SU823380A1 - Method of producing acrolenin or methylacrolein - Google Patents

Description

(54) METHOD FOR OBTAINING ACROLEIN. OR METHYLACROLEIN

This invention relates to organic synthesis, specifically to methods for producing acrolein or methylaclaine, which are widely used in industrial organic synthesis, in particular for the preparation of methionine, glycerin, acrylic or methacrylic acid, and esters, etc. The method for the production of acrol by oxidation of propylene is known. using an oxide cobalt-molybdenum bismuth iron catalyst with an acrolein yield of missed propylene 70-75% 1. A method is known for producing ° C, oxidized aldehydes and acids is oxidized it .or propylene isobutylene with molecular oxygen or gas with the use koslorodsoderzhaschim vaniem molibdenvismut oxide-cobalt-iron or kobssht molybdenum-bismuth-iron-chromium catalysts. At 400 ° С conversion of propylene on them is 96-98%. At the same time, the yield of acroleing reaches 50-55%, and the yield of acrylic acid is 30-32%. When oxidizing isobutyne on the same catalysts at 410 ° C, conversion of olefin to 90% with a yield of methylacrolein 50-60% and methacrylic acid 12-16% 21 and 3. Also known is a method of obtaining oi, p) -necane endehyde aldehydes and acids by oxidation of propylene or isobutylene using cobaltmolybdenum-bismuth-iron catalysts modified with an alkali metal oxide compound or a mixture thereof. At 380 ° C conversion of propylene or isobutylene on these catalysts reaches 97-99%. At the same time, the yield of acrolein or methylacrolein is 50-55% or 55-60%, respectively, the yield of acrylic acid is 2830%, and methacrylic acid is 1518% 4. The disadvantage of these processes is the low selectivity of formation of unsaturated aldehydes not exceeding 72-75%, respectively, small the yield of these substances (not higher than 70%). Other methods are also known for producing unsaturated aldehydes by oxidation of olefins using various catalysts 5. However, in most of these processes, catalysts containing volatile toxic components, for example Isla arsenic, selenium.

tellurium, and so, and the activity of most of them is quite low.

The closest to the present invention is a method for producing oh, p-unsaturated aldehydes by oxidation of propylene or eobutylene in the presence of an oxide cobap-molybdenum-bismuth-iron catalyst modified with an OXIDE4 compound of one or more alkali metals, which additionally contains an antimony oxide compound. At 380 ° C, the conversion of propylene reaches 98-99% with selectivity of formation of acrolein 82-85% (yield 80-84 and acrylic acid 2-5%. When iobutylene is oxidized under the same conditions, its conversion reaches 96-98% with selectivity the formation of methylacrolein 85-90% {yield 82-88%) and methacrylic acid 2-3% {6},

The disadvantage of this process is the relatively low selectivity in the oxidation reactions of propylene to acrolein (82-85%) and isobutylene to methyl acrolein (85-90%

The purpose of the invention is to increase the selectivity of the process and increase the yield of the target product.

The goal is achieved by agreeing to the method of producing acrolein or methylacrolein by oxidizing propylene and isobutylene with oxygen or oxygen-containing gas at 300-400 ° C in the presence of a catalyst based on oxide compounds of magnesium, cobalt, molybdenum, bismuth, iron, antimony, alkali metal, or a mixture thereof, using a catcher containing additionally an oxide compound of magnesium and having the following empirical composition.

SODMo, 2 FeaBicSb Mg MjOx, gDe M - alkali metal - lithium, sodium, potassium, rubidium, or cesium and a mixture; a 1-15; L 0.5-10; c 0, l-5; d 0.1-5; e 0.3-g5.0; f 0.01–1,, О and X is the number of atoms, oxygen in the system, corresponding to the number and valence of the metal atoms of the catalyst.

The process is preferably carried out in the presence of 10-40% by volume of water.

According to the proposed method, a pelletized catalyst is loaded into a flow reactor, through which a gas mixture containing 5-10 vol.% Of propylene or isobutylene in air at 300-400 ° C, preferably at 340-380 ° C and contact time 0.5, is passed. -5 s, preferably 2-4 s. In the gas mixture, it is desirable to have up to 20-40% by volume of water vapor. The conversion of propylene in this case reaches 98-99%. With a selectivity of the formation of acrolein of 85-90% (yield 83-89%) and acrylic acid 1.5-3%. With the oxidation of isobutylene

Its consierge reaches 97-99% with a selectivity of methylacrolein formation of 88-94% (yield 85-93%) and methacrylic acid 1-2%.

Carrying out the process in the presence of these catalysts allows increasing the yield of unsaturated aldehydes and the selectivity of their formation,

Example 1. 15 cm of oxide

Q catalyst. Fe, Co, (O45 is loaded into a stainless steel flow reactor with an inner diameter of 14 mm and a gas mixture containing 10 vol.% Isobutylene, 16 vol.% Oxygen, 63.2 vol.% Nitrogen and 10.8 vol. % water vapor. At 340 ° C and contact time 5 with isobutylene conversion is 98.5%, methyl acrolein selectivity is 88%, the yield of this aldehyde is 86.5%, and the yield of methanol of acrylic acid is 2-2.5%. the same catalyst gas mixture containing 10% by volume of propylene in air at a rate of 12.5 l / h, conversion of olefin at

5 is 95%, and the acrolein selectivity is 92.5%. The yield of acrolein reaches 88%.

