JPS61133124A - Method of removing gas impurity from mixed gas flow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

The present invention relates to the oxidation of hydrogen sulfide gas and the oxidation of sulfide gas from a gas stream containing one or two of hydrogen sulfide oxygen, carbon dioxide, carbon oxide, sulfur, hydrogen, water vapor, meta/other hydrocarbon gases. The present invention relates to the use of oxidizing reaction solids to remove hydrogen and other gases, such as carbon dioxide. The removal of oxidizable impurities, such as hydrogen sulfide, alone or in the presence of other gases, in the presence or absence of high temperature oxidation catalysts has been the subject of extensive research. This is because purification of such mixed gas streams is desirable for environmental and other reasons. Gamson and Elk
ins) Chemical Engineering/G Progress, 4
9°203-15 (b953)), the most widely used industrial process for removing hydrogen sulfide from gas streams is the Claus process. The Claus method has evolved through several modifications and improvements, but the underlying chemical reaction remains the same. The overall result of the Claus process is the conversion of hydrogen sulfide to sulfur as follows. H2S+1/20□-H20+5ulfur(Vl (
As stated by B1 Gamso/et al. in Chemical Engineering/Gineering Progress, 49, 203 (b953), the term sulfur Ml (hereinafter simply referred to as rs(V)j) refers to sulfur in the vapor state. It refers to the complex equilibrium that exists between elemental forms. If we look at the reaction (b1) as a whole, it is actually a combination of two reactions. In the first reaction, hydrogen sulfide 1 is oxidized to sulfur dioxide by gas-phase combustion without a catalyst. 1/3 H2S + 1/20□-1/3 H2O+
1/3 So. (2) The product of reaction (2) is reacted with the remaining hydrogen sulfide at about 200-400°C over a bauxite or alumina catalyst bed. 2/3 H2S + 1/3 So□ →2/3H20
(3) The catalyst bed must be kept at a high enough temperature to prevent sulfur condensation. That is, in the Claus method, problems such as catalyst poisoning occur at low temperatures. On the one hand, since this reaction is thermodynamically more advantageous at lower temperatures, it is desirable to carry out reaction (3) at as low a temperature as possible. Attempts have been made to oxidize hydrogen sulfide directly to sulfur by reaction (b1), thereby avoiding the thermodynamic limitations imposed by reaction (3). An example of this method is given by Baehr. Others (US Patent No. 2200529)
has disclosed. The gist of this patent is to disclose a method for converting large quantities of hydrogen sulfide directly to sulfur in the presence of stoichiometric amounts of oxygen and in a flame without external forces. Gammun (US Pat. No. 2,594,149) states that at extremely high temperatures reaction (b) becomes the dominant reaction. This patent describes the direct conversion of hydrogen sulfide to sulfur in a yield of about 75% at temperatures above about 1300°C, followed by minimizing the formation of sulfur dioxide due to the reaction between residual oxygen and sulfur products. Therefore, a method for rapidly cooling the generated gas has been disclosed. Gamso/ further discloses that oxidation of hydrogen sulfide does not appear to proceed at a practical rate at temperatures below about 500° C. in the absence of a catalyst. This patent does not disclose low temperature conversion using catalysts of the type disclosed in this invention. by Grekel. The paper published in Oil A/L-# Gas Journal VO1, 57, 76-79 (b959) describes a method of directly oxidizing hydrogen sulfide to produce sulfur in the presence of bauxite at a temperature of about 200 to 800°C. Disclosed. Grekel states that at low space velocities, low temperatures are preferred and infers the progress of reaction (3). Grekel further suggests that reaction 1 (3) becomes less important as the space velocity increases. The To/Pun/ patent (US Pat. No. 1,922,872) discloses a method for oxidizing hydrogen sulfide to sulfur in the presence of oxygen over a bauxite catalyst at temperatures of about 225-275°C. Thompson's catalyst is about 60% alumina and a small amount of ferric oxide. Contains titanium dioxide and silica. In the method disclosed by Thompson, the preference for low temperatures seems to suggest that reaction (3) is dominant. However, at the temperatures he reports, this catalyst has a tendency to collect sulfur vapors, resulting in catalyst poisoning. Haas (U.S. Patent No. 4,171,347)
discloses a process for the direct conversion of hydrogen sulfide to sulfur in the presence of oxygen and a vanadium oxide catalyst on a non-alkaline carrier at temperatures of about 120-230°C. The vanadium oxide catalyst is believed to convert some of the hydrogen sulfide to sulfur dioxide. It is believed that this sulfur dioxide product reacts with unreacted hydrogen sulfide in the same catalyst bed, for example by reaction (3), to produce sulfur. Scott's patent (U.S. Patent No. 41)
No. 64544) discloses a circulation method in which a high-temperature reducing gas is brought into contact with a desulfurization agent to desulfurize it, the used desulfurization agent is regenerated, and then the regenerated desulfurization agent is reused. Scott discloses the use of a sintered porous let bed consisting of the reaction product of manganese oxide and aluminum oxide as a desulfurization agent. The desulfurization agent is regenerated by contacting the k-let bed with an oxidizing gas atmosphere. The SCOTT method is considered to result in the formation of only S02, which is in contrast to the present invention, in which little or no SC2 is formed, although this may vary depending on the processing method. Scottoto's patent states that the bed temperature is approximately 500% for both desulfurization and regeneration methods.
Keep at ~1300°C. Scott uses the term ``reaction product'' to describe the porous rhet, but this term does not appear to refer to the chemical reaction between manganese oxide and aluminum oxide. Rather, the term is believed to refer to a product made by thoroughly mixing manganese oxide and aluminum oxide, forming the mixture into pellets, and heating and sintering the mixture. K, as discussed by Goar in Oil Ant Gas Journal 84.86 (b971,).
