DD299225A7 - METHOD AND DEVICE FOR PREPARING ACRYLNITRILE - Google Patents

Abstract

The invention relates to a method and a device for acrylonitrile synthesis with integrated continuous catalyst regeneration, which is carried out in an apparatus unit, divided by a separating tray in two separate Prozeszstufen. With the invention, an effective use of equipment and energy at the same time high Prozeszstabilitaet gewaehrleistet and achieved with the technological interconnection and apparatus on the increase of the catalyst circulation rate to a new large order a significant improvement of the oxidation state of the catalyst and thus its Aktivitaets- and Selektivitaetsverhaltens. At the same time, the inventive design of the autoregenerating zone of the synthesis reactor and the defined feed of the regenerator offgas at propene loads of the synthesis reactor (g propene / g catalyst content) of 0.06-0.15 g / gh ensure a thorough regenerative treatment of the oxidation catalyst. Oxidation catalyst; continuous catalyst regeneration; Synthesis reactor; Regenerator; apparatus unit; Catalyst circulation rate; Car regeneration zone; regenerator}

Description

Synthesis part Regenerator part

Bed density 200-500 kg / m ³ 600-900 kg / m ³

Linear gas velocity 0.4-0.7 m / s 0.02-0.15 m / s

Temperature 680-755 K 710-800 K

_Residual oxygen content] _Λ _ _ _rtW . ".

in the reaction product) 0.5-2.0 vol%

is operated, characterized in that the catalyst from the fluidized bed of the synthesis reactor (1) via 1-3 catalyst lines (21) is fed into the RegeneVatorwirbelschicht (4), in the regenerator (2) the conveying air (19) and the oxidizing agent (15 ) are added with 500-770K and the oxidized catalyst via 1-3 with conveying air (19) acted risers (20) with linear gas velocities of 0.05-3.0 m / s back through the separating tray (14) in the synthesis reactor (1) with the catalyst circulation rate being in the range of 0.5-1.5 g / gh and the residual oxygen content of the regenerator off gas being 14 ~ 19 vol%.

2. Apparatus for carrying out the method according to claim 1, wherein the synthesis reactor (1) and the regenerator (2) arranged underneath are separated from each other by a separating tray (14) in an apparatus unit as independent apparatus stages, the synthesis reactor (1) with Air (6) and raw material distributors (8) and in the catalyst fluidized bed projecting heat exchange tubes (10) is equipped, the coarse (11) and Feinkornabscheider (12) in the head of the synthesis reactor (1) are arranged and the regenerator (2) with oxidation - (16) and Heizmittelverteiler (18) is provided, characterized in that the diameter of the regenerator (2) is 0.8-1.5 times the synthesis reactor (1), the downpipes (13) of the separator of the synthesis reactor (1) extend into the region of the autoregenerative zone, the Katalysatorab- and -zugabestello the catalyst lines (21), which are evenly distributed over the circumference of the synthesis reactor (1), in the Wirbelschi lie of the synthesis reactor (1) and regenerator (2), the regenerator (2) with feed air supply (19) and riser (20) is fitted, which are arranged centrally or evenly over the regenerator, the diameter of the riser (20) the 0th , 05-0.3 times the regenerator (2) is, the conveying air supply (19) in the middle of the riser (20), at the head of the regenerator (2) are arranged 1-3 Grobkornabscheider (11) whose Zyklonabgasleitungen (25) as the riser (20) through the dividing floor (14) lead and their down pipes (13) to the level of Heizmittelverteilers (18) rich.

3. Apparatus according to claim 2 for carrying out the method according to claim 1, characterized in that the riser (20) extends up to the height of the air distributor, the integration height of the cyclone exhaust gas lines (25) in the synthesis reactor (1) 50-100% of the height of Rising line (20), the outlet openings of the riser (20), the cyclone exhaust gas lines (25) and the supply of the conveying air (19) with covers (26) are executed and the Katalysatorentnahmeabzugellen for the catalyst line (21) in a Angle of 30-50 ° relative to the reactor wall deflected and changes in the flow direction in the catalyst line (21) with a ratio arc radius to pipe diameter of 5-10 are executed.

