JPS6034736A - Molybdenum-containing catalyst composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel catalyst comprising a molybdenum-containing calcined composition for the dehydrogenation of ethane to ethylene.

Now, for example, it has been customary for ethylene to be produced industrially by thermally decomposing ethane in an endothermic reaction that takes place at a temperature of about 600 to 1000°C (U.S. Pat.
The reaction times in processes such as those described in US Pat. No. 5,541,179) are very short, making it difficult or impossible to efficiently recover heat from the process stream. In addition, the construction of the high temperature reactor furnace or reaction vessel used requires the use of special alloys. The cracking reaction also produces relatively large amounts of low boiling byproducts such as hydrogen and methane, making recovery of ethylene from such byproducts complicated and more expensive.

It is possible to oxydehydrogenate ethane using a variety of oxyhalogenation catalyst systems in an exothermic reaction. However, these reactions are only accomplished at temperatures of at least about 500-600°C (US Pat. No. 3,080,435). In addition, the presence of halogen atoms in this case increases the difficulty in recovering the olefins produced. Special and expensive construction materials are also required to withstand corrosion from halogens and hydrogen halides within the reaction system. Furthermore,
In order to carry out this process economically, the halogen itself must be recovered and recycled.

Selected letter ≧C resulting from an exothermic reaction at a relatively high temperature
, the oxydehydrogenation of furcane was also carried out using selected catalysts containing Hanacyram (U.S. Pat. No. 3,218,368;
3,541,179 and 3,856.88
No. 1) and selected catalysts containing vanadium and molybdenum (U.S. Pat. No. 3,320,331).

Also, from α,β-unsaturated aliphatic aldehydes such as acrolein to the corresponding α,β-unsaturated aliphatic aldehydes such as acrylic acid,
It is also known to use catalyst systems containing molybdenum and vanadium for gas phase oxidation to β-unsaturated carboxylic acids. These catalyst systems are covered by Belgian patent no. 821,32
No. 2, No. 821,324 and No. 821,325
Elements Mo, V as disclosed in each specification of No.
and X (where X is Nb%Ti or Ta).

However, using these catalysts known prior to the proposal of the catalyst of the present invention, it was not possible to dehydrogenate, for example, ethane to ethylene at relatively low temperatures with favorable conversion (%), selectivity (%), and productivity. was impossible.

Here, the conversion rate, selectivity and physiological properties are defined as follows.

■.

where A is the sum of mole ethane-equivalents (on a carbon basis) of all carbon-containing products excluding ethane in the effluent.

■.

efficiency)% A loxf vy (itsktff)Ji) (D
'JE,** (ag.

= the number of bonds of ethylene (or acetic acid) produced per cubic foot of catalyst (in the catalyst bed) per hour of reaction time. is 0.05 to 1, and k is 0.
03 to about 2).

The above numbers hj and k indicate the relative atomic proportions of the elements MO1Ti, Ti, Bis and St2 present in the catalyst composition.

The St used in the production of the catalyst composition shown above is other than St, which can be present in any carrier (support) that can be used to support the catalyst, as described below.

Elements MO1Ti, Mn, Bi in the new catalyst of the present invention
2 and St are physically present in the catalyst composition in combination with oxygen and are themselves believed to be various oxides, and oxides such as spinel and perovskite are chemically It can also be a combination.

The catalyst of the present invention is preferably prepared from a solution of a soluble compound (salt, complex or other compound) of each of the elements Mo, Ti, Bi and Si, but also from a colloidal sol in the case of St. 5ru. These solutions are 1
Preferably it is an aqueous system having a p of from 7 to 7 and preferably from 2 to 6. Solutions of the various compounds containing the aforementioned elements are prepared by dissolving sufficient amounts of soluble compounds of each element to provide the desired Durham atomic ratio of each element.

These compounds of the various elements selected must be mutually soluble to the extent possible. The St compound is usually added in the form of a colloidal silica sol. If any of the selected compounds of such elements other than 3i are not mutually soluble with the other compounds, they can be added last to the solution system. A catalyst composition is then prepared by removing water or other solvent from the mixture of compounds in the solution system by evaporation.

When using a catalyst deposited and supported on a carrier, the desired elemental compound is usually deposited on a fine porous carrier having the following physical properties (but not limited to these):

Surface area is approximately 0.1-500→ri Apparent porosity is 30
~60X, at least 90X of the pores have a pore size of 20 to 1500 microns, and the particle or pellet shape has a diameter of about 1 to 10 inches.

