UA64390A - Method and reactor for gas-cycle chemical processes by aerosol nanocatalysis - Google Patents

Abstract

The method for performance of gas-cycle chemical processes by aerosol nanocatalysis in the reactor in the presence of inert material and heterogeneous catalyst in aerosol state with equivalent diameter of the particles not more than 10 ým. The reactor or only the particles of inert material and heterogeneous catalyst with the concentration in the zone of reaction equal from 5.2À10-4 to 7.01À10-3 g/m3 of passed steam-gas mixture is subjected to the action of elastic vibrations with a frequency of 33-400 oscillations per minute and an amplitude of 10-20 mm with the energy of impacts of inert particles equal to 1.4À10-5 J. The reactor for the realization of gas-cycle chemical processes by aerosol nanocatalysis contains cylindrical housing with inlet and outlet ducts for reagents and reaction products, hatch for admission of heterogeneous catalyst and inert material. The end of the ducts is located inside the vibro-liquified layer. The gas distributors-filters (grids) which surface is located coaxially with the direction of motion of inert particles and heterogeneous catalyst are located at the ends of the ducts.

Description

Description of the invention

The invention belongs to methods and reactors for carrying out chemical processes by aerosol nanocatalysis in 2 industries and can be used for laboratory studies of kinetic characteristics of chemical reactions.

A known method of carrying out chemical processes in the presence of a heterogeneous catalyst consisting only of catalytically active material in an aerosol state and inert material in a reactor with a fluidized bed of a catalyst or inert material into which 70 is continuously introduced from above or below and removed from below or above inert material or catalyst (patent of Ukraine Mo9010, application 04.08.88, published 30.09.96).

The disadvantage of the known method is the need to recirculate the catalyst or inert material and the fluidized state of one of them, which significantly complicates the technological process and reactor equipment.

The closest in technical terms is the method of performing gas-phase chemical processes in the presence of a heterogeneous catalyst, which consists only of catalytically active particles in an aerosol state and a fluidized bed of inert material, into which the catalyst is continuously introduced from the bottom and removed from the top, while the concentration of the catalyst is 1-15g/m of the steam-gas mixture under normal conditions, with the equivalent diameter of the catalyst particles no more than 1Ωm (patent of Ukraine

Mo19014, MKV VO1.)8/08, application. 04/23/93, publ. 27.12.97, prototype).

The disadvantages of the known method are: - the need to recirculate the catalyst; - a rigid connection, characteristic of a fluidized bed, between the diameter and density of particles of inert material and the linear speed of the working mixture, which does not allow to significantly change the time of the reagents in the reaction zone; 29 - the activity and dispersed composition of the catalyst, which are provided by uncontrolled, chaotic interaction "with an efficiency of the order of 1095 particles of inert material and moving catalyst; - the need to overcome the resistance of the fluidized bed.

The closest technical solution to the device is a reactor block, which consists of a reactor and a catalyst circulation system: reactor-cyclone-filter-catalyst dispenser-reactor. The reactor looks like a cylindrical device in the lower part of which there is a non-fall gas distribution grid and below it (o) an additional volume that ensures uniform distribution of a larger flow of one of the reagents across the intersection of the distribution grid and the reactor. In the zone of the fluidized bed there are rigidly fixed horizontal distribution devices for supplying other reagents. The reaction products and the catalyst are removed from the top of the reactor and sent to the cyclone, and then to the filter to separate the catalyst particles from the reaction products. The catalyst is returned to the reactor. ("Chemical industry of Ukraine", Mo1-2, 2000, pp. 80-88). oh

The disadvantage of the known device is the presence of a complex gas distribution device, through which one of the reagents is introduced, which ensures uniform fluidization of inert particles across the entire cross-section of the device, the need for additional nozzles and gas distribution devices for the introduction of other reagents, located perpendicular to the direction of movement of reagents and inert material, and the complexity their fixation due to large - o dynamic loads, as well as a complex, bulky and insufficiently accurate system of providing a catalyst from the reaction zone. The invention is based on the task of creating such a method and reactor for the implementation of gas-phase chemical processes by zero-aerosol nanocatalysis, in which, thanks to the creation of a directed interaction of inert particles and a heterogeneous catalyst, consisting only of particles of a catalytically active substance or substances that are in an aerosol state , the introduction of reagents and the output of reaction products through nozzles, which end with gas distributors-filters (grids), and are located in the vibro-liquefied layer, achieve an increase