For this 1 drawing

Field of application of the invention

The field of application of the invention is the carrying out of the catalytic ammoxidation reaction of propene and acrylonitrile in the fluidized bed with continuous regenerative treatment of the oxidation catalyst, which takes place in separate process stages in an apparatus unit.

-2- 299 225 Characteristic of the known technical solutions

Catalytic fluidized bed reactions are usually carried out in upright cylindrical containers, wherein the feed of the reactants above the container bottom by means of corresponding distributor means the catalyst is uniformly flowed and forms a fluidized bed with intensive Feststuffdurchmischung. The fluidized bed is described in its hydrodynamic relationships by the bed height and bed density, which can be influenced mainly by the feed amount of reactants, depending on the catalyst characteristics and the effect of internals. To separate the reaction gases of entrained catalyst cyclone are usually arranged in the apparatus head of the fluidized bed reactor, which are usually equipped with downpipes to zurückfOhrung the separated catalyst and can dive for targeted recycling of this KatP / sators different depths into the fluidized bed. The good heat transfer properties of the fluidized bed are utilized in the acrylonitrile synthesis for temperature control by arranged in the region of the reaction zone heat exchange tubes. Fluidized bed reactors are usually carried out with an auto-regeneration zone in the apparatus base according to US Pat. No. 3,427,343 to counteract the deoxygenation in the catalyst grain during the synthesis reaction. In this case, the region of increased oxygen content in the fluidized-bed reactor between the reactant distributors in the apparatus lower part is generally regarded as the autoregenerative zone. The deoxygenation of the catalyst during the synthesis process leads to a change in the catalytically active phase structures in the catalyst grain, which cause a decrease in the catalyst activity and selectivity. With increasing propene load and longer catalyst life, this influence on the activity and selectivity behavior of the catalyst increases. '

A modification of this autoregenerative zone is shown in US Pat. No. 3,944,592. The main aim here is to counteract the olefin losses by reacting the olefin adsorbed on the catalyst grain in the region of the autoregenerating zone with the defined feed of a partial amount of ammonia as a reactant to the desired unsaturated nitrile. Since the maintenance of the fluidized bed but takes place in analogy to the means of the prior art via a arranged in the container bottom, especially with atmospheric oxygen distributor means, with the use of the subsequent perforated plate in the flow direction no separation of regeneration and reaction zone by suppression of intensive Katalysatorrückverrr and thus the targeted process parameter influencing in the area of the regeneration zone. If the propene load is increased from the technically usual range with 0.04-0.06 g / gh (g propene / g catalyst and h) to above G, 06 g / gh, the catalyst deactivation drop of the catalyst can no longer be decisively counteracted Raising the temperature in the auto-regeneration zone over which the reaction zone is prevented due to the high catalyst circulation in the fluidized bed reactor.

In DE-PS 2813227 a reactor for continuous thermal treatment of contaminated carbonaceous adsorbent is described which consists of 2 superimposed stages of Einzolwirbolschichten with lateral overflow ν Oi. the upper to the lower fluidized bed stage and vertical dividing plates on each fluidized bed stage, wherein the two fluidized bed stages are traversed by only a single uasstrom. The reactor is applicable to low expansion fluidized beds with relatively coarse solids. A further disadvantage is that a gas breakthrough over the solids overflow must be prevented by gas-tight solids sluices and the vertical partitions within a horizontal step with a broad particle size distribution of the solid particles for sedimentation and thus lead to non-uniform product quality of the executed chemical reaction on the solid. The increased activity decrease of the catalyst at propene loadings in the range of 0.06-0.15 g / gh can be counteracted by the prior art by:

1. Batchwise discontinuous addition of fresh catalyst with simultaneous withdrawal of deactivated catalyst combined with an overall shorter service life of the catalyst base. This addition of fresh catalyst, which takes place in addition to the technically caused, compensated catalyst losses in the fluidized bed reactor, will remain economically very limited by the increased Katilysatorverbrauch in their practical application.

