A method of producing a catalyst for oxidation of methanol to formaldehyde

 

(57) Abstract:

Usage: catalytic chemistry: production of catalysts for oxidation of methanol to formaldehyde. The inventive catalyst is produced by displacement of the metal iron, ammonium molybdate and chromium oxide in acetic acid in quantities which provide an atomic ratio of Fe/Cr+Fe 0.5 to 0.95 and Mo/Fe+Cr 2,5-3,0, when heated to 60-90C and stirring. The resulting paste is subjected to heat treatment at 500-550C. Receive the catalyst composition: Fe1-xCrx/Mo=1/2,5-3,0, where x is 0.05 to 0.5. table 1.

The invention relates to the production of catalysts for oxidation of methanol to formaldehyde.

Numerous studies of catalytic properties of oxide systems in relation to the oxidation of methanol to formaldehyde showed the promise of two catalysts: Fe-Mo and Fe-Cr-Mo [1, 2] As the one and the other catalysts obtained by coprecipitation of solutions of nitrate salts of iron, chromium and paramolybdate ammonium at a certain pH, which is maintained by adding ammonia solution. Further precipitation was filtered, washed, dried, calcined, is formed. This delivery method provides a complete chemical interaction with the formation of dorodnova harmful effluents, containing ions of iron, molybdenum, ammonium, nitrate ions, chromium ions, in concentrations considerably higher than the MPC. So, when producing 1 t of the catalyst is formed 16.5 m3wastewater containing 0.4 to 1.5 g/l Cr, 1.3 g/l Mo, 34 g/l NH4NO3.

Known attempts to develop closed getter zhelezorudnogo catalyst in [3] proposed drainage EDM method of obtaining Fe-Mo catalyst. Raw materials iron paste is obtained by applying an electric pulse to the iron in acetic acid medium in the reactor electrical discharge dispersion. Because of its specificity and the high cost of this method in industry is not used. Obtaining Fe-Cr-Mo catalyst on inland technologies previously not offered.

To date bezmetallny formalin get on Fe-Mo catalyst, accumulating at the Novosibirsk chemical plant by co-deposition, i.e. with a large number of harmful effluents.

Introduction chromium in Fe-Mo catalyst without affecting the activity and selectivity significantly increases the mechanical and chemical (thermal) stability of the system [1] which is of great value in industrial use ka is cnyh waters completely eliminates the possibility of developments in industrial scale Fe-Cr-Mo catalyst on existing technology.

Known method of preparing an oxide of Fe-Cr-Mo by coprecipitation from solutions of salts [4] is the following:

To a solution of PMA add ammonium hydroxide, and then to the resulting solution was added a mixture of solutions of the nitrates of iron and chromium to achieve a pH of 3.6 and 4.4, maintaining this pH value until the end of the deposition of the aqueous solution of ammonium hydroxide, followed by separation of the resulting sludge. The precipitate is washed with water, acidified with nitric acid to a pH of 3.6 and 4.4, dried in air and subjected to heat treatment at 400 to 450aboutC.

Wastewater containing harmful substances, are formed at the stage of filtering and washing the precipitate.

This method is chosen as a prototype.

The aim of the invention is to develop a new closed method of producing oxide Fe-Cr-Mo catalyst, to move to a zero-discharge technology developments.

Offer closed method of obtaining iron-chromium-molybdenum catalyst is as follows.

Raw materials are used: paramolybdate ammonium, iron metal, chromium oxide, acetic acid.

Iron is loaded into the reactor with acetic acid, then added to the reactor hydroxy what r)/Mo=1/2,5-3,0, next, the catalyst mass is heated at 60-100aboutWith stirring to form a paste. The paste is discharged, is subjected to heat treatment at 500-550aboutC. Wastewater no, the products of thermal treatment are water, CO2, pair of acetic acid, which is captured and returned to the reactor, and ammonia, ulavlivajushhij in the absorption column.

Distinctive features of the process are used as raw materials along with paramolybdate ammonium metallic iron and chromium oxide and conducting cooperation in the acetic acid medium.