ChK" activity of the catalyst and simplification of the technology. o The task is solved by the fact that in the method of performing gas-phase chemical processes verozolnym. nanocatalysis in a reactor in the presence of an inert material and a heterogeneous catalyst in an aerosol state (se) 50 with an equivalent particle diameter of no more than 1 Ωm, according to the invention, a reactor or only particles of an inert material and a heterogeneous catalyst with a concentration in the reaction zone equal to 5.210 to 7, 01710-Zg/m of the passed steam-gas mixture is exposed to elastic vibrations with a frequency of 33-400 vibrations per minute and an amplitude of 10-20mm with an energy of collisions of inert particles equal to 1.4710J. The size of the catalyst particle

It is located between 1079 and 10Zm. The mass of the inert particle is up to 1072 times greater than the mass of the catalyst particle.

The strength and wearability of inert particles is higher than that of the catalyst. » In a reactor for carrying out gas-phase chemical processes with aerosol nanocatalysis, which contains a cylindrical body with inlet and outlet nozzles for reagents and reaction products, a hatch for introducing a heterogeneous catalyst and inert material, the task is solved by the fact that the ends of the nozzles are located inside the vibro-liquefied layer, and at the ends of the nozzles, gas distributors-filters (grids) are installed, the surface of which is located coaxially with the direction of movement of inert particles and the heterogeneous catalyst.

Studies have shown that the activity of the catalyst, which is determined by the change in the reaction rate, increases from 2.52 to 8000 g/m? reaction volume compared to the prototype. This is achieved by the continuous interaction of the vibro-liquefied layer of inert particles with the same volume of heterogeneous catalyst under the influence of elastic 65 vibrations on the reactor or only on particles of inert material and heterogeneous catalyst. The frequency range of oscillations from 33 to 400 oscillations per minute allows you to control and optimize the intensity of interaction between inert particles and the heterogeneous catalyst. A feature of the proposed process is the continuous and long-term mechanochemical activation of the catalytically active material in the aerosol state due to the impact interaction of inert particles on the particles of the heterogeneous catalyst directly in the reaction zone. This leads to some fundamental differences with the prototype. Under the conditions of the prototype, the concentration of the catalyst in the calculation of the volume of the reactor and the volume of the passed reaction mixture are equal, since the catalyst is constantly introduced and removed from the reactor. Under the conditions of the proposed invention, a certain amount of catalyst is preliminarily introduced into the reactor and reagents are continuously introduced. At the same time, the catalyst is constantly subjected to the mechanical influence of the vibro-liquefied inert material. The catalyst disperses, defects in the structure appear, and the qualities of its 7/o surface, which determine its activity, change. All this leads to a significant decrease in the concentration of the catalyst and is from 5.27107 to 7.01710 g/m3 of the passed reaction mixture. The optimal ratio of the mass of the catalyst particle to the mass of the inert material particle is of the order of 1:10 15, which provides the necessary impact energy on the catalyst during collisions. The material of the inert particles is chosen in such a way that its strength is much higher than that of the catalytically active material, thanks to which the inert particles practically do not wear out 75 over several years, and the catalytically active material is dispersed to nanosize, which ensures the growth of the contact surface with the reagents and increases catalyst activity. Due to the constant presence of the catalyst aerosol in the reaction zone, the specific load on the raw material in terms of the mass of the catalyst increases significantly and the need for it decreases accordingly.

