CN1301346A - Apparatus, apparatus and method for testing heterogeneous catalysts for short contact time reactions - Google Patents

Abstract

The present invention relates to an apparatus, apparatus and method for testing heterogeneous catalysts for short contact time reactions. It is a new application of capillary technology, where capillaries and separation columns are used as on-line sampling probes and for compound separation. The apparatus comprises a furnace to obtain a wide and uniform temperature distribution, a tubular reactor, a junction unit, gas and liquid injection valves, a gas chromatograph equipped with suitable detectors, mass flow and temperature measurement controllers, injectors, reactor and pre-column pressure regulating valves, on-line sampling applications for capillary technology, sample splitting for capillary technology, pulse mode, simultaneous detection of hydrogen and compound responses.

Description

Apparatus, apparatus and method for testing heterogeneous catalysts for short contact time reactions

The present invention relates to a device, equipment and method for testing catalysts for short contact time reactions. It is a new application of capillary technology in which capillary and separation column are used as in-line sampling probes and for the separation of compounds. The equipment is suitable for testing short contact time catalysts and catalytic reactions, it is operated by pulse method, and the product is preferably analyzed by on-line gas chromatography.

Product yields, coke combustion, catalyst regeneration, and reaction kinetics studies of catalytic cracking are usually evaluated by experiments performed in fixed-bed tubular reactors. Feed times are long, often tens of seconds, which means that the product distribution is an average value and that the performance of the catalyst is unstable due to catalyst coking. This average value and transient nature of catalyst activity degrades the accuracy of the initial reaction product distribution and initial reaction rate assessment of the cracking reaction. In addition, traditional laboratory test methods, such as microactivity method (MAT) ASTM D3907-80, improved method D3909-87 and D3907-92 can only be used within strictly limited reaction conditions, from the point of view of reaction simulation, These reaction conditions are not broad enough. Conventional methods using cold traps without capillary technology are often used. Continuously operated reactors are not suitable for testing catalysis with short contact times, so the only solution is a pulsed reactor. The advantage of the pulse reactor used in different gas oil catalytic cracking experiments is that the activity of the catalyst can be considered to be constant due to the short contact time; and the temperature can be considered to be constant due to the small amount of injected oil.

For reaction simulations, the injected feed pulse should meet the catalyst as plug flow, so mixing of feed and carrier gas should be avoided. The only way to prevent gas mixing is to minimize the dead volume between the injection point and the catalyst. Mixing of gases also increases the sample pulse width and degrades compound resolution. Possible alternatives to avoid loss of resolution in compound analysis are to minimize the dead volume between the catalytic bed and the separation column or to use liquid nitrogen cold traps and fast vaporization.

There are several applications available that use a similar basic principle, they are the direct connection of a test reactor or furnace to a gas chromatograph (GC) and the connection of The feed is injected into a separate vaporization chamber or injector or the upper section of the reaction tube. In addition, a carrier gas is used to pass the vaporized feed over the catalyst and send the reaction products to a separation column. In addition, the same carrier gas is also used as the dilution gas in the separation column. The major differences between state-of-the-art applications are the choice of oven, separation column, sample well, split, and detector.

R. Collyer, M. Larocca and H. He Lasa published a device for the study of impulse reaction kinetics (Canadian Journal of Chemical Engineering 1989, 58, 513-516). In the experimental setup, a reactor and a thermal conductivity cell detector (TCD) were connected sequentially so that pulses of feed and product were measured. The reaction products are collected before the separation column. Responses for hydrogen were not measured.

J.F. Coopmans, P Mars and R.L. de Groot (Industrial and Engineering Chemistry, Research 1992, 31, 2093-2103) performed pulsed experiments on gas oil cracking over zeolite catalysts with a pulsed reaction unit connected to a packed column of a GC. Direct measurement of oil pulses without an analytical column. Because the pulse is broadened in the system, the resolution of the analysis becomes poor, for example, ethane and ethylene cannot be separated.

