DE2443899A1 - REDUCING CATALYST FOR THE SEPARATION OF NITROGEN OXIDES FROM EXHAUST GASES - Google Patents

Description

Reduction catalytic converter for the separation of nitrogen oxides from exhaust gases

The separation of nitrogen oxides from exhaust gas mixtures, which originate for example from boiler systems, has recently been carried out more and more urgent.

The subject of the invention is a novel reduction catalyst, which is used for the separation of nitrogen oxides (which are also generally referred to as "NO" in the following), by selective Reduction of these oxides is suitable.

It has already been suggested to remove N0__ by oxidizing NO in a dry gas mixture in the presence, a low level of oxygen amount to be deposited. The method described in German patent application P 24 22 708.5 consists in the fact that the brings dry gas mixture into contact with an adsorbing oxidation catalyst, which is produced by heating a naturally occurring occurring tuffs is available. This natural tuff consists essentially of SiOp, AIpO., And HpO and contains in total 1 to 10% by weight alkali and alkaline earth oxide and has an X-ray diffraction diagram, which roughly corresponds to that shown in Tables I and II below. The existing as well as the new

5098 1A / 1022

NO _{2 formed} are then adsorbed on the absorbent and then regenerated again in the usual way, for example by splitting it off by heating the absorbent, whereupon the oxidation-absorption process is repeated.

When using the exhaust gases from boiler systems, however, the method of removing nitrogen monoxide (NO) through oxidation has become proved to be unusable if the exhaust gas contains a larger moisture content of about 10 to 15% by volume, which is e.g. Exhaust gases from sintering furnace is not the case. Moist gases must be dried prior to using the process in order to keep the moisture does not affect the activity of the catalyst. In addition, the absorbent must be proportionate for the desorption of NOp be highly heated.

It is also known to reduce NO in a gas mixture by reduction with a gas, for example with H ₂ , CO, hydrocarbons or NtU as a reducing agent. The oxide of a metal, for example Cu, Fe, Cr, V, Mo or V / is used as the catalyst.

However, this method has significant disadvantages since the NO is very slow due to the low rate of reduction is deposited and the catalyst has an excessively short life. In addition, it requires a high reaction temperature and the catalyst is poisoned after a short time by the admixtures, e.g. sulfur dioxide.

The reduction process mentioned has therefore not yet been implemented because it is used on an industrial scale oppose the disadvantages mentioned. The invention is based on the object of a new selective reduction catalyst provide, with the help of which you can remove all nitrogen oxides (NO) from the exhaust gases in an effective and simple manner.

/ 3

5098U / 1022

The reducing catalyst of the present invention is prepared by treating a naturally occurring inorganic one Substance as a carrier for the. Catalyst with a solution containing cations of a metal from groups Ib, Hb or VIII des Periodic table or of Cr or Mn; the treatment is carried out in the manner customary for the production of catalysts, e.g. by dipping or spraying the support with an aqueous solution containing the cations and, if necessary, the following Heat.

Representative examples of the present invention catalyst supports are naturally occurring Tuffarten consisting essentially of SiO _2, AIpCU and KUO and a total of 1 to 10 wt% alkali oxide and or or alkaline earth metal oxide corresponds ¹ hold and whose X-ray diffraction pattern in Table I and II is shown.

/ 4 5098U / 1022

Table I.

2443833

Grid spacing
£ Relative
intensity
10 · 1 / I ₀ 5 Grid spacing
£ + 0.03 Relative
intensity
10-1 / I ₀ 6th 1 13.9 + 0.1 2 2 3.23 + 0.03 - 9.1 + 0.1 4th 4th 3.10 + 0.03 0 3 2 6.6 + 0.1 4th 6th 2.90 + 0.03 - 6.5 + 0.1 2 2.85 + 0.03 0 1 6.1 + 0.1 2 2.71 + 0.03 1 5.83 + O.O5 2 4th 2.58 ± 0.03 2 4th 4.55 + O.O5 2 2.53 0.03 - 3 4.30 + 0.10 0 - 2.49 + 0.03 0 - 2 4.26 + 0.10 0 - 2.47 + 0.03 0 ~ 4.08 + 0.10 0 - 8th" 2.45 + 0.03 0 2 4.05 + 0.10 0 - 2.04 + 0.03 1 4.01 + O.O5 7th 1.96 0.02 1 3.85 + O.O3 2 1.88 + 0.02 1 2 3.81 + 0.10 0 - 1.82 + 0.02 - 3.77 ί 0.05 1 1.82 + 0.02 0 1 3.48 + 0.03 10 1.79 ί 0.02 1 3.40 + 0.03 5 1.53 3.35 + 0.10 0 -

5098u7iV ~ 22

Table II

Grid spacing Relative Grid spacing Relative

Intensity intensity

X 10 · I / I 'jj 10'

