CS226198B2 - Method of producing acrolein or methacrolein and acrylic or methacrylic acid - Google Patents

Description

A process for the oxidation of olefins with various multi-component catalysts is known. U.S. Pat. No. 3,642,930 discloses that certain complex catalysts may be used in the oxidation of olefins to unsaturated aldehydes and acids. Indeed, these catalysts are very advantageous for oxidation reactions, but in the course of ongoing research other catalysts have been prepared which could improve the results obtained with the catalysts of the aforementioned US patent. The invention is the result of such research.

The present invention provides a process for producing acrolein or methacrolein and acrylic or methacrylic acid from vapor-phase propylene or isobutylene by oxidizing propylene or isobutylene with molecular oxygen at a temperature of 200 to 600 ° C in the presence of one molybdenum, oxygen, bismuth, phosphorus, tungsten catalyst. , nickel, cobalt and alkali metals, which is carried out using a catalyst of the formula I

WcWWx (I), where X is A is D is E is and is b is d is c, fx is niobium, germanium, chromium or a mixture thereof, alkali metal, copper, talium or a mixture thereof, nickel, cobalt, magnesium, zinc , cadmium, calcium, strontium, or a mixture thereof, phosphorus, arsenic, boron, tungsten, sulfur, aluminum, or a mixture thereof, and greater than 0 but less than 5, greater than 0, but less than 4 to 4, and g are 0 1 to 12 and the number of oxygen atoms required to saturate the bonds of the other elements present.

The oxidation reaction provides particularly advantageous results at atmospheric or elevated pressure.

The main feature of the invention is in particular the use of a catalyst. As the catalyst, one of the catalysts defined by the above formula may be used. In a preferred embodiment of the invention, each of the elements represented by X is introduced into the catalyst separately. This is usually achieved by independently adding component X in an amount proportional to the different elements. It is also preferable for the overall structure of the catalyst mixture if the catalysts contain potassium, rubidium, cesium or a mixture thereof and catalysts containing nickel, cobalt or a mixture thereof.

The catalysts of the invention can be prepared by a process well known in the art. This process involves the simultaneous precipitation of soluble salts. Specific information on the production of catalysts is provided in the Examples.

The catalysts of the invention may be used on a support or in the form of a support. Suitable materials include silica, alumina, electrothermally produced corundum, titanium dioxide, zirconia, silicon carbide, and the like. Catalysts can also be used in various physical forms. The catalysts can be used in fixed bed and fluidized bed reactors.

The process of oxidizing propylene or isobutylene is well known in the art. Generally, the mixture of olefins and molecular oxygen, optionally in the presence of steam or other diluent, is contacted with the catalyst at an elevated temperature of 200 to 600 ° C for a time sufficient to convert the olefins to the corresponding unsaturated aldehyde and acid.

Usually the product of these reactions contains a very large proportion of aldehyde and a minor amount of unsaturated acid as a by-product. The contact time can vary widely from a few to a large number of seconds. The reaction can be carried out at atmospheric, elevated or reduced pressure, the elevated pressure normally being used in the industrial range.

A particular advantage of the catalysts of the invention lies in their ability to resist the batch of large quantities of olefins that pass through the catalyst over a given period. This is normally measured in units of the ratio of the weight of olefin feed to catalyst weight per hour (WWH). In other words, the catalysts can work efficiently with large amounts of olefins. Prior art catalysts tend to be less effective when large amounts of olefins are deployed over a given period of time.

Examples 1 to 8

Oxidation of isobutylene at atmospheric pressure.

Various catalysts of the present invention containing 20% silica are prepared as described below.