The application of commercial pyrolysis-gas chromatography (Py-Gc) is an example of a furnace replacement. Pyrolysis-gas chromatography is a well-known analytical technique for high molecular weight samples as well as for catalytic pyrolysis and for the analysis of residues adsorbed on catalysts. Py-Gc was also used by G.Perez, M.Raimando, A.de Stefanis and A.A.G.Tomlinson to measure the catalytic reaction of ethylbenzene on mesoporous zeolites (J.Anal.Appl.Pyrol.35(1995)157-166) .

Another Py-Gc application by M.I. Nokkosm_ki, E.T. Kuoppala, E.A. Lepp_m_ki and A.O.I. Krause (J. Anal. Appl. Pyrol. 44 (1998) 193-204) is a method of pyrolysis steam cracking scots pine sawdust with zeolite method. In this method, the solid feed is pyrolyzed with a pyrolysis probe, while the vapor phase is contacted with the catalyst supported in the inner tube of the injection port.

A use of Py-Gc is also disclosed in patent application WO94/20848, which provides an improved sample injector for gas chromatography. The injector features an easier insertion of the pyrolysis probe into the vaporization chamber while vaporizing the sample in such a way that the sample is more efficiently fed to the column.

Although many methods are available, none can simultaneously measure feed pulses, separate compounds from _C1 to _C20 , and detect hydrogen. Typically, GC-distillation has been performed, but it can only determine compound types, not individual compounds. Capillary technology is another technical feature that is not used for on-line sampling in laboratory-scale catalytic test equipment. A cold trap is always used, requiring an additional condensation and re-vaporization step. Therefore, there is clearly a need for a method and apparatus for testing catalysts for short contact time reactions which operate over a large temperature scale, wide solvent to oil ratios and contact times in order to obtain reliable data on catalytic reactions and catalyst performance.

The object of the present invention is to provide a device, equipment and method for testing heterogeneous catalysts for short contact time reactions and for testing catalytic reactions.

Apparatus, equipment and methods for testing catalysts for short contact time catalytic cracking, skeletal isomerization, hydrogenation, dehydrogenation and methane coupling reactions are characterized by the features set out in the claims.

The present invention is a new application of capillary technology. Use flame ionization detector (FID) and/or mass selective detector and/or TCD and/or AED as detectors to simultaneously measure injected pulse mode, hydrogen response value and hydrogen, C ₁ -C ₂₀ hydrocarbon compounds in the product , and capillaries and separation columns are used as on-line sampling probes and for the separation of compounds. The apparatus for testing catalysts of the present invention is abbreviated herein as ETC. Coke deposited on the catalyst was determined by well known techniques by pulsed oxygen through the catalyst and analyzing the amount of product by on-line GC.

The apparatus and apparatus of the present invention are particularly suitable for testing and monitoring short contact time heterogeneous catalysts, catalytic reactions, cracking reactions, skeletal isomerization reactions, measurement of catalyst deactivation, dehydrogenation, methane coupling and hydrogenation. The apparatus is operated by the pulse method and the products are analyzed, for example, by on-line gas chromatography. The equipment preferably includes a furnace, a gas chromatograph with suitable detectors, a tubular reactor, gas and liquid injection valves, temperature measurement controllers, pressure regulator valves before the reactor and column, mass flow controllers and injectors. For catalytic cracking tests, gas oil was injected into the upper part of the reactor by generally known methods. Individual components and compounds are conveniently separated using capillary columns. Any oil and gas having a boiling point equal to or lower than 550°C can be used as a raw material. The reactor can be in the temperature range of 20-900°C (it depends on the feed, reaction and reaction environment). Operating under a wide solvent-to-oil ratio and a residence time of 0.01-0.1 seconds, the resolution of compound separation does not decrease. For skeletal isomerization and oligomerization, compound-level resolution can be achieved with residence times of 0.01-0.3 s when using feedstocks containing _≥C4 compounds. When longer residence times up to 5.9 seconds were used, the compound level resolution decreased and only GC-distillation results were obtained.

The device is preferably manufactured from commercial components and/or components designed for this purpose. The main elements are furnaces to obtain a broad and consistent temperature profile, tubular reactors (preferably glass, steel, other suitable metals, ceramic materials or quartz reactors), joint units, gas and liquid injection valves (preferably a six-port valve), gas chromatography equipped with a suitable detector (e.g. flame ionization detector (FID) and/or mass selective detector and/or TCD and/or AED, preferably FID and TCD), mass flow control Controller and temperature measurement controller, reactor and pre-column pressure regulating valve and injector (preferably semi-automatic injector).