16 This deposition immerses the support in the final mixture of all compounds, evaporates most of the solvent, and then reduces the system to about 80%
This is achieved by drying at ~220°C for 2-60 hours. The thus dried catalyst is then calcined by heating in air or oxygen at about 220-550°C for 24 hours to give the desired Mo1-(Ti, Mn)j-(B
i%Si)k composition.

Supports that can be used are 7 Lika, aluminum oxide, silicon carbide, zirconia, titania and mixtures thereof.

In this case, the supported catalyst usually contains about 10-50% by weight of the catalyst composition, the remainder being support.

The molybdenum is preferably dissolved in solution in the form of an ammonium salt of molybdenum, such as ammonium para-molybdate, or in the form of an organic acid salt of molybdenum, such as acerate, oxalate, mandelate and glycolate. Introduce it inside. Other water-soluble molybdenum compounds that can also be used are partially water-soluble molybdenum oxide, molybdic acid and molybdenum chloride.

Titanium is preferably introduced into the solution in the form of a water-soluble chelate coordinated with ammonium lactate. Other soluble titanium compounds that can be used are beta-diketonates, carboxylic acids,
Titanium is coordinated, bonded, or complexed to an amine, alcohol, or alkanolamine.

Manganese and bismuth are preferably introduced into the solution in the form of nitrates. Other water-soluble compounds of these elements that can be used are water-soluble chlorides and organic acids such as acetates, oxalates, toriterates, lactates, salicylates, formates and carbonates of such elements. It's salt.

Silicon is preferably introduced into the catalyst system in the form of an aqueous colloidal silica (SiOz) sol.

For the catalyst to be most effective, Mo, Ti.

It is believed that the copper, Bi and St metal components are somewhat reduced below their highest possible oxidation state. This is achieved during heat treatment of the catalyst in the presence of an organic reducing agent, such as a reducing agent or an organic lead agent, which is introduced into the solution system containing the catalyst. can also occur in reactors where the oxidation reaction is carried out by passing hydrogen or a hydrocarbon such as ethane, ethylene or propylene through a bed of catalyst.

Supported or unsupported catalysts can be used in fixed or fluidized beds.

The catalyst of the present invention selectively oxydehydrogenates ethane without the addition of diluents outside the water body to produce ethylene and acetic acid as the final products with conversion (%), efficiency (%) and productivity as shown below. It can be caused by

In this case, in a normal reaction process without addition of water, 1 mol of water is produced for every mol of oxydehydrogenated ethane. The water thus produced during this reaction yields about 0.05 to 0.25 moles of acetic acid for every mole of ethylene produced. However, when water is added, an additional amount of approximately 0.25
Resulting in the production of acetic acid increased to ~0.95 mole Final product (ethane) conversion % efficiency % Productivity ethylene (without added horse 0) 2-7 60-854-7.5 ethylene (added nta dust ) 2~8 50~802~8
．． 5 Acetic Acid (without added HtO) 2-7 15-25
1.5~4 Acetic acid (with added HtO) 2~8 15~
4525-5 The following examples illustrate the preparation of catalyst compositions of the present invention and their use in the oxydehydrogenation of ethane to ethylene.

The activity of the catalyst is determined in a small U-tube reactor in which oxygen and ethane are fed in a pulsatile flow (test method A), or in a standtube reactor in which ethane and oxygen are fed in a continuous co-current flow. (Test Method B) or by the back-mix autoclave method (Test Method C). These test methods are described in detail below.The test catalysts were screened for the determination of ethane oxydehydrogenation activity in a Catalyst Testing Corporation Tsutomu MTR microreactor.

The reaction zone containing this catalyst is 20 inches long and 8 inches in diameter.
A silica O-tube was heated by immersing it in a flowing liquid gas whose temperature was controlled by a thermometer.The thermocouple for temperature regulation and measurement was placed above the level of the catalyst in the U-tube. immersed in fluid sand at least 3 inches high.

A preliminary investigation of the temperature situation in the sand bath showed that from top to bottom the temperature varied by less than 3 degrees above the fixed point set by the regulator.

This microreactor was precisely coupled to a gas chromatograph to separate the reaction product stream.

