Sulfurous gas catalytic incineration catalyst and preparation method and application
Technical field
The present invention relates to sulfurous gas catalyst to burned and its production and application, be applicable to the exhaust-gas treatment of compounds such as all kinds of sulfide hydrogens, carbon disulfide and cos, above-mentioned sulfide can be converted into stink and all lower sulfur dioxide of toxicity, the catalytic burning that is specially adapted to sulfur recovery claus process tail gas, geothermal power plant's waste gas is handled.
Background technology
Hydrogen sulfide and organic sulfur compound (as carbon disulfide, cos) are that a class has the odorant pollutant of toxicity in various degree to human body, mainly from industrial tail gas such as oil refining, natural gas, chemical industry, sewage disposal, geothermal power generations.With the oil plant is example, contains a certain amount of hydrogen sulfide and organic sulfur compound in its sulfur recovery tail gas, for satisfying the odorant pollutant discharge standard, could discharge after must burning.Because the combustible component (as hydrogen sulfide, cos, carbon monoxide, carbon disulfide, hydrogen, elementary sulfur and a small amount of oil gas) in the tail gas often is lower than 3% of tail gas total amount, must postcombustion, could completing combustion, and be sulfur dioxide with sulfide oxidation.The tail gas burning process has thermal incineration and catalytic burning two classes.The thermal incineration method is carried out excessive oxygen and 700~820 ℃ usually.Owing to be difficult to accurately control operating conditions such as incineration temperature, the situation that incinerator crumples often appears in the practice, reduced the service life of incinerator.Catalytic burning can make hydrogen sulfide, carbon disulfide and cos in the tail gas be oxidized to sulfur dioxide with lower temperature (as 300~400 ℃) under catalyst action.The output investment ratio thermal incineration of catalytic burning is high approximately by 10%, and energy consumption and operating cost can save nearly 50%.The actual gain of catalytic burning is relevant with the scale of device, and the sulfur recovery unit of a 100t/d can be saved 1000m
3The combustion gas of/d, the fuel cost of catalyst length of life saving are more than 10 times of institute's spent catalyst expense.Therefore, catalytic burning can satisfy environmental protection and energy-conservation needs simultaneously.
Catalyst is the pith of sulfurous gas catalytic burning technology, and the key of this class catalyst performance is how to overcome the sulfation of catalyst active center, the stability of the long-time running of maintenance catalyst and active.CN1049299A discloses a kind of sulfur-bearing organic catalyst to burned waste gas and preparation method thereof, and this catalyst is a carrier with the natural mordenite zeolite of sulfuric acid treatment modification, V
2O
5Be main active component, noble metals such as a spot of platinum, palladium are the auxiliary activity component, V
2O
5Content is 0.4%~0.7% (mass percent, down with), and platinum content is 0.01%~0.02%, and palladium content is 0.02%~0.03%, also can contain one or more of 0.01%~0.07% cobalt, manganese, molybdenum, nickel, potassium, na oxide.At 320~380 ℃ of reaction temperatures, air speed 4800~10000h
-1, during organic sulfur concentration 800~10000mg/l, conversion ratio 〉=99%.This catalyst loading noble metal, cost is higher, sulfur poisoning-resistant is limited in one's ability.CN1410149A discloses catalyst to burned and the preparation and the using method of hydrogen sulfide in a kind of gas, and the carrier of this catalyst is a silica, and active component is the oxide of iron and vanadium.This invention is applicable to hydrogen sulfide, oxidation activity the unknown of organic sulfur.CN1163785A discloses the catalytic burning technique of hydrogen sulfide in a kind of gas, is suitable for handling Claus tail gases, and with the active carbon catalyst, be under 200~400 ℃ in temperature, be sulfur dioxide with the hydrogen sulfide catalytic oxidation.Hydrogen sulfide content is 0.5%~4% (v/v), moisture content 4%~30% (v/v), air speed 3000~10000h
