DD220827A1 - METHOD AND APPARATUS FOR COMBINED ACTIVITY AND ACIDITY DETERMINATION - Google Patents

Abstract

Method and apparatus for the combined determination of activity and acidity with the aim of achieving a low expenditure and a high informativeness. The task of developing a process and apparatus to obtain reliable parameters is achieved by first characterizing the catalyst with regard to its catalytic activity and then immediately thereafter at temperatures at least 10 K higher than the reaction temperature but at the maximum at the activation temperature of the catalyst Catalyst lie, is flushed in a stream of hydrogen with a load of at least 20 000 v / vh and then shock-cooled at 298 K metal oxide or on oxidic catalysts to reaction temperature and at this temperature the NH3 uptake after the pulse Stroemungsverfahren with subsequent Ad- and desorption of the non-chemisorbed by the catalyst ammonia is determined. The apparatus consists of a reactor with upstream gas diverter, which is connected to a sample dispenser. A sample dispenser, a gas diverter and a heat conductivity measuring cell are connected successively to the reactor. An output of the sampler is shorted to the gas diverter. The other one is connected to adsorption tube, separating column and thermal conductivity measuring cell. The invention enables a quality control.

Description

VEB Leuna-Werke 'Leuna, the

"Walter Ulbricht"

LP 83 142

Title of the invention

Method and apparatus for combined activity and acidity determination

Field of application of the invention

The present invention relates to a method and an apparatus for determining the catalytic activity and the acidity of catalysts for the purpose of quality control and for the preparation of the catalyst used in production plants.

Characteristic of the known technical solutions

The labeling of technical catalysts and Verauchskatalysatoren with regard to their catalytic activity in laboratory reactors is well known (eg "Chemistry-Technik, 4, 443, 1975) .The effectiveness of the catalysts depending on the gas composition, the pressure, the temperature, the Hatur the promoter additions and other parameters tested * It is 'onward'

It is known that NH.sub.j impulse chemisorption is used to determine acidity (Chem. Techn. 18, 466, 1966). Numerous studies use the results of acidity and activity determination to evaluate and further develop the utility properties of the catalysts with the results obtained from separate equipment. A disadvantage of this procedure, however, is that results are compared with each other, which were not obtained on the same catalyst. While the acidity tests are carried out on the virgin catalyst surface, the catalytic activity is measured on the formed catalyst. Another disadvantage of the known solutions is the increased expenditure of time and equipment.

Object of the invention

The aim of the invention is a combined process for the determination of the catalytic activity and the acidity of catalysts for quality control and for the preparation of the catalyst used in production plants with a high informativeness and a low cost and an apparatus for carrying out the process.

Explanation of the essence of the invention

The invention has for its object to develop a method and apparatus for determining the catalytic activity in hydrocarbon conversion reactions and the acidity of catalysts that allow, with the least possible time, material and energy expenditure reliable and meaningful "parameters for This object is achieved according to the invention by reacting 100 to 2000 rags of the catalyst at a given pressure in a reactor with a radiation furnace to the activation temperature in the activation gas

hochbeizt, activated and cooled to reaction temperature charged with reaction gas, after at least 30 min with respect to the catalytic activity checks, then in the same reactor at a gas load of at least 20,000 v / vh 10 to 180 min, preferably 30 min, rinsed with hydrogen while the temperature at least 10 K higher than the reaction temperature, but maximum setting on activation temperature »then shock-cooled to adsorption, the flow rate to a value of 5 to 10 l / h and then at normal pressure at a distance of 7 to 12 min'MHw pulses with a size of 0.2 to 0.4 cm leads to saturation of the catalyst surface over the catalyst, wherein the incoming at each dose after the catalyst Schehen NHo amount in an adsorption _x