2. "In situ" regeneration of the basic catalyst bed in the fluidised bed reactor The "in situ" regeneration always involves the interruption of the synthesis process and will, moreover, be limited in its frequency of use due to the short-term regeneration effect.

3. Continuous regeneration of a portion of the deactivated catalyst from the fluidized bed reactor in a stand-alone regenerator, which is the GewÃhr for that at comparable catalyst life even at higher Propenbelastungen the catalyst deactivation in the fluidized bed reactor can be met more or less.

While U.S. patents 4284583 and 4246192, as principles of continuous regeneration, use the FCC principle, e.g. According to US Patent 4310489, which was transferred to the Ammoxidatlonsreaktion of olefins, according to the prior art DD-PS 230528 and DD-PS 206462, a subset of the deactivated catalyst is oxidatively treated continuously in a stand-alone parallel to the fluidized bed regenerator. In the oxidative catalyst treatment, the catalyst is led to a higher oxidation state, restores the catalytically active phase structures and reactivates the catalyst core. The oxidation state of the catalyst gives a direct influence on the catalyst activity and selectivity.

The regenerator in single or moststiger execution is equipped according to the prior art with the usual technical installations, such as distributors and Zyklonabscheiderr ,,. By adding L jftsauerstoff as an oxidizing agent and a preferably used, native heating means disposed on the regenerator bottom distributors the catalyst is levitated and treated oxidatively under regeneration conditions. According to the state of the art, the oxidation state of the catalyst depends on the regeneration conditions, such as the regeneration temperature and the amount of catalyst treated oxidatively per unit time in the regenerator. A further increase in the oxidation state is achieved by the apparatus design of the regenerator, designed according to DD-PS 206462 as a multi-stage regeneration apparatus. Since the oxidation state of the catalyst is influenced essentially by the catalyst circulation rate {catalyst circulation / catalyst content of the fluidized bed reactor and time), a significant increase in the activity and selectivity behavior of the catalyst can be achieved primarily by increasing the catalyst circulation rate.

The regeneration temperature is limited in its absolute size by the process conditions, while in multi-stage regeneration apparatus, the cost-benefit ratio greatly restricts the number of stages.

The increase in the catalyst circulation rate is according to the prior art with independent regenerators, which are operated in parallel to the fluidized bed reactor, due to their arrangement and solids guidance limited. With the arrangement of the regenerator, taking into account the hydrodynamic pressure conditions in the fluidized bed reactor and regenerator fixed the solids between the two apparatuses, economic aspects, which are characterized by the catalyst wear and erosion of pipe wall material, but at high catalyst circulation rates a gentle Fest.ioffö promotion ahead. The application of gentle gravity between the fluidized bed reactor and the parallel regenerator affects the apparatus design of the regenerator, which in turn makes oine multi-stage Rogenaratorausführung in the acrylonitrile synthesis required.

Furthermore, the low regeneration temperature, which is important for a long catalyst life and high activity, combined with high catalyst circulation and catalyst oxidation state, can not be realized. Higher catalyst circulation rates at constant catalyst residence times in the regenerator require larger sized regenerators, with respect to the apparatus arrangement fluidized bed reactor to regenerator, in ih-er technological interconnection and apparatus design with special training of the autoregeneration zone in We, sischicht reactor, in the media management and energy and material recovery of the Regenerator offgas in the Wii belschichtreaktor are fundamentally new to develop.

Object of the invention

The invention aims to develop a method and a device with effective apparatus and energy input and high process stability, compared to the means of the prior art by the technological interconnection and apparatus design of the reactor-regenerator system in the ammoxidation of propene a Increase the catalyst circulation rate in a new order of magnitude and allow for a substantial increase in the oxidation state and the catalytic! Activity and selectivity of the catalyst in the fluidized bed reactor lead.