9-10 + 0.1 7th 5.18 + 0.05 4th 7.99 + o.l 4th 5.I5 ■■ + O.O5 4th 6.82 + 0.1 2 2.99 + 0.05 0-1 5.85 + 0.08 5 2.98 + 0.05 4th 5.29 + 0.08. 2 2.89 + 0.05 4th 5.12 + 0.05 5 2.85 + 0.05 0-2 4.67 + 0.05 2 2.81 + 0.05 5 4.50 + 0.10 0-5 2.74 + 0.05 1 4.26 + 0.10 0-2 2.55 + 0.02 2 4.08 + 0.10 0-4 2.49 + O.O5 0-4 4.05 + 0.10 0-6 2.47 + O.O5 0-5 5.98 + -.05 10 2.46 + 0.02 2 5.85 + 0.05 2 2.45 + O.O5 0-2 5.8.1 + 0.10 0-4 2.02 + 0.02 0.5 5.77 + O.O5 2 I.95 + 0.02 O.O5 5.47 + O.O5 7th 1.87 + 0.02 0.5 5.5 ^ + 0.10 0 - 8. 1.81 + 0.02 0-2 5.55 + O.O5 5 I.72 + 0.02 0.5 5-22 + O.O5 A-

509814/1022 - 5 -

The values for the location and the specific intensity 10'1 / I ₀ in X-ray diffraction spectrum may fluctuate slightly, depending on the used for measuring the humidity and temperature apparatus and the manner in which the crystals used v / ere.

The X-ray diffraction patterns were obtained in the usual manner. It became a Kc *. - Doublet radiation of copper and a Geiger counter spectrometer used with strip recording. The height of the peaks, I, and the position as a function of 2 C & *, where cS "is the Bragg angle, were taken from the spectrometer record read. This became the relative intensity

10.

calculated, where the J _{0 is} the intensity of the strongest line or the highest peak, and the grid spacing A is calculated.

The raw material according to Table I comes mainly from the Japanese districts of TohoKu. and Chugoku before, while the in Tuffs listed in Table II occur in the Tohoku and Kyushu districts.

The X-ray diffraction gratings and chemical composition of the tuffs listed in Tables I and II, which can be used as supports suitable for the catalysts of the invention, largely correspond to those for those known as "mordenite" and "crionite" Substances that are particularly useful.

The broken tuff is comminuted to a fineness of more than 0.29 mm, preferably from 4 to 6.7 mm, and then represents a support for the catalyst according to the invention. Catalyst beds with a content of smaller particles presumably show a better effect the separation of NO _x from exhaust gases, as they have a larger surface and better hold back the nitrogen oxides. However, the limiting factor for the fineness is that the. Pressure drops sharply when using fine-grained catalysts, which is why the catalyst is optionally in the form of granules,

5098U / 1022/7

Tablets or other contact bodies used.

The cation-containing solution used to treat the carrier thus obtained is obtained by dissolving a metal salt of a mineral _{acid (HCl, HNO 3} , H SO ^) in water.

Soaking the wearer with the aqueous saline solution can be lukewarm
be guided.

at room temperature or at an elevated temperature of up to 100 C

Instead of using cations, the inventive Catalyst can also be prepared in such a way that the carrier in granulated form with a metal powder, a metal salt, a metal oxide or a metal hydroxide, etc. are mixed, the mixture is granulated and, if necessary, tablets or others are made therefrom Contact body presses.

The ratio of metal to support is in the range from 0.01-5.0: 100, in particular 0.02-4.0: 100.

According to a variant of the production process, the carrier is, before the treatment with the cation solution, with a Treated solution containing NH ^ ions. As from the examples As a result, the removal of nitrogen oxides from exhaust gases can be improved.

According to a particularly preferred variant of the manufacturing process is the carrier several times in succession with a freshly prepared solution containing metal cations, treated.

If the catalyst is produced according to this preferred method, the reduction of the nitrogen oxides can be carried out at a relatively lower * temperature in the range from 290 to 380 ^° C., the temperature range being wider than when using the usual catalyst, which can be achieved, for example, by only one immersion was made into a cation solution.

/ 8 50981 A / 1022

In any case, the catalyst can be used immediately after its preparation without further treatment. However, it is advantageous if it is subjected before use to a heat treatment, wherein the temperature between 100 and 900 ° C, preferably between about 200 and 700 ⁰ C. The heat treatment is preferably carried out by blowing hot air in a tunnel furnace or in the open air onto the catalyst which is passed by in a conveyor belt.

The catalyst obtained in this way is combined with that containing the nitrogen oxides Gaseous mixture brought into contact in the usual way, whereby it is arranged, for example, as a fluidized bed or a fixed bed. Withdrawal the nitrogen oxides are based on the fact that they are evenly reduced, even if they are present in the gas in only a low concentration will. '

A reducing agent such as Hp, CH ^ OH, NH3, CO, paraffin, olefin or the like is preferably added in a small amount to the gas mixture to be treated, since this can greatly improve the reaction rate and the conversion of the nitrogen oxides. When using the catalyst according to the invention for the separation of nitrogen oxides in exhaust gases, the presence of H ₂ O, CO ₂ , O ₂ , which are generally contained in the exhaust gas, has no negative influence whatsoever. The catalyst according to the invention acts extremely selectively with respect to the nitrogen oxides present, so that the presence of oxygen in no way interferes. Even a sulfur dioxide content of several thousand ppm in the gas mixture does not adversely affect the effect of the catalyst.

