzer, the palladium of original water soluble and golden salt are changed into palladium and the gold of the insoluble hydroxide state of water; (3) in reducing gas, reduce palladium and the Au catalyst of hydroxide state, be reduced into palladium and the Au catalyst of metallic state; (4) be washed till without chlorion, dry; (5) soak Potassium ethanoate, after being dried, obtain described catalyzer.The space time yield of the catalyzer that the method obtains and selectivity are all lower.

Summary of the invention

Technical problem to be solved by this invention is space time yield and the low problem of selectivity existing in prior art, and a kind of new method of preparing allyl acetate is provided, and this preparation method has space time yield and the high feature of selectivity.

For solving the problems of the technologies described above, technical scheme of the present invention is as follows: a kind of preparation method of allyl acetate, with the reaction raw materials of propylene, acetic acid, oxygen, water composition, under 130～200 DEG C of temperature of reaction and 0.5～0.9MPa reaction pressure, contact catalyst obtains the reaction product that contains allyl acetate, the mol ratio of various reaction raw materials is oxygen: propylene: nitrogen: acetic acid=1: 5～7: 4～8: 1～2, and described catalyzer is with SiO ₂, Al ₂o ₃or its mixture is carrier, load active component comprises palladium metal, metallic gold and alkali metal acetate, in catalyzer, the content of palladium is that the content of 1～12g/L, gold is that the content of 0.1～9g/L, alkali metal acetate is 10～90g/L, the crystal grain median size that it is characterized in that described porpezite is 4～9nm, and the number of the crystal grain in median size ± 20% scope accounts for whole crystal grain 60～81%.

In technique scheme, the crystal grain median size of described porpezite is preferably 5～7nm; The number of the crystal grain in median size ± 20% scope preferably accounts for whole crystal grain 75～81%; Described alkali metal acetate is preferably Potassium ethanoate; Described temperature of reaction is preferably 140～160 DEG C; Described reaction pressure is preferably 0.6～0.8MPa.

Compared with prior art, catalyzer preparation of the present invention has adopted the method load active component of liquid carbon dioxide dipping, the feature that in the catalyzer that makes to prepare, the size of microcrystal of porpezite is evenly distributed, thus space time yield and the selectivity of catalyzer can be improved.Experimental result shows, reaction pressure is 0.7MPa, 140 DEG C of temperature of reaction, when reactant gases comprises the nitrogen, the acetic acid of 10% mol ratio of propylene, 43% mol ratio of 41% mol ratio and the oxygen of 6% mol ratio, the space time yield of catalyzer of the present invention is brought up to 417g/Lhr by the 375g/Lhr of prior art catalyzer, selectivity has also improved 3.6%, has obtained good technique effect.

Below by embodiment, the present invention is further elaborated.

Embodiment

[embodiment 1]

(1) catalyzer preparation

Step (a): getting the liquid carbon dioxide solution 1200ml that contains hexafluoroacetylacetone palladium (II) and dimethyl (trifluoroacetylacetone) gold (III) is steeping fluid, the palladium content 2.75g/L of this steeping fluid, gold content 0.625g/L, the preparing spherical SiO 2 carrier that floods 1100ml diameter and be 4～6mm under the dipping temperature of the impregnation pressure of 69MPa and 28 DEG C obtains catalyst precursor I;

Step (b): then decompression, with the liquid carbon dioxide in the speed evaporation catalyst precursor I of 0.3ml (liquid carbon dioxide)/min, until liquid carbon dioxide evaporates, obtains catalyst precursor II;

Step (c): catalyst precursor II is reduced in hydrogen atmosphere, and hydrogen flow rate is 0.2ml/min, and reduction temperature is 75 DEG C, obtains catalyst precursor III;

Step (d): the liquor kalii acetici 450ml that is 0.1g/ml by concentration infiltrates catalyst precursor III 5hr is then dried to obtain catalyzer finished product at 60 DEG C.

The main preparation condition of catalyzer is listed in table 1.

(2) physical property characterizes

Use inductively coupled plasma spectrum generator (ICP) to measure porpezite metal content in finished catalyst, adopt electronic transmission Electronic Speculum (TEM) that the size of microcrystal of palladium is measured and counted.The physical property of catalyzer is listed in table 2.

(3) catalyst performance evaluation

Use fixed-bed reactor evaluation, actual conditions is:

Catalyst loading volume: 700ml;

Reaction raw materials composition (with molar ratio computing): oxygen: propylene: nitrogen: acetic acid=1: 6.8: 7.2: 1.7;

Unstripped gas air speed: 2000hr ^-1;

Reaction pressure: 0.7MPa;

Temperature of reaction: 140 DEG C;

Reaction times: 500hr.

With the content of each component in gc analysis reaction product, then calculate space time yield and the selectivity of catalyzer.

Table 3 has been listed the appreciation condition of catalyzer, space time yield and selective data.

[embodiment 2]

Except other step increasing calcination steps between step (c) and step (d) all identical with embodiment 1.Wherein calcination steps is: catalyst precursor III roasting under nitrogen/acetic acid atmosphere, and wherein acetic acid divides and covers 5% of total pressure, and maturing temperature is 250 DEG C, and roasting time is 24hr.List in table 1 for ease of the preparation condition of catalyzer more just, the physical data of catalyzer is listed in to table 2, appreciation condition, space time yield and the selective data of catalyzer are listed in table 3.