Explanation of the essence of the invention

The invention has for its object to provide a method and apparatus for carrying out catalytic fluidized bed reactions with continuous regenerative treatment of the catalyst, the high catalyst circulation rates and the technical design of the autoregeneration zone of the fluidized bed reactor, the prerequisite for a deep regenerative Beht.idlung the catalyst at optimal regeneration - And synthesis conditions ensured.

According to the invention, the object is achieved by a novel technological-apparatus-related, energetic and process coupling of the designed as a fluidized bed reactor synthesis reactor with arranged underneath regenerator. The invention is based on the fact that the synthesis reactor and the regenerator are arranged in an apparatus unit, separated by a separating tray. By this coupling of synthesis reactor and regenerator and the thus clearly defined hydrodynamic pressure ratios between the two systems, catalyst circulation rates are achieved on a new scale compared to the prior art, which fully exploit the capacity of the catalyst. This arrangement of synthesis reactor and regenerator in one unit requires only a relatively small amount of equipment, with which a supplement existing synthesis reactors with a regenerator is given even in cramped structural conditions and further the regenerator exhaust a complete material and energy recovery in the synthesis reactor can be subjected.

The catalyst feed to the regenerator is designed so that, taking advantage of gravity and the flow properties of the catalyst, a gentle catalyst promotion is ensured and by the outer catalyst guide, the catalyst feed rate by means of a solids control valve depending on the fluidized bed height in the regenerator can be regulated. For the catalyst back transport from the regenerator to the synthesis reactor, the catalyst riser pipes projecting through the separating tray are exposed to conveying air in such a way that the catalyst is gently conveyed. For utilization of the residual oxygen in the regenerator exhaust gas including the oxygen of the conveying air for the catalyst riser whose line ends are passed through the gas-impermeable separating tray up to the level of the air distributor, in detail depending on its construction, in the synthesis reactor. With the use of the Regeneratorabgases well above the synthesis reactor temperature and its defined feed into the synthesis reactor floor, the regeneration effect of the autoregeneration zone is remarkably raised without significantly higher gas-side loading of the synthesis reactor.

By feeding the Regeneratorabgases in the synthesis reactor can further not only targeted increases the autoregeneration zone, but at the same time also the use of lying in the bottom of the synthesis reactor when using a manifold for air through which ir this case only up to this distributor guided catalyst risers , previously unused catalyst can be guaranteed. The high catalyst circulation rates which are possible due to the coupling of synthesis reactor and regenerator in one unit of equipment and the design of the auto-regeneration zone with the targeted utilization of the regenerator exhaust gas substantially increase the oxidation state of the entire fluidized bed catalyst in the synthesis reactor and thus significantly increase the nitrile yield in the ammoxidation reaction and / or allow a lowering of the regeneration temperature bsi comparable oxidation state of the catalyst in the synthesis reactor. By lowering the regeneration temperature of the residual oxygen content of the regenerator exhaust gas is raised due to the lower oxygen demand for the combustion of the heating means and also leads to the improvement of the oxidation state of the catalyst, which, as was shown, is directly dependent on the residual oxygen content.

When starting up the regenerator to regeneration conditions, a temperature of more than 670K is a prerequisite for the implementation of the heating medium. The hot catalyst from the synthesis reactor is the main heat supplier for the start-up of the regenerator and, with increasing the catalyst circulation rate, substantially simplifies the start-up technology. To better illustrate the nature of the invention, the technological coupling of synthesis reactor and regenerator is shown in an apparatus in Figure 1.