The rate of reduction is also ^a a ^ of an excess or deficiency relative to the stöchi.ometrischen amount of reducing agent, so that its setting is quantitative 8hängig very easily.

The reduction may be at atmospheric pressure and a temperature in the range of about 200 to 500 ° C, preferably from JOO be performed up to 400 ⁰ C and in particular at about 320-380 C.

5098U / 1022/9

The gas velocity is expediently in the range of

0.1 to 4 (x ioS ¹

The use of the catalyst according to the invention for deposition of nitrogen oxides from exhaust gases has the following advantages:

1) The reaction rate is extremely high;

2) the removal of nitrogen oxides is extremely rapid, even if their concentration in the exhaust gases is relatively high is low;

3) the moisture usually present in the exhaust gas does not have to be removed beforehand, so that the process steps necessary for this purpose and devices are saved;

4) the production costs for the catalytic converter are low and its service life is much longer than that of conventional catalytic converters, since it is dependent on additives such as S0 _? , is not poisoned.

The examples serve to explain the invention in more detail.

Manufacture of the catalyst:

Example; A-1:

A naturally occurring tuff that met the criteria given in Table 1 was reduced to a grain size of 4 to 6.7 mm crushed and the powder for more than 1 hour 600 ° C, whereupon it was allowed to cool.

The thus prepared support was for two hours in a 100 ° C on heated aqueous solution of CuNO, - sprayed (0.25 2.0 mol / l H ^ O) or with such a solution and in the air at 600 ⁰ C or dried at room temperature. The copper catalyst then contains 0.02 to 3.0% by weight of CuNO, calculated as metallic Cu, per 100 parts by weight of support.

/ 10

50981 4/1 022

Ag, Zu, Cd, Fe, Cr, Ni, Co, Mn, and Pd catalysts were prepared in the same way, each using an aqueous solution of the corresponding metal nitrate. Example B- 1

The carrier prepared according to Example A-1 was with a Mixed precipitate, which "had been obtained in the reaction of copper sulfate with sodium hydroxide solution, wet with pulverized kneaded and then granulated * e ± Eäß. By heating the

Granules at about 10O ⁰ C gave a catalyst with about 36.5 parts by weight of metal salts, calculated as metal per 100 parts of support.

Example C-1

A catalyst was prepared according to Example A-1 using a natural product which met the criteria in Table I. In in this case, however, the support was immersed in an aqueous solution at about 30 ° C. before it was treated with the cation solution immersed in NILCl (1Mo1 / sol) and dried at room temperature.

The carrier contained the same amount of copper nitrate as in Example A-1.

Using aqueous solutions of the corresponding metal nitrates, Ag-, Zn-, Cd-, Fe-, Cr-, Ni-, Co-, Mn- and Pb catalysts.

Example D-1

Using a natural product which met the criteria in Table I, a catalyst was prepared according to Example B-1, however, before mixing the carrier with the metal-containing fraction, immerse it in an aqueous solution of NtLCl (1 mol / soln) for 15 minutes. immersed in v / urde. The catalyst contained about 36.5% by weight metal salt, calculated as metal.

/ 11 5098U / 1 022

Example E ;

a-1) The natural product corresponding to the criteria in Table I. was reduced to 6.7 mm and the support produced in this way was immersed in an aqueous solution of 0.2 mol of Fe nitrate per liter and then heated in the air. The immersion and drying were repeated several times, each time with fresh Fe nitrate solution.

b-1) Instead of the Fe nitrate solution, a solution of 0.25 mol F.e chloride used per liter of water, the carrier being the same Material was as in Example E a-1, but this time it was comminuted to a maximum grain size of about 4 mm.

c-1) In the same way were using the corresponding Metal nitrates Ag, Zn, Cd, Cu, Cr, Ni, Co, Mn and Pd catalysts prepares.

Examples A-2, B-2, C-2, D-2, E a-2), Ξ b-2 and E c-2

It was as above under Example A-1, B-1, C-1, D-1 E a-1), E b-1) worked, however, a natural starting material as a carrier was used, the criteria of which corresponded to those listed in Table II.

Usage example :

The respective catalyst according to the invention was in a tube with an internal diameter of 25 mm and a length of 100 or 150 mm abandoned. Gas mixtures containing nitrogen oxides (NO) and moisture were sent through the pipe. Of the

4 - 1

The gas throughput was 0.1 to 4 (× 10 hr.) And the temperature was 1 ^ 0 to 400 ° C.

The gas mixture contained a reducing agent. in an amount of up to 2.62 Hol per mole of NO and also O ₀ and SO ₀ , their

X c. ti.

Quantitative proportion is shown in Table III. The other constituents of the gas mixture were H ₂ O (11 to 15% by volume), CO ₂ (12 to 13 volume-y-), the remainder being N ₂ .

/ 12 5098U / 1022

Table III lists: the metal and its proportion in% by weight, the concentration of NOp when it is introduced into the pipe, the reducing agent and its amount in ppm, the molar ratio of reducing agent to NOp, the temperature of the reduction reaction and the O content ₂ in % and SO ₂ in ppm.