P R I m e R 1. To 400 ml of 10% acetic acid, add 10 g of iron, of 92.7 g of paramolybdate ammonium and 50 ml of 6% aqueous solution of chromium oxide. All mixed while heating to 90aboutWith to form a paste in a few hours. Next, the paste is dried and made red-hot at 500about4 hours Later molded and tabletroute.

You get the catalyst composition of Feof 0.85Crof 0.15Mothe 2.5(Fe/Cr+Fe= 0,85; Mo/(Fe+Cr)=2,5).

P R I m m e R 2. To 400 ml of 10% acetic acid, add 10 g of iron, 105 g of paramolybdate ammonium and 95 ml of a 6% aqueous solution of chromium oxide. All mixed while heating to 75aboutTo UB>the 2.5(Fe/Cr+Fe= 0,75; Mo/(Fe+Cr)2,5).

P R I m e R 3. To 400 ml of 10% acetic acid, add 10 g of iron, 131 g of paramolybdate ammonium and 190 ml of a 6% aqueous solution of chromium oxide. All mixed while heating to 80aboutWith to form a paste. Next, as in example 1.

The resulting catalyst composition of Fe0,5Cr0,5Mothe 2.5(Fe/Cr+Fe=0,5; Mo/(Fe+Cr)=2,5.

P R I m e R 4. To 400 ml of 10% acetic acid, add 10 g of iron, 74,1 g paramolybdate ammonium and 50 ml of 6% aqueous solution of chromium oxide. All mixed while heating to 70aboutWith to form a paste. Next, as in example 1.

This gives a sample of the compound Feof 0.85Crof 0.15Mo2,0(Fe/Fe+Cr=0.85; The Mo/(Fe+Cr)=2,0.

This example shows that reducing the content of molybdenum in the sample catalytic properties deteriorate.

P R I m e R 5. To 400 ml of 10% acetic acid, add 10 g of iron, 111,3 g paramolybdate ammonium and 50 ml of 6% aqueous solution of chromium oxide. All mixed while heating to 80aboutWith to form a paste. Next, as in example 1.

The resulting catalyst composition of Feof 0.85Crof 0.15Mo3,0(Fe/Fe+Cr= 0.85; The Mo/(Fe+Cr)=3,0).

P R I m e R 6. To 400 ml of 10% acetic acid dabawenyo 60aboutWith to form a paste. Next, the paste is dried and made red-hot at 550aboutC.

The resulting catalyst composition of Feof 0.95Cr0,05Mothe 2.5.

The catalytic properties were determined in a flow-circulation installed in the gas mixture containing 6.5% of CH3OH (the rest of the air) at 300aboutC. the feed Rate of the reaction mixture 10000 h-1. Gas chromatographic analysis of the products. The grain size of the test catalyst of 0.5-1 mm

As can be seen from the table, the iron-chromium-molybdenum catalysts obtained by the closed method, characterized by high catalytic activity and selectivity.

The proposed method of obtaining, providing high activity and selectivity of the catalyst, prevents the formation of harmful effluents.

Due to the absence of harmful effluents upon receipt of the catalyst, the possibility of industrial concentration iron-chromium-molybdenum catalyst and, consequently, improve the economic efficiency of production preparation of formaldehyde due to the much higher thermal and mechanical strength as compared with currently used iron oxide-chromium-m is based on iron oxides, molybdenum and chromium, wherein the mixed metal iron, ammonium molybdate and chromium oxide in acetic acid in quantities which provide an atomic ratio of Fe/Cr + Fe 0.5 to 0.95 and Mo/Fe + Cr 2,5 3,0, when heated to 60 90oC and stirring to form a paste with subsequent thermal treatment at 500 550oWith receipt of the catalyst composition of Fe1-xCrx/Mo 1/2,5 - 3,0, where x is 0.05 to 0.5.

