WO2022172864A1 - 希硫酸製造装置及び希硫酸製造方法 - Google Patents
希硫酸製造装置及び希硫酸製造方法 Download PDFInfo
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- WO2022172864A1 WO2022172864A1 PCT/JP2022/004391 JP2022004391W WO2022172864A1 WO 2022172864 A1 WO2022172864 A1 WO 2022172864A1 JP 2022004391 W JP2022004391 W JP 2022004391W WO 2022172864 A1 WO2022172864 A1 WO 2022172864A1
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- sulfuric acid
- dilute sulfuric
- combustion
- gas
- oxygen
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- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 611
- 238000004519 manufacturing process Methods 0.000 title claims description 106
- 239000007789 gas Substances 0.000 claims abstract description 204
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 189
- 239000001301 oxygen Substances 0.000 claims abstract description 189
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 188
- 238000002485 combustion reaction Methods 0.000 claims abstract description 183
- 239000002994 raw material Substances 0.000 claims abstract description 143
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 75
- 238000001816 cooling Methods 0.000 claims abstract description 72
- AKEJUJNQAAGONA-UHFFFAOYSA-N sulfur trioxide Chemical compound O=S(=O)=O AKEJUJNQAAGONA-UHFFFAOYSA-N 0.000 claims abstract description 70
- 239000000567 combustion gas Substances 0.000 claims abstract description 67
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 53
- 229910052815 sulfur oxide Inorganic materials 0.000 claims abstract description 48
- 239000003054 catalyst Substances 0.000 claims abstract description 45
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 29
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 29
- 239000011593 sulfur Substances 0.000 claims abstract description 29
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 28
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000012495 reaction gas Substances 0.000 claims abstract description 25
- 230000001590 oxidative effect Effects 0.000 claims abstract description 8
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 129
- 238000006243 chemical reaction Methods 0.000 claims description 96
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 claims description 74
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 61
- 239000007788 liquid Substances 0.000 claims description 49
- 238000006477 desulfuration reaction Methods 0.000 claims description 43
- 230000023556 desulfurization Effects 0.000 claims description 43
- 239000002699 waste material Substances 0.000 claims description 42
- 229910021529 ammonia Inorganic materials 0.000 claims description 26
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical group O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 claims description 26
- 239000007864 aqueous solution Substances 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 25
- 239000011449 brick Substances 0.000 claims description 21
- 239000002918 waste heat Substances 0.000 claims description 15
- PQUCIEFHOVEZAU-UHFFFAOYSA-N Diammonium sulfite Chemical compound [NH4+].[NH4+].[O-]S([O-])=O PQUCIEFHOVEZAU-UHFFFAOYSA-N 0.000 claims description 13
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 13
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 13
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 13
- 238000002156 mixing Methods 0.000 claims description 11
- 238000007254 oxidation reaction Methods 0.000 claims description 8
- 238000006555 catalytic reaction Methods 0.000 claims description 7
- 239000003426 co-catalyst Substances 0.000 claims description 7
- 230000003647 oxidation Effects 0.000 claims description 7
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 6
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 6
- 238000001704 evaporation Methods 0.000 claims description 6
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 5
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 15
- 230000008569 process Effects 0.000 description 11
- 238000004088 simulation Methods 0.000 description 11
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 10
- 238000002474 experimental method Methods 0.000 description 10
- 239000003546 flue gas Substances 0.000 description 10
- 239000000243 solution Substances 0.000 description 10
- 238000005260 corrosion Methods 0.000 description 9
- 230000007797 corrosion Effects 0.000 description 9
- 238000000354 decomposition reaction Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 238000011144 upstream manufacturing Methods 0.000 description 8
- 229910000975 Carbon steel Inorganic materials 0.000 description 7
- 239000010962 carbon steel Substances 0.000 description 7
- 238000001035 drying Methods 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 238000001784 detoxification Methods 0.000 description 6
- 239000003595 mist Substances 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 5
- 239000002253 acid Substances 0.000 description 5
- 239000000571 coke Substances 0.000 description 5
- 229910001882 dioxygen Inorganic materials 0.000 description 5
- 230000007613 environmental effect Effects 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 239000012467 final product Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 4
- 238000004064 recycling Methods 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000000809 air pollutant Substances 0.000 description 2
- 231100001243 air pollutant Toxicity 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 238000011143 downstream manufacturing Methods 0.000 description 2
- 239000012717 electrostatic precipitator Substances 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 238000004868 gas analysis Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 150000003464 sulfur compounds Chemical class 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000004448 titration Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000003905 agrochemical Substances 0.000 description 1
- SOIFLUNRINLCBN-UHFFFAOYSA-N ammonium thiocyanate Chemical compound [NH4+].[S-]C#N SOIFLUNRINLCBN-UHFFFAOYSA-N 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000013626 chemical specie Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 229910000856 hastalloy Inorganic materials 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005987 sulfurization reaction Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- -1 undecomposed NH 3 Chemical compound 0.000 description 1
- 239000012719 wet electrostatic precipitator Substances 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/74—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/74—Preparation
- C01B17/76—Preparation by contact processes
- C01B17/765—Multi-stage SO3-conversion
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/74—Preparation
- C01B17/76—Preparation by contact processes
- C01B17/78—Preparation by contact processes characterised by the catalyst used
- C01B17/79—Preparation by contact processes characterised by the catalyst used containing vanadium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/74—Preparation
- C01B17/76—Preparation by contact processes
- C01B17/80—Apparatus
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/24—Sulfates of ammonium
Definitions
- the present invention relates to a diluted sulfuric acid manufacturing apparatus and a diluted sulfuric acid manufacturing method.