For Examples 3 to 67 and 68, catalysts prepared with a carrier meeting the criteria were used from Table I. In the following Examples 103 to 156 and 157, the carrier corresponded to the catalyst used the criteria of Table II.

In Examples 3 to 56 and 63 to 68 according to Examples A-1 and B-1 prepared catalysts and in the Examples 57 to 62 those prepared according to Examples B-1 and D-1 Catalysts used.

In the column for the reduction ratio in Table III, the results of the tests were given under I and II, respectively which used catalysts which were prepared according to Examples A-1 and B-1 or C-1 and D-1.

In Examples 103 to 144 and 151 to 156, the catalysts prepared according to Examples A-2 and C-2 were used in Examples 145 to 156, those prepared according to Examples B-2 and D-2 Catalysts used.

In the column for the reduction ratio of Table III the results of the tests are given in which those prepared according to Examples A-2 and B-2 (I) or C-2 and D-2 (II) Catalysts were used.

Examples 68 and 157 describe the results of experiments' which were carried out continuously for 300 hours to test the life of the catalysts.

/ 13 5098U / 1022

- 13 Table III

Catalyst ^

Conc. Reduction Red. Gas

in the middle temp, through-

By weight exhaust gas rate

game parts mole _ft "" ^ 4

No. Metal ppm ppm ^{Ratio W} C CJ.-1

x10,

Mr"

SO ₂

χ

ppm

Reduction ratio II

Cu 0.8 729

Cu 0.8 7 44

Cu 0.8 779

Cu 0.8 759

Cu 0.8

729

Cu 0.8 880

Cu 0.8 930

Cu 0.8 930

Cu 0.8 930

1.30

NH _Λ .

1.01

NH ₃

0.64

NH,

0.46

NU «

0.23

NII ₀

1.24
NH.,

0.77
NH ₃

0.52

NH

35Ο Ο.38

NU «

330 3IO 29Ο 28Ο

325 305 295 275 265

320 300 280 270

320 300 285

320 310 300

320 310 300 290 280 270 260

320 300 290 280 270 260

320 310 290 270 260

320 300 285 28Ο

98.9 99-0

99
99

99
99

, 1 .1

.3 .3

99.3 99.3 99.3

99-4

99.4 99.4

99.4 99.4 98.0

65.3 58.7 55.8

99.1

99-1

99.2

99.2

99

99

, 3, 3 99.2

99
99
99
99
99
99

.5 .5 .5 .5 .5 .5

99.6 99.6

99. 99

.6, 4 99.6

99.6 99.6 99.4 1

99.3 99-5 99-7 99.7

99-9 99-9 99.9 99.9 99.9

99-9 99-9 99.9 99-9

99-9 99.9 99.9

71.5 65.2 63.9

99.5

99.99 99.99.

99.9

99.9 99.9 99.9 99.9 99.9 99.9

99.9 99.9 99.9 99.9 99.9

99.9 99.9 99.9 99.6

KD981 hl 1/14

from Tat »#ll« XXI

Cu 0.8 64O I56O 2.44 310

NH 305

^J 300

“29O

28O

270

260

Cu 0.8 640 95O I.49 325

NH 320

^J 3IO

300 29O 28O 27O 260 25O 240

500 0.78 320

Cu 0.8

Nile 310

295 28O 270 26O

Cu 3.0 490 950 1.94 340 1.2.

NH.

NH

Cu 2.7 49O

Cu 2.7 49O

Cu 2.7 49O

NH.

NH.

NH

320 300 25O

Cu 3.0 490 950 I.94 340

320 300 250

95O I.94 330

310 29O

95O I.94 315

285

95O I.94 320

29O 27O

Cu 2.7 49O 95O I.94 29O

4th

NH

270

99.4 99.9 99-8 99-9 99-8 99.9 99.8 99-9 99.8 99-9 99.8 99-9 99-7 99.9 99-7 99.9 99.7 99.9 99.8 99.9 99.8 99.9 99.8 99.9 99.8 99-9 99.8 99.9 99-8 99.9 99.8 99-9 99.8 99.9 99.7 99.9 99.8 99.9 99-8 99.9 99.8 99.9 99.8 99-9 99.8 99.9 98.2 99.0 98.5 99.1 98.7 99-5 98.3 99.0 98.2 98.9 98.5 99-1 98.7 99-5 98.3 99.0 98.7 98.9 98.7 - 98.9 98.5 - 98.8 98.8 - 98.9 - 98.9 _ 98.9 -

50981 A / 1 / 15

XXX

21 Cu 1.8 565 950
NH ₃ I.45
* 300
280 1.2 4th - 1 - 1 - 95.0
96.1 - 22nd Cu 1.8 565 950
NH ₃ 1.45 390 1.2 4th 1 - 96.6 98.6 23 Cu 1.3 593 950
NH ₃ I.6O 300
280 1.2 0.5 - 95.8
96.1 97.9
98.5 24 Cu 1.3 593 950
NH ₃ 1.60 290 4.0 0.5 96.3 98.4 25th Cu 2.3 650 950
NH ₃ 1.46 320
280 1.2 0.5 97.8
97.9 - 26th Cu 2.3 650 950
NH 1.46 320
280 1.2 0.5 97.8
97.9 - 27 Cu 3.0 677 600
NH ₃ 0.89 325
290 0.1 4th 98.7
98.8 - 28 Cu 3.0 814 1100
NH- 1.35 320
300 0.3 4th 99.3
99.3 99.9
99.9

