JPS5845740A - Sulfur resistant shift catalyst - Google Patents

Abstract

PURPOSE:To obtain a sulfur resistant shift catalyst suitable for water gas conversion reaction, by allowing a nickel component partially containing nickel sulfide to be carried by an MgO-Al2O3 solid solution. CONSTITUTION:A catalyst, wherein a nickel component is supported by an MgO- Al2O3 solid solution with an Mg/Al atomic ratio of 2-4 in an amount of 10- 70wt% on the basis of NiO to a final catalyst and the part of the nickel component is present as sulfide, is used as a sulfur resistant shift catalyst. This catalyst is used in water gas conversion reaction, especially, the water gas conversion reaction of a gas containing CO in the coexistence of a sulfur compound and excellent in sulfur resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shift catalyst suitable for use in water gas shift reactions, and in particular, a shift catalyst that is sulfur-resistant and suitable for use in water gas shift reactions of carbon monoxide-containing gases in which sulfur compounds coexist. It relates to a shift catalyst with excellent properties.

A water gas shift reaction (shift reaction) in which water gas or other carbon monoxide-containing gas is reacted with steam in the presence of a shift catalyst to produce hydrogen and carbon dioxide is obtained by gasifying coal or heavy oil. When producing hydrogen using carbon monoxide-containing gas as a raw material gas, or when CO/H in the gas,
It is widely used to adjust the molar ratio of However, conventional shift catalysts (C% and low temperature shift catalysts) have poor sulfur resistance, whereas carbon monoxide-containing gases obtained by gasifying coal or heavy oil typically contain sulfur compounds. Since it is contained in the form of hydrogen, when carrying out a water gas modification reaction using this type of gas as a raw material, there is the hassle of having to desulfurize the raw material gas in advance.

Under these circumstances, several sulfur-resistant shift catalysts have been proposed recently. For example, Japanese Patent Application Laid-Open No. 49-130385 discloses 1 alumina carrier with nickel and/or co/? Catalysts supported on sulfide of rut and sulfide of molybdenum have been taught.

JP-A-50-8791 describes a catalyst in which a nickel and/or conocert sulfide, a molybdenum sulfide, and an aluminum sulfide are supported on an alumina carrier. Also, Wangka Magazine, Vol. 71, Page 1484 (1)
968) and a miscellaneous paper by Morita et al. published on page 1488 (1968), using alumina or magnesia as a carrier.

Catalysts in which Ni-Mo, IIH-Co, etc. are supported have been introduced. However, among these sulfur-resistant shift catalysts, alumina-supported catalyst minerals (as seen in the miscellaneous papers of Morita et al.) have inferior catalytic activity compared to magnesia-supported catalysts, while magnesia-supported catalysts have low initial activity. Although it is expensive.

Since magnesia easily spreads in a high-pressure steam atmosphere and causes sintering, there is still room for improvement in terms of service life.

The present invention aims to improve the service life of the magnesia-supported catalyst without sacrificing its high activity by replacing the above-mentioned magnesia-supported catalyst with a solid solution of magnesia'lMgO-Alρ. Mg0-AI, 03 with an atomic ratio of Mg/Al of 2 to 4
A solid solution and a 9 nickel component supported on it,
The amount of nickel component supported is 1 in the final catalyst in terms of NiO.
A sulfur-resistant shift catalyst in which the nickel component is 0 to 70 wt% and at least a part of the nickel component is present as a sulfide, and Mg0-AI having an atomic ratio of Mg/At of 2 to 4;
It consists of a solid solution and a nickel component and a molybdenum component supported thereon, and the total supported amount of the nickel component and molybdenum component is Ni0-1-Mo0. The ratio of the nickel component and the molybdenum component is 10 to 79w1% of the final catalyst in terms of the atomic ratio of N1/(Ni + Mo2), which is 0.
2 to 1.0, and in which at least a portion of the nickel component and at least a portion of the molybdenum component are each present as sulfides.