The synthesis reactor 1 and the regenerator 2 are arranged one above the other in an apparatus, but are divided by a separating tray 14 into two separate apparatus units. By feeding in air 5 and ammonia and propene as raw material 7 by means of corresponding distributors 6, 8 arranged in the bottom region of the synthesis reactor 1, the catalyst is fluidized and a fluidized bed 3 forms in the synthesis reactor 1. With the arranged in the synthesis reactor head Grob-11 and downstream Feinkornabscheidern 12, the Roaction gases are separated by entrained catalyst. While the reaction product 9 passes after passing through the Feinkornabscheiders 12 for further processing, the separated catalyst is returned via downcomers 13 in the synthesis reactor fluidized bed 3. The downpipes 13 end in the area of the autoregeneration zone and are provided with the usual scavenging air in order to avoid dislocations. With the return of the deposited catalyst near the bottom of the synthesis reactor 1 in the Autorepenerationszone ensures that also the separated fine grain fraction repeatedly through the reactor reactor fluidized bed 3, thus leading to an approximately constant catalyst grain distribution over the height of the synthesis reactor fluidized bed 3 and thereby the entire grain spectrum of the fluidized bed catalyst for the oxidative treatment both in the auto-regeneration zone and in the regenerator 2 is detected.

For temperature control, the synthesis reactor 1 is equipped with heat exchange tubes 10 which protrude into the synthesis reactor fluidized bed. The catalyst grain during the Nitrilsynthesereaktion caused by deoxygenation reductive damage leads to a loss of activity and selectivity of the catalyst, which is counteracted by the oxidative Katalysatoi treatment in the regenerator 2 and by the technical design of the Autoregenerationszone of the synthesis: eaktors 1 under targeted inclusion of hot regenerator , Thus, a uniformly high level of activity with maximum yield of target product is achieved even at propene loads of more than 0.06 to 0.15 g / gh. The reductively damaged catalyst is therefore guided out of the synthesis reactor fluidized bed 3 over one or three catalyst lines 21 distributed as uniformly as possible around the circumference of the synthesis reactor 1 to the regenerator 2. Utilizing gravity and flow characteristics of the catalyst, taking into account the catalyst slip angle, resulting in a tilt angle of 30-50 ° relative to the reactor wall for the catalyst removal and addition point, as well as piping guidance, catalyst transport is also gentle at catalyst circulation rates of zero , 5-1.5g / gh. With regard to the piping, stalls should be avoided and manifolds with a radius of arc ratio of 5-10 mm should be used. After Katalysatorentnahme- and before-draw-tie bind in the flow direction each Fördergaseinbindungen 22 to support the Katalysatoratortra isportes. Due to different operating conditions in the synthesis reactor 1 and regenerator 2, expansion compensators 23 for absorbing thermal expansions and the use of fixed-solids fittings 24 are provided in the catalyst lines 21. With the solids control valves 24, the catalyst feed to the regenerator 2 is regulated as a function of the height of the regenerator fluidized bed 4.

By subjecting the regenerator 2 to atmospheric oxygen as the oxidizing agent 15 via the oxidant distributor 16 arranged on the regenerator bulb, the catalyst is fluidized at linear gas velocities of 0.02-0.15 m / s, whereby a density of the regenerator fluidized bed 4 of 600-900 kg / m ^{3 is} established. By using the heat of combustion of the heating means 17, which is fed through the Heizmittelverteiler 18 evenly over the regenerator, the temperature is carried by the regenerator 2. By supplying conveying air 19 in the one to three risers 20, which are arranged centrally or evenly over the Regeneratorquerschnirt and having 0.05-0.3 times the diameter of the regenerator 2, the catalyst is fed back through the separating tray 14 in the synthesis reactor 1 at Lineargasgeschwir.digkeiten of 0.5-3m / s. To separate the catalyst entrained with the regenerator exhaust gas, one to three coarse grain separators 11 are arranged in the regenerator head, which are designed with downpipes 13 for returning the catalyst into the regenerator fluidized bed 4. The regenerator exhaust gas is introduced via Zyklonabgasleitungen 25 through the separating tray 14 in the synthesis sector 1. At the bottom of the synthesis reactor 1 and the regenerator 2, emptying residues 27 are provided. In order to prevent displacement of conveying air feed 19 with catalyst or to ensure a defined regenerator exhaust gas guidance and catalyst conveying via riser 20, the pipe ends thereof are each provided with cover hoods 26. The shape of the cover 26 minimizes catalyst wear and erosion of wall materials.