- Sulfuric acid (H 2 SO 4 ) is a strong acid that is produced in large quantities and used in various fields. Sulfuric acid is broadly classified into industrial concentrated sulfuric acid with a sulfuric acid concentration of 90% by weight or more and industrial dilute sulfuric acid with a sulfuric acid concentration of less than 90% by weight, each having different properties. Of these, dilute sulfuric acid is strongly acidic, but unlike concentrated sulfuric acid, it does not have an oxidizing action or dehydrating action, but exhibits strong corrosiveness to metal materials. Dilute sulfuric acid is used in various applications such as industrial products, medicines, agricultural chemicals, and reagents.
- the production of sulfuric acid requires raw materials containing sulfur.
- desulfurization waste liquid and recycled sulfur from the gas (coke oven gas: hereinafter "COG") generated in the process of manufacturing coke used in iron manufacturing, etc., and discharged from the copper refining process
- COG coke oven gas
- Patent Document 1 is known as a method for producing sulfuric acid.
- This document describes: (a) providing heat for burning a carbon-containing fuel to form sulfur dioxide from a sulfur-containing material; (b) forming a gas mixture containing sulfur dioxide and gases resulting from combustion of the fuel; ) drying the mixed gas, which after drying contains not less than 30% by volume of carbon dioxide and more than 16% by volume of sulfur dioxide.
- Patent Document 2 discloses a wet treatment system for desulfurization waste liquid.
- desulfurization waste liquid is supplied to a combustion device together with fuel gas and air, and is combusted at 1050 to 1100 ° C.
- Patent Document 3 discloses a catalytic sulfuric acid production method using sulfur-burned gas as a raw material, in which an oxygen enrichment device is incorporated to convert oxygen-enriched air into sulfur combustion. A method of feeding a furnace and/or converter is described.
- Patent No. 2519691 Chinese Patent CN110282606A JP-A-1-160809
- the method of Patent Document 1 includes a step of drying the mixed gas, so it aims to produce concentrated sulfuric acid with a high concentration of sulfuric acid instead of dilute sulfuric acid.
- dilute sulfuric acid is produced by a method of producing concentrated sulfuric acid and then diluting it with water, or by using a sulfuric acid production apparatus with a special temperature controller that can adjust the condensation temperature (boiling point) of sulfuric acid.
- the former method requires equipment such as a dehumidifying tower for once dehumidifying the high-temperature combustion gas to less than 100° C. and a drying tower utilizing the dehydration action of concentrated sulfuric acid in order to adjust the moisture concentration.
- the sulfuric acid produced by the system described in Patent Document 2 is high-concentration sulfuric acid with a concentration of 93% by weight, and dilute sulfuric acid with a concentration of 90% by weight or less is not produced.
- the washing tower is supplemented with water in the latter stage of the combustion means and the preceding stage of the reaction means. does not increase the water content of Therefore, dilute sulfuric acid cannot be produced even if the washing tower is replenished with water.
- air is supplied to the combustion device, and a purifying device and a denitrification reactor are essential components after the combustion device.
- Patent document 3 does not describe the production of dilute sulfuric acid. Oxygen enrichment devices have also been used to increase the equilibrium conversion of SO2 to SO3 by raising the relative concentration of O2 to SO2 ; do not have.
- An object of the present invention is to provide a dilute sulfuric acid production apparatus and a dilute sulfuric acid production method capable of producing dilute sulfuric acid at low cost.
- dilute sulfuric acid can be produced by using a raw material containing a large amount of water in addition to sulfur and nitrogen and burning the raw material with an oxygen-containing gas with a high oxygen concentration. perfected the invention.
- the present invention provides a raw material supply means for supplying a raw material containing at least sulfur, nitrogen, and 40 to 80% by weight or more of water, and an oxygen-containing gas that produces an oxygen-containing gas having an oxygen concentration of 22 to 40% by volume.
- gas generating means, and combustion means for burning the raw material with the oxygen-containing gas to generate a combustion gas containing sulfur oxides (SOx, where 1 ⁇ x ⁇ 3) and 10% by volume or more of moisture.
- a cooling means for cooling the combustion gas; a reaction means for oxidizing the sulfur oxides (SOx) with a catalyst to generate a reaction gas containing sulfur trioxide (SO 3 ); and dilute sulfuric acid generating means for generating sulfuric acid, and generating less than 90% by weight of dilute sulfuric acid only from the water content of the raw material without adding water at least from the combustion means to the dilute sulfuric acid generating means. It is a dilute sulfuric acid manufacturing device characterized by this.