In the "sponge iron" process, hydrogen sulfide reacts with ferric oxide to form ferric sulfide. Beds of ferric sulfide can be reconverted to ferric oxide via air oxidation, but the beds eventually become saturated with sulfur solids and must be replaced. The "sponge iron" process is usually limited to the treatment of gases containing low concentrations of hydrogen sulfide due to the economics of bed replacement. Furthermore, the sulfur removed by this method is usually lost. That is, it is difficult to regenerate a waste iron oxide bed because the waste bed is normally discarded. Zinc oxide is often used to remove hydrogen sulfide from mixed gas streams containing low concentrations of hydrogen sulfide. (
"Anomonia" Part ■, A, V, Slack and Hi G,
R0 James, Marcel Detzker Incorporated, New York. (1974, p. 338) This application is similar to the sponge iron application. Zinc sulfide products are not easily recyclable and are typically discarded after one use. “Welss (U.S. Patent No. 1971168)
) has the general formula M (HMnO3) 2 and M (Mn
A method for making an oxidation catalyst represented by Oa) is disclosed. That is, in the above general formula, the symbol M represents one of various metals that can be combined with bustard to form the catalyst. These metal acids are called manganites. - Shown to be useful for oxidizing carbon oxide to carbon dioxide. In this Uniis patent. There is no disclosure of removing impurities other than carbon monoxide from a mixed gas stream. Haacke US Pat. No. 3,914,389
The issue describes the use of the general formula La as an oxidation catalyst for the conversion of carbon monoxide to carbon dioxide in automobile exhaust gas systems.
Compounds having Gu o, s Mno, 503 are disclosed. Remeika et al., U.S. Pat. No. 4,001,371, discloses that NOx pollutants,
Catalysts of the general formula La o, s K o, 2Mn03 are disclosed that catalyze the conversion of substances such as N2 and oxygen. This catalyst is also said to be useful in promoting reactions such as the oxidation of carbon monoxide to carbon dioxide. Each of the catalysts disclosed in the Raymeca patent requires the presence as a component of at least one rare earth element, namely La%Pr and Na. None of the foregoing descriptions or disclosures disclose the present method of using reactive solids to remove impurities such as hydrogen sulfide and carbon dioxide from a gas mixture. The present invention oxidizes a gas such as hydrogen sulfide and extracts hydrogen sulfide from a gas stream containing one or more of hydrogen sulfide, oxygen, carbon dioxide, carbon oxide, sulfur, hydrogen, water vapor, methane, and other hydrocarbon gases. , relates to the use of oxidizing reactive solids that can be used to remove carbon dioxide, sulfur and other gases. As discussed in more detail below, the present invention utilizes an oxidizing reactive solid that oxidizes hydrogen sulfide contained in a mixed gas stream to produce primarily sulfur and water. The solid also has
It may be used to remove carbon dioxide from a mixed gas stream. To make this disclosure, the oxidation-reactive solid is generally l
In this formula, D is selected from alkali metals and alkaline earth metals consisting of potassium, sodium, lithium, calcium, and magnesium. M is manganese. Copper, iron, titanium, and selected from the group consisting of group vB (starting with vanadium), group VIB (starting with chromium), group ■B (starting with manganese), group 1, and group 18 of the periodic table. 0 represents oxygen. In the present invention, 1 of the oxygen in the D-M-0 reactive solid
was found to react easily with hydrogen sulfide gas to produce only sulfur and water as products. This oxygen, hereinafter referred to as "active oxygen", can be easily introduced into the DM-0 reactive solid. "The oxidation-reactive solids containing active oxygen used in the present invention react by a different mechanism than transition metal oxides that do not contain active oxygen. These transition metal oxides react with hydrogen sulfide and react with elemental sulfur. The oxidation-reactive solid of the present invention produces elemental sulfur in an amount corresponding to its active oxygen content.After the active oxygen component has been reduced to zero, such a solid is mixed with hydrogen sulfide gas. When contacted, sulfur compounds rather than elemental sulfur are formed. A useful and advantageous property of the oxidation-reactive solids used in the present invention is that they readily react with oxygen, thereby depleting the active oxygen component. The invention may be used in a catalytic process isothermally or in a cyclic two-stage process. In a catalytic process, hydrogen sulfide, carbon dioxide, carbon oxide,
A gas stream containing the other is passed over the bed containing the oxidation-reactive solids in the presence of approximately stoichiometric amounts of oxygen necessary to convert hydrogen sulfide to sulfur. The temperature of the floor is about 5
Maintain between 00°C and about 700°C. The lower temperature limit is determined by the lowest temperature at which sulfur vapor remains in the gas phase. If sulfur vapor condenses within the reactive solids or reaction zone, there is likely to be increased formation of sulfur oxides. Within said temperature range, the formation of sulfur dioxide is minimal and a conversion of about 80% hydrogen sulfide to sulfur can be achieved. As already mentioned, the process according to the invention can also be carried out in a two-stage circulation process. In the first step, a gas stream containing hydrogen sulfide, carbon oxide, carbon dioxide, and other gases is passed over a bed containing oxidation-reactive solids. In this step, the solid reacts directly with hydrogen sulfide in the gas stream to form elemental sulfur. In the second step, the oxidation-reactive solid is regenerated, and the active oxygen is regenerated by flowing air or 0□ over the reactive solid at a pressure higher than atmospheric pressure for a time and temperature sufficient for this regeneration. Contain in a solid. This two-step process can be repeated and the bed can be regenerated many times without losing much of its reactivity. The D-M-0 compound exhibits the ability to remove carbon dioxide through a reversible reaction. This property causes partial removal of carbon dioxide from the mixed gas stream when used in a double circulation process as described above. It is therefore an object of the present invention to promote the direct oxidation reaction of hydrogen sulfide to sulfur in a first order reaction using nearly stoichiometric amounts of oxygen in the presence of an oxidation-reactive solid. H2S+ 1/20□-HzO+5 (V1 A further object of the present invention is to
The purpose is to promote the above reaction. A further object of the invention is to remove gases such as CO2, H2S, and S from a gas stream. It is a further object of the present invention to remove hydrogen sulfide from a gas stream using a method comprising contacting a bed of oxidation-reactive solids with a mixed gas stream and then regenerating the oxidation-reactive solids. That is, this method can be carried out many times without substantially losing the reactivity of the reactive solid. A further object of the invention is the use of said reactive solid in a method for removing carbon dioxide from a mixed gas stream. A further object of the invention is to provide a process that can be used economically for purifying gas streams, in particular for removing hydrogen sulphide and carbon dioxide from said gas streams. These and other objects and advantages of the present invention will become apparent with reference to the drawings and detailed description of the invention provided below. FIG. 1 is a schematic diagram of the apparatus used to test the method of the invention. FIG. 2 is a graph showing the reaction rate of pure H2S and the --Mn-0 compound under two different initial pressures of H2S. FIG. 3 is a graph of a typical thermal cycle showing various characteristics of the thermal cycle. Figure 4 shows the two-stage circulation method. Particularly by -Mn-0 compounds. It is a figure showing the conversion rate of H2S. FIG. 5 is a graph showing the catalytic properties and reaction properties of the Ni-Mn-0 compound. FIG. 6 shows various oxygen-hydrogen sulfide volume ratios and
1 is a graph showing the conversion rate of hydrogen sulfide and the rate of formation of sulfur dioxide by the -Mn-0 compound under various temperatures. FIG. 7 is a graph showing the temperature dependence of H2S removal from a mixed gas containing 3% H2S and So2 formation carried out using the -Mn-0 compound in the catalytic method. FIG. 8 is a graph showing the H2S conversion rate and the S02 formation rate from a mixed gas containing 5% H2S conducted in a catalytic method using a -Mn-0 compound at various temperatures. FIG. 9 is a graph showing the H2S conversion rate and the S02 formation rate under various space velocities performed using the -Mn-0 compound in a catalytic method. FIG. 10 is a graph showing the H2S removal rate and SO□ formation rate in a catalytic method using a -Mn-0 compound and varying the H2S pressure. FIG. 11 is a graph showing the removal rate of pure CO□ under various pressures by the -Mn-0 compound. FIG. 12 is a graph showing the conversion of hydrogen sulfide by the -Mn-0 compound as a function of exposure time. FIG. 13 is a graph showing the conversion of hydrogen sulfide to sulfur dioxide as a function of oxygen pressure and oxidative regeneration temperature of the -Mn-0 compound bed. The present invention is useful for removing gaseous impurities such as hydrogen sulfide and carbon dioxide commonly found in the gaseous by-products of coal combustion.