A preferred embodiment of the apparatus and apparatus of the present invention for testing short contact time catalysts and catalytic reactions is shown in Figure 1 of the accompanying drawings.

In the measuring arrangement of FIG. 1 , the tubular reactor is connected to the injection port 36 of the GC 20 by means of two joint units 29 and 16 . In the first connection unit 29 there are 6 inlets for the reactor 2, the separation column 38, the split gas capillary inlet 14, the split gas outlet 13, the temperature measurement probe 30 and the pulse measurement and hydrogen sample capillary probe 31 hole. A separation column 38 is inserted upwards into the reactor tube 2 through the injection septum 19 and the sleeve 37 . 30 mm below the catalyst bed 5 there is a specially made second joint 16. In this way, the separation column 38 can be used as a sample probe for on-line sampling as well as for compound isolation. The reactor and injector are separated by a gas-tight septum 17 . The top of the thermocouple 7 is just below the catalyst layer 5 . The two junction units 29 and 16 are heated to a constant temperature (200° C.) with a heating block 10 . Feed 24 is injected into reactor 2, preferably manually or with a semi-automatic injector or gas or liquid injection valve, and the compound to be analyzed is separated from the product by capillary column 38 and detected by FID 39 . In the carrier gas line 23, a six-way valve or a gas or liquid injection valve 22 and sample loop can be used in case a gaseous feed is provided in the test. TCD26 is used as a pulse mode detector, while another TCD27 is used for hydrogen detection, which is placed in the coke measurement system. In catalyst regeneration, it is also used to detect permanent gases and unreacted oxygen in oxidation pulses. In addition, 1 is a manual injection block, 21 is a manual injection diaphragm, 3 is a heating furnace, 4 and 6 are quartz wool, 8 is the top of the sample probe, 9 is the top of the split gas tube, 11 is the pressure relief valve, and 12 is the Reactor and pre-column pressure regulating valve, 13 is the split gas outlet, 14 is the split gas inlet, 15 is the split gas tube, 18 is a replaceable needle block, 28 is the top of the capillary column, 35 is the capillary column inlet needle, 23 is a carrier gas inlet, 32 is a pulse measurement mass flow controller, 25 is a pulse and hydrogen measurement mass flow controller, 33 is a molecular sieve, 31 is a sample probe inlet and 34 is a mode selection valve. The correct order of the top 7, 8 and 9 is important for sampling.

The principle of action and preferred embodiments associated with the device of the present invention will be briefly described below. Microreactors operate in three ways. It acts simultaneously as vaporizer or injector, reactor and sample splitter. The upper part of the reactor acts as a vaporization section where the liquid feed is vaporized. The carrier gas carries the vaporized feed into the middle of the reactor where it contacts the catalyst and reacts. Using capillary technology, the lower part of the reactor becomes the sampling zone, with the top of the sample probe for pulse measurement and hydrogen analysis just below the catalyst. The split of product gas between pulse measurement and compound analysis can be adjusted with a mass flow controller connected to the outlet of the TCD. Downstream of the sampling probe, the product gas is diluted with an additional helium flow from the split gas capillary. Samples for compound analysis are taken from the diluted product stream with a second sampling probe. The reaction section is the area where the temperature distribution of the heating furnace is the most uniform. During the test operation, the flow rate of the carrier gas was used to control the residence time of the feed on the catalyst, and the flow rate of the split gas was used to control the split ratio. The outflow gas flow rate of the reactor pressure was adjusted with a pre-column pressure regulator connected to the split gas outlet line.

In the experiment, a tubular reaction was used. In the middle of the reactor, there is a funnel-shaped limiter, where a layer of quartz wool or other suitable material is placed to adjust the position of the catalyst. At the same temperature at which the regeneration was performed, the reactor was flushed with a pulse of oxygen to wash away the contaminants. A suitable amount of catalyst is 0.01-300 mg, and it is placed in the middle of the tubular reactor, in the zone where the furnace temperature is most evenly distributed.