Intercept the helium supply line inside the chromatograph at a point immediately after the flow regulator and connect it to the port (8) and through the valve in the 2-position [Union, Carbide Co., Special Machinery Department, model C4-703]. Manual sample injection valve with opening (6) [Union, Carbide, Model 2112-5
The helium carrier feed flowing through the microreactor was collected from the chromatograph by directing it through 0-21' into the inlet leg of the U-tube reactor. The system is equipped with an injection port with a rubber septum at the reactor inlet. The flow of product gas from the reactor was conducted via a valve with an opening (8) which served to branch the flow of product gas through the cold trap to one of the two analysis systems of the chromatograph. Each valve is equipped with a bypass valve that can be adjusted to equalize the pressure drop across the chromatographic columns within that analytical system.

Injection of the feed gas (composition: 6.5% by volume oxygen, 8.0% by volume ethane, remainder nitrogen) in 2.0-minute pulses was carried out by means of a gas-tight syringe through the port just before the catalyst. The gas is diluted by helium carrier gas which passes through the reactor at 60 d/min throughout and passes through an analytical gas chromatograph to remove the catalyst 3. I carried it onto Of.

Analysis of the generated mixture was performed using Poropak.
)(T,M,)R wrapped in a 10' x 1/8' diameter stainless steel column. The column was heated starting at 30° C. with an increase of 10° C. per minute. The retention times under these conditions were 2 minutes for air, 2.5 minutes for carbon dioxide, 3.4 minutes for ethylene, and 4.0 minutes for ethane. The identity of the product was then confirmed by chromatography of a pure known sample and mass spectrometer examination of each distinct peak. Boropack R is a polystyrene resin in the form of fine particles and spheres crosslinked with divinylbenzene.

Catalyst test method B The catalyst was tested in a tubular reactor under the following conditions.

The ethane gas supply composition (volume %) was 9.0% C, Ha,
.

6.0%0□ and 85%N2, space velocity is 34-Q
) hr-'s total reaction pressure is 1 atm. We also recorded the activity of the catalyst as the temperature rose. The reactor consists of a 1/2' stainless steel standpipe with a melt bath approximately 12' deep.
It is heated using DuPont Hytic (dark name) heat transfer salt. A 1/8' thermocouple sleeve was passed through the entire length of the reaction tube and through the center of the catalyst bed. The temperature status of the catalyst could be determined by sliding a thermocouple through the sleeve.

Twenty six catalysts were introduced into the snow such that the top of the catalyst bed was 4' below the surface of the heat transfer salt. The catalyst bed is >10
The length was set to 5 to 5 f so as to have a depth-to-section ratio of . The upper zone of the catalyst bed was enriched with glass and glass which served as a preheater. The gas effluent from the reactor was passed through a condenser and trap at 0°C. The gas and liquid products thus obtained were analyzed as described below.

The reactor used for the high pressure studies of catalyst testing methods was a bottom-stirred Magnedrive autoclave with a centrally located catalyst basket and side product effluent lines. A variable speed, magnetically driven fan continuously recirculated the reaction mixture over the catalyst bed. This reactor was presented at the 64th International Conference of the American Institute of Op, Chemical, and Engineers held in New Orleans, Louisiana, USA from March 16 to 20, 1969. Submitted as Proceedings 42E to the Second Part of the Symposium on ``Advances in High Pressure Technology'' by the United States of America,
As depicted in Figure 1 of the paper by Partey, Hamprick, Maron, and Wlotzuk et al. entitled "Reactor, Four, Paper Phase, Catalytic, Studies," available from AIChE, 345 47th Street, East, New York, 10017, New York. It is of the same type.

The backmix autoclave has a stainless steel catalyst vessel located above the stirring fan blades. The fan blows gas upward and inward through the catalyst bed in a conventional manner.

Measure the temperature at the inlet and outlet with two thermocouples ♂
1/2 through the rotameter at a pressure of approximately 150 psig.
A gaseous ethane-COX mixture, with oxygen fed into the reactor through four lines, was fed via a rotameter and was then combined with the silicon feed just before introduction into the reactor. The liquid was then pumped directly into the reactor via the same feed line as the gas. However, after the gases were mixed, a liquid inlet was connected to the line. Effluent gas was removed via a port on the reactor side. Condensable liquid products were removed by a series of cold traps in two baths. The first bath contained moist ice at 0° C. and had two cold traps immersed therein. A second bath of dry ice and acetone at -78°C had two cold traps.

The non-condensable components of the discharge stream were discharged via a dry gas-test meter at atmospheric pressure to determine their total volume.

A sampling valve with a port (8) allowed direct sampling of both product and feed gas via lines directly connected to the reactor feed and product streams. No external recirculation was used.