Example 2. 15 cm of the oxide catalyst Co4Mo jBis Sbo.Fe, eMgg, IA

 load into the flow reactor willows

the conditions of example 1 with and

contact time 3 s, convert

 isobutylene 96% and selectivity

methylacrolein 76%. Output

 methacrylic acid not more than .3-4%,

and unsaturated aldehyde - 73%.

Example 3. 15 cm of oxide catalysts. Co-Mo, 2 MD Cad5 O5d153 are loaded into a flow reactor and in the conditions of Example 1 at

0 and contact time 3 cconversion, isobutylene, 99%, selectivity for methylacrolein 73.3% and methacrylic acid 6.6%. The output of unsaturated aldehyde of 72.5%.

5 Example 4. 15 cm of the oxide catalyst, Mg, 1C, MF) 7 6 are loaded into the flow reactor and in the conditions of example 1 at 360 ° C and a contact time of 3 s, convert

l isobutylene 97%, the selectivity for methylacrolein 74,5% and methacrylic acid to 6.5%. The output of unsaturated aldehyde 72%.

Example 5.15 cm of an oxide catcher, Mg2Nafl, is loaded into a flow reactor and under conditions of example 1 at 375 ° C and a contact time of 3 s, isobutylene conversion of 99%, methylacrolein selectivity of 73.2% and methacrylic

0 acid 6.2%. The output of unsaturated aldehyde of 72.5%.

Claims (6)

Example 6. 15 cm of an oxide catalyst, jFe Bi,) si, e are loaded into the flow reactor and under conditions of example 1 at 370 ° C and contact time 2 s, conversion of isobutane 95%, selectivity p methylacrolein 93%, and methacrylic acid 2.1%, The yield of unsaturated aldehyde reaches 88.5 |. Example 7. 15 cm of the oxide catalyst With MoijFe Bi sb4Mg Cso. O4t.blogs into the flow reactor and under the conditions of example 1 with a contact time of 2 s, isobutylene conversion of 98%, methylacrolein selectivity of 91.5% and methacrylic acid of 2.5%. The output of unsaturated aldehyde reaches 90%. Under the same conditions, a gas mixture containing 8 vol% propylene, 80 vol% air and 12 vol% water vapor is passed over this catalyst, olefin conversion is 99%, acrolein selectivity is 91%, and acrylic acid yield 4.2% and acrolein 90%. Example 8. Catalyst 15 cm of an oxide catalyst, fig Ц, оа0 K о, СSq, O5 is loaded into a straight reactor and, under the conditions of Example 1, with contact time 3 with isobutylene conversion of 99%, methyl acrolein selectivity 90% and methacrylate acid 2.2%. The output of unsaturated aldehyde reaches 89%. Example 9. 15 cm of the oxide catalyst CoeMOi2 Fe ,, (Ko loaded into the reactor of example 1 prn 380 ° C and contact time 3 s pass a gas mixture containing 8 vol.% Isobutylene in air. Under these conditions, the olefin conversion is 99% selectivity to 89% methacrylate acid and 2.1% methacrylic acid. You run an unsaturated rate of 88%. Example 10. A 15 cm catalyst catalyst of Example 3 is loaded into the reactor and at a time of about 3 seconds, a gas mixture containing 6% by volume, isobutylene, 40 vol.% of water vapor and 54 vol.% of air. At the same time, conversion of olefin to 99%, selectivity for methacrolein 9 2% and methacrylic acid 2.3%. Output of unsaturated aldehyde 91%. Claim 1. Technique for producing acrolein or methylacrolein by oxidation of propylene or isobutylene with oxygen or oxygen-containing gas at 300-400 C in the presence of a catalyst based on oxide compounds of cobalt, molybdenum, bismuth , iron, antimony, alkali metal or mixtures thereof, characterized in that, in order to improve the process selectivity and increase the yield of the target product, a catalyst is used, which additionally contains magnesium oxide compound and has The following empirical composition is SODMo, 2 Fe in B ig Sbj M, .0, where M is an alkali metal — lithium, sodium, kegshy, rubidium, cesium or their mixture; a 1-15; L 0.5-10; c 0.1-5; c1 0.1-5 e 0.3-5.0; f 0.01–1.0 and X is the number of oxygen atoms in the system, corresponding to the number and valences of the metal atoms that make up the catalyst. 2. A method according to claim 1, wherein the process is carried out in the presence of 10-40% by volume of water. Sources of information taken into account in the examination 1. France Patent 1604942, cl. From 07 C, 1970. 2. Authors certificate of the USSR 384269, cl. On 01 J 11/52, 1971. 3. Authors certificate of the USSR 384325, cl. C 07 C 45/04, 1970. 4. USSR author's certificate 598862, cl. C 07 C 45/04, 1976. 5. Isaev OV, Navalkhina MD The current state and trends of acid production of acrylic acid. M., NEITAHIM, vol. 20, 1976, p. 110. 6. USSR author's certificate of application No. 2617634 / 23-04, cl. C 07 C 45/04, 04/14/78 (prototype).