The greatest feature of the catalyst according to the present invention is that it uses a Mg0-AI, O, solid solution as a carrier for the nickel component or molybdenum component, and the Mg/At atomic ratio of this solid solution is in the range of 2 to 4. There must be. Too much MgO will reduce catalyst life.

This is because if it is too small, the catalyst activity will be impaired.

Mg0-person! , O3 solid solution has a structure in which AI partially substitutes the Mg position in the MgO crystal, and MgO and AI,
It can be clearly distinguished from a mixture with O, by X-ray diffraction measurement as follows. That is, when the Mg0-AI, O, solid solution absorbs water vapor, Mgx 1 y (OH)z -
Whereas it gives sharp X-ray diffraction nine turns based on aH,O.

Even if a mixture of AI, O, and MgO absorbs water vapor, M
Only a part of gO becomes Mg(OH), and no double salt formation is observed.

What is the amount of the component supported on the above solid solution?

If the component is a nickel component alone, it is converted to 0, and if a nickel component and a molybdenum component are used together, it is converted to N.
l0-1-Mo0. Converting to 10~70w of final catalyst
It is allowed to be within the range of t%.

If the supported amount is less than this, the activity will not be sufficient.

If the temperature is too low, sintering of the supported components becomes noticeable during use of the catalyst, resulting in a shortened catalyst life.・For catalysts that use both nickel and molybdenum components as supported components, the ratio of one component is Ni/(Ni −)-Mo
) is preferably in the range of 0.2 to 1.0. This is because if a molybdenum component is contained in such a large amount that the atomic ratio is less than 0.2, the activity of the catalyst will decrease.

In the catalyst of the present invention, at least a portion of the nickel component exists in the form of a sulfide, and when a molybdenum component is present, at least a portion of the molybdenum component also exists in the form of a sulfide. The amounts of nickel and molybdenum components present in the sulfide barrier in the catalyst can be changed arbitrarily by selecting the sulfiding conditions, but in order to exhibit a satisfactory function as a sulfur-resistant shift catalyst, nickel and molybdenum components must be The nickel sulfidity in the components is NI, 8. It is preferable that f100% is 30 or more, and if a molybdenum component is present, the sulfidity of the molybdenum contained therein is preferably <30 or more when Mo8 is 10096.

The sulfur-resistant shift catalyst of the present invention is prepared in advance by using MgO-AI, 0
As long as the procedure of preparing a jlil' solution or its precursor and loading it with a nickel component or a nickel component and a molybdenum component is followed.

Since the catalyst can be manufactured using conventionally known catalyst preparation means, the details thereof will be omitted, but an example of the method for manufacturing the catalyst of the present invention is as follows.

That is, an aqueous solution having an atomic ratio of Mg/Al in the range of 2 to 4 is prepared using appropriate water-soluble aluminum salts and magnesium salts. Next, this aqueous solution is mixed with a soda carbonate solution or a charcoal-soda solution containing caustic soda, and the pH of the mixed solution is 9 to 12. Preferably, the temperature is maintained at 10 to 11 to form a precipitate, and this precipitate is filtered and washed to obtain a solid solution precursor.

Just to be sure, lMgO/Al, 0. To make the solid solution, MgxAly(pH)z-Co is used as a precursor.
The production of a hydrotalcite-like compound called 3.4H10 is essential. Since the stable range of x and y of this compound is 2, 3, 4.5 when one portion is 1, the range of stable x and y of this compound is 2, 3, 4.5. , free alumina and magnesia are not mixed in the calcined product of this precipitate. The nickel component and molybdenum component to be supported on the solid solution can be prepared individually or by a coprecipitation method.