*> / (Cekachrom3)

tube, which is filled with 2 to 3 g of styrene-divinylbenzene copolymers, adsorbed at temperatures of from 190 to 210 K and desorbed for 4 to 9 minutes after dosing for 2 to 3 minutes at temperatures of 273 to 373 K and the desorbed amount of NEW is determined katharometrisch and that during the entire process, the gas flow is such that the gases flow through first the catalyst bed and only then the pritte of the reactor. This object is further achieved by means of an apparatus for combining activity and acidity determination in accordance with the invention in that before the reactor 3 a gas diverter 1 for the hydrogenase hydrogen, substrate hydrogen and carrier gas for the adsorption measurement with the subsequent sample dispenser 2 for the dosing of NH-a Pulses during the acidity measurement is installed and between the reactor outlet and separation column of the gas chromatograph 8 successively the sample generator 5 for the metering of the reaction product, a gas diverter 6 and a filled with styrene-divinyl-benzene copolymers, temperature-controlled, U-shaped adsorption 7 are integrated in which the gas diverter 6 is charged with the carrier gas coming from the gas chromatograph, the central output of the gas diverter 6 is connected to the second input of the sample dispenser 5.

             , , - 4 - '·,

"""-,'-.'/"'. ^k

/ ''.

is short and the binding and exit of the adsorption tube 7 is short-circuited, so that in the Reakt onsproduktdosierung during the catalytic reaction coming from the gas chromatograph carrier gas can pass through the gas diverter 6, Trimmer 5 and separation column 8 to the measuring chamber of the thermal conductivity cell 9 and in the case of Acidity measurement coming from the gas diverter 1 for 3 gases carrier gas on the probe 2, reactor 3, tester 5, gas diverter 6, probe + encoder 5, adsorption tube 7 and column 8 flows to the measuring chamber of the thermal conductivity cell 9 and wherein the free volume

 '. ', · ·. , '. Is between 5 and 250 cm, preferably between 10 and 20 cm, and that the free volume, after the reactor has been primed, is no greater than 250 cm as far as the inlet of the measuring chamber of the thermal conductivity measuring cell.

          '3 ·' "'' ·

It is advantageous if basic substances are used as the separating column materials. "It has surprisingly been found that, in addition to the determination of the catalytic activity, the acidity of the catalyst can also be determined under the process conditions described Conclude the results significantly better than in the separate determination of the physicochemical characteristics of the catalysts.

Essential for the implementation of the method according to the invention is that the flushing with hydrogen after the catalytic test in a period of 10 to 120 minutes, preferably 30 minutes, takes place. After rinsing, the catalyst is quenched to the NH 2 adsorption temperature and held at this temperature for 15 minutes. Subsequently, the catalyst is loaded at this temperature at intervals of 7 to 12 minutes with Mi ^ pulses and arriving at each dosage after the catalyst layer NHv amount in an adsorption tube, which is filled with 2 to 3 g Cekachrom 3, at a temperature of 190 to. 210 E is adsorbed and 4-9 minutes after dosing for 2 to 3 minutes shock-like desorbing at temperatures of 273-373 K, wherein the desorbed UH ₃ amount is determined by catharometry.

In addition is. important for carrying out the method that the gas flow is such that the gases flow first against the Katalyaatörachüttung and only then through the frit of the U-shaped reactor ·

Furthermore, the 'volume' between the probe 2 and Katalyaatorschüttung and from the frit of the reactor to a transition of the measuring chamber of the vrärmeleitfähigkeitsmeßzelle have to have certain sizes. While the former should be between 5 and 250 cm, preferably 10 to 20 cm, the volume after the preparation of the reactor to the entrance of the measuring chamber may not be greater than 250 cm, preferably 25 cm. Essential for the implementation of the Verfahreria according to the invention is also that the flow rate of the carrier gas for ammonia at Katalysatorörowaagen from 0.1 to 2g, 5 to 10 l / h. It is also important that _t 7 sorption adsorption temperatures are set from 190 to 210 K and Desorptionatemperaturen 273-373 K in the ad. Equally important for the implementation of the inventive method is that the heating of the Adsbrptionsrohres 7 schockärt ^ g occurs during desorption. Pur to carry out the process of the invention is also favorable that a basic substance is used as the separation column material. .

The dosage is carried out automatically, with the triggering of the dosing process via a microelefctronic device a micrometer-based Aüwertseinheit for quantitative determination of the HEU concentration or for determining the quantitative composition of the reaction product 'is put into operation.

For activation, the catalysts in the reactor are temperature-programmed by means of a radiation oven 4 to a reduction temperature, the temperature being controlled by a thermocouple projecting into the catalytic layer. -

AusfUhrungabeiapiele

1. Comparison

Λ ·. "·. ·.

