DE1417731B - Process for the production of a catalyst which contains bismuth, molybdenum, silicon, oxygen and optionally phosphorus - Google Patents

Description

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In patent 1,263,712, abrasion-resistant catalysts and excellent abrasion resistance are

gates for the oxidative conversion of coals when used as fluidized bed catalysts

Hydrogen is described as being bismuth, molybdenum.

Silicon, oxygen and possibly phosphorus The process is divided into the following stages:
contain. "Oxidation" here is the combination of 5 _{(1) production of a} suspension of the ausnation of components contained in the hydrocarbons, which has the specified number of carbon atoms only electronegative elements, ammonium nitrate,
like ζ. B. oxygen or nitrogen to understand. So
can be carried out using these catalysts (2) spray drying the slurry and

from hydrocarbons through oxidation with acid ίο ₍₃₎ calcination of the spray-dried product,

fabric ζ. B. aldehydes, by reaction with nitrogen ^v ' ^{v ö}

and oxygen produce nitriles. Production To produce the slurry, the

According to the patent, these catalysts are carefully combined with the appropriate starting components.

Way that a silica sol mixed with bismuth and other. The ones aimed at according to the invention

Molybdenum-containing salts and possibly 15 properties are always achieved if the

with phosphoric acid or its salts in such a slurry of the starting ingredients at least

Amount proportions is mixed that the atom contains about 1 weight percent ammonium nitrate.

Ratio of bismuth to molybdenum in the Kataly amounts of more than 10 percent by weight leave the

sator is over 2: 3. Preferably, the general will not recognize any further advantage. The

The slurry does not need input substances in such proportions with ammonium nitrate

otherwise mixed, that the mixed elements are added in as such, but can be in it

Catalyst formed within the following ranges by reacting other constituents

lie: will.

For the remaining weight percent of the starting components are intra-bismuth-4 5 to 55 ^2S ^ b ^ ^it above any frame AusMolybdän 2'5 to 32 gear substances suitable. For bismuth one can

0: 1:,.;., "Η'ή KJc αϊ dissolution of bismuth metal in nitric acid or

OUlClUm U, DL) Ib ti. .-r> τ ■ ...., ^r . ,

Oxygen 20 is used to 50 ^{eme wa} ^ ^{n e} g solution of a bismuth salt

Phosphorus (if 'present) ".'.". ' 0.1 to 5 can also be used for molybdenum.

30 dene connections are used. Should that

It has now been found that the abrasion resistance of ammonium nitrate in the slurry itself

and so that the service life of after the formation, one preferably uses a

drive this patent by spray drying her- ammonium molybdate, such as. B. Ammonium hepta-

The fluidized bed catalysts provided are improved by molybdate or ammonium dimolybdate. For phosphorus

If one can produce the catalyst, it can be phosphoric acid or phosphomolybdic acid

Analyzers used starting hybrid one can be used through which one at the same time

Adds a certain amount of ammonium nitrate, if it can supply molybdenum and phosphorus,

not through the starting components anyway

Contains ammonium nitrate. low alkali content and 30 percent by weight

The invention therefore preferably relates to a silica.

drive to produce an improved abrasion The main advantage of the spray drying process is solid catalyst for the oxidative conversion of, in the end result, spherical particles of hydrocarbons, the bismuth, molybdenum, silicon are formed, which one after other drying cium, Oxygen and possibly phosphorus can usually not be extracted from the process. Which holds, being a silica sol with bismuth and 45 spray drying process and what devices in the Molybdenum-containing salts and, if appropriate, individual salts are used, is not critical: with phosphoric acid or compounds that five- one can use conventional devices and procedures, contain valuable phosphorus in such quantities. The device usually consists of proportions is mixed that the atomic ratio of a drying chamber, a source of hot gases. from bismuth to molybdenum in the catalyst over 2: 3 50 a device for atomizing the liquid rests, according to patent 1 263 712, the thereby marked goods and a device for separating the It is noted that in the case of catalysts, after the dried product. The system can be operated with a counter-spray drying process produced and work in the fluidized bed or co-rotating gas flow direction. the reactors are to be used, the inlet gas temperatures can be controlled via a th starting mixture in those cases where not 55 wide range vary; generally exuberant through the starting components ammonium one preferably does not step through about 538 ° C. nitrate incorporated in the claimed amounts. 1 to 10% ammonium nitrate is added. borrowed spray devices are made.

