SU1213976A3 - Catalyst for cleaning waste industrial gases - Google Patents

Description

This invention relates to a catcher for the purification of residual industrial gases containing sulfur compounds. In particular, it relates to a titanium dioxide catalyst containing alkaline earth sulphates used in Claus catalysis for the recovery of sulfur from residual gases containing, in particular , hydrogen sulphide, sulfurous anhydride, and possibly organic sulfur products such as CS and COS

The aim of the invention is to increase the catalyst activity due to the additional content of alkali-sulphate-ground metal and the ratio of ingredients8

In the proposed catalyst, the following measuring methods are used.

The specific surface area (SBE) is measured by the nitrogen absorption method j called the BET method,

Pore volumes (V RT) and average pore diameters (Fr) are determined by mercury penetration. There is a microporous volume (V ,, J), which corresponds to pore diameters less than 50 and a macroporous volume (V HP), which corresponds to pore diameters larger than 50 to them; for each category, the average porous volume is determined

Mechanical strength is measured by crushing grains (ECjG). It consists in measuring the maximum ush squeeze of J KOTOR51 can out hold the granular product until it breaks when the product is: placed between two planes. overhang. | still at a constant speed of 5 cm / min. In the case of spherical surfaces, force is exploded: in newtons,

In the case of protruding surfaces or oversized products, the force is applied perpendicularly to one of the constituent products, and the crushing of the grain is expressed as the ratio of the force to the length of the component AND | hence expressed in newton / grah

Mechanical strength is measured by resistance to abrasive wear (R, .A). This method consists in measuring the amount of dust deposited per 100 g of granulated products under screen No. 24 with a diameter of 20 cm AFNOR HP-501 series, driven by vibration for 10 minutes.

0

s

0

5 o

five

through a vibrator company Fenwick Rex. Resistance to abrasive wear is determined by the weight of the collected pie.

Example 1, The suspension obtained after hydrolysis of titanium tetrachloride is decanted, filtered and then dried in a suilnum furnace for 24 hours at. The resulting powder has an amorphous structure in the x-ray spectrum and loss on ignition (PAF) of about 18%.

The mixture consisting of this powder, WATER AND carboxymethylcellulose is mixed for 30 minutes in the following proportions,%: powder 66., water 32, carboxymethylcellulose 1.

This mixture is then extruded through a 3 mm diameter diameter, the extruded products are dried for 8 hours at p and then calcined for 2 hours at 450 ° C. The resulting extruded products have the following properties:

Specific surface

(SBE).,

Porous volume

(VPT), cm ° Oj32

Grain crush (EQG) ,, N / m 15.7-10

Resistance to

abrasive wear

(RA)

1 kg of the product is first impregnated with 310 cm of ammonium sulphate solution in order to obtain a ratio of 0-6 times and dried for 4 hours.

40

45.

at 100 s.

Then dried products are propi. 300 cm of a nitrate nitrate solution are used to obtain a ratio of

by weight 0.025.

The product is dried for 12 hours at

Then ignites for 1 h at 450 Cz get the following indicators

Specific Surface (SBE), I7

Porous volume

(VPT), Oj30

Crushing

grain (EU, a), N / m 26 „5-10

Resistance to

abrasive wear

(R..A,)

Therefore, the catalysts have an explicit mechanical strength (EQG and R.A),

EXAMPLE 2. The extruded products described in Example 1 are impregnated with a solution of sulfuric acid in order to complete the ratio.

SO n 1.

-fio,

by weight - T- U, i; after drying for 4 hours, the strontium acetate solution is soaked in such a concentration as

S2

get the ratio

by weight -G--

 0.091.

After drying for 4 hours at 110 ° C, then calcining for 2 hours at 450 ° C, catalysts are obtained with the following properties:

Specific Surface (SBE),

Porous volume

(VPT), cm / g

Crushing

grain (), N / m

Resistance to

abrasive wear

(R.A.),%

PRI me R 3. The suspension obtained after hydrolysis of titanium tetrachloride is decanted, filtered, then dried in a drying oven for 24 hours at.