-1, the conversion ratio of hydrogen sulfide is 100%, sulfur dioxide production rate 90%~99%.USP4576184,4444908,4528277,4444741,4444742,4314983 disclose a class hydrogen sulfide oxidation catalyst and a technology, this activity of such catalysts component comprises vanadium and bismuth, also can constitute by vanadium and tin or antimony, carrier is the porous refractory oxide, by aluminium oxide, silica-alumina, silica, titanium dioxide, zirconia, silica-titania, silica-zirconia, one or more formations in silica-zirconia-titanium dioxide, hydrogen sulfide can be oxidized to sulphur or sulfur dioxide, characteristics are when steam exists, and still have high activity and stability.For example active component is 11.6%Bi
2O
3+ 8.6%V
2O
5Catalyst, at 240 ℃ of reaction temperatures, air speed 2000h
-1, the hydrogen sulfide of 2717ppm is converted into sulfur dioxide fully, and hydrogen and methane are not oxidized.USP4427576,4937058 disclose a kind of catalyst and preparation technology thereof who hydrogen sulfide or organic sulfur is oxidized to sulfur dioxide, the carrier of this catalyst is a titanium dioxide, or the mixture of titanium dioxide and zirconia or silica, active component is made of at least a of a kind of alkali earth metal sulfate and following metal: copper, silver, zinc, cadmium, yttrium, lanthanum, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, tin and bismuth, the content of carrier is 60%~99%, the content of alkali earth metal sulfate is 1%~40%, and the specific surface of catalyst is 20~500m
2/ g.380 ℃ of reaction temperatures, air speed 1800h
-1Feeding gas sulfide hydrogen 800ppm, cos 100ppm, carbon disulfide 500ppm, sulfur dioxide 400ppm, oxygen 2%, steam 30%, nitrogen 67.82%, the catalytic conversion of hydrogen sulfide>99%, the catalytic conversion 61%~98% of carbon disulfide, the catalytic conversion 52%~94% of cos.USP4148760 discloses a kind of selective oxidation of sulfur containing compounds in particular catalyst, and its carrier is an alumina cement, and active component is V
2O
5And Fe
2O
3, also can contain titanium and silver-colored oxide.This catalyst can be oxidized to sulfur dioxide with the hydrogen sulfide in the Claus tail gases, cos, carbon disulfide.USP4197277 discloses a kind of selective oxidation of sulfur containing compounds in particular catalyst, and its carrier is an aluminium oxide, and active component is V
2O
5And Fe
2O
3, also can contain titanium and silver-colored oxide.This catalyst can be oxidized to sulfur dioxide with the hydrogen sulfide in the Claus tail gases, cos, carbon disulfide.It can be the catalyst of sulfur dioxide with selective oxidation of sulfur containing compounds in particular that USP5278123 discloses a kind of, and carrier is a titanium dioxide, and active component is iron and platinum.USP6019953 discloses a kind of gas burning process, is applicable to the catalytic burning of sulphide-rich gas.First metal component of catalyst is bismuth, molybdenum or chromium, and second metal component is one or more of Group IIA metal, and carrier is a refractory oxide, can not contain aluminium and phosphorus simultaneously in the carrier.The hydrogen sulfide complete oxidation temperature that example provides is 500 ℃.USP4169136,4092404,4171347,4088743 discloses the catalytic burning technique of hydrogen sulfide in the class gas, this technology can be oxidized to sulfur dioxide with hydrogen sulfide, operating temperature is 150~480 ℃, the activity of such catalysts component is the oxide of vanadium and/or the sulfide of vanadium, and carrier is non-alkaline porous refractory oxide.A kind of well behaved catalyst is 5%~15% V
2O
5/ hydrogenation mordenite or aluminium oxide.Hydrogen in the feeding gas, carbon monoxide, lighter hydrocarbons and ammonia are not oxidized, and patent has been used for geothermal power plant's treatment of waste gas.USP4399112 discloses a kind of sulphur-containing exhaust gas catalytic burning technique, can be used for the processing of Claus tail gases, this technology has two stages to constitute, be hydrogen sulfide at first with carbon disulfide, cos, mercaptan sulfides hydrogenating reduction, and then be sulfur dioxide with the hydrogen sulfide catalytic oxidation, the catalyst of its oxidation panel is ferric sulfate/titanium dioxide.
Summary of the invention
Sulfurous gas catalyst to burned that the invention provides a kind of active height, good stability and preparation method thereof reaches Application of Catalyst.
Sulfurous gas catalyst to burned of the present invention is a carrier with silica, is active component with vanadium and titanyl compound.In catalyst weight: the content of silica is 65%~95%, and the oxide content of vanadium is 0.5%~15%, and is preferred 1%~8%, and titanyl compound content is 0.5%~20%, is preferably 2%~10%.The specific area of catalyst is 200~350m
2/ g, pore volume are 0.3~0.8ml/g.