29 Cu 2.7 660 950 1.44 290 1.2 4 - 98.7

NH

30 Cu 2.7 660 1100 1.44 300 2.4 4 - 98.2 99.2

NH ₃ 28O 98.9 99.8

31 Cu 2.7 660 950 1.44 290 1.2 4 - 98.7

NH ₃

32 Cu 2.7 795 1700 2.14 290 1.2 4

NH 270

^J 250

■ 33 Pd 2.7 795 1100 I.38 280 1.2 4

Nile 260

34 Zn 0.05 645 500 0.77 29O 1.2 4 ".

5098 U / 1.0 2 2/16

99.2
99.4
99.5 98
99 _ 98.I
98.4 66 .1
.1 4.61 .3

Continuation from Table III

35 Zn 0.05 645 950 1.47 290 1.2 4 - 4.61

NH

36 Zn 0.05 645 I56O 2.42 29Ο 1.2 4 1 46.1

NH.

37 Cr 0.5 621 500 0.80 34o

NH

38 Cr 0.5 621

NH

305

500 0.80 300 CO

39 Cd 0.5 531 950 1.79 320

300

40 Ni 0.5 5318 950 P.94 340

NH

4th 63.9
73.7 73.3
77.7 4 _ 76.5 79.5 4th 50.9
41.4 59.9
52.3 4th 70.2 72.9

41 Ni 0.5 531

500 Ο.94 350 CO

55.7 57.8

42 Co 0.5 720

43 Ag 0.5 720

44 mn o.l. 582 45 Mn O. 610 46 Fe 0.1 601 47 Fe 0.5 611 48 Cu 0.36 634 49 Cu 0.36 616 50 Cu 0.20 620

950 1.32 320 1.2 4th ■ 4th - 1 - 82.9 85.9 NH ₃ 950 1.32 34ο 1.2 4th - _ 86.4 88.4 NH ₃ 500 0.86 335 1.2 4th - 56.9 69th Ο NH 300 44.5 68.5 -950 1.55 290 1.2 4th _ 44.6 _ NH 500 0.83 320 1.2 4th _ 71.3 _ NH ₃ 28 ο 64.7 - 950 1.55 320 1.2 4th 98.4 99.5 NH 500 0.79 320 1.2 4th 86.7 90.1 NH 950 1.54 320 1.2 4th 88.4 91.9 NH 500 0.81 330 1.2 40.8 44.8 NH, 5CT9 8U / 1 022 f • / 17

^ from Τ3 & «11 & IXI

51 Cu 0.02 620 500 3 3 0, .81 320 0. 3 4th - 43.0 51- NH ₃ 52 Cu 3.0 626 1560 950 500 2, Λ9 320 1. 2 4th 95-7 NH NH NH 300 97.1 170 280 - 97.3 NH 255 96.8 53 Cu 3.0 637 - 1 .49 320 1. 2 4th 98.3 300 98.7 280 99.1 260 99.1 54 Cu 3.0 637 0 .79 310 1. 2 4th _ 99.2 99- 290 99.0 99 55 Cu 3.0 637 0 .27 315 1. 2 4th 87.I 91. 5OO 56 Cu 3.0 565 CO 320 1. 2 20th 39.9 51. 250 - 4.1.3 51. 230 39-9 50. 57 Mn 36.5 611 I56O - 320 i. 2 4th 41.8 47. Cu NH " 280 ^ 9.5 50. j 240 48.5 51. 200 49.5 51. 58 Mn 20.5 611 0 , 82 340 1. 2 4th 76.2 Cu 300 80.8 950 26O 20th 8 4.7 NH 200 82.9 59 Mn 36.5 596 170 2 .62 240 1. , 2 4th 77.2 Cu NH, 200 88.3 j 175 92.5 t 160 93.9 140 96.9 120 99-4 60 Mn 20.5 58 4 1 .62 195 2. .4 4th . 77.6 Cu 155 87.7 61 Mn 36.5 584 0 .29 215 1. .2 4th 60.3 Cu 170 66.5 130 66.5

5098U / 1022

Continuation from Table III

62 Mn
Cu 10.0 461 500
NH ₃ 63 Ni
Cu 0.4
1.8 601 950
NH ₃ 64 Ni
Cu 0.4
1.8 601 1200
NH ₃ 65 Cu 3-0 776 950
NH ₃ 66 Cu 3.0 795 1200
NH " 67 Cu 3.0 900

68 Cu 3.0 663

103 Cu 3.0 490

104 Cu 3.0 490 105 Cu 2.7 490

106 Cu 2.7 490 107 Cu 2.7 490 1.55

1.19

1.34

1.4
245

320 1.2

320
310
340
330

34 ₅
34o

335

350
340
325
310
280

1.6

1.6

1.6

950
NH 1.43 325 1.2 950
NH 1.94 M UJ UJ UJ
03 H UJUl
OUl O O 1.2 950
NILE· 1.94 same as
Ex. L03 .1.2 950
NH ₃ 1.94 335
320
300
280 1.2 950
NILE· 1.94 335
300 1.2 950
NH ₃ 1.94 335
305
280 1.2

- 48.0 45.1

O.83 320 1.2 20

78.9

- 98.6

13 98.2 98.2 98.8 98.9

13 99.1

99.3 99.8

13 99.5

.99.3

99.2

98.0

91.0

10 98.9

98.2 99-3

98.4 99-5

98.7 99.8 98.4 99-6

same as Ex.