 

Same patents:

The invention relates to methods of making catalysts, in particular catalysts for the isomerization of n-paraffin hydrocarbons, and can be used in the refining and petrochemical industry

The invention relates to catalysts for the oxidation of o-xylene into phthalic anhydride in an organized fluidized bed and the method of their preparation

The invention relates to methods for oxide catalysts used in the deep oxidation of carbon monoxide and organic impurities in the gas emissions from industrial productions

The invention relates to oxide type catalysts obtained on the basis of cobalt oxide, and can be used for oxidation of carbon monoxide

The invention relates to a method for producing a molded block and granular) catalysts for purification of gases from nitrogen oxides and can be used in the processes of selective catalytic reduction in the presence of ammonia (SLE)

-olefins" target="_blank">

The invention relates to methods of producing olefin polymers (a name sometimes used to refer to both homopolymers and copolymers of olefins by polymerization (the term is sometimes used to refer to as homopolymerization and copolymerization) of olefins

- olefins" target="_blank">

The invention relates to methods for applied catalyst ziperovich type containing as an active ingredient a compound of vanadium deposited on a magnesium-containing carrier, and used in combination with an alkyl aluminum as acetalization

The invention relates to a catalyst for producing phthalic anhydride and more particularly to a catalyst for producing phthalic anhydride by means of catalytic oxidation in the vapor phase orthoxylene and/or naphthalene with molecular oxygen or gas containing molecular oxygen

The invention relates to a catalyst for producing phthalic anhydride and more particularly to a catalyst for producing phthalic anhydride by means of catalytic oxidation in the vapor phase orthoxylene and/or naphthalene with molecular oxygen or gas containing molecular oxygen

The invention relates to a catalyst for producing phthalic anhydride and more particularly to a catalyst for producing phthalic anhydride by means of catalytic oxidation in the vapor phase orthoxylene and/or naphthalene with molecular oxygen or gas containing molecular oxygen

The invention relates to methods of making low-interest catalysts on a carrier and can be used for purification of exhaust gases of internal combustion engines (ice) and industrial waste gases from harmful impurities

The invention relates to methods of making low-interest catalysts on a carrier and can be used for purification of exhaust gases of internal combustion engines (ice) and industrial waste gases from harmful impurities

The invention relates to methods of making low-interest catalysts on a carrier and can be used for purification of exhaust gases of internal combustion engines (ice) and industrial waste gases from harmful impurities

The invention relates to the field of refining gasoline over zeolite catalysts and can be used in refining and petrochemical industry

FIELD: chemistry.

SUBSTANCE: invention relates to a homogeneous catalyst based on tetra-4-(4'-carboxyphenylsulphanium)-5-cobalt nitrophtalocyanine(II) of tetrasodium salt of formula .

EFFECT: invention allows to produce a compound having a high catalytic activity in the oxidation of sodium diethyldithiocarbamate.

4 dwg, 1 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: nanotubular materials crystallising in the system of K2O-TiO2-X-H2O (X=NiO, MgO, Al2O3, Cr2O3, CO2O3, Fe2O3) are characterized by the fact that in their composition up to 10% of ions Ti4+ is replaced by doping two- or trivalent metal. The method of synthesis of nanotubular materials is characterized by the fact that the synthesis of the samples is carried out by hydrothermal treatment of a pre-prepared mixture of hydroxide in KOH solution, to produce the initial mixtures of hydroxides, a solution of titanyl chloride synthesised by reaction of TiCl4 with chilled distilled water, is mixed with aqueous solutions of salts of finished elements in a predetermined ratio, and then the precipitation of hydroxides is produced by adding NH4OH to the aqueous solution mixture at pH=9-9.5 followed by washing with distilled water, drying at 70-90C and mechanical crushing, then the crushed precipitate is mixed with 10 M KOH solution and subjected to a hydrothermal treatment at 170-180C for, at least, 24 hours, after which the resulting product is washed with distilled water.

EFFECT: invention makes it possible to synthesise potassium-titanate nanotubes with an average outer diameter of 5 to 12 nm.

2 cl, 5 dwg, 2 ex

Up!