Catalyst of the present invention can be used for the burning disposal of one or more sulfur-containing compounds in hydrogen sulfide, carbon disulfide and the cos etc. in the gas, is sulfur dioxide, carbon dioxide and water with above-mentioned selective oxidation of sulfur containing compounds in particular.
The thing of silica supports is amorphous phase mutually, can select water-fast gross porosity spherical silica gel for use, and its specific area is 200~400m
2/ g, pore volume are 0.4~0.9ml/g.The oxide of vanadium is V
2O
5, titanyl compound is TiO
2
The optimum shape of catalyst of the present invention is 4~6mm sphere, can adopt immersion process for preparing, and two kinds of preparation procedures are arranged, and is as follows:
(1) use organic titanic compound (as isopropyl titanate Ti (OCH (CH earlier
3)
2)
4, butyl titanate Ti (OC
4H
9)
4, tetraethyl titanate Ti (OC
2H
5)
4Deng) organic solution (as toluene, ethanol or isopropyl alcohol etc.) or the ethanolic solution impregnation of silica carrier (through 120 ℃ of oven dry) of titanium trichloride, with the organic solvent evaporated in vacuo, after gained sample drying, the roasting, use the oxalic acid solution dipping of the water soluble compound of vanadium again, dry then, roasting, titanium compound is decomposed into TiO through roasting
2, the water soluble compound of vanadium is decomposed into V through roasting
2O
5The water soluble compound of vanadium is one or more in ammonium metavanadate, vanadic sulfate, the vanadium oxalate, and the water soluble compound of vanadium is preferably ammonium metavanadate, and the water soluble compound of vanadium is dissolved in the oxalic acid solution of 1.0~2.0mol/L.The water soluble compound of titanium is preferably butyl titanate.
(2) elder generation after drying, the roasting, uses organic titanic compound (as isopropyl titanate Ti (OCH (CH with the oxalic acid solution impregnation of silica carrier (through 120 ℃ of oven dry) of the water soluble compound (as ammonium metavanadate) of vanadium again
3)
2)
4, butyl titanate Ti (OC
4H
9)
4, tetraethyl titanate Ti (OC
2H
5)
4Deng) organic solution (as toluene, ethanol or isopropyl alcohol etc.) or the ethanolic solution of titanium trichloride dipping, with the organic solvent evaporated in vacuo, dry then, roasting.Titanium compound is decomposed into TiO through roasting
2, the water soluble compound of vanadium is decomposed into V through roasting
2O
5
Baking temperature is generally 110~150 ℃ in the above-mentioned preparation process, and be 2~12h drying time, and sintering temperature is 450~550 ℃, and roasting time is 4~5h.
Catalyst of the present invention is used for the catalytic burning of sulfurous gas (as hydrogen sulfide, carbon disulfide, cos etc.), is specially adapted to the catalytic burning of oil plant Sulfur Recovery Unit process tail gas.Its technical process is: sulfurous gas is mixed with excess air, after the preheating, with 2000~10000h
-1Air speed by the catalytic burning stove, under 200~400 ℃ of reaction temperatures, hydrogen sulfide, carbon disulfide and cos are sulfur dioxide, carbon dioxide and water by catalytic oxidation.
Owing to have the effect of influencing each other between each component of catalyst, have different serviceabilities so different components cooperates.The characteristics of catalyst of the present invention are: the catalytic activity height, and under optimum condition, the oxygenation efficiency of hydrogen sulfide is higher than 99%, and the oxygenation efficiency of carbon disulfide and cos is higher than 85%, and the sulfur dioxide production rate is higher than 96%; Catalyst life is longer, all anti-sulfation of carrier and active component; 200~400 ℃ of operating temperatures, empty scooter 10000h
-1
The specific embodiment
Embodiment 1
Take by weighing isopropyl titanate [Ti (OCH (CH
3)
2)
4] 18.4g is dissolved in the 100ml toluene, to be dipped in wherein through the water-fast gross porosity spherical silica gel of the 4~6mm 100g of 120 ℃ of oven dry 2h and stir evenly, leave standstill 12h, then under 60 ℃ with rotary evaporator with the solvent evaporate to dryness, at 120 ℃ of dry 6h, next 500 ℃ of roasting 4h in air immerse by 7.1g ammonium metavanadate, 25.2g oxalic acid (C
2H
2O
42H
2O) and in the solution formed of 100ml distilled water, after stirring evenly under 30 ℃, leave standstill 12h, then under 50 ℃ with rotary evaporator with the water evaporate to dryness, behind 120 ℃ of dry 6h, 500 ℃ of roasting 4h obtain catalyst sample in air.This catalyst consists of: silica 90%, V
2O
55%, TiO
25%.On small-sized catalytic burning experimental rig, this catalyst to be estimated, feed composition is hydrogen sulfide 1% (v/v), carbon disulfide 0.1% (v/v), cos 0.1% (v/v), steam 30% (v/v), 300 ℃ of reaction temperatures, air speed 5000h
-1Evaluation result sees Table 1.