When using the coprecipitation method, dissolve appropriate nickel salts and molybdates in water at a ratio such that the atomic ratio of Ni/(Ni + Mo) is 0.2 to 1.0.2 Add ammonia to this aqueous solution. Water, caustic soda solution or soda carbonate solution is added to form a precipitate, which is filtered and washed. Next, this precipitate is thoroughly mixed with the solid solution precursor described above in a predetermined ratio in water. In this case, the solid solution precursor is prepared by firing it in advance to form Mg0-AI, 0. It may be converted into a solid solution and then mixed with the precipitate. After mixing, the mother liquor is filtered, and the mixture is dried and calcined at a temperature of 350 to 700°C.
It is possible to obtain a composition in which a nickel component and a molybdenum component are supported in the form of oxides in Mg0-AttO, a solid solution. ' This composition is then subjected to a sulfurization treatment. Sulfurization treatment is t
The above mixture is heated at 300-400°C in a gas in which more than o ppm of sulfur compounds, typically hydrogen sulfide, are present.
This is generally completed by contacting the catalyst for about 2 to 3 hours, thereby making it possible to obtain the sulfur-resistant shift catalyst of the present invention in which at least a portion of the nickel component and molybdenum component exist in the form of sulfides.

The catalyst of the present invention can be used under normal shift reaction conditions, but it can be used at a reaction temperature of about 200 to 500°C and a general Ka of about 1 to 500°C.
It is possible to employ a reaction pressure of about 100 atm, preferably about 5 to 70 atm. This is because the temperature of one reaction is 200
This is because the catalyst becomes less active at temperatures below 50°C, while temperatures above 50°C are not only disadvantageous in terms of equilibrium, but also cause significant deterioration of the catalyst. Regarding the reaction pressure, 1
The higher the pressure, the higher the activity of the catalyst of the present invention (t/c), but the higher the pressure, the higher the dew point of water, which causes the inconvenience of having to raise the zero reaction temperature. Therefore, the reaction pressure is preferably maintained in the range of 5 to 70 atmospheres. As the raw material gas for the shift reaction, any water gas or other carbon monoxide-containing gas can be used.

This raw material gas may contain hydrogen sulfide and other sulfur compounds, and does not require preliminary desulfurization. Rather, it is preferable that 100 ppm or more of sulfur compounds coexist in the raw material gas in order to maintain the sulfided state of the catalyst and maintain its activity at a high level.

As is clear from the above, the shift catalyst of the present invention is sulfur resistant, so if this catalyst is used,
Carbon monoxide-containing gas that is obtained by gasifying coal or heavy oil and containing relatively high concentrations of sulfur compounds.

It can be subjected to a shift reaction without special desulfurization treatment. Furthermore, the catalyst of the present invention has higher activity than conventional sulfur-resistant shift catalysts.

Can be used at low temperatures that are equilibriumally favorable for shift reactions;
Moreover, the shift reaction can be carried out at a low water vapor ratio.

Comparative example 1 Dissolve 42g of soda carbonate in 400cc of pure water.

To this, r-AI crushed to less than 100 mesh, 0°s
Add og and suspend. Add 1 part of nickel sulfate to this suspension.
270 ec of a mol/l solution was added dropwise over 30 minutes at 70'C. After aging at the same temperature for 2 hours, 8. After filtration and washing, dry at 110'C for 15 hours, and then dry under air circulation for 4 hours.
Calcined at 50"C for 4 hours.Catalyst composition is NiO20w
t%, y-AI, 0.80wt%. This will be referred to as catalyst 1.

y-At, o, 18 amount 0. , Tie, , Coo
, , Same method as catalyst 1 except for replacing MgO
o-sto,, Nho-:to,.

Nl0-Ce0. , Nl0-MgO catalysts were obtained.

These will be referred to as catalysts 2 to 5 in the order of description.

Example 1 318 g of soda carbonate is dissolved in 31 g of pure water and heated to 70°C. A solution of 346 g of magnesium sulfate and 312 g of aluminum sulfate dissolved in 21 g of pure water was added over 60 minutes. After aging at 70°C for 2 hours, filter and wash. 110
After drying for 15 hours at °C.

Grind to less than 100 mesh and add carbonated soda ITdll
Suspend in 400 cc of solution. Regarding the subsequent operations, a Ni0-Mg0-Al2O catalyst was obtained in the same manner as in Catalyst 1. Catalyst composition: NIO 20wt%, MgO 56wt%
.