For FCC tests, gas oil was injected into the upper part of the reactor either manually or with a semi-automatic injector. For gaseous feeds, a gas circuit is preferably used for injection. A liquid injection valve may also be used if the boiling range of the feed is sufficiently low, eg 100-150°C.

In the device of the present invention, the capillary column is used as a sample probe for on-line sampling as well as for the separation of compounds. Place the top of the separation column approximately 15 mm below the top of the split gas capillary. Use the split gas flow to adjust the split ratio and delay time in the sampling area. In order to achieve resolution of compounds from _C1 to _C20 , due to the small dead volume in the sampling area, the initial temperature is 0 °C (2 min) and the heating rate to reach the final temperature of 300 °C is 1.5 °C/min. preferred and suitable method.

The amount of coke can be measured, for example, with a separate device using the pulse method. The calculation of the coke amount is based on an external correction performed in the same manner using a coke sample as a reference, the coke amount of which is analyzed by a commercially available method.

The lowest possible operating temperature of the reactor is related to the boiling range of the oil. The liquid feed is vaporized at the beginning of the catalyst/substrate bed where the gas phase reaction takes place. The high mass ratio between the catalyst/inert bed and the feed is used to ensure vaporization of the liquid feed, the temperature drop due to vaporization being small. It is also possible to feed gas phase feeds into the reactor. The maximum operating temperature is limited to 900°C.

The feedstock can be any liquid or gaseous feed having a boiling point equal to or lower than 550°C. In order to ensure uniform injection, the viscosity of the liquid phase material must be sufficiently low. In the case of high viscosity at room temperature, it is necessary to heat the feed to a sufficiently high temperature. The amount of feed can be varied in the range of 0.1-1.0 microliter without loss of resolution and temperature stability.

Any heterogeneous catalyst can be used in these experiments and tests. Due to the temperature distribution of the furnace, the maximum length of the catalyst bed is limited to 30 mm. The temperature profile in the catalyst bed region should be as flat as possible to ensure uniform temperature in the bed and thus uniform reaction conditions.

The agent-to-oil ratio can be varied within a wide range of 0-300. For example, when the feed density is 780 kg/ ^m3 and the injected oil volume is 0.5 μl (0.43 mg), the catalyst-to-oil ratio can range from 0 to 45 g catalyst/g oil, and the diameter of the reactor is 2 mm. The length or volume of the catalyst/inert bed remains constant, only the mass fraction of catalyst in the bed is changed.

The residence time of the feed in the catalyst can be controlled indirectly by varying the flow rate of the carrier gas through the reactor. The flow rate of the carrier gas can be varied from 0.1 to 83.3 cm3 ^/ min (standard temperature and pressure), which corresponds to a residence time of the carrier gas of 0.01 to 5.9 seconds at 600°C and a bed volume of 22.9 ^cm3 . As a preferred embodiment of the present invention, variations of the test method are described below.

In this test method, the first step is to load a known amount of catalyst in a tubular reactor. After installation, the reactor was connected to the joint unit of the test equipment, and the heating furnace was placed on the reactor so that the position of the catalyst bed was in the middle of the uniform temperature distribution area of the heating furnace. Connect the carrier gas line with the manual injection block to the upper end of the reactor, then flush the reactor with carrier gas through the pressure relief valve. Mass flow controllers are used to adjust the carrier gas flow rate, split ratio between capillaries and sample split and pulse mode measurement. Manually adjust the reaction pressure with a needle valve connected to the split gas outlet. After the test temperature exceeds the set point and stabilizes and the catalyst pretreatment step is performed, the test reaction is initiated by manually or sample loop injection of feed into the reactor. After completion of the product analysis, the reaction tube containing the coked catalyst was removed from the test unit and connected to the coke measuring device fitting. The amount of coke deposited on the catalyst is measured by the pulse method (oxygen/helium mixture pulse) with a suitable highly sensitive method, eg methanation, which detects carbon monoxide and carbon dioxide as methane. Analytical instruments were controlled and data collected using commercial software for personal computers. Calculation of hydrogen and coke amounts with external corrections.