Example 1 ^Pr 0.5 ^K 0.1 ^Ni 2.5 ^Co 4.5 ^Fe 3 ^BiMo 12 ^O x

A suspension of 63.56 g (NH ^ ^ Og ^ JgMo .ěHgO, 52.33 g of 40% silica sol (Nalco) and 2.60 g _2> Separately, a solution of 36.36 g FeíNQ-j ^. SHgO, .14,55 g Bi (NO ₃ ) ₃ .5H ₂ O, 39,29 g (Co (NO ₃ ) ₂ .6H ₂ O, 21,80 g Ni (NO ₃ ) ₂ .6H ₂ O and 3 The suspension and solution were combined, the liquid evaporated to a paste and the paste dried at 120 ° C overnight The catalyst was heat treated at 290 ° C for three hours, at 425 ° C for three hours and at 550 ° C. ° G.

Examples 2 to 3

Catalysts were prepared in the same manner as described above except that the appropriate amounts of manganese and thorium nitrate, germanium chloride and niobium oxide were added instead of praseodymium.

Example 6

Mn, Ca _{5 0 j 0, 5 Κ} θ, _jNig,? 0ο ₄ , jFe ^ iMo, ₂ Ο _χ

Solution 2.72 g CaKO ₃ , 1.19 g HNO ₃ , 20.33 g Ni (NC> ₃ ) ₂ .6H ₂ O, 36.61 g (0ο (Ν0 ₃ ) ₂ · 6Η ₂ Ο,

33.9 g Fe (NO ₃ ) ₃ .9H ₂ O, 13.6 g Bi '(NC ₃ ) ₃ .5H ₂ O are added to a suspension of 2.5 g Mn (NO ₃ ) ₂ , 59.2 g (NH 4 _g ) Mo ₇ 0 ₂₄ .4H ₂ O and 50 g of 40% silica sol (Nalco). The mixture was evaporated, dried and worked up by heating as in Example 1.

Examples 7 and 8

The catalysts were prepared in the same manner except that 1.46 g of GeOg or 1.84 g of NbgO4 was added instead of manganese nitrate.

A fixed bed reactor made of a stainless steel tube with an inner diameter of 0.75 cm is not charged with 5 ml of each of the above catalysts. These catalysts are tested at a reaction temperature of 371 ° C using isobutylene, air and steam at a ratio of 1:10: 4 and an actual contact time of 3.3 seconds. The results of these tests are shown in Table 1. ·

The results shall be determined as follows:

moles of product x 100% yield in one pass = .......------------ moles of isobutylene feed moles moles of isobutylene moles x 100% conversion = - ^{1 1 1} —..... ... .................

moles of feed isobutylene moles of product formed x 100% selectivity = .......... — ..... —- moles of isobutylene recovered

In the tables, MA is methacrolein and MAA is methacrylic acid.

Table 1

Oxidation of isobutylene to methacrolein and methacrylic acid at atmospheric pressure using a catalyst of the formula YNig _g Co ₄ gFe ^ iMoj ₂ 0 _χ

Example Catalyst, Y = Results, % Yield in one pass MA MAA total conversion selectivity 1 ^Pr 0.5 ^K 0.1 61, 6 2.2 63.8 91.3 69.9 2 ^Mn 0.5 ^K 0.1 68.5 2.9 71.4 100.0 71, 4 3 ^Ge 0.5 ^K 0.1 67.0 4,5 71.5 100.0 71.5 4 ^Nb 0.5 ^K 0.1 52.2 2.5 54.7 82.9 66.1 5 ^Th 0.5 ^K 0.1 74.3 2.6 76.9 100.0 76.9 6 ^Mn 0.5 ^Cs 0.5 ^K 0.5 68.3 3.4 71.7 100.0 71, 7 7 ^Ge 0.5 ^Cs 0.5 ^K 0.5 77.1 ', 0 78.1 94.3 82.9 8 ^Kb 0.5 ^Cs 0.5 ^K 0.5 75.3 1,2 76.5 94.7 80.8

Examples 9 to 13

Oxidation of isobutylene under elevated pressure.