Three SiO.sub.2 O.sub.10 O.sub.x catalysts prepared by vaporization were characterized in a .sup.-1 chemisorption apparatus and in a standard catalytic pressure apparatus under the experimental parameters given in Tables 1 and 2. The results are summarized in Table 3.

Table 1 .

Conditions of NHo chemisorption measurement

method

Impulse flow method.

Catalyst weight Grain size Flow rate of the bake-out water 500 mg 0.2-0.4 mm 10 l / h the carrier gas (H ₂ ) 5 l / h Size of HEU pulses 0,2 ow? dosing 15 see Doaierabstände, 7 min Activation temperature adsorption temperature 737 K 673 K

Table 2

Conditions of the catalytic characterization of the catalysts in the cleavage under normal pressure

Reactor Uf örmiger ^j flow reactor

with G1 frit

Catalyst weight 500 mg

Grain size 0.2-0.4 mm

Flow rate of the heating water. , substance, _t 10 l / h I

of the substrate hydrogen 10 l / h

Load 1.8 g of cumen / gcat »h ·

Activation temperature 773 K

Reaction temperature 673 K

Reaction time 1h.

2nd example (invention) '

Three differently prepared Al20o-SiO 2 catalysts A, B, and G were investigated by the following inventive method * 500 mg of the catalyst are transferred to a shapeless reactor 3 and by means of radiation oven 4 at a heating rate of 7 K / min in a stream of hydrogen (101 / h ) heated to 773 K and left for 1 h at this temperature. After this activation, the sample is cooled to 673 K and the gas diverter for 3 gases 1 is switched to the cumene-hydrogen peroxide mixture (101 / h, 0.9 g cumen / h). In this case, the reactor outlet is connected to the dosing loop of the sample dispenser "5", whose second gas inlet is charged with the carrier gas II (H ₂ , 31 / h) coming from the gas chromatograph via the gas chromatograph 6. In addition, the inlet and outlet of the adsorption tube 7 short-circuited.

1 h after the start of the reaction takes place by means of sample 5 a

Dosing of the reaction product in the carrier gas II, which flows through the separation column of the gas chromatograph to the measuring chamber of the thermal conductivity cell 9.

Immediately after dosing, the gas diverter for 3 gases 1 to hydrogen peroxide (151 / h) is changed, the reactor temperature is increased shock-like to 773 K and rinsed with hydrogen for 30 min. Subsequently, the catalyst is shock-cooled to 673 K, the gas diverter for 3 gases 1 converted to carrier gas and the adsorption tube 7 -in the Strör mungsweg included · After the sample in the reactor for 15 min at 673 K iat been, the adsorption tube 7 in a brought to 198 K kept temperature bath. 1min ° after the transfer of the adsorption tube 7 in the cooling bath is. By means of sample dispenser 2, a NEW pulse (0.2 cnr) metered into the water stream and gelei- over the catalyst sample in the reactor; In this case, the switching positions of the sample generator 5 and the Gösumstellers 6 are such that the EH ^ pulses with the carrier gas through the catalyst, the probe 5, the gas diverter

6 and the probe 5 to the adsorption tube 7 arrive. Here, the NHo not absorbed by the catalyst is adsorbed on the cooled styrene-divinylbenzene copolymer (Cekachrom 3).

7 min after the beginning of dosing, the adsorption tube 7 is transferred to a water bath maintained at 298 K and left at this temperature for 2 min. The thereby deaerating NH ^ is fed to the measuring chamber of the Wärmeleitfähigkeitsmeßzelle for determining the concentration. If the temperature is maintained at 298 K for 2 minutes, the adsorption tube 7 is again placed in the cooling bath and 1 min later IffiU is again Meter 2 and proceed as described above. The dosages are repeated until saturation of the catalyst surface. The device according to the invention is represented by the drawing. The dosing processes and gas changes are carried out automatically · With the triggering of the dosing process, a microcomputer-supported evaluation unit for the calculation of the

meleitfähiglceitahlßzelle measured concentrations are taken into operation.

The results are summarized in Table 3. They show that the acidity and activity values obtained by the process according to the invention (device) congruate significantly better than the results obtained according to the comparative example, the cost of the process (apparatus) according to the invention being considerably lower than those of the known solutions. In addition, the reliability of the results obtained by the method (device) results significantly higher.