The MAT-plant is a commercial facility suitable for comparing different FCC (Fluid Catalytic Cracking) catalysts for catalytic cracking of heavy hydrocarbons. According to the present invention, the combination of reactor and furnace with GC has several advantages over MAT in terms of process variables and analytical techniques in testing catalysts for catalytic cracking reactions.

In the MAT-device, the gas phase sample is collected in the aspiration tube during the experiment, while the liquid phase sample is separated off as condensate. Therefore, two separate analyzes are required. Furthermore, samples with average properties were collected over relatively long reaction times (20-75 s), while the activity of the catalyst decreased during the experiment due to coking. With the ETC-device according to the invention, the product gas is simultaneously capillary split into two sample streams and analyzed, thus resulting in pulse mode, hydrogen response and compound analysis. Moreover, the activity of the catalyst remained unchanged during the experiment due to the short contact time.

In catalyst performance testing, several variables are used, such as temperature, catalyst-to-oil ratio, residence time, and feed accumulation. In ETC devices, these variable ratios can be varied within a considerable range in MAT. In ETC-plants, the lowest possible temperature of the liquid feed is determined by the boiling point of the feed, whereas for gaseous feeds this temperature may be below 100°C. For example, for a gas oil feed, this temperature may range from 20-900°C. The agent-to-oil ratio can be 0-300. The residence time can be varied by adjusting the carrier gas and split gas volumetric flow rates; in the apparatus of the present invention, the residence time is typically in the range of 0.01-0.1 seconds. For skeletal isomerization and oligomerization, compound-level resolution can be achieved with residence times of 0.01-0.3 seconds when using feedstocks containing _≥C4 compounds. The volume of liquid feed injected can be varied in the range of 0.1-1.0 microliters without any temperature control issues.

In addition, after the cracking reaction, regeneration of the catalyst can be performed in a pulsed manner. The cumulative amount of coke formed during the reaction was obtained by adding the CO and _CO2 produced. The reaction kinetics of coke combustion can also be evaluated by feeding a fixed volume of air into a pulse with a known residence time and by analyzing the CO and _CO2 formed after each pulse. In a commercial MAT-device, the catalyst was regenerated after the experiment and the accumulated _CO2 amount was analyzed with an IR-detector. In the ETC-device, CO and _CO2 are first converted into methane and then analyzed with FID, which is several orders of magnitude more sensitive than IR. Less than 0.1 micrograms of coke can be analyzed with the FID, which corresponds to less than 0.025% by weight coke in the catalyst. Furthermore, regeneration in MAT does not yield any additional information on the kinetics of the coke combustion reactions.

The main characteristics of the ETC-devices and MAT-devices are summarized in Table 1. Table 1 Main features of ETC-device and MAT-device features ETC MAT(ZETON) temperature range 20-900℃ Room temperature -650°C Agent to oil ratio 0-300 seconds 0-20 dwell time 0.01-0.3 seconds 20-75 seconds feed phase liquid or gas liquid Catalyst quality 0-300mg 5-6 grams sample instant average Coke Analysis Pulse method, CO and _CO2 Cumulative CO ₂

For catalytic cracking experiments, the advantage of this type of reactor is that the activity of the catalyst can be considered constant due to the short contact time; the reaction temperature can be considered constant due to the small amount of oil injected. It shows that the repeatability of the experiment is excellent.

Preferred embodiments of the present invention are given below as examples, which are not intended to limit the scope of the present invention. Preferred modifications of the process of the invention are provided below as Examples 1-5.

Example 1

thermal cracking

Thermal cracking was studied by charging the reactor with 20 mg of inert material (Inert Micropheres MX-3X, the same material used with the catalyst to obtain the desired amount of catalyst in the bed) and quartz wool. The reactor material was quartz glass and the feed was light gas oil (96%, Gas Oil 1 ) boiling in the range 221-420°C. The experiments were carried out with the temperature varied between 500-700°C, the residence time of the carrier gas was constant (t=0.055 sec, Rep=5) and the feed volume was 0.5 microliter (0.43 mg). Product distributions were pooled into 5 distinct groups, namely converted feed (<221°C), yield of gasoline (C ₅ -221°C) (kg/100 kg feed), liquefied petroleum gas (LPG C ₃ -C ₄ ), dry gas (C ₁ -C ₂ ) and coke. The results of these experiments are listed in Table 2.

