SU385957A1 - - Google Patents

Description

METHOD OF OBTAINING MALEIN ANHYDRIDE

one

This invention relates to a method for producing maleic anhydride from dicyclopentadiene and gases containing their dicyclopentadiene.

Dicyclopentadiene is a byproduct of the production of coke benzene. Cyclonentadiene and dicyclopentadiene are widely used in fine chemical synthesis for the production of pharmaceuticals, herbicides and other valuable products.

A known method for producing maleic anhydride by the oxidation of dicyclopentadiene or hydrocarbons containing mainly dicyclopentadiene.

There is also known a method of vapor-phase oxidation of these substances to maleic anhydride in a vanadium-molybdenum catalyst supported on pumice.

In the oxidation of dicyclopentadiene, a mixture of air and nitrogen is used. The productivity of the process is relatively low and amounts to about 70-80 g / l-hour (yield of maleic anhydride is 113% by weight. When oxidizing cycloneptadiene over a vanadium-molybdenum catalyst on pumice, a yield of maleic acid is 62-94%. Odua.co simultaneous use of two gases — air and nitrogen — complicate the process considerably.

It is also known to oxidize benzene under the conditions of cyclopentadiene oxidation (the maximum yield of maleic acid is 66.5%). It should be noted that in these studies

experiments were carried out at large weight dilutions of the reaction mixture (on the order of 150).

Carrying out the process with such large

dilutions of the reaction mixture are related to

large energy costs for heating large areas of the air supplied to the reactor, in addition, there are great difficulties in the condensation (or water absorption) of maleic anhydride from contact gases.

In order to increase the yield of the target product, it is proposed to use a vanadium-molybdenum catalyst containing phosphorus and promoters — sodium and silver (or nickel), as well as cadmium oxide, cobalt copper, and cerium, and the oxidation should be carried out mainly in the presence of water vapor at a weight ratio of water and dicyclopentadiene 0.5-5: 1. The results of the oxidation of technical dicyclopentadiene, a mixture of benzene and dicyclopentadiene, and a mixture of hydrocarbons containing mainly dicyclopentadiene, both at large and at low dilutions of the reaction mixture of air, are given below. The catalyst used is a vanadiesic acid contact promoted with silver and a vanadium-molybdenum phosphorus catalyst promoted with sodium and nickel (or copper, cadmium, cobalt, cerium, silver). Electrocoruid is used as a carrier.

The catalyst is prepared by the method of evaporation in a hydrochloric acid medium and activated at a temperature of 400 ° C. The number (g) of a-tive components and carrier changes in the following6, 35-10.08 -10.13 0.1-1.12

The results of the vapor-phase oxidation of dicyclopentadiene (DCPD) to maleic anhydride with a vanadium catalyst promoted with silver (atomic ratio, 003) and deposited on

electrocorundum

The silver-promoted vanadium catalyst is characterized by high productivity. At a temperature of 400 ° C, a contact time of 0.3-0.42 sec and dilution. The effect of water on the vapor-phase oxidation of dicyclopentadiene

 Electrocorundum carrier. Temperature 400 ° C.

0.3

0 0 0 0 0 0

0.15

0.28

0.089

0.40

0.01

Eh 100

In the oxidation of technical dicyclopentadium and vanadium oxide catalyst,

silver promoted at temperature

380-400 ° C, contact time 0.25-1.7 seconds

and air dilution by weight: Dicyclopentadiene 39-122 The weight yield of maleic anhydride is 50-80% (see Table 1).

Table 1

air: dicycloentadiene 53-57 with a productivity of 137-220 g / l-hour yield of maleic anhydride 73-77% (see table. 2).

Table 2 maleic anhydride

Results close to those indicated above were obtained by the vapor-phase oxidation of dicyclopentadiene on a wahiadium-molybdenum phosphorus catalyst promoted with atrium and nickel and deposited on electrocorundum. With

The results of the vapor-phase oxidation of dicyclopetadiene to maleic anhydride of a vanadium-molybdenum phosphorus catalyst, promotion of INIa and IN) (atomic ratio V: Mo: P: Isia: l i l: 0.268: 0.0136: 0.041: 0.022)

and applied on electrocorundum

During the oxidation of dicyclopentadiene, the enrichment of the reaction mixture with water vapor leads to a significant increase in the yield of maleic anhydride (see Table 2).

