Catalyst for selectively catalytically oxidizing hydrogen sulfide, catalyst for burning tail-gas, and process for deeply catalytically oxidizing hydrogen sulfide to element sulfur

Abstract

A catalyst for selectively oxidizing hydrogen sulfide to element sulfur, catalyst for burning tail-gas, and process for deeply catalytically oxidizing hydrogen sulfide to sulfur are disclosed. The catalyst for selectively oxidizing hydrogen sulfide to element sulfur is prepared by: 10-34% of iron trioxide and 60-84% of anatase titanium dioxide, and the balance being are auxiliary agents. Also a catalyst for burning tail-gas is prepared by: 48-78% of iron trioxide and 18-48% of anatase titanium dioxide, and the balance being auxiliary agents. The catalyst of the present invention has high selectivity and high sulfur recovery rate. An isothermal reactor and an adiabatic reactor of the present invention are connected in series and are filled with the above two catalysts for reactions, thus reducing total sulfur in the vented gas while having a high sulfur yield and conversion rate.

Claims

1. A catalyst for selectively catalytically oxidizing hydrogen sulfide, comprising components of a mass percent of: 10-34% of iron trioxide, 60-84% of anatase titanium dioxide and a balance which are auxiliary agents.

2. A catalyst for burning tail-gas, comprising components of a mass percent of: 48-78% of iron trioxide, 18-48% of anatase titanium dioxide and a balance which are auxiliary agents.

3. The catalyst for burning tail-gas, as recited in claim 2, further comprising a mass percent of 0.4-0.8% of vanadium pentoxide.

4. A method for deeply catalytically oxidizing hydrogen sulfide to element sulfur comprises the following steps: adopting an isothermal reactor and an adiabatic reactor which are connected in series; and filling the isothermal reactor and the adiabatic reactor with a catalyst for selectively catalytically oxidizing the hydrogen sulfide and a catalyst for burning tail-gas respectively for reaction, wherein the catalyst for selectively catalytically oxidizing the hydrogen sulfide comprises components of a mass percent of: 10-34% of iron trioxide, 60-84% of anatase titanium dioxide and a balance which are auxiliary agents; and the catalyst for burning the tail-gas comprises components of a mass percent of: 48-78% of iron trioxide, 18-48% of anatase titanium dioxide and a balance which are auxiliary agents.

5. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 4, comprising the catalyst for burning the tail-gas with a mass percent of 0.4-0.8% of vanadium pentoxide.

6. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfphur, as recited in claim 4, using the catalyst for selectively catalytically oxidizing the hydrogen sulfide under following conditions: a temperature of 150-300° C., a space velocity of 300-2000/h, and an O.sub.2/H.sub.2S mole ratio of 0.5-1.5.

7. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 6, wherein the space velocity is between 300-1000/h, the O.sub.2/H.sub.2S mole ratio is between 0.5-1.0.

8. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfphur, as recited in claim 4, using the catalyst for burning the tail-gas under following conditions: a temperature of 180-350° C., a space velocity of 1000-2000/h, an O.sub.2/H.sub.2S mole ratio of 1.0-3.0.

9. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfphur, as recited in claim 8, wherein the O.sub.2/H.sub.2S mole ratio is between 1.5-2.0.

10. (canceled)

11. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 4, injecting air into a gas mixture at an entrance of the isothermal reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for selective oxidation and the gas mixture passes through a source gas; a sulfur recovery rate of an isothermal reaction is ≧95%; injecting air at an entrance of the adiabatic reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for burning tail-gas; in an adiabatic reaction a sulfur recovery rate is ≧90%, a conversion rate is ≧99%; in vented tail-gas, SO.sub.2 is ≦400 mg/m.sup.3, H.sub.2S is ≦5 mg/m.sup.3.

12. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 5, injecting air into a gas mixture at an entrance of the isothermal reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for selective oxidation and the gas mixture passes through a source gas; a sulfur recovery rate of an isothermal reaction is ≧95%; injecting air at an entrance of the adiabatic reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for burning tail-gas; in an adiabatic reaction a sulfur recovery rate is ≧90%, a conversion rate is ≧99%; in vented tail-gas, SO.sub.2 is ≦400 mg/m.sup.3, H.sub.2S is ≦5 mg/m.sup.3.

13. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 6, injecting air into a gas mixture at an entrance of the isothermal reactor according to the O.sub.2/H.sub.2S mole ratio required by the catalyst for selective oxidation and the gas mixture passes through a source gas; a sulfur recovery rate of an isothermal reaction is ≧95%; injecting air at an entrance of the adiabatic reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for burning tail-gas; in an adiabatic reaction a sulfur recovery rate is ≧90%, a conversion rate is ≧99%; in vented tail-gas, SO.sub.2 is ≦400 mg/m.sup.3, H.sub.2S is ≦5 mg/m.sup.3.

14. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 7, injecting air into a gas mixture at an entrance of the isothermal reactor according to the O.sub.2/H.sub.2S mole ratio required by the catalyst for selective oxidation and the gas mixture passes through a source gas; a sulfur recovery rate of an isothermal reaction is ≧95%; injecting air at an entrance of the adiabatic reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for burning tail-gas; in an adiabatic reaction a sulfur recovery rate is ≧90%, a conversion rate is ≧99%; in vented tail-gas, SO.sub.2 is ≦400 mg/m.sup.3, H.sub.2S is ≦5 mg/m.sup.3.

15. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 8, injecting air into a gas mixture at an entrance of the isothermal reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for selective oxidation and the gas mixture passes through a source gas; a sulfur recovery rate of an isothermal reaction is ≧95%; injecting air at an entrance of the adiabatic reactor according to the O.sub.2/H.sub.2S mole ratio required by the catalyst for burning tail-gas; in an adiabatic reaction a sulfur recovery rate is ≧90%, a conversion rate is ≧99%; in vented tail-gas, SO.sub.2 is ≦400 mg/m.sup.3, H.sub.2S is ≦5 mg/m.sup.3.

16. The method for deeply catalytically oxidizing the hydrogen sulfide to the element sulfur, as recited in claim 9, injecting air into a gas mixture at an entrance of the isothermal reactor according to a O.sub.2/H.sub.2S mole ratio required by the catalyst for selective oxidation and the gas mixture passes through a source gas; a sulfur recovery rate of an isothermal reaction is ≧95%; injecting air at an entrance of the adiabatic reactor according to the O.sub.2/H.sub.2S mole ratio required by the catalyst for burning tail-gas; in an adiabatic reaction a sulfur recovery rate is ≧90%, a conversion rate is ≧99%; in vented tail-gas, SO.sub.2 is ≦400 mg/m.sup.3, H.sub.2S is ≦5 mg/m.sup.3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a flow chart of a method of the present invention

[0028] Element number: 1. air filter; 2. air compressor; 3. pressure regulator; 4-1. first water-vapor separator; 4-2. second water-vapor separator; 5. air flow meter; 6. acid gas storage tank; 7. acid gas filter; 8. entrance stop valve; 9. acid gas flow meter; 10. acid gas heat exchanger; 11. gas mixing valve; 12. mixing heat exchanger; 13. isothermal reactor; 14. adiabatic reactor; 15-1. first collector; 15-2. second collector; 16. modified activated carbon filter tank; 17. heat conduction oil tank; 18. heat conduction cycling pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] Referring to the drawings, according to a preferred embodiment of the present invention is illustrated, wherein

[0030] The following instruments and condition are adopted for the catalyst activity evaluation in the embodiments.

[0031] CHT-02 small catalyst activity evaluation device (Beijing Wekindu Technology Co., Ltd);

[0032] TY-2000 integrated trace sulfur analyzer (Automation research branch of Southwest research & design institute of chemical industry);

[0033] 3420A—gas chromatography analyzer (Beijing Maihak analytical instrument Co. Ltd.).

[0034] Note: Due to the H.sub.2S concentration of the acid gas of the source gas and the tail-gas of the reactor (≦100 mg/m.sup.3) differs greatly, different analysis methods are adopted. So, the thermal conductivity detector of the gas chromatography is adopted for the source gas; the flame photometric detector is adopted for the analysis of the tail-gas. Another gas line of the gas chromatography adopts 4A molecular sieves as the support for analysis of the oxygen content in the acid gas.