Table 2 Conversion and yield of thermal cracking of gas oil 1 conversion/yield temperature/℃ Conversion rate dry gas LPG gasoline Coke 500 3.6 0.07 0.13 3.34 0.04 500 3.6 0.07 0.23 3.30 0.11 550 4.2 0.24 0.43 3.53 0.03 550 6.0 0.22 0.45 5.26 0.09 600 9.2 1.17 1.30 6.51 0.23 600 10.0 1.06 1.09 7.79 0.05 650 32.4 6.83 6.99 18.5 0.09 650 30.0 6.15 6.41 17.2 0.20

According to the experimental results, the thermal reaction is negligible below 600 °C. Therefore, in order to study only catalytic reactions, it is advantageous to keep the reaction temperature below 600 °C. However, thermal cracking has always been associated with catalytic cracking, and due to the complexity of the interactions between the molecules involved in these reactions, it is difficult to separate the two phenomena.

Example 2

catalytic cracking

Catalytic cracking experiments were carried out with changes in reaction temperature, catalyst-to-oil ratio and residence time. The gas oils used were light gas oil with a boiling range of 221-420 (96%, Gas Oil 1) and light gas oil with a boiling range of 227-530 (96%, Gas Oil 2). The reaction temperature varies between 400-650°C, the agent-to-oil ratio varies between 0-29.8 and the residence time varies between 0.03-0.09 seconds. The amount of oil injected was always 0.5 microliters (0.43 mg), and the catalysts and zeolites used were commercial average catalysts and zeolite catalysts containing rare earth elements.

Experiments were carried out by varying the bed temperature, agent to oil ratio of 11.2 and residence time of 0.055 seconds. The results of this experiment as a function of temperature are listed in Tables 3-5. The catalytic cracking results of gas oil 1 as a function of residence time on the equilibrium catalyst are listed in Table 7.

      Table 3 Gas Oil 1 in Equilibrium Catalyst

Conversion and yield of catalytic cracking as a function of temperature

According to the experimental results, the yields of different product groups with the increase of reaction temperature conformed to the expected trend: the conversion rate increased, the primary cracked product gasoline increased to the maximum, and then it began to decrease due to the secondary cracking reaction to generate LPG. LPG is assumed to be a primary cracking product and a secondary cracking product. Dry gas and coke yields increased slowly and quite linearly (mainly gasoline and secondary products) with reaction temperature.

     Table 4 Gas oil 1 in zeolites containing rare earth elements

Conversion and yield of catalytic cracking over catalyst as a function of temperature

According to the results listed above, the zeolite catalysts containing rare earth elements are significantly more active than the average catalyst. The conversion of the cracking reaction was 15-20 higher over the entire temperature range, with the maximum gasoline yield being obtained at 550 °C.

Table 5 Gas Oil 2 on Equilibrium Catalyst

Conversion and Productivity of Catalytic Cracking with Temperature

According to the above results, the cracking of gas oil 2 is easier than that of gas oil 1 on the equilibrium catalyst. In both cases, the yields of the different reaction product groups as a function of temperature followed the same logical trend, except that the yield of gas oil 2 was higher.

Experiments were performed as a function of the catalyst-to-oil ratio by varying the amount of catalyst in the inert material. The mass of catalyst in the bed was varied between 4.0-34.4% by weight, while the volume of the catalyst bed was constant. The temperature in these experiments was 550°C, the residence time was 0.055 seconds, and the resulting particles had a Reynolds number of 6.6. The results are listed in Table 6.

Table 6 Gas oil 1 on the equilibrium catalyst

Conversion and Productivity of Catalytic Cracking with Fuel-to-Oil Ratio

The conversion and the yields of gasoline and LPG increased slightly as the F/O ratio increased, then they started to level off. In the range of this agent-to-oil ratio, the yields of dry gas and coke also increase almost linearly.