Under the conditions of the oxidation of dicyclopentadiene, the oxidation of benzene is carried out, and the yield of maleic anhydride is 70 wt. %

In the vapor-phase oxidation of dicyclopentadiene to vanadium-molybdenophosphorous. catalysts Results Paraphase oxidation of the head 15 of the coke-chemical fraction of production, which contains, besides dicyclopentadiene and benzooptimum contact conditions (temperature 420 °, contact time 0.3 sec and weight dilution 117), the yield of maleic anhydride is 73 wt. % (see tab. 3).

Table 3

silver and sodium mixed mash (V: Mo: P: Na: Ag 1: 1.001: 0.0543: 0.034:: 0.035) applied to electrocorundum, at a temperature of 410-430 ° C, relatively small weight dilutions of the reaction mixture 60-79 and a contact time of 0.29-1.18 seconds, the yield of maleic anhydride is 62-71%. The productivity of the process is 107-160 g / l-hour (see Table 4).

Table 4 of the vapor-phase oxidation of dicyclopentadnene and the head of the coke-chemical production fraction into maleic anhydride, also thiophene and other impurities. As a catalyst, in ala moth days, biphosphoric contact promoted by nat7

and nickel. However, under optimal conditions for the vapor-phase oxidation of slolenadiene and using the head fraction as a raw material, a low yield of maleic anhydride is obtained, not exceeding 32 wt. %

Thus, when using as a raw material for the production of maleic anhydride, the head fraction must first be cleaned of sulfur-containing anhydride with organic and other compounds capable of strength. adsorption of impurities.

The results obtained on these, as well as on other eanadium-containing catalysts, show that dicyclopentadiene is a promising type of raw material for the production of maleic anhydride, since the process is characterized by a high yield of maleic anhydride and high productivity. The oxidation is carried out at relatively low dilutions of the reaction mixture, which causes a high concentration of the target product in contact gases. Therefore, maleic anhydride can be isolated both by the dehydration method and by the direct method: condensation of maleic anhydride from contact gases.

Example 1. The catalyst is a mixture of V2O5 and Ag2O (atomic ratio V: Ag 1: 0.003) on alumina. Above 20 ml of catalyst, a mixture of dicyclocetadiene and air is passed through, containing 0.011 g of dicyclopentadiene in 1 liter, at a rate of 2.9 l1 min. At a temperature of 390 ° C, the yield of maleic anhydride is 80 wt. % with a capacity of 81 g / l-hour.

Example 2. A catalyst consists of a mixture of UzOb, MoO3, P2O5 NagO and NiO (atomic ratio V: Mo: P: Na:: 0.268: 0.0136:: 0.041: 0.022) applied to electrocorundum.

Above 20 ml of catalyst, a mixture of dicyclopentadiene and air vapor is passed, containing 0.011 g of dicyclopentadiene in 1 l, at a rate of 4.2 l / min. At 400 ° C, the yield of maleic anhydride is 73 wt. % with a capacity of 103 g / l-hour. Example 3. The catalyst is a mixture of V203 and Ag2O on electrocorundum.

Above 20 ml of catalyst, a mixture of dicyclopentadiene vapor, water and air is passed, containing 0.023 g of dicyclopentadiene and 0.022 g of water in l, at a rate of 3.9 l / min. At a temperature of 400 ° C, the yield of maleic anhydride is 77.3 wt. % with a capacity of 210 g / l-hour.

Example 4. The catalyst is a mixture of VsOs, MoO3, P2O5, Na2O and Ag2O on electrocorundum.

Above 20 ml of catalyst, a mixture of dicyclopentadiene and air vapor is passed, containing 0.019 g of dicyclopentadiene in 1 l, at a rate of 4.2 l / min.

At 420 ° C, the yield of maleic anhydride is 65.6 wt. % with a capacity of 156.5 g / hour.

Subject invention

Claims (3)

1. Method of producing maleic anhydride by vapor-phase oxidation of dicyclopentadiene or hydrocarbons containing mainly dicyclopentadiene with air oxygen vanadium molybdenum or vanadium oxide catalyst, characterized in that, in order to increase the yield of the target product, the process uses a vanadium molybdenum catalyst containing phosphorus and promoters - atrium and silver or nickel. 2. A method according to claim 1, characterized in that cadmium, copper, cobalt and cerium oxides are used as npoMOiiOipOB. 3. The method according to. 1, characterized in that the oxidation of dicyclopentadiene is carried out in the presence of water vapor, with a weight ratio of dicyclopentadiene and water of 1: 0.5–5.