98.2 98.8

98.8. 98.5

98.7 98.7

98.3 98.8 98.9

5098U / 1022

/ 19th

Ttbfll * XlX (continued)

108 Cu 2.7

109 Cu 1.8

110 Cu 1.8

111 Cu 1.3

112 Cu 1.3

113 Cu 2.3

114 Cu 2.3

115 Cu 3.0

116 Cu. 3.0

117 Cu 2.7

118 Cu 2.7

119 Cu 2.7

120 Cu 2.7

490 950
NH ₃ I.94
• 295
280 1.2 4th 1 98.9
93.9 - 565 950
NH 1.45 325
290
270 1.2 4th - 94.4
95.8.
95.8 - 565 95O
NH ₃ 1.45 320
295 1.2 4th 1 96.3
96.5 98.2
98.5 593 950
NH ₃ 1.60 310
290
270 1.2 0.5 - 95.8
96.1
95.7 97.9
98-3
97.7 593 95O
NH 1.60 390 4.0 0.5 1 96.3 98.4 650 95O
NH 1.46 34ο
300 1.2 0.5 1 97.8
97.9 - 650 950
NII ₃ 1.46 340
300 1.2 0.5 - 97.8
.97.9 - 677 600
NH ₃ O.89 335
310 0.1 4th - 98.4
98.7 - 814 1100
NH 1.35 330
310 0.3 4th - 99.3
99-4 99-9
99-9 660 950
NH 1.44 300
28 ο 1.2 4th - 98.6
98.9 - 660 1100
NH ₃ 1.44 310
290 2.4. 4th - 98.0
98.5 99.0
99.7 660 950
Nile 1.44 300
280 1.2 20th - 98.6
98.9 - 795 1700
NH ₃ 2.14 310
280
260
24ο 1.2 8th - 98.0
99 * 4
99.5
99.5 -

5 0 9 8 U / 1 0 2

νβϋ 'ifib &

121 Pd 2.7 795 1100 1.38 300 1.2 4 - 97.0 98.O

270 98.4 99.4

^J »250 98.4 99.4

122 Zn 0.05 645 500 0.77 330 1.2 4 - 46.1 66.3

NIl ₀

123 Zn 0.05 645 950 1.47 300 1.2 4 - 46.1

NH ₃

124 'Zn O.O5 645 I56O 2.42 300 1.2 4 1 46.1

NH ₃

125 Cr 0.5 621 5OO 0.80 35O 1.2

95O I.52 320

I56O 2.5I 29O

4th 62.3
71.4
78.5 72.5
74.4
80.2 4th 76.5 78.8 4th 48.6
46.0 58.8
56.7

126 Cr 1.0 621 5OO O.8O 300 0.3

CO

127 Cd 0.5 531 95O 1.79 340 1.2

NH ₃ 310

128 Ni 0.5 531 5OO O.94 320 1.2 4 - 77-4 79-9

NH ₃

129 Ni 0.5 531 500 O.94 300 1.2 4 - 52.7 55-7

CO

130 Co 0.5 720 950 1.32 350 1.2 4 - 86.4 88.8

NH

131 Ag 0.5 720 950 1.32 340 1.2 4 - 75.9 77.1

NH ₃

132 Mn o.l 582 500 0.86 355 1.2 4 - 64.9 75-5

48.1 69-3

133 Mn 0.1 610 950 I. 55 300 1.2 4 - 4?, 1

134 Fe 0.1 601 500 Ο.83 340 1.2 4 - 77-6

JII ₃ 300

5 0 98U / 1Q22

NH ₃ 300 68.6

/ 21

voa T & oei..u Hl.

135 Fe 0.5 611 950
Nile 1 .55 330
310 1.2 4th 1 98.1
98.0 99-2
99.0 136 Cu 0.36 634 500
NH 0 -79 330
310 1.2 4th - 89.6
85.3 93.3
89.6 137 Cu 0.36 616 950
NH 1 .54 330
310 1.2 4th - 90.3
83.7 95-3
86.7 138 Cu 0.20 620 500
NH ₃ 0 .81 340 1.2 4th - 42.0 49.0 139 Cu 0.02 620 500
NlI ₃ 0 .81 340
300 0.3 . 4th - 45.O
42.0 52.2
49-3 i4o Cu 3.0 626 1560
NH ₃ 2 .49 330
310
290
270
245 1.2 4th 94.6
96.4m
97-2
97.4
95-7 - 141 Cu 3-0 637 950
Nile 1 .49 330
310
290
270 1.2 4th 97.9
98.4
98.9
99.1 - 1-42 Cu 3.0 637 500
NH ₃ 0 .79 345
300
280 1.2 4th - 98.9
99-2
98.6 99.9
99-9
99-9 143 Cu 3.0 637 I70
NII ₃ 0 .27 325
305 1.2 4th - 89.9
84.3 93.4
90.6 144 Cu 3.0 5'65 - - 340
283
240 1.2 20th - 46.9
50.7
49.9 50.9
52.3
51.1 145 Mn
Cu 36.5 611 34o
300
250
220 1.2 4th 43.9
46.2
49.5
49.5 46.0
48th Ί
51-8
51.9 146 Mn
Cu 20.5 611 500
CO 0 .82 360
320
280
240 1.2 4th 75.0
80.1
8 >>. L
84.1 77.1
82.3
86.4
86.5

