JPS609859B2 - Catalyst that converts hydrogen sulfide to sulfur dioxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a catalyst used in a method of converting a gas containing hydrogen sulfide into sulfur dioxide by contacting the gas with oxygen to the catalyst.

(Background of the Invention) Conventionally, as methods for converting hydrogen sulfide into sulfur dioxide, in addition to the method of adding fuel and combustion oxidation at high temperature, the method of catalytic oxidation using a catalyst has mainly been used. Ta.

Although the method of combustion oxidation at high temperature is simple, it consumes a large amount of fuel and is not economically preferable.
Catalytic oxidation methods are preferred because they can convert hydrogen sulfide to sulfur dioxide at relatively low temperatures.

In general, catalysts for this reaction include iron oxide, bauxite, alumina, platinum metals, and zeolites (for example,
0-68955) catalysts are known. However, these conventional catalysts do not have sufficient activity and the reaction temperature is 200°C.
00 or less, hydrogen sulfide cannot be completely oxidized to sulfur dioxide, and a considerable amount of sulfur is also produced. Furthermore, alumina-based catalysts and catalysts with an alumina support have the disadvantage that when used for a long time, sulfur dioxide and oxygen in the generated gas react with alumina, producing sulfuric acid alumina, and reducing catalyst activity. It was found that this is the same with iron oxide catalysts, which change into sulfates and deteriorate. (Objective of the Invention) The object of the present invention is to eliminate the drawbacks of the above-mentioned conventional techniques, and to provide a catalyst for converting hydrogen sulfide into sulfur dioxide, which exhibits high activity at low temperatures and is not altered by sulfur dioxide and has excellent durability. It is about providing.

(Summary of the Invention) The present invention is characterized in that a catalyst containing titanium and molybdenum oxides as active components is used as a catalyst for converting hydrogen sulfide into sulfur dioxide.

The catalyst of the present invention can be generally used in the process of converting hydrogen sulfide into sulfur dioxide gas. , oxidation of collected hydrogen sulfide contained in the exhaust gas from the till gas treatment equipment of Krauss sulfur recovery equipment, or oxidation of hydrogen sulfide (and mercaptans) contained in pulp factory exhaust gas, human waste treatment exhaust gas, combustion exhaust gas of sulfur-containing organic materials, etc. The catalyst of the present invention was tested for activity in comparison with various conventional catalysts, and was found to have excellent low-temperature activity. .

In addition, since this catalyst contains sulfated solid substances such as titanium oxide and molybdenum oxide as catalyst components, it was found that it has much better durability than an alumina-supported catalyst. When hydrogen sulfide is catalytically oxidized using the catalyst of the present invention, reactions of the following formulas (1', (2)) mainly occur depending on the amount of oxygen.

Day 2S + Di2=S and others.

(1) Day 2S ten and 2 = S.

20th 20 (2) The reaction of {2l type} occurs extremely selectively depending on the amount of oxygen, so ``In order to generate sulfur dioxide, oxygen must be present in an amount 1.5 times more than hydrogen sulfide.

When converting hydrogen sulfide into sulfur dioxide using the catalyst of the present invention, the reaction temperature is preferably 100 to 60,000, particularly 120 to 500, from the viewpoint of catalyst activity and heat resistance.
00 is preferred. Also, the space velocity of gas (converted to standard conditions)
is preferably 200 to 5,000 oh-1, particularly preferably 200 to 20,000 oh-1, from the viewpoint of economical catalyst usage and conversion rate of hydrogen sulfide to sulfur dioxide.

The catalyst for converting hydrogen sulfide to sulfur dioxide of the present invention uses oxides of titanium and molybdenum as active components. 99:1~50:50
is preferably in the range of 98:1, especially titanium and molybdenum.
A range of 70:30 is particularly preferred.

As titanium raw materials for preparing the catalyst of the present invention, various titanium oxides and titanic acids such as titanium tetrachloride, titanium sulfate, titanyl sulfate, etc., which produce titanium oxide when heated, can be used.