Embodiment 1-3

[0035] In the embodiment 1-3, the isothermal reactor adopts catalyst A, B, C for selectively catalytically oxidizing hydrogen sulfide respectively. The evaluation condition parameter of the catalyst activity is listed in chart 1. The activity evaluation data and catalyst composition is listed in chart 2.

[0036] Contrast 1

[0037] In the contrast 1, the isothermal reactor adopts conventional catalyst D. The evaluation condition parameter of the catalyst activity is listed in chart 1. The activity evaluation data and catalyst composition is listed in chart 2.

TABLE-US-00001 CHART 1 Evaluation condition of the activity of the selective oxidation catalyst Space velocity Acid gas flow Volume of the Granularity of the (based on the after air is injected catalyst sample mixed acid gas) in Air flow 8 ml 20-40 mesh 1500 h.sup.−1 200 ml/min 136 ml/min Acid gas after air Residual oxygen Water content of Source acid gas is injected in content in tail- Oxygen content in saturated water H.sub.2S % H.sub.2S % gas % air % vapor (40° C.) 11.75 8.45-8.65 0.14 21 5.8%

TABLE-US-00002 CHART 2 Activity evaluation data of the selective oxidation catalyst Composition A B C D Fe.sub.2O.sub.3: 10% Fe.sub.2O.sub.3: 24% Fe.sub.2O.sub.3: 34% Fe.sub.2O.sub.3: 5% TiO.sub.2: 84% TiO.sub.2: 70% TiO.sub.2: 60% TiO.sub.2: 75% Tail-gas Temperature H.sub.2S % SO.sub.2 % S % H.sub.2S % SO.sub.2 % S % H.sub.2S % SO.sub.2 % S % H.sub.2S % SO.sub.2 % S % 160° C. 0.4165 0 95.1 0.4165 0 95.1 0.4080 0 95.2 0.6201 0.4001 87.9 0.3995 0 95.3 0.4080 0 95.2 0.3910 0 95.4 0.6513 0.4012 87.6 200° C. 0 0.1700 98.0 0 0.2465 97.1 0 0.2310 97.2 0.2104 0.5691 91.9 0 0.2550 97.0 0 0.2550 97.0 0 0.2165 97.4 0.2204 0.4660 91.9 250° C. 0.0010 0.3390 96.0 0.0070 0.2883 96.6 0.0109 0.2676 96.7 0.3728 0.6372 88.2 0.0009 0.3221 96.2 0.0080 0.3137 96.3 0.0110 0.2760 96.6 0.3120 0.4956 90.4 300° C. 0.0015 0.3895 95.4 0.0091 0.3734 95.5 0.0254 0.3486 95.6 0.2023 0.6627 89.8 0.0014 0.3726 95.6 0.0089 0.3561 95.6 0.0161 0.3494 95.7 0.2013 0.6042 90.5

Embodiment 4-7

[0038] In the embodiment 4-7, the adiabatic reactor adopts tail-gas burning catalyst E, F, G, H. The evaluation condition parameter of the catalyst activity is listed in chart 3. The activity evaluation data and catalyst composition is listed in chart 4.

TABLE-US-00003 CHART 3 Evaluation condition of the activity of the tail-gas burning catalyst Space velocity Volume of the Granularity of the (based on the Acid gas flow after catalyst sample mixed acid gas) air is injected in Air flow 8 ml 20-40 mesh 1500 h.sup.−1 200 ml/min 136 ml/min Acid gas after air Residual oxygen Water content of Source acid gas is injected in content in tail- Oxygen content in saturated water H.sub.2S % H.sub.2S % gas % air % vapor (40° C.) 5.20-5.34 3.15-3.25 0.52 20 5.8%

