DE2428633C3

DE2428633C3 - Process for the production of methakrolein

Info

Publication number: DE2428633C3
Application number: DE19742428633
Authority: DE
Inventors: Albert; Dufour Henri; Meile Bouniot (Frankreich)
Original assignee: Rhone-Progil S.A., Courbevoie, Hautsde-Seine (Frankreich)
Priority date: 1973-07-04
Filing date: 1974-06-14
Publication date: 1976-10-21

Claims

Range of the mixture's explosive limits: to be able to work even in the event of an accidental slowdown in the supply of isobutyraldehyde.

1. Modification of the manufacturing process _R. . .
of methakrolein according to patent 19 38 842, there- 5 example

characterized in that the man works out in a cylindrical reactor

Oxidation of isobutyl aldehyde vapors using stainless steel 40 cm in diameter and 40 cm

a silver level deposited on silica; this is up to Zd with a height of 20 cm

catalyst charged in the reaction zone in practically the catalyst: the reactor is more car-diabatic Way, where you thermally insulate io, and its floor on which the

Introduces water in vapor form into this zone. Catalyst rests, consists of a perforated

2. The method according to claim 1, characterized GE plate for the distribution of the gas (760 holes of indicates that the amount of water is 35 to 1.5 mm in diameter). The catalyst consists of 45 percent by weight of the isobutyraldehyde is. Silicon oxide with a specific surface area of

3. The method according to claim 1 or 2, da- 15 12 m ² / g, which is characterized in grains of about 3 mm in diameter, that the duration of contact is broken; 10 percent by weight of the reaction mixture and of the catalyst silver are deposited on this, namely by impregnating less than 1 second. gnetting of the silicon oxide with an aqueous solution

of silver nitrate and subsequent calcination.
20 When carrying out the process one leaves

a mixture of the reactants continuously from bottom to top through the catalyst bed in gas-vapor phase preferably at a temperature

The main patent 19 38 842 relates to a process temperature of 150 to 160 ° C under atmospheric pressure for the production of methakrolein through catalytic 25 flow. The gases and vapors of the mixture of isobutyraldehyde and oxygen in the oxidation are intimately mixed with one another, and the contact gas phase at elevated temperature. It is characterized by duration with the catalyst not reaching the duration that the oxidation takes place at 150 to one second. The pressure loss caused by contact with the ge-300 ° C in the presence of a metallic silver perforated plate, which is carried out around the holding catalyst, which is at 30-10 cm water column, ensures a sufficiently uniform distribution of the silica carrier with a specific, uniform distribution of the Reaction mixture is precipitated over an area of 14 to 380 square meters / g. the entire cross section of the catalyst bed.
The temperature is preferably between the following per hour are added:

170 and 250 ° C. 22 m ³ air (measured under normal conditions)

The present invention relates to a further 35 ₂ 4.3 kg of isobutyraldehyde vapor

Formation of this process for the production of 17 ke water vapor
Methakrolein and is characterized in that

the isobutyraldehyde is oxidized with Under these conditions the temperature is

With the aid of a reaction mixture precipitated on silica at the outlet from the catalytic converter

Silver catalyst in the reaction zone in practically 40 lysatorbett 610 to 620 ° C.

adiabatic manner, whereby water is used after rapid cooling of the mixture, condensation

is introduced into this zone in vapor form. sation of the vapors and a wash of the return

The steam dilutes the reaction mixture to recover the gases still in it

and limited the temperature increase of the mixture contained usable products one obtains the following

at the exit of the catalytic zone, which is connected by 45 compounds:

the exothermic character of the reaction is caused. Isobutyraldehyde 8 36 kg

The amount of water is preferably 35 to methakrolein .. '.'. '.'. '.'. '.'. '.'. '.'. '.'. '.'. 746kg

45 percent by weight of the isobutyraldehyde; acetone is 1 55 ke
the contact time of the mixture with the catalyst

low and is less than 1 second. The following yields can be derived from these figures

Calculate an advantage of the improved method according to:

of the invention consists in an isobutyraldehyde conversion 65 »/ 0

of the same order of magnitude, a significantly increased yield of methakrolein 46 «/.

Ensure conversion of isobutyraldehyde; Acetone yield 12%

this requires a considerable increase in production 55

the reaction apparatus and a relief of the residual gases no longer contain oxygen,
subsequent separation of the components of the reac- The tion product not converted into methakrolein and acetone. Another advantage of the presence of isobutyraldehyde is converted into products of combustion and cracking of the water vapor in the reaction mixture: CO, CO ₂ and light coals are possible within a further 60 hydrogens.