50981 4/1022

Continuation from Table III

147 Mn
Cu 36.5 596 156O
NH ₃ 2.62 260
220
I90
170
I50
130 1.2 4th 20th 77.2
84.1
90.6
92.9
95.2
99.4 79.3
86.3
92-9
95.5
97.7
99.9 148 Mn
Cu 20.5 58 4 950
NH ₃ I.62 230
165
145 2.4 4th 70.5
82.9
8 4.4 72.5
85.I
86.9 149 Mn
Cu 36.5 58 4 170 O.29 190
150
130 1.2 4th - 66.5
66.5
66.5 68.4
68.3
68.5 150 Mn
Cu 10.0 461 - - 365
270 1.4 20th - 46 ^ 5 48.8,
49.I 151 Ni
Cu 0.4
1.8 601 500
NII3 0.83 340
300 1.2 20th - 81.9
77.6 85.I
79.6 152 Ni
Cu 0.4
1.8 601 950
NH I.58 330
300 1.2 20th - 98.4
98.6 99.3
99.5 153 Cu 3.0 776 1200
NII ₃ 1.55 320
310
340
330 1.6 4th 13th 98.O
98.O
98.6
98.7 99.1
99.1
99.5
99.9 154 Cu 3.0 795 950
NH 1.19 345
340
335 1.6 4th 13th 99.1
99.1
99.0 99.9
99.9
99.7 155 Cu 3.0 900 1200
NH ₃ 1.34 350
340
325
310
280 1.6 k 13th 99.3
99.2
99.1
98.O
91.6 99.9
99-9
99.9
99.5

I56 Cu 3.0 663 95O 1.43 325 1.2 20 10 99.9 99.9

NH ₃

200 - - 509 5OO O.98 300 1.2 4 - 28.9

NII ₃

201 - - 509 5OO O.98 320 1.2 4 '- 32.8.

NII

300 28.9

5098U / 1022

In the table above, Examples 200 and 201 are comparative examples in which only the carrier itself produced from the tuffs was used as a catalyst. As can be seen from the results obtained here, the reduction ratio is not sufficient when using the catalyst carrier alone. In contrast, when working with metal catalysts according to the invention, practically the entire proportion of NO _{x was} always removed at a considerable rate. It turned out to be unnecessary to dry the exhaust gas before starting the process.

The life of the catalyst according to the invention was more than 300 hours.

In the following Table IV the results of experiments are listed, which were carried out according to Example E-a-1 (b-1) and (c-1) produced catalysts were achieved.

The gas mixtures and the procedure corresponded to the above examples, but in all of the following examples NH ^ gas was used as a reducing agent and the SOp content was varied between 0 and 2000 ppm.

Table IV shows how often and for how long the wearer is was immersed in the metal cation solution, as well as the heating temperature of the finished catalyst.

The in Examples 311, 312 and 313 as well as 407, 408 and 409 catalysts used had been made using a natural tuff specified in its criteria corresponded to Table II, as a support, while the catalysts used in the other examples on a support according to Table I were applied.

/ 24

5098U / 1022

Those used in Examples 314, 315, 320, 321 and 322 Catalysts were prepared according to Example E-c-1.

In Table IV are Examples 401 to 410, in which catalysts prepared according to Examples A-1 and A-2 are used were, comparative examples.

In the preparation of the catalysts for Examples 404, 405, 406 and 408, the support was repeatedly immersed in a metal cation solution immersed, but the same solution was used / ended several times.

125

5098U / 1 022

Table IV

Catalyst * *

Diving Erhit-Red. ting temp.

Examples weight ^tei as total? ^pe ~ play me- parts often std. ^raxur
No. tall ⁰ C ⁰ C

Conc 2443899 Reduc- Red. from Gas- functional with NO ge behaves tel in ^x A black nis gas
ppm ^b - X10 ⁴ % ppm hr- ¹

Fo 8.I9 2 1.5

Fe 8.16 2 1.5

Fe 8.1 2 1.5

Fe 13.1 3 2

Fe 8.5I 3 2

Fe 14.0 4 2.5

Fe 6.43 2 1.5

Fe I5.O 5 3

Fe 6.9I 2 1.5

400

300

200

400

100

100

400

4oo

4oo

380 350 330

4oo 380

360 340

4oo

380

360 34o

4oo 380 360 34o

400 380 360 335

4oo 380

335 290

4oo 380 360

335 300

400 380 360 34o 320 300

4oo 380 360 340

~ 124

121

123

118

118

128

125

135

126

1.5

1-5

1-5

1.5

1-5

1-5

1.5

2.4

99.7 99.8 99.4 98.4

99-4 99.45 99.5 99.1

99.5 99.4 99.4 99.1.