A gas-dynamic regime is created in the reactor, close to ideal mixing in the solid phase. In the proposed reactor, it is possible to study and carry out industrial production with reagents of liquid initial aggregate state. The design of the reactor, in comparison with the prototype, is simplified. Due to the coaxial location of the inlet and outlet nozzles of the reagents, which coincide with the direction of movement of inert particles and the heterogeneous catalyst, the working surface of gas distributors-filters (grids) is constantly cleaned of catalyst particles by inert particles that move coaxially. The presence of filters (nets) eliminates the removal of the catalyst from the reaction zone and the need to use additional equipment: cyclones and filters. "

The movement of the layer of inert particles due to external influence practically eliminates the resistance of the layer and the loss of pressure during the passage of material flows through the reactor.

The proposed method is carried out as follows.

Inert material and a heterogeneous catalyst are loaded into the reactor. Turn on the vibrating device and prepare the catalytic system for at least 2 0.5 hours. Before starting, the catalytic system is heated to operating temperature with the help of an additional starting heater. Heating is carried out by blowing the reactor with air, combustion substances or inert gas, or by supplying thermal energy through a heat exchanger installed in the vibrating bed. co

Reagents are continuously supplied in separate streams or in a mixture to the lower or upper part of the reactor through special nozzles-gas distributors, which end inside the apparatus with filters (nets). Reagents C pass through a catalytic system: a vibro-liquefied layer of inert material and a heterogeneous catalyst. At the same time, a chemical interaction takes place. The time the reagent stays in the vibrating bed is determined by the kinetics of a specific process and, if necessary, can be easily changed within wide limits. The reaction products are removed through special nozzles designed in accordance with the above, but the point of their selection is located higher in the gas flow. "reactions are directed to the utilization of heat and further to the release of target products.

To implement the proposed method, a reactor was developed, the technical essence and principle of which - c are explained by the figure showing: 1 - reactor; 2 - input pipe; C - output nozzle; 4, 5 - hatches for input and output of the catalytic system; 6 - filter element; 7 - vibrating device. "» Reactor 1 is a cylindrical device with inlet and outlet nozzles 2, C for reagents and reaction products (the number of nozzles is determined by the pressure reserve at the entrance to the reactor), hatches 4, 5 for the input and output of inert material and heterogeneous catalyst. The end of the nozzles- of gas distributors 2, З are located (o) inside the vibro-liquefied layer, at the ends of which filters (nets) are installed 6. A 1" vibrating device is installed inside the reactor 7. Before feeding the reagents into the reactor, the catalytic system is introduced, and the vibrating device is turned on.

The catalytic system is heated to the required temperature. Reagents are introduced from below or from above through nozzles 2, (95) Z, at the ends of which filters (nets) b are installed, thanks to which the catalyst is not carried out of the reaction zone and co 50, together with vibration, gas distribution of the incoming and outgoing flows is carried out.

A laboratory reactor for studying kinetics works as follows. 62 The reactor is thoroughly blown, if necessary, washed with a solvent. Then, inert material and the required amount of catalyst are loaded into it. The hatch is closed, mounted in a tubular furnace, connected to a vibrating device and a communications system. The tightness of the system is checked. Then the furnace is turned on and the reactor is heated to the specified temperature. A gaseous reagent - air - is fed into the reactor and the vibrating device is turned on. In z», depending on the condition of the filter, which is installed on the line of reaction products, the operation of the filter installed in the reactor is monitored. In the case of removal of the catalyst from the reaction zone, the experiment is stopped and the cause is eliminated.

If we assume, in accordance with the experiment, that the removal of the catalyst is no more than 295 per day, then the catalyst placed in the reactor works for 50 days. In industry, the removal of catalyst 60 is compensated by the periodic introduction of additional catalyst. At the same time, in 50 days, the consumption of the catalyst will double and amount to: 275.27 107 to 7.01710Zg/m? of the omitted reaction mixture.

Example 1 (comparative).