TABLE-US-00004 CHART 4 Activity evaluation data of the tail-gas burning catalyst Composition E F Fe.sub.2O.sub.3: 48% Fe.sub.2O.sub.3: 48% G H TiO.sub.2: 48% TiO.sub.2: 48% Fe.sub.2O.sub.3: 60% Fe.sub.2O.sub.3: 78% V.sub.2O.sub.5: 0.4% V2O.sub.5: 0.8% TiO.sub.2: 26% TiO.sub.2: 18% Tail-gas Temperature H.sub.2S % SO.sub.2 % S % H.sub.2S % SO.sub.2 % S % H.sub.2S % SO.sub.2 % S % H.sub.2S % SO.sub.2 % S % 180° C. 0 0.2526 92.1 0. 0.2231 93.0 0 0.2353 94.1 0 0.1032 96.7 0 0.2401 92.5 0. 0.2064 93.5 0 0.2754 94.4 0 01008 96.8 250° C. 0 0.1504 95.3 0 0.1485 95.3 0 0.2433 92.3 0 0.1876 94.1 0 0.1440 95.5 0 0.1523 95.2 0 0.2305 92.7 0. 0.1794 94.3 300° C. 0.01 0.1823 93.7 0.0094 0.1586 94.7 0.0016 0.1978 93.7 0. 0.2643 91.7 800.0233 0.1704 93.9 0.0078 0.1608 94.7 0.0008 0.2105 93.3 0 0.2712 91.5 350° C. 0.0124 0.2311 92.3 0.0041 0.2853 90.9 0.0122 0.3023 90.1 0.0014 0.3132 90.1 0.0145 0.2115 92.9 0.0068 0.2794 91.0 0.0136 0.2984 90.2 0.0023 0.2983 90.6

Embodiment 8

[0039] The process for deeply catalytically oxidizing hydrogen sulfide to element sulfur of the present invention adopts an isothermal reactor and an adiabatic reactor connected in series, which are filled with the catalyst for selectively catalytically oxidizing hydrogen sulfide and the catalyst for burning tail-gas respectively for reaction.

[0040] As illustrated in FIG. 1, the air after being filtered by the air filter 1 passes through the air compressor 2, the pressure regulator 3, the first water-vapor separator 4-1, the air flow meter 5 and reaches the gas mixing valve 11; the acid gas from the acid gas storage tank 6 passes through the second water-vapor separator 4-2, the acid gas filter 7, the entrance stop valve 8, the acid gas flow meter 9, the acid gas heat exchanger 10 and reached the gas mixing valvell to blend with air. The mixed gas passed through the mixing heat exchanger 12, the isothermal reactor 13, the first collector 15, the adiabatic reactor 14; the second collector 15-2, and is emitted after being treated by the modified activated carbon filter tank 16; the heat conduction oil tank 17 is set between the mixing heat exchanger 12 and the isothermal reactor 13; the heat conduction cycling pump 18 recycle and utilize the heat. The acid gas enters the isothermal reactor after being filled with air; the isothermal reactor adopts the catalyst A for selectively catalytically oxidizing hydrogen sulfide; the method parameters are listed in Chart 1; the space velocity is 1500/h; the reaction temperature is 200° C.; the tail-gas composition and sulfur recovery rate are listed in Chart 2; the tail gas enters the adiabatic reactor after being filled with air; the adiabatic reactor adopts the catalyst E for burning tail-gas; the space velocity is 1000/h; O.sub.2/H.sub.2S mole ratio is 1.5; the reaction temperature is 250° C.; the sulfur recovery rate of the adiabatic reaction is 95.3%; the conversion rate is 99.5%; in the vented tail-gas, SO.sub.2 is 0.1504 mg/m.sup.3, H.sub.2S is 0.

Embodiment 9

[0041] The process for deeply catalytically oxidizing hydrogen sulfide to element sulfur of the present invention adopts an isothermal reactor and an adiabatic reactor connected in series, which are filled with the catalyst for selectively catalytically oxidizing hydrogen sulfide and the catalyst for burning tail-gas respectively for reaction. The method is explained in the embodiment 8. The acid gas enters the isothermal reactor after being filled with air; the isothermal reactor adopts the catalyst B for selectively catalytically oxidizing hydrogen sulfide; the method parameters are listed in the Chart 1; the space velocity is 1500/h; the reaction temperature is 250° C.; the composition of the tail-gas and the sulfur recovery rate are listed in the Chart 2; the tail-gas enters the adiabatic rector after being filled with air; the adiabatic reactor adopts the catalyst F for burning tail-gas; the space velocity is 2000/h; the O.sub.2/H.sub.2S mole ratio is 2.0; the reaction temperature is 300° C.; the sulfur recovery rate of the adiabatic reaction is 94.7%; the conversion rate is 99.8%; in the vented tail-gas, SO.sub.2 is 0.1608 mg/m.sup.3, H.sub.2S is 0.0094 mg/m.sup.3.