The conversion ratio of table 1 sulfide and the production rate of sulfur dioxide
|
Hydrogen sulfide |
Carbon disulfide |
Cos |
Conversion ratio, % |
100 |
85 |
88 |
The sulfur dioxide production rate, % |
100 |
96 |
98 |
Embodiment 2
Catalyst consists of: silica 85%, V
2O
55%, TiO
210%.Feed composition is hydrogen sulfide 1% (v/v), carbon disulfide 0.1% (v/v), cos 0.1% (v/v), steam 30% (v/v).300 ℃ of reaction temperatures, air speed 5000h
-1Evaluation result sees Table 2.
The conversion ratio of table 2 sulfide and the production rate of sulfur dioxide
|
Hydrogen sulfide |
Carbon disulfide |
Cos |
Conversion ratio, % |
100 |
88 |
90 |
The sulfur dioxide production rate, % |
100 |
98 |
99 |
Embodiment 3
Catalyst consists of: silica 90%, V
2O
55%, TiO
25%.Feed composition is hydrogen sulfide 1% (v/v), carbon disulfide 0.1% (v/v), cos 0.1% (v/v), steam 30% (v/v).300 ℃ of reaction temperatures, air speed 10000h
-1Evaluation result sees Table 3.
The conversion ratio of table 3 sulfide and the production rate of sulfur dioxide
|
Hydrogen sulfide |
Carbon disulfide |
Cos |
Conversion ratio, % |
99 |
75 |
80 |
The sulfur dioxide production rate, % |
100 |
95 |
96 |
Embodiment 4
Catalyst consists of: silica 90%, V
2O
55%, TiO
25%.Feed composition is hydrogen sulfide 1% (v/v), carbon disulfide 0.1% (v/v), cos 0.1% (v/v), steam 30% (v/v).350 ℃ of reaction temperatures, air speed 5000h
-1Evaluation result sees Table 4.
The conversion ratio of table 4 sulfide and the production rate of sulfur dioxide
|
Hydrogen sulfide |
Carbon disulfide |
Cos |
Conversion ratio, % |
100 |
88 |
92 |
The sulfur dioxide production rate, % |
100 |
98 |
99 |
Embodiment 5
Catalyst consists of: silica 80%, V
2O
510%, TiO
210%.
Embodiment 6
Catalyst consists of: silica 85%, V
2O
510%, TiO
25%.
Embodiment 7
Catalyst consists of: silica 93%, V
2O
52%, TiO
25%.
Embodiment 5~7 described catalyst are used for the catalytic burning of sulphur-containing exhaust gas to be handled.Feed composition is hydrogen sulfide 1% (v/v), carbon disulfide 0.1% (v/v), cos 0.1% (v/v), steam 30% (v/v).350 ℃ of reaction temperatures, air speed 5000h
-1Evaluation result sees Table 5.
Table 5 embodiment 5~7 catalyst application results
Conversion ratio, %/sulfur dioxide production rate, % |
Hydrogen sulfide |
Carbon disulfide |
Cos |
Embodiment 5 |
100/100 |
89/99 |
93/99 |
Embodiment 6 |
100/100 |
88/98 |
92/99 |
Embodiment 7 |
99/99 |
83/96 |
85/98 |
Comparative example
By the catalyst A that CN1410149A embodiment 1 makes, estimate by the evaluation method of the embodiment of the invention 1, the results are shown in Table 6.
Table 6 comparative example catalyst experiment result
|
Hydrogen sulfide |
Carbon disulfide |
Cos |
Conversion ratio, % |
100 |
55 |
70 |
The sulfur dioxide production rate, % |
99 |
85 |
90 |