This disclosure discloses the use of M-0 oxidation reaction mixture. In the D-M-0 solid form, a precursor of the D-M-0 solid in which the M component has a high positive valence, such as Mn, is heated to an elevated temperature under an inert atmosphere. . In such a case, the M component is reduced and its positive valence is reduced. Alternatively, the M component of the DM-0 is oxidized to a higher positive valence by reacting the M component nitrate in a strongly alkaline solution. Oxidation-reactive solids can be effectively produced by any of these methods. The D-M-0 solid produced by any of the above methods has a low density. These low density solids tend to develop resistance to gas flow after use. In order to reduce this tendency, it is preferable to form the reactive solid into an R-let shape and use this R-let shape when carrying out the method of the present invention. Alternatively, the D-M-0 solid may be formed into pellets after thorough mixing with a small amount of alumina, as described below. Such a ret has superior physical strength and exhibits lower alkalinity than an R-ret prepared without using alumina. The methods of the present invention relating to the use of the D-M-0 solids are generally formed during the combustion of coal. It may be referred to as a method for removing hydrogen sulfide from a gas stream containing H2S, including a gas stream. In this method, hydrogen sulfide is converted to sulfur. That is, since the oxidation reaction ends at the stage of elemental sulfur, no sulfur oxide is formed. Since the D-M-0 reactive solid is easily reoxidized,
It can be grown in a continuous circulation manner. The general chemical reaction that occurs when using D-M-0 solids in the method of the invention can be expressed as follows. D
The -M-0 reaction mass is reduced and the hydrogen sulfide is oxidized to form sulfur vapor as follows. D-M-ox+7 ” YH2S→DM-Ox+ Y
H20+ YS(Vl (4) followed by reduced D-
fiD-M-0 by contacting the M-0 solid with oxygen
Regenerate reactive solids. D-M-Ox+Y/20□-D-M-OX+y (51 Once oxygen is introduced into the reactive solid, it becomes active in the next desired reaction.

[0]+H2S-+H20+5(v)(6) (0)
represents active oxygen fixed in the reactive solid by reaction (5). Therefore, reaction (6) is reaction (4) and reaction (5)
This is the final reaction following. Two ways of implementing the invention are best understood with reference to FIG. In catalytic methods, a feed gas (e.g. H
2, CO and CO□ (supplied from tack 10 and H2S from tack 12) are mixed in a gas manifold (14).Furthermore, the supplied gas is hydrogen sulfide, oxygen, nitrogen, helium, or arbor. The ratio of hydrogen sulfide to oxygen is adjusted approximately to the amount necessary to satisfy the stoichiometry of reaction (b). The mixture is then placed in the reactor 16. The reactor was heated to approx.
Heat to a temperature of 00-700°C. The space velocity of the gas entering the reactor is in the range of about 100 to 10,000 hr-'. In the reactor 16 the gas is supplied with a bed (
(not shown). The D-M-0 reaction bent solid is described in more detail below, but
While the formation of sulfur dioxide is minimal. The mixture of hydrogen sulfide and oxygen is rapidly converted to sulfur. Effluent gas containing sulfur vapor exits reactor 16 and condenses in sulfur trap 18 . Next, the effluent gas containing the remaining gas is collected at the gas collector 2.
2 and subjected to analysis by gas chromatograph 24. Excess gas may then be vented through ventilation holes 28. Gases such as water vapor that tend to condense under these conditions are removed in the condensate collector 20. In the two-stage process of the invention, the feed gas is in a carrier gas such as helium or argon, or carbon dioxide. Hydrogen sulfide present in a gas mixture containing one or more of nitrogen, hydrogen, water vapor and -carbon oxides. The feed gas flows into gas manifold 14 where it is mixed before being transferred to reactor 16. After the hydrogen sulfide reacts with the reactive D-M-〇 solids. One reactor is flushed with an inert gas for a sufficient period of time to vent all sulfur vapors formed in the first step from reactor 16, which vaporizes and is captured in sulfur trap 18. Subsequently, at a temperature of about 280 to 600°C,
Oxygen or air is flowed into the reactor 16 from 26 in the evening.