Results of the comparison and embodiment.

mmol HH ₃ / giCat

  "." ''

Sales in % ounces.

mmol KH ₃ / gcat sales in % Gurans:

Comparative Example Cat. A, Cat. B Cat. G 34.7 · 21.4 43.9

30.4

25.6

24.2 2)

·

Inventive example

Cat. A Cat. R Cat. 0 30.1 20.8 19.1

30.0

25.8

Standard deviation of the acidity determination of the comparative example is 3.7 / t.mol

² 'Tue

'The standard deviation of Aciditätsbestimmung of the inventive method is 1.1 / <. Mol HH ^ / g of catalyst.

Claims (3)

invention claim (1) incoming carrier gas flows via the sample donor (2), reactor (3), sample donor (5), gas diverter (6), sampler (5), adsorption tube (7) and separation column (8) to the measuring chamber of the thermal conductivity cell (9) and wherein the free volume between donor (2) and Katlysatbrschüttung , .. ο. - 3 5 to 250 cm, preferably 10 to 20 cm, and the free volume after the pritte of the reactor to the entrance of the measuring chamber. the conductivity measuring cell (9) is not 3 '3' greater than 250 cm, preferably 25 cm. 1. A method for combined activity and Acidity determination of granular catalysts in the temperature range of 273-873 K at normal pressure up to'Pressures of 50 MPa, the activity in Koblenwasserstoff conversion reactions with a U-shaped flow reactor and the acidity after the Pulse flow method of 'WH ο-Ch θ miaorption be identified / characterized in that one heats 100 to 2000 mg of the catalyst at a given pressure in a reactor with a radiation furnace on the activation temperature in Aktivierungsgaa, activated and cooled to reaction temperature, at Reaction temperature with reaction gas, after at least 30 min with respect to the catalytic activity / tat checks, then in the same reactor at a
Gas load of at least 20000 v / vh 10 to 180 min,
'' preferably 30 min, rinsed with hydrogen while the temperature at least 10 K higher than the reaction temperature, but maximum activation temperature sets, then abruptly cooled to adsorption, the flow rate is set to a value of 5 to 10 l / h, and then at normal pressure at intervals of 7 to 12 min. TJH pulses of a size of - 3 ' ? ^; '' 0.2 to 0.4 cnr. Over the catalyst until saturation of the catalyst surface, with the amount of moiety arriving after the catalyst layer in an adsorption tube filled with .2 to 3 g of styrene-divinylbenzene copolymers, adsorbed at temperatures of 190 to 210 K. -. ' and 4 to .9 min after dosing for 2 to 3 minutes shock-like desorbing at temperatures of 273 to 373 K and the desorbed UH, amount determined katharometrisch,
/ is and that during the entire process, the gas guide is carried out so that the gases first flow through the catalyst bed and then the Pritte the reactor. 2. Apparatus for the combined activity and _{Aciditätsbestim-:} - ^.:: Mungi characterized in that upstream of the reactor (3) a 'Gasumsteller (1) for the 3 Ausheizwasserstoff gases, hydrogen and substrate carrier gas for the adsorption measurement with. Tiach connected sampler (2) for the dosage of WHo pulses during acidity measurement is installed and between the reactor outlet and separation column of the gas chromatograph (8) successively the sample generator (5) for the dosage of Reaktionsproduktea, a gas diverter (6) and a , _; :. · Temperable U-shaped adsorption tube (7) filled with styrene-divinylbenzene copolymers, vior in the gas diverter (6) with the gas chromatograph :: " coming carrier gas is charged, the central output of the gas diverter (6) is connected to the second input of the sampler (5) and the inlet and outlet of Adsorptionsrohrea (7) is shorted, so that in the reaction product Döaierung during the ^; 'catalytic' reaction, the carrier gas II coming from the gas chromatograph passes via the gas diverter (6), the tester (5) and the separation column (8) to the measuring chamber of the thermal conductivity cell (9) and -> . ''. Case of acidity measurement of the gas diverter for 3 gases 3. Apparatus after Pkt '. 2, characterized in that basic substances are used as separating column materials · This includes 1 sheet drawing