AI was 0.24'wt%. This will be referred to as catalyst 6.

As a result of X-ray diffraction, no peak due to γ-alumina is observed in this catalyst.

Comparative Example 2 For comparison with catalyst 6, Ni0-Mg0 was prepared using the following method.
-AI, O, catalyst was prepared.

γ-AI ground to 100 mesh or less, 0. 24
g in 1 mol/l aqueous sodium carbonate solution 2.11
Heat to 0°C. Add to this 1.4 mol/l of an aqueous solution of magnesium sulfate! was added dropwise over 60 minutes.The resulting precipitate was filtered and washed, and then 1 mol/! Sodium carbonate solution of 400
Suspend in cc. Then 1 mole of nickel sulfate/! water f
Add lj solution 2rocc-@30 minutes dropwise. 2 at 70”C
After aging for some time, it was filtered and washed. Drying and calcination were carried out in the same manner as for catalyst 1, with NIO20wt166Mg056wt%,
A catalyst of 24 wt% was obtained. This is used as a catalyst. As a result of X-ray diffraction, the peak of r-alumina can be seen in this catalyst.

Example 2 Catalysts with different NIO content and different Mg/Al ratio were prepared by the same method as Catalyst 6.

Catalyst 910 63.0 27 3 Catalyst 1070 21.0 9 3
Catalyst 1180 14.0 6
3 catalyst 1220 35 45.0
1 catalyst 1320 485 31.1
2 catalyst 14 20 60.7 19.3
4 catalyst 1520 63.7 16.
3 5 Comparative Example 3 Nickel nitrate 38g and ammonium molybdate 23.7g
was dissolved in 150 cc of aqueous ammonia, and the pH was adjusted to -9 to 10. In this solution, y-A crushed to 100 mesh or less
Add 0.70 g of I, and mix well. After the liquid was evaporated to dryness, it was dried at 110"C for 15 hours, and then calcined at 500°C for 4 hours to obtain a catalyst.The catalyst composition was Ni
O10wt%, MoO320wt%, y-
AI was 0.70 w 1%. This will be referred to as the catalyst 21.

7-AI, O, to 8 l OH, T i OHt Ce
Ni was prepared in the same manner as catalyst 21 except that O2 and MgO were replaced.
0-Mo0. -8i0. , Ni0-Mo0. -TiO
, , Nip-Mob, -Coo, , N10-Mo0
．． -MgO catalysts were obtained. Catalyst 22
~25.

Example 3 Dissolve 318g of soda carbonate in 3ml of pure water.

Heat to 70°C. A solution prepared by dissolving 306 g of magnesium nitrate and 142 g of aluminum nitrate in two volumes of pure water was added over 60 minutes. After aging at 70"C for 2 hours, filtration,
Wash. Then, after drying at 110°C for 15 hours, it is ground into 100 meshes or less.

The dried product obtained here is a composite carbonate of Mg-Al.

This double salt was dissolved in 150 cc of ammonia water with 38 g of nickel nitrate and 23.7 g of ammonium molybdate, and the pH
== Add 9 to 10 little by little to the 9 solution.

Mix well and evaporate to dryness. The steps after drying were the same as those for catalyst 21 to obtain catalyst 26t.

Catalyst composition is NiO10Wt%0Mob, 20w1
%, Mg049 Wt%, AI! O821wt
% Terrorism.

Comparative Example 4 For comparison with catalyst 26, N i O.
MoOs-MgO・person 1!0. A catalyst was prepared.

γ-AI crushed to less than 100 mesh, 0.21 g
It is suspended in 1.81 t-1' mol/l of aqueous sodium carbonate solution and heated to 70°C. To this was added dropwise 1.231 of a 1 mol/j aqueous solution of magnesium nitrate over 60 minutes. The obtained precipitate is filtered, washed, and then dried at 110° C. for 15 hours. The dried product obtained here contains basic magnesium carbonate and y-At.
It is a mixture of o.