The residence time was varied between 0.03-0.09 seconds by controlling the flow rate of the carrier gas. The corresponding particle Reynolds number is 4.1-12.6. Likewise, the experiment was also carried out at 500°C and an agent-to-oil ratio of 11.2. The experimental results as a function of residence time are listed in Table 7.

Table 7 Conversion and yield of catalytic cracking of gas oil 1 as a function of residence time

The conversion and the yields of the different reaction product groups increase with residence time. With long residence times, conversions and yields start to level off, which is a symptom of a mass transfer limited reaction rate. Indeed, with the longest residence time of 0.09 s, the particles have a Reynolds number of 4.1, which appears to be too low to ensure that the kinetic rate of the reaction controls the overall reaction rate.

Example 3

Skeletal isomerization

Skeletal isomerization experiments were performed as a function of reaction temperature, using a constant solvent to oil ratio (60) and residence time (0.23 sec). The feed was light gas oil (96%) with a boiling range of 47-97° containing n- and iso-paraffins, n- and iso-olefins. The temperature range is 275-350°C. The volume of oil injected was always 0.5 microliters (0.43 milligrams) and the catalyst used was a ferrierite catalyst. The results of these experiments are listed in Table 8.

Table 8 Conversion rate and yield of light oil skeletal isomerization with temperature Conversion/yield of n-olefins temperature/℃ Conversion rate n-alkanes Isoparaffin n-Olefins Isomerized olefins 275 50.8 9.34 46.8 9.61 22.1 275 47.0 9.29 49.1 10.4 19.5 300 40.1 9.37 46.6 11.7 20.7 300 43.8 9.95 48.3 11.0 18.0 325 35.6 9.60 48.3 12.6 16.9 325 33.5 9.90 48.4 13.0 16.5 350 25.9 9.85 46.5 14.5 16.4 350 20.2 9.59 47.7 15.6 15.1

According to these results, the yields of the different products follow a logical trend with increasing temperature: the conversion of n-olefins decreases and the selectivity to iso-olefins decreases due to the increased activity of side reactions. Therefore, lower temperatures are advantageous for isoolefin selectivity and yield. It can also be noted that the type of reaction, catalyst and type of feed all have an effect on the residence time.

Example 4

Dehydrogenation test

The dehydrogenation experiments were performed as a function of the reaction temperature, using a constant solvent-to-oil ratio and oil-off time (0.055 seconds). The feed was n-butane gas (99.7%). The reaction temperature range is 400-475°C. The total amount of gas injected was 500 microliters, and the catalyst used was a dehydrogenation catalyst. The results of these experiments are listed in Table 9 in mole %.

Table 9 Conversion and productive rate of n-butane dehydrogenation as a function of temperature Conversion/yield of n-butane temperature/℃ Conversion rate n-butane C ₄ olefins hydrogen other 400 3.7 96.3 1.8 1.5 0.5 400 3.5 96.5 1.7 1.3 0.5 425 4.9 95.1 2.5 1.9 0.4 425 5.0 95.0 2.6 2.0 0.5 450 9.1 91.0 4.8 3.8 0.5 450 8.7 91.3 4.6 3.7 0.5 475 11.9 88.1 6.4 5.1 0.5 475 12.0 88.0 6.4 5.2 0.5

According to these structures, the yield of olefins follows a logical trend with increasing reaction temperature: due to the increased activity of the catalytic reaction, the conversion of n-butane increases and the selectivity to olefins and hydrogen increases.

Example 5

cracking catalyst deactivation

Cracking catalyst deactivation was studied by repeating the injection steps several times (1, 2, 3, 10, 20 and 30 times) under the same conditions and taking samples from the last injection for compound analysis. The experiment was carried out at 600°C, agent-to-oil ratio 11.2, and residence time 0.055 seconds. The feed oil was a light gas oil (96%, Gas Oil 1) with a boiling range of 221-420°C. The amount of oil injected was always 0.5 microliters (0.43 milligrams), and the catalyst used was a commercial zeolite catalyst containing rare earth elements. The time scale of the operation is 0.055-1.65 seconds. The accumulated coke amount was measured after each test and the final coke amount was calculated from the measured accumulation as the difference between the last two injections. The cumulative results are listed in Table 10 and the final results are listed in Table 11.