In the same manner as described above, the catalysts produced above were used in the reactions under elevated pressure. Catalysts are produced as follows:

Example. 9 ^Cr 0.5 ^Cs 0.5 ^Ni 2.5 ^Co 4.5 ^Fe 3 ^BiMo 12 ° x

Prepare a solution of 1.1 g CsNO _3, 8.2 g Ni (NO _{3) 2} .6H ₂ O, 14.8 g Cs (N0 _{3) 2} .6H _£ 0, 13.7 g of Fe (NO _{3) 3} .5H ₂ O, 5.5 g B1 (NO ₃ ) ₃ .5HgO e 2.3 g Cr (NO ₃ ) ₃ .9H ₂ O and a suspension of 23.9 g (NH ₄ ) ₆ Mo ₇ 0 ₂₄ . '4H ₂ 0 and 20 g of 40% silica sol (Nalco). The catalyst was dried and heated to 430 ° C for four hours and 600 ° C for three hours.

Examples 10 to 13

Catalysts were prepared in the same manner as in Example 9 using the appropriate components as starting materials.

Unless otherwise stated, the procedure is performed at 0.08 MPa. The reaction temperature and results are shown in Table 2. The same mixture as described above was used. The actual contact time is 3.5 to 4.1 seconds and the ratio of the weight of olefin feed to catalyst weight per hour is 0.098 to 0.159.

Table 2

Oxidation igobutylenu not methacrolein and methacrylic acid at an elevated pressure using a catalyst of Formula ₂ YNi .jKe Bimo ^ ₂ 0 _χ

Example Catalyst, Y = Results,% temperature Noc: 2 ° C Yield at one MA passage Conversions Selectivity MAA total 9 ^Cr 0.5 ^Cs 0.5 371 58.9 2.9 61, 8 81, 7 75.6 10 ^Ge 0.5 ^Cs 0.5 371 68.4 5.6 74.0 96.5 76.7 11 ^Mn 0.5 ^C8 0.1 343 64.5 4.8 69.3 99.6 69.5 12 ^Th 0.5 ^Cs 0.5 343 61, 5 3.5 65.0 89.0 73.0 13 ^Ce 0.5 ^Cs 0.2 363 70.3 6.4 76.7 98.9 77.6

Example 14

Production of acrolein

In the same manner as described in the examples above, acrolein and acrylic acid are prepared from propylene. The catalyst used is 80% Ge ^ _Q ^ Κθ .mu.g Bimo Pe ^ _{2 χ} 0 + 20 95 SiO. The catalyst was heat treated at 550 ° C for 16 hours! Use 5 ml of catalyst, a reaction temperature of 350 ° C and an actual contact time of 3.5 seconds. Propylene, air and steam are used in the ratio 1: 11: 4. The acrolein yield per pass was 84.8%, the acrylic acid yield per pass was 5.2%. Conversion of propylene 93.0 95 and selectivity to acrolein and acrylic acid 96.8 95 are achieved.

Claims (1)

SUBJECT OF THE INVENTION Process for producing acrolein or methacrolein and acrylic or methacrylic acid from propylene or lsobutylene in the vapor phase by oxidizing propylene or isobutylene with molecular oxygen at a temperature of 200 to 600 ° C in the presence of one molybdenum, oxygen, bismuth, phosphorus, tungsten, nickel cobalt and alkali metals, characterized in that a catalyst of formula 1 is used WAW12 ° z ^(I) 'wherein X is niobium, germanium, chromium or a mixture thereof, And is an alkali metal, me5, thallium or a mixture thereof, D is nickel, cobalt, magnesium, zinc, cadmium, calcium, strontium or a mixture thereof, E is phosphorus, arsenic, boron, tungsten, sulfur, aluminum or a mixture thereof and is greater than 0 but less than 5, b is greater than 0 but less than 4, d is 0 to 4, c, f and g are 0, 1 to 12 and x is the number of oxygen atoms required to saturate the bonds of the other elements present.