It turned out that eir. 3 defined solids guide over the riser 20 to the synthesis reactor 1 by the mounting heights of the riser 20 and cyclone exhaust line 25 is ensured. While the riser 20 extends to the height of the air distributor 6, the integration height of the cyclone exhaust line 25 should be 50-100% of the riser 20 in the synthesis reactor 1. At the same time, a targeted conveyance and thus deep regeneration of the fine grain portion of the catalyst bed in the regenerator 2 are ensured with these embedment heights.

Only through this described inventive arrangement and execution of synthesis reactor 1 and regenerator 2, whose diameter is 0.8-1.5 times the diameter of the synthesis reactor 1, in a unit of equipment Katalysatorzirkulationsratan of 0.5-1.5 g / gh can be realized. This makes it possible to ensure high oxidation states of the catalyst in the synthesis reactor 1 even at regeneration temperatures in the range from 710 to a maximum of 800K. By lowering the regeneration temperature and the simultaneous use of a preheated to 500-770 K oxidizing agent 15 and the conveying air 19 oxygen contents in Regeneratorabgas of 14-19Vol .-% are reached and influence with the full use of the oxygen of Regeneratorabgases the Speisemolverhältnis the synthesis reactor 1 crucial. At the synthesis reactor 1, which is operated at temperatures of 680-755K, a linear gas velocity of 0.4-0.7 m / s with a density of the synthesis reactor fluidized bed 3 of 200-500kg / m ³ , wherein the residual oxygen content in the reaction product 9 0.5 -2.0 vol.%, The feed molar ratio for the nitrile synthesis reaches propene: ammonia: air ranges of 1: 0.95-1.05: 4-8.

embodiment The invention will be explained in more detail with reference to two examples and a drawing. Fig. 1: the schematic diagram of the device according to the invention. example 1

Synthesis reactor 1 and regenerator 2 are arranged in an apparatus unit according to FIG. In this case, the height of the regenerator 2 was 0.25 times that of the synthesis reactor 1, while the apparatus diameter of the synthesis reactor 1 * and regenerator 2 behaved as 1: 1.3. In the head of the synthesis reactor 1 2 two-stage cyclone systems, each consisting of coarse grain 11 and downstream Feinkornabscheider 12, arranged, the downpipes 13 ranged to the level of the raw material distributor 8. The distance of the air distributor 6, which was below the raw material distributor 8, to the separating tray 14 was 300 mm. Both distributors were designed as manifolds. Catalyst removal took place via a catalyst line 21 with a nominal diameter of 80, the removal and supply nozzles of which were deflected 45 ° to the reactor wall. In the vertically falling part of the catalyst line 21 of the expansion compensator 23 and the solids control valve 24 were arranged. To support the catalyst transport or avoid dislocations, feed gas 22 was metered in the direction of flow in the deflections, which were designed with a ratio arc radius to pipe diameter of 5. The catalyst feed into the regenerator 2 took place via the catalyst line 21 directly at the level of the heating medium distributor 18, which lay above the oxidant distributor 16 and how it was arranged in the bottom region of the regenerator 2. Directly above the heating medium distributor 18 was the feed air feed 19 whose outlet opening, designed with a cover hood 23, led centrally into a riser pipe 20 arranged centrally in the regenerator 2. The riser 20, whose diameter was 0.1 times that of the regenerator 2, reached to the lower edge of the air manifold 6. Their outlet opening was just like the Zyklonabgasleitungen 25 of 3 over the cross section evenly distributed and arranged in the regenerator head Grobkornabscheider 11 performed with covers 23 , While the downpipes 13 ranged to the level of the heating medium distributor 18, the embedding height of the cyclone exhaust gas lines 25 was 60% of that of the riser 20.