The mixture consisting of this powder, water and calcium sulfate is stirred for 45 minutes in the following weight proportions,%: powder 71, calcium sulfate 8, water 21.

Ca Weight ratio: composition f 2

in this case, it is 0.04, and correspondingly

28

34.3-10

0.8

wearing by weight

| 5 ° C ° - Then this mixture is extruded through a 5 mm diameter die plate; the extruded products are dried for 4 hours at, then calcined for 1 hour at 600 ° C. The resulting catalyst has the following properties: Specific surface (SBE), 58 Porous volume (V PT), cm / g - 27

Crushing

grain (Eqq), N / m 18.6-10 Resistance to abrasive wear,% 0.4

And p. Example 4. The suspension obtained after hydrolysis of titanium tetrachloride is washed, then filtered. The layer is then dispersed in a solution of ammonium sulfate, and the resulting solution is dried by spraying;

S04

weight ratio -t-- in this

X

case is 0.

The resulting powder is mixed for 30 minutes with water and calcium acetate in the following; their proportions,%: powder 66; calcium acetate 8: water 26.

Sa

 The ratio by weight gt-- composition X 1,} l

lt 0.041.

The mixture is then extruded through a die of 3 mm in diameter, the extruded products are dried for 4 hours at, then calcined at 500 ° C for 2 hours. The resulting catalyst has the following properties:

Surface area (SEE), 96

Porous volume

(VPT), m / g 28

Crushing

Grains (Eqq), N / m 22.5-10

Resistance to

abrasive wear

(RA)% 0.5

Example5. In the suspension of titanium dioxide, obtained after hydrolysis and filtration by the usual method of sulfur etching of ilmenite, containing sulfate anions in such quantity that the ratio by weight

what

  0.08 Calcium nitrate added

qi to bring all sulphates into the reaction; weight ratio

Ca - T-- is in this case

LiU 2

0.033.

The suspension is dried for 1 h at 150 ° C.

The resulting powder is stirred for 2 hours with water in the following proportions,%: powder 64; water 36.

The mixture is then extruded through a 4 mm diameter die plate, the extruded products are dried for 4 hours at 110 ° C, then calcined for 2 hours at 400 ° C,

The resulting catcher has the following properties:

146

0.35

23.5

0.4

ten

S

Specific Surface (SEE),

Porous volume

(VPT),

Crushing

grain (EGq), N / m

Resistance to

abrasive wear

(R.A),%

PRI me R 6. A suspension of titanium dioxide, obtained after hydrolysis and filtration by the usual method of sulfur etching of ilmenite, is dried for 1 hour at

.., o „S04

180 С; weight ratio

llUg

 0.08.

The resulting powder is mixed for 2 hours and 30 minutes with water and barium nitrate in the following proportions, powder 64; barium nitrate 8; water 2

Wa Weight ratio -t-- compositionilUg

in this case, it is 0.113.

The mixture is extruded through a fipiera with a diameter of 5 mm; extruded products are dried for 4 hours and then calcined for 1 hour at 500 ° C. The resulting catalyst has the following media:

Specific Surface (SBE),

Porous volume

(VPT), cm / g-

Crushing

grain (EG, q), N / m

Resistance to

abrasive wear

(RA)% 0.2

Example, Suspension of titanium dioxide, obtained after hydrolysis and filtration by the usual method of sulfur etching and pymeny107

0 32

28,410

This is dried in a heat exchanger, in which the suspension is 45, then the powder is stirred by means of a screw.

SO o Weight ratio -t-J, 3LU

equally

0.085.

By mixing for 20 minutes, a mixture is obtained containing / o,%: powder 69J water 30.8; polyacrylamide 0.2.

This mixture is introduced into an extruder and passed through a 5-mm die. The resulting extruded products are dried for 24 hours.

Sh

f5

20

25 0

five

Uh

at, then calcined for 2 hours at 350 ° C in an electric air-blown furnace.