Determine the bulk volume of the weighed catalyst sample (approximately 150 cc)
, this sample was placed into the catalyst basket. In each case, the amount of catalyst charged was approximately 1311f. Stainless steel screens were placed above and below the catalyst bed to minimize catalyst wastage and circulation of catalyst fines. After loading the reactor with the catalyst basket and sealing the reactor, the process line was pressure tested at ambient temperature to a pressure of about 100-200 psig, which is above the highest expected working pressure. All nitrogen was used in this test.

When the reactor was found to be leak-free, pure N was passed through the reactor and the temperature was raised to between 275°C and 325°C. Gas feed composition is 76-97% C by volume,
H6, 3-6% 02.0-10% H, 0, and 0-1
It was within the range of 0% COX. After the desired temperature was obtained, the mixture of oxygen and ethane-Ox was adjusted to give the desired steady state proportions under the desired overall flow rate. The concentration of each component in the effluent gas was measured by the gas chromatography analysis described below. Approximately 0.5 to 1 hour was allowed to reach the desired temperature and steady state throughout the reactor. The liquid product trap was then drained and the dry gas test meter reading was taken to note the start time. The effluent gas samples during the operation process were CtHe, C
Analyzed for 2H4,02, CO, Co, and other volatile hydrocarbons. At the end of the run, the liquid product was collected and the volume of effluent gas was recorded.

These liquid products were analyzed by mass spectrometry.

The reactor inlet and outlet gases for all tests conducted with Test Methods B and C were Ox, 1% and 5A molecular sieves (14/30 (03, N
3. CO is the same), CO,, ethylene, ethane, H
, 14'X 1/8' tower Boropack Q for 0
(80/100 mesh) at 95°C.

The liquid product, when fully obtained, was analyzed by mass spectrometry for N20, acetaldehyde, acetic acid, and other components. Borovac Q (T, Mi is a fine particle spherical polystyrene resin crosslinked with divinylbenzene.

The conversion and selectivity in all these cases were based on stoichiometry according to the following equation, without applying individual response factors to the eluted peak areas of the chromatograms.

CzHe + 1/20 → CtH4+ HtOCeH
e + 7/201 →2COt + 3N20 3 above
The reaction conditions for the seed test method were as follows.

A 3.3 200-650 -- B 1 300-400 10.6 340 In testing a catalyst, the lowest temperature at which catalytic activity is initially imparted by the catalyst is first tested and this is compared to the temperature of initial activity. (To). The selectivity of the catalyst for oxydehydrogenating ethane to ethylene using To was then measured.

T. Then 10% conversion of ethane to ethylene is achieved.

In order to determine the above minimum temperature, the activity of each catalyst was evaluated at a higher temperature, and this temperature is shown in Table 1 as eT1o. The selectivity of the catalyst for the oxydehydrogenation of ethane to ethylene at T,oK was also determined and shown in Table 1.

Example 1 457f ammonium para-molybdate (2.6 g atom Mo) was dissolved in 0.71g water with stirring at 60-80°C in a t-stainless steel oven.

To the resulting solution was added 249 t of titanium lactate solution, 1 Tyser LA'' (0.21 gram atoms of Ti), 2
5- Add 8 M to 110 d of water containing concentrated nitric acid 10
4t bismuth nitrate pentahydrate (0.21 g atom Bi) and 153t nitrate wl manganese 50.3
% solution (0,43 g atom seed), then 86f
Ludotsux (LLJDO) is a colloidal silica solution of
X) LS was added.

The resulting mixture was heated with stirring to give 7702 (100
0d) two-tone silica-alumina 5A52051/4
'The spheres were added and then evaporated to dryness with stirring on a steam bath and further dried for 16 hours at a temperature of 120°C.

The thus dried material was then transferred to a cage made from a 10-mesh stainless steel wire mesh sieve and calcined for 5 hours in a Matsufuru furnace at 400° C. under an ambient atmospheric atmosphere.

The amount of catalyst deposited on the carrier calculated from the amount increasing power of the obtained catalyst was 32.5%.

The above (D TYZOR) I, A (PJA trademark) is a colloidal titanium lactate manufactured by DuPont, De, Nemoas, & Corporation.

LUDOX LS (trade name) is also a colloidal silica solution manufactured by the same company.

The effluent gas in the evaluation test of the catalyst of this example does not contain hydrogen, methane or higher alkanes produced during this process, and the products produced are ethylene, acetic acid,
They were water, ■ and CO2.

Claims (1)

[Claims] General formula Moh-(T4, Mn)j-(Bi,
Dehydrogenation of ethane to ethylene, consisting of a calcination composition of St Molybdenum-containing catalyst compositions for use.