The way in which the ammonium nitrate The size of the final product depends on the properties of the finished catalyst affected, 60 degree of spray of the slurry and can in are not fully clarified. It is to be assumed, however, that it can be varied in a known manner. One size range that the ammonium nitrate in spray drying in from 5 to 250 μ is preferred.

due to its relatively low melting point, the calcination of the spray-dried product

Matrix forms in which the other starting stock is at 371 to 593 ° C, preferably at about

parts are embedded. At the subsequent calci- 65 427 ° C, carried out. Any

kidneys of the spray-dried product then devices remain suitable, such as ordinary calcining

the remaining components in the form of spherical ovens and rotary kilns. It is sufficient for the latter

Particles that usually have a smooth, glassy appearance when the spray-dried product is

duct only for a short time, d. H. about 5 to 10 minutes the elevated calcination temperature. You can also use the spray-dried product in the Calcine the fluidized bed reactor in which it will ultimately be used.

The invention is further illustrated by the following example.

226.80 kg of aqueous silica sol with a low alkali content and containing 30% silica were into a stainless steel mixing vessel equipped with an electric stirrer brought in. Then 1.2 l of phosphoric acid and then 42.7 l of an aqueous solution were added, which contained 37.784 kg of ammonium heptamolybdate. For this they finally gave 42.7 1 one 5% nitric acid containing 77.56 kg of bismuth nitrate. The mixture was then thoroughly stirred. This slurry was then fed into a conventional at a rate of 5.9 kg per minute Pumped spray dryer, which worked on the synchronous principle, and a drying chamber Concrete drum with a diameter of 5.5 m and a flat bottom. During the drying process the inlet gas temperature was maintained at about 218 ° C while the temperature of the outgoing gas was about 85 ° C. The slurry was made using a 5000 rev / min. sprayed circumferential borehole disc.

The spray-dried product was removed from the bottom of the drying chamber and then into a Transferred calciner, in which it is gradually heated to 427 ° C and kept at this temperature for 10 hours was held. The calcined catalyst had a particle size in the range from 33 to 250 microns.

When this product was tested for abrasion resistance, it was found that it contains catalysts of the same composition, which had been produced by the process of the main patent was superior. Other experiments showed that the catalytic activity of the catalyst in the oxidative conversion of hydrocarbons was excellent.

The wear resistance test was carried out as follows and yielded the following Results:

An apparatus was assembled consisting of a lower section consisting of 69.9 cm in length of copper tubing with an inner diameter of 3.81 cm. This copper pipe was connected to a disengagement chamber with an inner diameter of 12.70 cm and a total length of 55.88 cm. A bottle and an extraction chamber were connected to a top of the release chamber. A brass plate with holes 0.397 mm in diameter was attached to the bottom of the copper pipe and an air supply was connected, allowing air to ^{enter through the brass plate to the copper pipe at a constant rate of 0.4245 m 3} / hour .

The test was carried out by charging the copper pipe with a 50 g sample of the Catalytic converter and admitting air at normal speed. The collection bottle and the Extraction chambers were tared and the fines coming out of the release chamber were carried overhead were collected in the extraction chamber and collection bottle and at total time series weighed from 5 and 20 hours to determine the amount of catalyst lost due to wear.

The catalyst A (according to patent 1263 712) and the catalyst B (according to the invention) were subjected to a test for wear resistance in accordance with that described Subject to the procedure with the following results:

Weight percent fine material from start to finish

Catalyst A
Catalyst B

5 hours 20 hours

17th
3

30th

According to this, the catalyst B is superior to the catalyst A in terms of wear resistance.

Claims (1)

Claim: Process for the preparation of an improved abrasion resistant catalyst for oxidative conversion of hydrocarbons, bismuth, molybdenum, silicon, oxygen and optionally Contains phosphorus, being a silica sol with salts containing bismuth and molybdenum and optionally with phosphoric acid or compounds containing pentavalent phosphorus, is mixed in such proportions that the atomic ratio of bismuth to molybdenum in the catalyst is above 2: 3, according to Patent 1263 712, characterized in that in the case of catalysts produced by the spray-drying process and in fluidized bed reactors should be used, the slurried starting mixture in those cases in which not already introduced by the starting components ammonium nitrate in the claimed amounts 1 to 10% ammonium nitrate is added.