This dried material is ground to 100 meshes or less and added little by little to 150 cc of an ammonia aqueous solution (pH -9 to 10) containing 38 g of nickel nitrate and 237 g of ammonium molybdate. After thorough mixing, the mixture was evaporated to dryness, and the steps after drying were the same as those for catalyst 21 to obtain catalyst 27.

The catalyst composition was NIO' 10 wt%, Mob, 20
wt%, MgO49wt%, AItOs2
It was 1 wt%.

Example 4 The following catalysts were prepared by the same method as Catalyst 26, differing only in the content of NiO and Mob.

MgO amount MoOH amount Ni/(Ni-1-Mo)
Atomic ratio catalyst 28 1.6wt9J 28.0w1
% approx. 0.1 catalyst 29 3.5 26
．． 5 Approximately 0.2 catalyst 30 7.8
22.0 approx. 0.4 catalyst 31 20.0
10.0 approx. 0.8 catalyst 32 2
5.0 5.0 Approx. 0.9 Catalyst 33
1.5 B. 0 Approximately 0.5 Catalyst 34 3.3 7.0 Same catalyst 35 17.0 33.5 Same catalyst 36 23.6 47.0
Same catalyst 37 26.5 54.0
Same as above Example 5 MgO and AI by the same method as catalyst 26! The following catalysts were prepared with varying amounts of O. however.

Ni0-)MoO, content line 30vt, Nl/Ni+M
o atomic ratio #i was set to 0.5.

MgO amount Al2O, amount Mg/At atomic ratio catalyst 3
8 30.5vvt% 39jwt% Approximately 1 catalyst 39 42.8 27.0 Approximately 2
Catalyst 40 53.0 1? , 0 about 4 catalysts 41 55.5 14.5
Approximately 5 [Reaction Example 1...Activity test] An activity test was conducted under the following conditions using a flow-through reaction tube with an inner diameter of 3 mm.

Catalyst 0.5g (20-32 meshes).

Temperature: 300℃, normal pressure.

G, H, 8, V, 1000h-' (Co standard).

H,0/CO: 3. Omol/mol, H,8
: 2. Q vo1% pH,: 15vo1%,
co: 83vol 1% (dry pace) The catalyst was sulfurized in advance at 300°C for 2.5 hours in hydrogen containing 2, fivo 1% H, 8 before the reaction and used in the test.

The activity was determined by measuring the CO conversion rate using a gas cloth.

Find the multirate constant using the following formula.9.

k=F/W XJ2. ．． 1/(1-X)x: Co conversion rate F: CO supply amount (mol/h) W: catalyst amount (g) The results are shown in Tables 1 and 2.

[Reaction Example 2... Life test] A life test was conducted under the following conditions using an adiabatic reaction tube with an inner diameter of IQ mm.

Catalyst 20g (1-2mm), temperature: 250°C.

Pressure crab 12Kg/cm”g.

G, HoS, V,: 1000 h'''1 (Co standard)
.

H,0/Co: 3. Omol/mol, H,
8: 2 vol%.

H: 1 gvol 1%, CO: 80 VO19b The degree of deterioration was measured by comparing k at the beginning of the reaction and after 100 hours.

The results are shown in Table 3.

Claims (1)

[Claims] 1. Mg0-A with an atomic ratio of Mg/At of 2 to 4;
I! It consists of a 0° solid solution and a nickel component supported thereon, and the supported amount of the nickel component is 10 to 70 wt% of the final catalyst in terms of NIO, and at least a part of the nickel component is in the form of sulfide. Sulfur-resistant shift catalysts present. l Mg0-At with an atomic ratio of Mg/At of 2 to 4
, 0° solid solution and the nickel component and molybdenum component supported thereon, the total supported amount of the nickel component and molybdenum component is 10 to 70 wt of the final catalyst in terms of N10 + MoOs. The ratio of nickel component to molybdenum component is Ni/(Ni
+Mo) atomic ratio Te 0.2-1. OC [lKI shi,
A sulfur-resistant shift catalyst in which at least a portion of a nickel component and at least a portion of a molybdenum component each exist as a sulfide.