Reactivate the reactive solids of the invention. In order to provide a thorough understanding of the invention, a series of examples is presented. However, in these examples and the method of the present invention, D-M-
In order to understand the advantageous properties exhibited by 0 solids, first D-M
It is necessary to summarize the chemical reaction mechanisms that are thought to occur when -0 solids are used. For this purpose, anti-Z! containing potassium, manoga/and oxygen is used. Solid (hereinafter referred to as “K-
Mn-OJ). Based on experimental data〈
The following mechanism is thought to occur. Therefore, these mechanisms are not meant in a limiting sense. In the reaction between K-Mn-0 compound and H2S, K-Mn-
0 compound is reduced and hydrogen sulfide is oxidized to form elemental sulfur as follows. KMnOx+7+YH2S-4KMnOx+YH20+
YS(7) The -Mn-0 compound is then oxidized and regenerated with an air stream containing 02 or pure 02 over the bed containing the primary compound. KMnO+ Y/20 □-+KMnOx+, (
8) The final reaction is as follows. Y H2S + Y (S→Y H2O+ YS M
(91 This reaction order is

In the presence of [0],
It is suggested that the reactive solid reacts catalytically with H2S to form elemental sulfur and water. In the method of the invention. A method for producing a reactive solid containing potassium, manganese and oxygen and a method for using the solid thus produced is described in the following example. [Example 1] K-Mn-0 anti-core solid is produced as follows. One gram mole of KMnO4 (b58Ji') is placed in a large boat placed in the center of a tube in a horizontal tube furnace. A slow flow of argon is passed through the tube. After about 30 minutes, the temperature inside the tube is 600°C. At this point, the tube is cooled to room temperature under an Albod atmosphere. Bulk product weighing 131.8g (bulk volume 180CC
) is obtained. Assuming that all weight loss is due to oxygen, the composition of the product is calculated to be KMnO2,4. The di-Mn-0 compound produced by the method described herein is a crumbly powder with a low bulk density of about 0.6 J/CC, and with long-term use, it sinters and
They tend to have resistance to gas flow. The powder shape can be changed to increase density and prevent sintering. This powdered product (31) was mixed with a diameter of 1 inch (2,
54cWL) into a cylindrical die. Compress into discs less than 0.1 inch (0.25 an) thick (working pressure approximately 1ooo to 2000° bond (4
54yu~9oskl? )) The density of a compressed substance is approximately 31
Close to 1/CC. The disks are baked in air at 150° C. for 30 minutes to embrittle them into irregularly shaped pieces. The bulk density of these pellet beds in the reactor 16 shown in FIG. 1 is approximately 0.9. Chill with li'/CC. [Example 2] Another method for producing an alumina-containing Ni-Mn-0 compound is as follows. That is, 1 mole (b58,9) of KM
Dissolve nO4 in 1.5 J of hot water. Add aluminum nitrate solution (0.037 l in 0.11 l hot water) to the first solution. The mixed solution is dried to form a solid cake and heated to 600° C. for 30 minutes under arbo/atmosphere. The alumina component is calculated to be approximately 2% by weight. This product was ground into a fine powder, 3/16 inch x 1 innote (
Compress to a disk of approximately 0.48cWLX2.54crn). The disk is baked in air at 150° C. for 30 minutes to embrittle it and break it into small pieces. By forming the K-Mn-0 compound in this way, it becomes difficult to cause broken sintering, and the alkalinity increases. [Example 2] In order to prove the ability of the K-Mn-0 compound to oxidize H2S, the following experiment was conducted. A di-Mn-0 compound produced as shown in Example 1 and reacted with carbon dioxide for about 80 cycles as shown in Example 2 is charged to reactor 16 of FIG. The reactor shown in Figure 1 is heated to 300 DEG C., flushed with argon under -atmosphere and pressurized to 3.7 atm with H2S. As shown in curve A of Figure 2, the pressure of H2S decreases rapidly, indicating that I(2S) is being removed from the gas stream. Sulfur and water vapor are observed in the effluent gas. The bed is then brought into contact with air at about 300°C for the time necessary to reoxidize the -Mn-0 compound.Reoxidation takes place as the bed temperature rapidly increases by about 20°C. After reoxidation, the bed is again brought into contact with H2S at an initial fE of 4.3 atm. Again, the pressure of H2S drops rapidly, as shown in curve B of Figure 2, which causes further , it is established that H2S is excluded from the gas stream. During this reaction, a homogeneous green compound of approximately 1=thickness is formed on the surface of the compressed -Mn-0 pellet; The K-Mn-0 compound is
When exposed to an amount of H2S in excess of its active oxygen component, the K-Mn-0 compound appears to be reduced to form a green magenta/ganese-sulfur material. [Example 2] The method of the present invention, in which a --Mn-0 compound is used in a two-stage circulation method for removing diluted H2S from a mixed gas stream, will be described with reference to FIG. The cycle shown in Figure 3 is a relatively low temperature (about 280-300°C)
The part where S is removed (Fig. 3, a-b) and the relatively high temperature part (Fig. 3, a-b)
500-600°C) to reoxidize and regenerate the bed (third
Figure c-d). Argon is passed through the apparatus before and after contacting the H2S-containing gas with the bed to prevent hydrogen sulfide gas or sulfur vapor products from mixing with the air stream used to reoxidize the bed. The air flow may be passed through the heating and cooling portions of the cycle, or may be introduced only briefly near peak temperature (Figure 3, p). The oxidation rate is only above about 500°C. The peak oxidation temperature is an important factor. The total effluent gas at points a-c in Figure 3 was collected in gas collector 22 and analyzed by gas chromatograph 24 (Figure 1). This collection method provides accurate measurements of gas volume and allows sufficient mixing of the gases to obtain a homogeneous sample for analysis. Non-oxidation process (Fig. 3,
The effluent gas from c-d) does not contain any sulfur or sulfur compounds on leaving the reactor. -Mn-0 compound used according to the cycle of Figure 3. Approximately 24% CO□ by volume, approximately 73% by volume N2. The H2S removal rate from a mixed gas stream containing about 3% by volume H2S is shown in FIG. 4 as a function of tickle number. Although the steam was just generated by the method of Example 1 in which the steam was added to about 10 volumes of the total volume, the high activity of -Mn- 〇 for H2S removal was demonstrated by the conversion of hydrogen sulfide to sulfur in the first 40 cycles in Figure 4. This reflects a conversion rate of approximately 90-100%. (No SO2 was observed during the experiment). As the experiment progresses (40-80 cycles), the H2S removal rate decreases (approximately 50 hours of H2S introduced). This is 545℃
This is a reflection of the bed's loss of ability to readily reoxidize at peak oxidation temperatures. 82? Ikurte inflow casca,
Approximately 24%Co2.10910.63%H2 and approximately 3%
The removal rate is similar when replacing the gas mixture containing H2S. Within the limits of the ability to detect H2S in the effluent gas, H2S is quantitatively removed by increasing the peak temperature by 40 DEG C. to 585 DEG C. in cycles 120-185 of FIG. Approximately 20-40% of CO2 is removed during the first 120 cycles. However, as the cycles progress, the amount of CO2 removed decreases continuously until, at the end of the experiment (cycle 185), the amount removed is about 50% of the effluent Co2.