      Table 10 Gas oil 1 in zeolites containing rare earth elements

Time-dependent conversion and yield of catalytic cracking over catalyst

As the operating time increases, the amount of accumulated coke increases and deactivation of the catalyst is observed as the conversion and LPG yield decrease.

      Table 11 Gas oil 1 in zeolites containing rare earth elements

Time-dependent conversion and selectivity of over-catalyst catalytic cracking

According to these results, the amount of coke produced decreased during the deactivation process. For example, in the first 0.055 seconds, the coke yield was 2.25% by weight, but after the activation period of the operation (1.6 seconds), the amount of coke formed was only 0.06% by weight.

Claims (11)

1. A device for testing heterogeneous catalysts for short contact time reactions, characterized in that it comprises a heating furnace (3) consisting of a tubular reactor (2) with a wide and uniform temperature distribution; an outlet for a capillary column Through and connection unit (16, 29) of the reaction tube, split gas capillary inlet, split gas outlet, temperature measurement probe, pulse measurement and hydrogen sample capillary probe, through which the volume of the product gas chamber is controlled; feed gas or Injection valve for feed liquid (22); gas chromatograph (20) equipped with suitable detectors (26, 27, 39); mass flow and temperature measurement controllers (25, 32); injector (36), reactor (2) and pre-column pressure regulating valve (12); On-line sampling equipment (8, 9, 28) with sample splitting with capillary technology; And pulse mode (26), hydrogen response (27) and compound response (39) Simultaneous detection. 2. Device according to claim 1, characterized in that a residence time of 0.01-0.3 seconds is used. 3. Device according to claim 1 or 2, characterized in that a residence time of 0.01-0.1 seconds is used. 4. The device according to any one of claims 1-3, characterized in that the agent-oil ratio used is 0-300. 5. 4. Apparatus according to any one of claims 1-4, characterized in that a temperature of 20-900°C is used. 6. The apparatus according to any one of claims 1-5, characterized in that oil and gas having a boiling point equal to or lower than 550°C are used as raw materials. 7. Device according to any one of claims 1-6, characterized in that the injection volume is 0.1-1.0 microliter. 8. A method for testing heterogeneous catalysts for short contact time reactions, characterized in that it comprises loading the catalyst into a tubular reactor (2) and then connecting the reactor (2) to a joint unit (29) of the test apparatus, Put the heating furnace (3) on the reactor, connect the carrier gas pipeline (23) with the injection block to the upper end of the reactor (2), and then flush the reactor (2) with the carrier gas; adjust the carrier gas velocity, capillary Split ratio between columns and sample split, pulse mode measurement and reaction pressure; start of the test reaction by injecting a feed sample into the reactor after the test temperature has exceeded the set point and stabilized and after an optional catalyst pretreatment step; control Analyze instruments and collect data and calculate hydrogen and carbon quantities. 9. A method for measuring heterogeneous catalysts for short contact time catalytic cracking, skeletal isomerization, hydrogenation, dehydrogenation and methane coupling reactions, characterized in that it comprises loading the catalyst into a tubular reactor (2) and then The reactor (2) is connected to the joint unit (29) of the test equipment, the heating furnace (3) is set on the reactor, and the carrier gas pipeline (23) with the injection block is connected to the upper end of the reactor (2), Then flush the reactor (2) with carrier gas; adjust carrier gas flow rate, split ratio between capillary columns and sample split, pulse mode measurement and reaction pressure; test temperature exceeds set value and stabilizes and carries out optional catalyst pretreatment After the procedure, the test reaction is initiated by injecting a sample of the feed into the reactor; controlling the analytical instruments and collecting data and calculating the amount of hydrogen and carbon. 10. Method according to claim 8 or 9, characterized in that hydrogen and C ₁ -C ₂₀ hydrocarbons are detected. 11. A method according to claim 8, 9 or 10, characterized in that, after the analysis, the reaction tube (2) containing the coked catalyst is removed from the test device, connected to the joint unit of the coke measuring device, and then pulsed The method measures the amount of coke deposited on the catalyst with a suitable highly sensitive method for the detection of CO and _CO2 as methane.

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