The final product has the following properties:

Surface area (SHE), 217

Porous volume

(VPT), cm / 100 g 0.29

Average diameter

(P) neither 7

Crushing

Grain (NaO), N / m 17.6-10

Resistance to

abrasive wear

. (R.A.),% 1.2.

1000 g of these extruded products are impregnated with 230 cm of calcium nitrate solution in order to obtain

Ca weight ratio -m-- 0.035.

2

The product is dried for 4 hours at, then calcined for 2 hours at 400 ° C. The resulting catalyst has the following properties:

Specific surface area (SBE), Porous volume (VPT), cm / g Crushing of grain (EQQ), N / m Resistance to abrasive wear (R, A.),%

- (

158

0.28

28.5-10

0.3

EXAMPLE 8: The same extruded products are used as the products described in Example 1, 1000 g of these extruded products are impregnated with 310 cm of calcium nitrate solution in order to obtain a weight

Sa

ratios -m-- 0.02. iiO

The product is dried for 2 hours at.

The product is calcined for 7 hours at a gas stream of the following volumetric composition,%;

Air90

The resulting catalyst has the following properties: Specific Surface Area (SBE), 95 (Porous Volume VPT),, 31

Crushing.

grains (EC, Q), N / m 22.5-10

Resistance to

abrasive wear

(R.A.),% 0.8

Example 9. The catalysts obtained according to examples 1 and 5 are used in the reaction:

 + SOg ---- Sn + H, 0. n

Per- At pri- (1) 10 th measure 5 83 85 86 86 86

Gas is supplied to a series of three isothermal reactors under the following conditions.

SOz

N,

The volume composition of the gas at the inlet of the first reactor,%: HjS 9

SOz N., 0 20

NZ 66.5 The temperature of the reactor 300 C. The catalyst is the catalyst obtained in example 5.

The volume composition of the gas at the inlet of the second reactor,%: 2.5 1.25 27

69.25

The temperature of the reactor is 250 ° C. Catshizator - catalyst obtained in example 5.

The volumetric composition of the gas at the inlet of the third reactor,%: HjS 1 ЗОг 0,5 HjO 30

N2 68.5. The temperature of the reactor 220 C. The catalyst is the catalyst obtained in example 1.

Sulfur yield, specified in Table 1, is calculated by dosing with chromatographic analysis of the gas at the inlet and outlet of each reactor. It should be noted that for the first reactor the thermodynamic yield is 86.2%, for the second - 75.9Z and for the third - 72.5%.

As a comparison, Table 1 also indicates the results obtained using conventional catalysts. on aluminum hydroxide.

Table 1

From Table 1 it can be seen that the proposed catalysts allow to obtain a sulfur yield higher than the yield using conventional catalysts at the same contact time.

In addition, the introduction of 5,000 hours per 1000 oxygen does not change the yield obtained when using the proposed catalysts, while using conventional catalysts, the yield is reduced by about 25%.

Example 10. The catalysts prepared according to example 6 are used in the reactions:

2 + SO, Sn + (1)

CSj + 2H, rO-COj + 2H2S.

(P)

H, S

so "

CSa

N

Hjo

2

gas is supplied to the reactor with the following volume composition,%: 6 4

t

28 61

The reactor is set to a temperature regime close to that established in industrial reactors (adiabatic) under the conditions given in Table 2.

Table 2

Input gas temperature in the reactor.

The resulting hydrolysis yield (P) is shown in table 3.

TABLE 3. From the table it can be seen that the proposed catalysts allow to obtain a HYDROLYSIS yield CSj higher than the yield obtained using a conventional catalyst at the same contact time.

The resulting output of sulfur (1) is shown in table 4. The thermodynamic yield corresponding to the reaction conditions is 66.5%.

Table 4.

five

a- to 121397610

The introduction of 2% oxygen does not change the yield obtained by using the proposed catalysts, while using conventional catalysts, this yield is halved.

Example I. The catalysts prepared according to example 6 are used in reactions;

SO,

-3- sn p

H, 0;

Hgo

COg + HgS.