% or less. Similarly, shortly after the incoming gas stream changed to a CO-containing gas stream (cycle 82), some oxidation of Go to CO2 occurred. Once again, the whole experiment (cycle 185)
), the amount of CO oxidized had decreased to less than 5% of the inflow CO. EXAMPLE V The di-Mn-0 reactive compound produced as shown in Example 1 acts as a reagent and catalyst in the conversion of hydrogen sulfide to sulfur. This activity is shown in FIG. 5 and is explained below. A bed of Ni-Mn-0 compound (65, L
5 gmol) for 50 cycles. Each cycle is 50 psig in 02-Mn-0
After heating the solid to 610°C, the pressure was reduced from 0□ to 1 atm, and the -Mn-0 solid was then cooled to 300'C. This oxidation treatment is believed to increase the "active" oxygen content of -Mn-0. H2S (3,4%), 0□ (b%) and He (95
, 6%) and contacted with the reactive oxidizing solid at 300°C. Analyze by effluent gas chromatography. No 02 is found in the effluent gas. As shown in curve C in Figure 5, during the first 5 minutes of the experiment,
All H2S is removed (as confirmed by analysis of the effluent gas), but as the experiment progresses, the amount of H2S in the effluent gas increases. At 150 minutes, H2S in the effluent gas is approximately 1,
Levels off at 5 capacity. This leveling off is due to −Mn
This indicates a nearly steady-state reaction in which the -0 compound primarily acts as a catalyst. In steady state, H2S
Approximately 1.9 volumes of H2S and 0° were converted by the -Mn-0 catalytic reaction. Thus, as shown in Figure 5, the conversion of H2S takes place by reaction with "active" oxygen (area A, Figure 5) and catalytic reaction (area B, Figure 5). During the experiment, the SO□ in the effluent gas varied from 0.09 to 0.17 volume H, with an average of about 0.12 volume H. This value supports the conclusion that inlet 02 reacts rapidly with the K--Mn-- compounds as well as with the sulfur produced by H2S conversion. Therefore, the reaction between this bed and oxygen reintroduces active oxygen to further convert hydrogen sulfide to sulfur. It appears to regenerate the K-Mn-0 reactive solids. The ratio of oxygen gas reacting with the Crab-Mn-0 compound and sulfur is usually 0□ to H2S in the feed gas, as explained in Example ■.
is a ratio of approximately 0.3:1. [Example 2] Changes in hydrogen sulfide conversion rate and sulfur dioxide formation rate due to K-Mn-0 compound decomposition are as shown below. K-Mn-0 compound (401) at 300'C and 160C
C/min flow rate Te0□ vs. H23 0.35 to 0.65:
<7) 3% H2S in an inert helium carrier containing 02% by volume of 1% H2S. The effluent gas is analyzed by gas chromatography. 0 in the effluent gas
2 was not detected. As shown in Figure 6, 0□ vs. H
As the ratio of 2S increases above the above ratio. The amount of H2S detected in the effluent gas decreases from about 1.2% to about 0.35%. In other words, the amount of H2S removed from the gas stream increased from about 1.8% to about 2.65%. Additionally, as the ratio of 02 to H2S increases above the above ratio, the amount of S02 detected in the effluent gas increases from about 0.1% to about 0.6%. As shown in Figure 6, increasing the temperature causes an increase in the amount of H2S converted. H2S conversion rate or S02 formation rate is 6
No change is observed in the flow rate range of 5-650 CC/min. The ratio of 0□ to H2S of 0.50:1 is 300-6
It is chosen as a comparison point in a series of experiments at a temperature of 0.000C. At each temperature, the flow rate is from a minimum of 65 CC/min to a maximum of approximately 65 CC/min.
0 CC/min, but no change in H2S conversion rate or SO□ formation rate is observed. As shown in Figure 7, H2S
Approximately 80 inches of the water is converted at 300°C. The reaction temperature is about 30
By increasing the temperature from 0°C to approximately 600°C, H converted
The amount of 2S conversion increases slightly and the amount of SO□ formed decreases slightly. In both cases, the concentration of S○ is unconverted H2S
Very close to half the concentration. This temperature dependence indicates that the Claus reaction (reaction 3) cannot have a thick line. This is because the thermodynamics of reaction 3 is extremely favorable at 300°C, but the temperature is about 600°C.
This is because it would be extremely disadvantageous if it rose to . It is better to explain that this result is due to convenient reaction distribution at 0° inflow. That is, K-Mn-
This is because the reaction occurs more rapidly with a 0-<let bed. 02 reacting with K-Mn-0 < let forms active oxygen, which is later added to the reaction (b1). 400
5 in a helium carrier at a space velocity of 0 to 4200 hr-'
%H2S, the ratio of 0□ to H2S is 0.5:1
Mix with 0□. Analyze the effluent gas by gas chromatography. As shown in Figure 8, about 2.5% of the H2S is converted at 400°C and about 3.25% of the H2S is converted at about 550°C. Therefore, in the above temperature range, the H2S conversion efficiency increases from about 40% to more than 60%. Throughout the temperature range, $02!1 degree in the effluent gas is approximately half of the unconverted H2S# degree. As shown in Figure 9, the inflow gas (5% H in helium carrier)
2S, 0□ to H2S ratio 0.5:1), the space velocity is about 4000 hr-' to 1000 hr-' at about 500 to 550°C.
