SU245032A1 - Method for preparing catalyst for producing phthalic anhydride - Google Patents

Abstract

A METHOD FOR PREPARING A CATALYST FOR OBTAINING PHTHAL ANHYDRIDE by vapor-phase oxidation of o-xylene by applying a melt of active components, including vanadium pentoxide, to a carrier, characterized in that, in order to simplify the technology of preparation of the catalyst, increase the composition and productivity, a medium, a material, oxygen, and oxygen can be used. with a dispersion of about 9-12 microns with titanium dioxide and nitric acid, shaping the resulting mass and drying it at 110-320 '' 's and calcining at 1200-1250''s.

Description

A known method of preparing a catalyst for the production of phthalic anhydride by vapor-phase oxidation of o-xylene by applying a melt of active components, including vanadium pentoxide, on a corundum carrier.

In order to simplify the catalyst preparation technology, increase its selectivity and productivity, the proposed method involves preparing a catalyst support by mixing alumina with a dispersion of about 9-12 microns with titanium dioxide and nitric acid, molding the resulting mass., Drying it at 110-320 ° С and calcination at 120_0-1250 ° C. Thus obtained ’catalyst has a high catalytic activity in the oxidation of o-xylene to phthalic anhydride. The output of phthalic anhydride on the passed o-keilol 98-99% with a catalyst productivity of 250-360 g of phthalic anhydride with 1 liter of catalyst per 1 h.

Example. 50 parts by weight alumina is ground in a vibratory mill for 2.0-2.5 hours to a particle size of 9-12 microns. Alumina is crushed with steel grinding bodies, and by 50 parts by weight alumina requires 700 parts by weight grinding bodies (cylinders or balls of various diameters).

100 parts by weight ground alumina zag10

Calcined tablets are weeded out from fines and dust. Received ’media has the following characteristics:

Bulk weight, g / cm ³ Crushing strength on a knife, kg / tablet Porosity,% Water absorption,% Specific surface, m ² / g Granule size, mm; Diameter Height

1.4-1.5

-40 -45

2.0

4,5-5

4-6

In a ball mill load weight.h. vanadium pentoxide, grade chda and 0.0975 parts by weight tungsten acid brand pure. The mixture is thoroughly mixed for 3040 minutes, and then loaded into the bath and melted at 740-750 ° C. The carrier obtained by the described method is preheated to 750 ° C in a bucket with holes of 2-3 mm, placed in the melt for 10-15 minutes. Then the bucket is raised above the melt, held for 15 minutes to stack excess melt, and the contents of the bucket are thrown onto a vibrating screen with blowing of cold air. After cooling, the obtained catalyst grains are sieved from small particles on a grid with 3 mm holes. ’Is pulled into a kneading machine, 1 part by weight is added. titanium dioxide and peptize 30 parts by weight nitric acid concentration of 20 wt.%. The components loaded into the kneading machine are thoroughly mixed for 4 hours until a homogeneous plastic mass is obtained, which is then molded on a screw press into 40 cylindrical granules with a diameter of 5 mm and a height of 5-6 mm.

The formed granules are dried on a baking sheet for 10-12 hours in a steam dryer at 110-120 ° C, and then in a flue gas mixture at 300-320 ° C for 10-12 hours. Dry granules are calcined and sintered in a bunker furnace at 1200-1250 ° C ~ for 1-1.5 hours in a stream of flue gases. The operating mode of the bunker furnace is as follows: the temperature in the furnace is 1200-1250 ° C, at the outlet from the bunker 400-600 ° C, the consumption of sulfur-free gas is 12-15 nm Uch, the air flow into the furnace is 300 nm ^ / h.

Get the catalyst characteristic:

The volumetric weight of the catalyst, g / cm ³

Specific surface, m ^g / g

Granule Size, mm: Diameter

Height next 1.6-1.8

1.0-1.5

4,5-5

-6 weight parts the resulting catalyst is loaded into an element of an industrial reactor with reaction tubes (3 pcs.) with a diameter of 20 mm and a length of 2.5 m, heated by a bath with a nitrite nitrate melt. ' According to the contact temperature of 440-450 ° C, the volumetric rate of the gas stream up to 8000, the concentration of o-xylene in the gas mixture is 0.75-0.8 vol.% The yield of phthalic anhydride reaches 98-99% with a catalyst productivity of phthalic anhydride up to 350 g / l.h.

Claims (1)

METHOD FOR PREPARING KATS LIZATOR FOR PRODUCTION OF PHALYTIC ANHYDRIDE by vapor-phase oxidation of o-xylene by applying a melt of active components, including vanadium pentoxide, to a carrier, characterized in that, in order to simplify the preparation of the catalyst, increase its selectivity and productivity, the carrier is prepared by mixing alumina with dispersion about 9-12 microns with titanium dioxide and nitric acid, molding the resulting mass and drying it at 110-320 ° C and calcining at 1200-1250 ° C.