[embodiment 3～14]

In changing liquid carbon dioxide steeping fluid, concentration, impregnation pressure, dipping temperature, reducing gas, reduction temperature, reaction raw materials mol ratio, unstripped gas air speed, reaction pressure and the temperature of reaction of the kind of the concentration of porpezite, porpezite compound, liquor kalii acetici, other operation steps is all identical with embodiment 2.List in table 1 for ease of the preparation condition of catalyzer more just, the physical data of catalyzer is listed in to table 2, appreciation condition, space time yield and the selective data of catalyzer are listed in table 3.

[comparative example 1]

Get and contain H ₂pdCl ₄and HAuCl ₄aqueous solution 1000ml be steeping fluid, wherein in solution, palladium content is 2.75g/L, gold content is 0.625g/L, the preparing spherical SiO 2 carrier that dipping 1100ml diameter is 4～6mm obtains catalyst precursor; 27.5g nine hydrated sodium silicates are made into the 100ml aqueous solution and are added in above-mentioned catalyst precursor, shake to avoid caking, leaves standstill 24hr, then successively at 80 DEG C of dry 8hr for several times.

The hydrazine hydrate 30ml that is 85wt% by concentration infiltrates dried product and reduces, and the recovery time is 5hr, and the 450ml liquor kalii acetici that is then 0.1g/ml with concentration mixes, and leaves standstill 5hr, is dried to obtain catalyzer finished product at 60 DEG C.The method of evaluating performance of catalyzer physical property sign and catalyzer is with embodiment 2.List in table 1 for ease of the preparation condition of catalyzer more just, the physical data of catalyzer is listed in to table 2, appreciation condition, space time yield and the selective data of catalyzer are listed in table 3.

[comparative example 2]

Get and contain H ₂pdCl ₄and HAuCl ₄aqueous solution 1000ml be steeping fluid, wherein in solution, palladium content is 2.75g/L, gold content is 0.625g/L, the preparing spherical SiO 2 carrier that dipping 1100ml diameter is 4～6mm obtains catalyst precursor; 27.5g nine hydrated sodium silicates are made into the 100ml aqueous solution and are added in above-mentioned catalyst precursor, shake to avoid caking, leaves standstill 24hr, then successively at 80 DEG C of dry 8hr for several times.Dried product is reduced in hydrogen atmosphere, and hydrogen flow rate is 0.2ml/min, and reduction temperature is 75 DEG C, is down to room temperature, and the 450ml liquor kalii acetici that is 0.1g/ml with concentration mixes, and leaves standstill 5hr, is dried to obtain catalyzer finished product at 60 DEG C.The method of evaluating performance of catalyzer physical property sign and catalyzer is with embodiment 2.List in table 1 for ease of the preparation condition of catalyzer more just, the physical data of catalyzer is listed in to table 2, appreciation condition, space time yield and the selective data of catalyzer are listed in table 3.

Table 1 catalyzer preparation condition

Table 2 catalyzer physical data

Table 3 evaluating catalyst data

Claims

1. a preparation method for allyl acetate, step is as follows:

(1) catalyzer preparation

Step (b): then decompression, with the liquid carbon dioxide in the speed evaporation catalyst precursor I of 0.3ml liquid carbon dioxide/min, until liquid carbon dioxide evaporates, obtains catalyst precursor II;

Catalyst precursor III roasting under nitrogen/acetic acid atmosphere, wherein acetic acid divides and covers 5% of total pressure, and maturing temperature is 250 DEG C, and roasting time is 24hr;

Step (d): the liquor kalii acetici 450ml that is 0.1g/ml by concentration infiltrates catalyst precursor III5hr is then dried to obtain catalyzer finished product at 60 DEG C;

(2) physical property characterizes

Use inductively coupled plasma spectrum generator to measure porpezite metal content in finished catalyst, adopt electronic transmission Electronic Speculum that the size of microcrystal of palladium is measured and counted; The physical data of catalyzer is as follows: palladium content is 3.0g/L, and gold content is 0.64g/L, and Potassium ethanoate content is 30g/L, and porpezite crystal grain median size is 6.7nm, and the percentage ratio that the number of the crystal grain in median size ± 20% scope accounts for whole number of dies is 81%;

(3) allyl acetate is synthetic

With fixed-bed reactor, actual conditions is:

Catalyst loading volume: 700ml;

Reaction raw materials forms with molar ratio computing: Yang Qi ︰ Bing Xi ︰ Dan Qi ︰ acetic acid=1 ︰ 6.8 ︰ 7.2 ︰ 1.7;

Unstripped gas air speed: 2000hr ^-1;

Reaction pressure: 0.7MPa;

Temperature of reaction: 140 DEG C;

Reaction times: 500hr;

With the content of each component in gc analysis reaction product, then calculate space time yield and the selectivity of catalyzer, space time yield is 417g/Lhr, selectivity is 97.6%.