When increasing to 0 hr""', H2S conversion decreases only slightly. At 500° C., H2S conversion decreases from about 60 inches to about 50% at that space velocity. Approximately 5000
Above hr''-' the SO2 concentration is unconverted H2S 9
It is slightly below half the degree, and 0° can be detected in the outflow gas. In both cases, the sum of 0□ and SO□ is very close to approximately half of the unconverted H2S. Therefore, the decrease in H2S conversion at high flow rates is due to -Mn-0-! This appears to be the result of 9□ bypassing the let floor. Similar experiments were carried out at temperatures between 400 and 500 °C, varying the pressure of the apparatus in the range of 1 g per day from 4 to 20 p. It was carried out at a space velocity of approximately 4000 hr-'. As shown in FIG. 10, increasing the pressure of the H2S and 02 mixed inlet gas slightly increases the amount of hydrogen sulfide conversion and slightly decreases the amount of sulfur dioxide formation. [Example ■] To remove CO2 from a gas stream containing pure Co.
The capacity of Mn-0 reactive solids is expressed as first order. A pellet of di-Mn-0 compound produced as shown in Example 1 ('61L 0.4 gmole) is charged to the reactor 16 shown in FIG. 1 and the next cycle is carried out. 28
Pressurized carbon dioxide at 0° C. is introduced for 2 minutes. The 4-let bed is then heated to approximately 500° C. under an air flow of 1 atmosphere. After cooling to about 200°C, the cycle is repeated. The CO2 content of the effluent air is analyzed by washing with standard sodium hydroxide solution. As shown in FIG. 11, the amount of CO□ removed increases as the CO2 pressure rises to about 2 atmospheres, but does not increase even if the CO□ pressure rises beyond this point. The capacity of the bed is about 0.03 gmole CO□ per gmole of Id, -Mn-0 compound at a pressure of about 2 atmospheres or more. CO2
At a pressure of 1 atm, about 0.017 moles of CO2 are removed per mole of K-Mn-0 compound. This ability does not change even after repeating this cycle 79 times. Example ■ The alumina-containing -Mn-0 reactive solid produced in Example ■ removes carbon dioxide from a mixed gas stream containing carbon dioxide and nitrogen in a first order manner. The reactor 16 shown in FIG. 1 was charged with alumina-containing -Mn-0 compound Rlet 59#, and the next cycle experiment was conducted. The reactor was flushed with argon for 7 hours, and the -Mn-0 compound was added to the reactor for 50 minutes.
psig, about 290°C and a space velocity of about 1000 hr"-' with 25%'CO□ in N2. The reactor is flushed with argon at 5 Q psig. The reactor is then flushed with argon at 5 Q psig. Heat to 585° C. Cool the reactor to approximately 300° C. with a stream of air and repeat the cycle. Collect the effluent gas from the 25% CO□-N2 stream and subsequent argon flush and The volume of the gas sample is measured separately, and the two samples are thoroughly mixed. The CO2 in the resulting mixed gas is analyzed by gas chromatography. From the analysis results, the CO2 in the inflow gas and the outflow gas.
Calculate quantity. The alumina-containing -Mn-0 compound 59F removes approximately 130 CC of CO□ in the first cycle (measured under standard temperature and pressure). This removal rate drops sharply to below about 20 CC by %18 cycles. at this point
Steam is added one after another for five cycles, but there is no noticeable effect. If the experiment continues for another 15 cycles without adding steam, CO
The removal rate of □ is less than 10CC. Further experiments were carried out by changing only the amount of steam added to the H2S stream, and the amount of steam introduced was 25% Go□-N.
The optimum CO2 removal rate from a 25% C02-N2 stream, i.e. 140 CC of CO2, is approximately twice the amount of the 2 stream.
The removal is done. In addition to the above-mentioned -Mn-0 compounds, reactive compounds containing potassium, iron and oxygen (hereinafter limited to -
The Fe-0 compound) reacts similarly to the -Mn-0 compound. Based on experimental results, the following reaction reduces the -Fe-0 compound and oxidizes hydrogen sulfide to form elemental sulfur and water. KFeOK+A+YH2S→KF'eOx+YH20+
YS(v) αα -Fe-0 reaction mixture can be regenerated by flowing oxygen or air over the reduced -Fe-0 solid, as shown in the following reaction. KF'eOX+Y/20□→KFeOK+7
The final result of the αυ reaction 0ω and αD is as follows. YH2S + Y (0:] → YH20+ Y S (
V ) (b3 in formula,

[0] Hani-Fe-0
Shows the active oxygen provided by the compound. Example X The production of a reactive solid containing potassium, iron and oxygen proceeds as follows. That is, ferric nitrate hydrate, Fe(
NO3)3-9820 (b72,9,0,43 gmol) is added to the molten KOH300,9 with stirring. The resulting mixture is heated to slightly elevated temperatures above 360°C. The green melt is cooled, ground and dissolved in 50% of potassium hydroxide.
Add to 500 ml of 0% cold solution with stirring. An insoluble brown precipitate is collected by filtration. The precipitate is reslurried once more in cold, 1 molar KOH solution and filtered again. The furnace mass is dried at 100° C. in a nitrogen atmosphere. The weight of the dried product recovered is 100 grams. EXAMPLE DEG C. This example illustrates the process of the present invention using the 7Fe-0 compound produced as shown in Example X in a two-stage circulation process. A pellet weighing 37 N was placed in the reactor 16 of FIG. 1 and heated to about 620° C. in a He flow, followed by about 80 ps
Six cycles of oxidation at about 650° C. for 1 hour under ig of oxygen and cooling to room temperature under 1 atm of oxygen were performed. During heating to about 650°C, about 40 CC of oxygen (measured under standard temperature and pressure) was released, most of which was released above 400°C. K-Fe-0 compound 8
When oxidized for approximately 15 hours under 0 psig oxygen, 0□
The total release amount increased to about 60 CC. K-Fe-0<1 diluted bed with helium carrier
, 1% H2S flow followed by oxidation and regeneration in a four-cycle experiment. The results of the fifth cycle of this cycle experiment are shown in FIG. K-Fe-0 was first reoxidized for 20 minutes at 288° C. under 1 atmosphere of O2. During the first minute of reoxidation, the bed temperature increases by 14°C. Reoxidation is completed at 500°C under 1 atm 0□ for the next 15 hours, and the reactor is cooled to about 290°C. 1.1% H2S in He
The stream is brought into contact with the bed at a space velocity of 1200 hr. No H2S is detected in the effluent gas for the first 2 minutes. However, at the end of the 45 minute run, the effluent gas contains approximately 0.5 volumes of H2S. In other words, at the beginning of the experiment, all the H2S in the gas stream had been converted to S. After 45 minutes, approximately 0.6 volumes of H2S had been converted to S. The total conversion of H2S is approximately 220 CC (measured under standard temperature and pressure). After the experiment, 1
A temperature increase of 0°C occurs. A small amount of SO2, constant at 0.03 volume i%, is detected throughout the experiment, because the strongly oxidized bed releases a small amount of SO2 into the mixed gas stream, and this SO2 is the sulfur product. indicates that it participates in the gas phase oxidation reaction. In addition, SO□ may also be formed due to the oxidation of the bed sulfides that may form under these conditions. [Example xn] Ni-Fe-0 produced by the method described in Example
In the presence of 2% H2S reacts as a catalyst to convert to sulfur. A let bed (37 g) of K-Fe-0□ was injected with about 2.4-2.6 vol.% H2S and 1.9 vol.