Natural gas is oxidized with air oxygen in a flow-type reactor with an internal diameter of 0.05 m and a height of 1.2 m, the initial heating of which is provided by an electric heater. Air, which is a fluidized b5 agent of solid inert material, is fed into the lower zone of the reactor. The volume of liquefied inert material, which uses glass balls with a diameter of 0.7-1.0 mm, is 1000 cm3. Natural gas is fed into the lower zone of the reactor. The flow component is a deep oxidation catalyst, which uses metals of the transition group, its oxides and combinations. The catalyst is fed into the lower part of the reactor, and removed from the upper part and returned to the beginning of the process, oxidation is carried out at a temperature of 600".

The concentration of the catalyst in the reaction zone is determined by polluting the waste gases directly after the reactor.

Examples 8 and 12 are carried out under the conditions of a prototype on an installation with a fluidized bed of inert material.

The catalyst is introduced into the lower part of the apparatus and removed from the top. The diameter of the reactor is 50 mm, the height is 1.2 m.

The results of the research are given in the table. 70 Examples 2-7

Oxidation of natural gas is carried out with air oxygen in a reactor with a reaction volume of 38 ml, mounted in a tubular furnace. The diameter of the reactor is 4 mm, the height is 40 mm. Air consumption is 97, bg/h. The inert material for creating a vibro-liquefied layer occupies 7095 bulk volume of the reactor. As an oxidation catalyst, the original parts of iron oxide 400-2000 Ohm are used. The catalyst is loaded into the reactor through the hatch along with 7/5 solid inert material. In examples 2-4, glass balls with a diameter of 1-1.3 mm are used as an inert material, the reaction is carried out at a temperature of 6007C and a frequency of oscillations of 150 oscillations per minute with a change in the amplitude of oscillations within 10-20 mm. In examples 5-7, quartz sand with a particle diameter of 1-2 mm is used as an inert material, the reactor is heated to a temperature of 700"C and the oscillation interval of 66-168 oscillations per minute with an amplitude of oscillations of 100 mm is examined. The efficiency of the chemical transformation is judged by the support in the source gases di- and mono-oxides of carbon. As a result of these data, the rate of chemical reactions is calculated. The selection of reaction products is carried out through the upper fitting of the reactor. Their composition is determined on the sensor analyzer of continuous control M5I-150 Vavis. The results of the studies are shown in the table.

Examples 9-14

Oxidation of acetic acid and 1,2-dichloroethane is carried out with air oxygen. To carry out the process of using a reactor mounted in a tubular furnace with a reaction volume of 8 ml. The diameter of the reactor is 20 mm, the height is 25 mm. Air consumption 18.8 g/h. The frequency of oscillations is 33-400 oscillations per minute, the amplitude of oscillations is 15 mm. "

The inert material for creating a vibro-liquefied layer (glass balls with a diameter of 1-1.3 mm) is 7090 bulk volume. The oxidizing substance is fed into the reactor through the bottom pipe. As an oxidation catalyst, particles of iron oxide are used for examples 9-12 and copper oxide for examples 13-14, with an initial size of 400-2000 nm. The catalyst is loaded into the reactor through the hatch along with solid inert material. The reactor is heated to a temperature of 600 °C, and for examples 13-14 to 580 °C, air is supplied and the vibrating device is turned on. The selection of reaction products is carried out through the upper fitting of the reactor. - carbon oxides for examples 9-12 and carbon dioxide, hydrogen chloride and chlorine for examples 13-14. The composition of the reaction products is determined by the tetrametric method, on the Tsvit chromatograph and on the M5I-150 continuous control sensor analyzer

Vazis The results of the research are given in the table.

The research results showed that the volume of the reactor does not affect the activity of the catalyst, the frequency and amplitude of oscillations are the main characteristic specific for this technological and apparatus design of the process. "

The given examples confirm that the implementation of the process by the proposed method in the proposed reactor allows to significantly reduce the cost of the catalyst per unit of processed product due to the increase in the activity of the heterogeneous catalyst while maintaining the optimal degree of conversion of the reactants;" substances

Examples 2-4, 9-11 and 13-14 show that the use of a vibroreactor leads to a significant increase in the productivity of raw materials in terms of the mass of the catalyst (column 10) in comparison with the data of the prototype.