Example 2 In an operated according to Example 1 Acrylnitrilsynthesereaktor with arranged below Regenerator 2 was after The feed molar ratio propene: ammonia: air at the synthesis reactor

was 1: 0.99: 9.3. The synthesis reactor 1 was reacted at a reaction temperature of 720K, a linear gas velocity of

0.49 m / s and a top pressure of 0.1 MPa overpressure, whereby a synthesis reactor fluidized bed 3 with a

Bed density of 280 kg / τι ³ and 6.1 m bed height adjusted. The synthesis reactor 1 was at a residual oxygen content of

1.0 vol .-% in Reaktionsproduki 9 driven, the propene charge based on the amount of catalyst in the synthesis reactor 1 was 0.05 g / gh. With start-up of the regenerator 2 and the continuous catalyst circulation between synthesis reactor 1 and regenerator 2, propene charges up to 0.12 g / gh of the reductive catalyst damage were specifically counteracted and the catalyst was raised to a new higher oxidation level. The regeneration temperature was 783 K, the head pressure in the regenerator 0.12 MPa overpressure.

The entry stamp nature of the conveying air 19 and the oxidizing agent 15 was 643 K. The regenerator 2 was at a Linear gas velocity of 0.075 m / s operated, with a regenerator fluidized bed 4 with 710 kg / m ³ bed density and

1,4 m height adjusted. The linear gas velocity in the riser 20 was 2.1 m / s, whereby at constant hydrodynamic conditions in the regenerator 2, catalyst circulation rates of 0.75 g / gh were achieved.

The residual oxygen content in the regenerator exhaust gas was 16.7% by volume and resulted from the use of residual oxygen in the regenerator Synthesis reactor 1 and due to the high catalyst circulation rate to a disproportionate lowering of the Propylene content of propylene air from 1: 9.3 to 1: 5.8. With this arrangement of synthesis reactor 1 and regenerator 2 of Figure 1 is compared with the means of the prior Technik, the parallel to the acrylonitrile synthesis reactor operated regenerator, a new quality in the catalyst activity

and thus achieved an increase in the acrylonitrile yield by an average of 3.2%. '

In the following tabular listing, at the same process conditions in the synthesis reactor 1 (pressure, temperature,

used catalyst) quantitative process parameters for various apparatus embodiments of the reaction system compared. The method and apparatus of the invention are compared with prior art methods consisting of a synthesis reactor 1 with auto-regeneration zone operated without and according to DD-PS 230528 or DD-PS 206462 with external continuous regeneration. While the information on the regeneration temperature and the

Catalyst circulation rate refer to the stand-alone regenerator are in the tabular listing Percentage of acrylonitrile yield and catalyst lifetime (base value in column 1 equal to 100%

set).

unit without separate 0.082 with separate DD-PS -6- 299 225 inventions process parameters regenerating regenerating 206462 dungsgem. 1: 10.3 to 10.9 0.105 method - according to u.Vor- DD-PS 1: 8.8 to 9.5 direction - 230528 820 g / gh 0,052 about 98 0,101 0.12 propene about 40 0,035 Dining Emol ratio - 1: 9.8 to 10.3 1: 8.8 to 9.5 108 1: 5.8-6.0 Propene: air K - 820 75 783 Regeneration catalyst g / gh - 0.05 0.75 circulation rate % 100 106 112 acrylonitrile yield % 100 75 75-100 Catalyst life

From the table, the significant influence of the propene load on the acrylonitrile yield and the catalyst life is apparent. Despite extremely high propene loading, the use of the process and apparatus of the invention over the prior art agents achieves a new quality in catalyst activity with high economic results. '

Claims (1)

-1-claims: 1. A process for the preparation of acrylonitrile by catalytic ammoxidation of propene in the fluidized bed with integrated continuous catalyst regeneration using a reactor containing the Regeneraiorteil and the synthesis part as an apparatus unit directly above one another and using the following reaction parameters in