and a mixed gas stream containing. The experiment continues until steady state is reached as determined by the composition of the produced gas. Analyze the effluent gas by gas chromatography. Additional experiments were conducted in the same manner. The details are summarized in Table 1. The results are shown in Table 1. From the large value of sulfur with respect to SO□, it can be seen that 1 reaction (b1 is the main reaction. In addition, as the volume ratio of 0□ to H2S decreases, the amount of SO2 formed and the amount of H2S reacted are Both decrease. Table 1 Capacity ratio H2S5O□ 0□ s (v)
Ax 0.77 0.120.70 0.05 1.60.
73 0.130.66 0.09 1.80.64
0.300.51 0.03 1.80.57 0.4
80.28 0.09 1.8% S (v) is the inflow H
It is determined by subtracting the outflow H2S capacity and outflow SO2O2 capacity from the 2S capacity. It is clearly demonstrated that the compound 1-Fe-0 has catalytic activity to convert H2S to sulfur. In addition to the K-Mn-0 compound and the -Fθ-〇 compound,
Reactive solids containing potassium, copper and oxygen (hereinafter referred to as 1”
K-Cu-0 compound) was investigated. It is believed that this compound undergoes a reaction similar to that of the -Mn-0 and -Fe-0 compounds. Based on the experimental results, it is also believed that the -Cu-0 compound is reduced and the hydrogen sulfide is oxidized to form elemental sulfur and water, as shown in the following reaction. (The -Cu-0 reactive solid is regenerated by flowing air or oxygen over the solid, as shown in reaction α4.)
(According to b4, the final result of reactions 0 and I is as follows: Y H2S+Y(0)-Y H20+Y S
In the tJ5 formula, (0) represents active oxygen fixed in the Ni-Cu-0 reactive solid. A method for producing K-Cu-0 solids and the use of the solids thus produced is illustrated in the following example. [Example 2] K-Cu-0 reactive solid is prepared as follows. That is, 20% of copper nitrate hydrate (b50J, 0.645 mol)
011E/ dissolved in water. Add an aqueous solution of 2801 potassium hydroxide in 280d of water while stirring. Ice chips are placed in the resulting solution to prevent dehydration of the gelatinous copper hydroxide product. Decant the supernatant and filter the gelatinous product and air dry. Pour the wet gel at about 2000 peig to a thickness of about 0.2 inches (approx.
51c1rL) into 1 inch (2.54 m) diameter pellets. After drying the R-let at 150° C. for 1 hour, break it into small pieces. Pellets were placed in a carbon dioxide atmosphere for 1 hour.
Baking at 500°C decomposes residual nitrates and converts liberated potassium hydroxide to carbonate. The weight of the recovered product is 6511 and has a bulk capacity of 70 CC. [Example Further] A Ni-Cu-0 compound moving bed (351) produced by the method described in Example Heat to 360-500°C for oxidation and regeneration in the presence of pressurized 02 in a similar repeated cycle as shown in Figure 13. Pressurized 02 is introduced for 3 minutes including the peak oxidation temperature. As shown in , in both experiments, H
All 2S is completely converted to sulfur or a mixture of S02. H2S converted to either sulfur or SO□
The amount of is determined by the oxidation temperature and oxygen positivity. If the oxidation temperature is about 360°C and the pressure at 0□ is 5 psig, then S0
2 is detected in the effluent gas stream and no sulfur is detected. The regeneration temperature increases to 500℃ and the pressure of 0□ is 22 ps
When ig, only 2% of H2S is converted to S02,
98% is converted to sulfur. Temperatures above about 500°C cannot be used to regenerate the Ni-Cu-0 reactive compounds. This is because at such high temperatures the pellet bed tends to develop resistance to gas flow. The K-Cu-0 compound is similar to the -Mn-0 metal compound and the -Fe-0 compound discussed above, and its ability to convert H2S to sulfur depends on how much active oxygen it contains obtained in the regeneration process. Depends on what you do. K-Cu-0 compound Crab-Fe-0
The difference from the compound and the -Mn-0 compound is that -Cu
-0 compounds, even after their active oxygen components become zero,
This means that it continues to rapidly react with H2S. However, in this case, SO3 is formed instead of sulfur as a product. The thermodynamics of the one-step formation of hydrogen sulfide to sulfur by anti-11i5fl is extremely favorable for this reaction. Quantitative conversion of H2S with alkali metal oxides can be expected. Reaction (b) is carried out on a large scale using the Claus method. In the Claus method, one reaction (b) is the reaction (2) and (3)
). The thermodynamics of reaction (3) is the reaction (
2) Or the thermodynamics of anti-EJI is not favorable. For this reason,
Due to the stb unfavorable thermodynamics of reaction (3). The efficiency of the Claus method is determined. In the present invention, H2S by using D-M-0 compound
The conversion from to sulfur does not involve intermediate reactions (2) and (3) and is therefore not influenced by the less favorable thermodynamics of reaction (3). For example, the quantitative conversion of H2S within the detection limit as seen in Example ① is achieved using the Claus method.