(one)

(P)

The gas of the following composition,%, is fed to the reactor under the conditions described in Example 2; 7.7

BODE COS

N

4.4 0.3 28 60

The resulting hydrolysis yield (IV) is indicated in Table 5,

Table3

5: bn, .- "..

From Table 5 it can be seen that the proposed catalysts allow a COS hydrolysis yield to be higher than the yield obtained using a conventional catalyst at the same contact time.

Example 12. The catalysts prepared according to example 1 in the reaction are used.

2H2S + 2 n

Sn

at a low temperature after simulating the oxygen inlet in the process gas, the gases are on the order of 2%,

The following gas composition is fed to the reactor:% J

one

0.5

thirty

68.5

H ,, s

sd

Eyo

N,

The temperature of the reactor is 220 ° C.

P

The catalyst of example 1 is used to treat the aforementioned gases for 24 hours,

. The resulting yield of sulfur, depending on type of contact time, is given in Table 6.

Table

In the gas to be treated, 2% of nitrogen is replaced with oxygen; in this case, the composition of the gas to be treated is as follows,%:

0.5 30

66.5 2

After 24 hours, oxygen is removed and returned to the initial composition of the gases; after 2 hours of work without oxygen, the yield of sulfur is given in table 7,

 Table

Therefore, it is clear from these results that the activity of the proposed catalyst does not change at all as a result of the occasional significant entry of oxygen into the gases being processed. This advantage of the proposed catalysts is of considerable practical importance for the treatment of residual industrial gases containing sulfur compounds.

PRI me R 13. The suspension obtained after hydrolysis of titanium tetrachloride is washed by decantation, filtered, then dried in a drying oven at 110 C for 24 hours. The resulting powder has an amorphous structure in x-rays, and its PAF is em

1 1, OL

Within 30 minutes, the mixture is mixed with the mixture containing this mixture.

1397612

powder with the addition of water and carboxymethylcellulose in the following proportions,%: powder 66; water 32; carboxyl methylcellulose 2. 5 Then this mixture is squeezed through a die of 3 mm in diameter, the extruded products are dried at 110 ° C for 8 hours and then calcined at A50 ° C for 2 hours. The resulting extruded products have specifications:

15

20

thirty

SBE, MVr VPT, CMVr V EqQ, N / m RA.,%

133

0.32

1015, 7 1.9

1 kg of the product is first impregnated with 310 cm of ammonium sulphate solution and then dried for 4 hours. The dried products are then soaked with 300 cm of calcium nitrate solution.

The product is dried for 12 hours, then calcined at 450 ° C for 1 hour and then

25 it has the following characteristics:

. / -

SBE, m / g VPT, cm / g EQC ,, N / m RA,%

CaSO.,% TiOj,%

35 40

45

115

0.28

24,5,10

0.5

35

65

Therefore, the proposed catalysts have increased mechanical strength (EQQ and RA).

Example 14. These operations are carried out, and the extruded products described in Example 13 are sulphured with a solution of sulfuric acid; after drying at 100 ° C for 4 h, strontium acetate solution is impregnated.

After drying at 110 ° C for 4 hours and further calcining at 450 ° C for 2 hours, the resulting catalysts have the following characteristics:

SBE, VPT,

50

55

110

29,

EQQ, li / M35.9-10

RA,% 0.6

SrS04,% 1.5

TiO,% 98,5

Example 15. A suspension of titanium oxide, obtained after hydrolysis and filtration in the classical method of sulphate etching of ilmenite, is dried at 180 ° C for 1 hour.

Order 788/63 Circulation 527 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PGSch Patent, Uzhgorod, Proektna St., 4

Claims (1)

CATALYST FOR CLEANING INDUSTRIAL GASES, including sulfur compounds containing titanium dioxide, characterized in that, in order to increase activity, it additionally contains an alkaline earth metal sulfate selected from the group consisting of calcium, barium, strontium,. with the following ingredients, wt.%: Alkaline earth metal sulfate selected from the group consisting of calcium, 1.5-35.0 barium, strontium Titanium dioxide 65.0-98.5 _about S SU .1213976>