99-8 99.9 99-9 99.7

99.7 99.6

99.5 99.2

99
99

.3 .1

98.8 96.2

1-5 99.6 99.7 99-6

99.5 95.7

99-7 99.7 99.5 99.7 98.8 96.4

99.4

99.1 96.Ο

5098U / 1 022

from T * b «il · XV

1 .5 150 400 125 121 1 .59 99.2 -155 -99-4 360 120 96.5. -99.0 1 .5 400 Ίο 0 110 95 1 .5 98-6 -170 -99-3

Fe 8.2

Fe 8-9 2

Fe 12-1 3 2 400 4θΟ 120 "99.6 1-5 99.2

-150 -99 -4

Cu 7.7 2 1.5 450 400 100 95 2.4 97.7

-165 '-98.8

Cu 10.8 3 1.5 200 400 160 104 2.4 99.7

360 99.2

3 40 98 .1

315 94.5

Fe 14.0 4 2.5 ^ 50 400 150 108 2.4 99.8

370 ■ 99.6

350 99-0

320 95.8

Fe 13.3 3 2 300 400 150 104 2.4 99.4

360 98.8

340 ■ 97.7

317 95-7

295 91.3

Fe 8.0 2 1.5 4θΟ 400 I5O 102 2.4 99.4

360 98.5

340 97.5

310 93.3

Fe 12.5 3 2 400 400 I50 102 2.4 99.7

360 99.2

340 98.5

320 96.4

300 93.8

Cu 7.5 2 1.5 400 400 150 99 -2.4 99.0

360 '98.0

34o 96.9

310 92.2

η 7

5098U / 1022

Forte «t £ Uütig Von ittbtll« XV

321 mn

322 notes

401 feet

402 feet

403 feet

404 Fe

405 feet

406 feet

407 feet

408 feet

40 9 Cu

8.9 2 1.5 4oo
* 400
360
34o
310 7.9 2 1.5 4oo 4oo
360
340
310 4.8 1 1 400 400
38o
360 5.3 1 1 4oo 4oo
380
350 4.9 1 1 4oo 4oo
380
360

5.5 2 1.5 4oo 4oo

150

96

i4o 126

i4o 132

121

122

410 Fe

8.0 4th 9.5 4oo 400 130 122 380 8.1 8th 3.5 400 4oo 130 122 380 360 4.5 1 1 400 4oo 130 125 + 20 385 36o 7.0 2 1.5 4oo 400 120 122 400 150 400 180 380 150 360 150 3.5 1 1 450 400 85 • 99.6 400 120 380 150 360 150 340 150 320 150 5.0 ■ "1 1.0 400 400 150 104 360 150 340 150 50 98 U / 1 022

2.4

2.4

1.5

1.5

1.5

1.5

1.5 '

1.5

1.5

1.5

2.4

99.5 98.4 97.2 92.O

98.9 98.I 96.8

91.7

98.2 97.4 96.3

98.I 97.7 95.6

98.5 98.I 97.0

95.8 94.O 90.I

93.7 92.7

89.2

85.5 82.0

98.2 98.O 95.0

98.6

98.4

97.0

98.25

97.2

88.7 98.7 98.4 97.4 95.0 90.9 92.6

88.3 80.6

As can be clearly seen from Table IV, one can especially Good results are obtained if the carrier is placed several times in succession in a freshly prepared solution, the metal cations contains, immersed.

Claims

509814/1022

Claims (5)

Claims 1. Reduction catalyst for the separation of nitrogen oxides from exhaust gases with a carrier made of naturally occurring inorganic material, characterized that the catalyst support consists essentially of SiOp, AlpO-. and HpO existing tuff with a total grade 1 to 10% by weight of alkali or alkali earth oxide, inclusive of so-called "Mortenite" and "Critonite", and that it is catalytic active constituent a metal of group Ib, Hb or VHI of the periodic table or chromium or manganese or a mixture of such metals. 2. Reduction catalyst according to claim T, characterized in that the carrier is a natural one Is tuff, which has the X-ray diffraction gratings listed in Table I or Table II. 3. A method for producing a reduction catalyst according to claim 1 or 2, characterized in that that the support, preferably by dipping or spraying, is impregnated with a solution, the cations of a or more metals of groups Ib, Hb or VHIdes periodic System or of chromium or manganese and then optionally heated to 100 to 900 ° C. / 2 5 098U / 1022 INSPECTED V 50- 4. The method according to claim 3 »characterized in that that the carrier is impregnated with a solution before treatment with the solution containing metal cations, which contains NH, cations. 5. The method according to claim 3 or 4, characterized in that the carrier several times in succession immersed in the newly prepared solution with a content of metal cations. ■ y: 5098U / 1022