Ge" In the prototype, the catalyst spends a considerable time in the external transport cycle: exit from the reaction zone-cyclone-filter-dispenser-entry into the reaction zone. In the given examples, the reaction rate compared to the prototype increases from 2.52 to 8000 times, which is explained by the continuity of mechanochemical activation of the catalyst in 2) the reaction zone.

Examples 2-4 show that with a constant number of oscillations, an increase in their amplitude in the range of 10-20 mm leads to an increase in productivity, reaction speed and a reduction of almost 2000 times the need for a catalyst and more than 3.5 times the volume of the reaction zone . A decrease in the last two indicators (columns 12, 13) leads to a decrease in operating costs and capital investments. This is due to a 2.52-fold increase in catalyst activation efficiency compared to the prototype.

In examples 5-7, quartz sand of arbitrary shape is used as an inert material.

Productivity and reaction rate decrease despite the increase in temperature from 00°C to 700°C. It

P is explained by a decrease in the intensity of activation due to the irregular shape of the inert material. The best performance in this series is sample 5 with the lowest number of oscillations.

Acetic acid in the conditions of the prototype was repeatedly studied. The productivity and speed of the reaction increases by 554 times, and the required volume of the reactor decreases by the same amount, the need for a catalyst decreases by 11,000 times, examples 9-11.

In examples 12-14, compared to the prototype, the volume of the reactor is reduced by almost 8,000 times, and the concentration of the catalyst is reduced by 34,400 times.

In modern industrial reactors, the concentration of the catalytically active component reaches 200-400 kg/m 65 of the reaction volume. Thus, aerosol catalysis in a vibroreactor allows reducing the need for a catalyst while simultaneously increasing the reaction rate.

On the basis of the above, it is possible to conclude that the proposed technical solution is new, has a technical level and is industrially suitable. substance - 7 - oxidation reaction i;

Matters | air | mass consumption |Concern-tration | frequency |amplitude substance per mZ/h concentration volume reaction volume catalyst |reactorr g/h g/h g g/h ginm Zr.sum. fluctuations kg/gkat g/imZr.obes per minute then I 1314 15161718 18111111" change PEN BABYN NN BY and Po NBN NBN 10-5 446 97.6 1011 9.27 1.210-3 144 10 1.01710 6 25.84 10-5 sen and new -5

Acetic acid 0.41 4078 52 16.5 0.21 0.058 1.0 1.0 in prototype conditions

Bl -5 -5 -5 12 Dichloroethane 0.02 4795 77.78 21.0 0.011 31310-3 1.0 1.0 in "prototype" conditions)

From F

Claims (5)

Formula of the invention (ze) 1. The method of carrying out gas-phase chemical processes by aerosol nanocatalysis in the reactor in the presence of "I inert material and a heterogeneous catalyst in an aerosol state with an equivalent particle diameter of no more than 10 μm, which differs in that the reactor or only particles of inert material and a heterogeneous catalyst with a concentration of reaction zone equal to 5.20107 to 7.0101073 g/m? of the passed vapor-gas mixture is exposed to elastic vibrations with a frequency of 33-400 vibrations per minute and an amplitude of 10-20 mm with an energy of collisions of inert particles equal to 1.40107 J. 2. The method according to claim 1, which differs in that the size of the catalyst particle is in the range from 1039 to 1078 2 s Sh y 3. The method according to claims 1, 2, which differs in that the mass of the inert particle is up to 107? times greater than the mass of the "" catalyst particle. 4. The method according to claims 1-3, which differs in that the strength and abrasion resistance of the inert particles is higher than that of the Catalyst. Gee! 5. A reactor for carrying out gas-phase chemical processes by aerosol nanocatalysis, which contains a cylindrical body with inlet and outlet nozzles for reagents and reaction products, a hatch for the introduction of a heterogeneous catalyst and inert material, which is distinguished by the fact that the ends of the nozzles are inside the vibro-liquefied layer, and at the ends of the nozzles, gas distributors-filters (grids) are installed, the surface of which is located coaxially with the direction of movement of the inert particles and the heterogeneous catalyst. (42) 60 b5