cannot be achieved under the same pressure and temperature conditions. Krauss also uses a solid catalyst, but the mechanism is a reaction (b
The mechanism that acts on the D-M-0 compound during the catalytic reaction of No. 1 is different. This difference in mechanism is expected given that the reactivity of the D-M-0 compound toward hydrogen sulfide depends on its ability to react with oxygen, which is not present in the Claus process catalyst. It is. Due to the high activity of the D-M-0 compound as a catalyst for directly converting H2S and 02 into sulfur, it is possible to convert effluent gas in coal combustion as well as in related technologies currently used on a large scale. This opens the possibility of practical application. For example, the ratio of 02 to H2S in the incoming gas stream is 0.5:
1, the product gas flow is unreacted with SO2 (1fi) (2
Contains S in a ratio of 0.5:1. This is the ratio required for the Claus method (reactions (2) and (3)). Using a Kraks catalyst chamber downstream of a device based on the process of the invention, an almost complete conversion of unreacted gas (a small portion of the total charge) to sulfur should therefore occur. More than! Although the method of the present invention has been described in terms of several methods of using oxidation-reactive solids and examples have been provided for the use of specific oxidation level 5a solids, the invention is not so limited. Those skilled in the art will appreciate that various modifications and changes can be made without departing from the scope and spirit of the invention. All such modifications and variations are therefore considered to be within the scope of this invention.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the apparatus used to test the method of the invention. FIG. 2 is a graph showing the reaction rate of pure H2S and the --Mn-0 compound under two different initial pressures of H2S. FIG. 3 is a graph of a typical thermal cycle showing various characteristics of the thermal cycle. Figure 4 shows the two-stage circulation method. Particularly by -Mn-0 compounds. FIG. 3 is a diagram showing the conversion rate of H2S. FIG. 5 is a graph showing the catalytic properties and reaction properties of the Ni-Mn-0 compound. FIG. 6 shows various oxygen-hydrogen sulfide volume ratios and
1 is a graph showing the conversion rate of hydrogen sulfide and the rate of formation of sulfur dioxide by the -Mn-0 compound under various temperatures. FIG. 7 is a graph showing the temperature dependence of H2S removal from a gas mixture containing 3% H2S and SO2 formation in the catalytic method using -Mn-0 compounds. FIG. 8 is a graph showing the H2S conversion rate and SO□ formation rate from a mixed gas containing 5 H2S in a catalytic method using a -Mn-0 compound at various temperatures. FIG. 9 is a graph showing the H2S conversion rate and the SO□ formation rate under various space velocities performed using the -Mn-0 compound in a catalytic method. FIG. 10 is a graph showing the H2S removal rate and the S02 formation rate in a catalytic method using a -Mn-0 compound and varying the H2S pressure. FIG. 11 is a graph showing the removal rate of pure CO2 under various pressures by the -Mn-0 compound. Figure 12 is plotted as a function of exposure time. -Mn-
1 is a graph showing the conversion rate of hydrogen sulfide by a compound of FIG. 13 is a graph showing the conversion of hydrogen sulfide to sulfur dioxide as a function of oxygen pressure and oxidative regeneration temperature of the -Mn-0 compound bed.

Claims (1)

[Claims] 1. A method for converting hydrogen sulfide in a gas stream by directly oxidizing hydrogen sulfide to elemental sulfur vapor; mixing with oxygen gas present in a stoichiometric amount; and at a temperature of about 300° C. or above, converting said mixed gas stream into a D-M-O
In the general formula, D is selected from alkali metals or alkaline earth metals; M is manganese, copper, iron, and VB and VIB of the periodic table. , VIIB
, VIII and I represent a transition metal selected from the group consisting of B groups; O represents oxygen which converts said hydrogen sulfide into elemental sulfur vapor by direct oxidation; Method for converting hydrogen sulfide in streams. 2. The method of claim 1, wherein said mixed gas stream is contacted with said reactive solid at a temperature of less than about 700°C. 3. The method according to claim 1, wherein D is potassium, M is manganese, and O is oxygen. 4. A process for converting hydrogen sulfide in a gas stream by directly oxidizing the hydrogen sulfide to elemental sulfur vapor; (a) converting said gas stream to a temperature of about 300° C. or higher to form a compound of the general formula D-
M-O (where D is selected from alkali metals or alkaline earth metals; M is manganese, copper, and iron and I of the periodic table)
a transition metal selected from the group consisting of groups B, VB, VIB, VIIB and VIII; O represents oxygen which converts said hydrogen sulfide into elemental sulfur vapor by direct oxidation. (b) after completion of step (a), by passing a stream of oxygen-containing gas over said reactive solid at about atmospheric pressure for a time and at a temperature sufficient to re-oxidize said reactive solid; a process for converting hydrogen sulfide in a gas stream by direct oxidation of the hydrogen sulfide to elemental sulfur vapor. 5. The method of claim 4, wherein said gas stream is contacted with said reactive solid at a temperature of less than about 700°C. 6. The method according to claim 4, wherein D is potassium, M is manganese, and O is oxygen. 7. The method of claim 4, wherein the oxygen-containing gas stream is air. 8. The method of claim 4, wherein the oxygen-containing gas stream is oxygen. 9, D is potassium, M is manganese, and O is oxygen, and the reactive solid is heated at about 500° C. in the presence of an inert gas.
5. A process according to claim 1 or claim 4, characterized in that it is produced by heating potassium permanganate to a temperature of ~900<0>C. 10, D is potassium, M is manganese, and O is oxygen, and the reactive solid is prepared by dissolving (a) potassium permanganate in water, and (b) about 0.01 mole per mole of potassium permanganate. ~0.20 mole of aluminum nitrate is added to the potassium permanganate solution, (c) the resulting solution is dried to a solid, and (d) the resulting solid is heated under an inert atmosphere at ~600°C. Claim 1 or 4, characterized in that it is produced by heating to a temperature of about 900°C.
The method described in section. 11, where D is potassium, M is iron, and O is oxygen, and the reactive solid is dissolved by (a) adding hydrated ferric nitrate to excess potassium hydroxide; (c) cooling the mixture; (d) adding the cooled mixture to excess concentrated cold potassium hydroxide solution; (e)
The resulting product, an insoluble brown precipitate, is filtered and
(f) washing the filtrate in cold dilute potassium hydroxide;
(g) refiltering the brown precipitate; and (h) drying the resulting solid.
The method described in Section 4 or Section 4. 12, D is potassium, M is copper, and O is oxygen, and the reactive solid is prepared by (a) dissolving copper nitrate hydrate in water, and (b
) adding a concentrated potassium hydroxide solution with stirring and cooling; (c) decanting the supernatant; (d) filtering the resulting product; and (e) drying the solid. The method according to claim 1 or 4.