Alternatively, a preferable method is to neutralize an aqueous solution of titanium tetrachloride, titanium sulfate, etc. with aqueous ammonia, carbon alkali, alkali carbonate, urea, etc. to form a precipitate, and then thermally decompose the precipitate to obtain an oxide. Further, as a raw material for molybdenum, molybdenum oxide, molybdic acid, or various molybdate salts can be used. For the preparation of the catalyst of the present invention, any of the precipitation methods, kneading methods, etc. used in normal production can be used, and is not particularly limited.

In addition, the final catalyst molding method is the usual tablet molding method.
Any method can be used depending on the purpose, such as extrusion molding or transfer granulation method.Furthermore, titanium oxide can be molded first and then impregnated with molybdenum. It can also be formed by specifically loading the active ingredient on a ceramic carrier.
The catalyst may be used in a conventional manner such as fixed bed or fluidized bed.

(Examples of the Invention) Hereinafter, the present invention will be described in more detail based on Examples.

Example 1 Metatitanic acid slurry containing about 55% by weight as titanium oxide 800 g and ammonium rosemolybdate 10 g
It took 8 nights and the wires were thoroughly mixed in the kneader.

The resulting paste-like mixture was dried at 120°C for one day and then crushed. Graphite was added for 15 minutes, and the molding pressure was 50°C.
Since the weight is 0 kg, it is compressed into a cylindrical tablet with a diameter of 6 sides and a thickness of 6 cm. The obtained molded article is fired at 50,000 ℃ for 4 hours. The catalyst thus obtained has an atomic ratio of Ti:Mo=9:1. The catalyst performance test was conducted as follows.

The reaction tube is made of quartz with an inner diameter of 17 mm and is heated from the outside by an electric furnace. Approximately 40M of catalyst crushed to 10 to 20 mesh was packed in the center of the reaction tube, and 80M of a gas having the following composition was charged.
It ran at evening/h (space velocity 20,000 h-1). Gas composition date 2SO.
5%02 1.8±
0.2%N2
The remaining products were analyzed by gas chromatography.

The horse S conversion rate and S02 production rate were determined using the following formulas.

Black S conversion rate = Inlet day 2S concentration - Outlet & S concentration Inlet day concentration x 100 (%) *S.

2 generation rate = Eime Todoroki Fumoto production x 〇.

(%) The results obtained are shown in Table 1. Hydrogen sulfide is converted to sulfur dioxide at a very high conversion rate. Comparative Example 1 Take 50 g of aluminum hydroxide 2009 and ammonium paramolybdate, add about 100 g of water, and mix well.

Hereinafter, the mountain 203-
A Moo3 catalyst was prepared. The performance of the obtained catalyst was measured under the same experimental conditions as shown in Example-1, and the results shown in Table 1 were obtained. Table 1 Example 2 Ti:Mo=98:2, by the same preparation method as Example 1 except that the ratio of titanium oxide and molybdenum oxide was changed.
Catalysts were produced containing the following ratios: 80:20, 60:40, and 40:60.

The performance of these catalysts was measured under the same experimental conditions as shown in Example 1, and the results shown in Table 2 were obtained. Table 2 Example 3 This example describes the results of a long-term life test of a catalyst.

Using the catalysts shown in Example-1 and Comparative Example-1, a continuous test for 300 hours was carried out using a gas having the following composition at a reaction temperature of 150 oo and a space velocity of 30,000 and 1,000 blood-1 and 500 blood-1, respectively. I did it.

For analysis of ratio S and S02, TCD equipped and FPD (
Flame Photometric Detector,
A gas chromatograph (manufactured by Hitachi) was used. Gas composition date 2SO. 1%02
3.0%N2
Remaining Table 3 It was found that the catalyst of the present invention had high durability, with no deterioration in performance or change in appearance even after continuous use for 30 cycles.

Claims (1)

[Claims] 1 The catalytic active component consists of oxides of titanium and molybdenum, and the ratio of the two is 9 as an atomic ratio of titanium and molybdenum.
A catalyst that converts hydrogen sulfide to sulfur dioxide in the range of 9:1 to 50:50.