- a raw material containing sulfur and nitrogen as well as a large amount of water is used, and by burning the raw material with an oxygen-containing gas with a high oxygen concentration, sulfuric acid is produced in a state containing a certain amount or more of water. manufacturing. Therefore, the sulfuric acid to be produced is dilute sulfuric acid, and there is no need to install dehumidifying equipment or drying equipment to produce sulfuric acid as in the conventional method. Therefore, the cost for producing dilute sulfuric acid can be reduced as compared with the conventional method.
- dilute sulfuric acid in the present invention, less than 90% by weight of dilute sulfuric acid can be produced only from the water content of the raw material without adding water, from the combustion means to the dilute sulfuric acid production means. Since the present invention does not require a special device such as a water supply device, the production cost of dilute sulfuric acid can be reduced.
- the raw material is burned with an oxygen-containing gas having an oxygen concentration of 22 to 40% by volume.
- nitrogen oxides (NOx) are likely to be generated when the oxygen concentration and combustion temperature during combustion of the raw material are increased.
- the amount of generated exhaust gas itself can be reduced (the amount of exhaust gas generated when PVSA 45d described later is 10951 Nm 3 /h and , exhaust gas amount 13207 Nm 3 /h without PVSA 45d).
- the amount of nitrogen oxides contained in the combustion gas does not increase, and on the contrary, the amount of NOx contained in the combustion gas becomes smaller than when air (oxygen concentration 21% by volume) is used (described later). See Figure 4).
- the combustion gas generated by the burning means is oxidized with nitrogen.
- the amount of matter is less than the amount of nitrogen oxides in the combustion gas that would be produced if the raw materials were burned under the same conditions using air with an oxygen concentration of 21% by volume.
- Combusting the feedstock with oxygen-containing gas in this way reduces the amount of nitrogen oxides in the resulting combustion gases compared to burning the feedstock with normal air. be able to.
- the combustion means burns the raw material at 900 to 1100°C.
- the present invention Compared to conventional sulfuric acid production plants, the present invention has a higher oxygen concentration, so it is possible to reduce the amount of combustion improver (COG, etc.) required to maintain combustion, which can reduce combustion costs.
- COG combustion improver
- COG combustion improver
- the oxygen concentration is high or the combustion temperature is high, air pollutants such as nitrogen oxides (NOx) are likely to be generated.
- NOx nitrogen oxides
- the amount of nitrogen oxides produced does not increase, thus making it possible to reduce the environmental load. Therefore, the equipment for removing nitrogen oxides is unnecessary or can be minimized, so that the production cost of dilute sulfuric acid can be reduced.
- the combustion means burns the raw material at 1050°C or lower.
- the combustion means by setting the combustion temperature to 1050° C. or less, the NOx concentration in the combustion gas can be reduced (because the NOx concentration increases as the temperature rises as shown in FIG. 15, which will be described later). Therefore, special equipment for denitrification can be dispensed with in the wake.
- the oxygen concentration of the oxygen-containing gas introduced from the oxygen-containing gas generation means is within a range of 22 to 30% by volume, and the oxygen concentration in the combustion gas generated by the combustion means is It is within the range of 2.0 to 7.0% by volume.
- the SO 3 conversion rate is the same as in air (without oxygen enrichment) combustion. Equivalent values can be maintained. For this reason, it is possible to set the SO 3 conversion rate shown below in the combustion gas generated by the combustion means to a low value, for example within the range of 1.0 to 3.0%.
- SO3 conversion ( SO3 /SOx) x 100 (Here , SO3 is the volume concentration of SO3 contained in the combustion gas , and SOx is the volume concentration of SOx contained in the combustion gas). As a result, the acid dew point in the exhaust heat boiler downstream of the combustion furnace is not affected, and the air (without oxygen enrichment) supply can be handled in the same manner.
- gas removing means for removing unreacted sulfur dioxide in the dilute sulfuric acid generating means.
- sulfur dioxide can be detoxified without being released into the environment.
- the gas removal means reacts the unreacted sulfur dioxide with ammonia to produce ammonium sulfite ((NH 4 ) 2 SO 3 : ammonium sulfite), which is oxidized to form ammonium sulfate ((NH 4 ) 2 SO 4 : ammonium sulfate).
- the ammonia may absorb sulfur dioxide with ammonia water or with ammonia contained in the desulfurization waste liquid.
- the latter desulfurization waste liquid is reacted with the unreacted sulfur dioxide. It is preferable to recycle it later as the raw material.
- the desulfurization waste liquid as an ammonia source and recycling the desulfurization waste liquid after reaction with sulfur dioxide as a raw material, the desulfurization waste liquid can be effectively used.
- the combustion means employs a combustion furnace having a partially open grid-shaped brick inside.
- Bricks have a heat retention effect when heated, so unreacted raw materials can be post-burned.
- the lattice-like bricks have appropriate openings, which can improve the flow of raw materials, oxygen-containing gas, and combustion gas as a rectifying effect. Therefore, the raw material can be efficiently burned by the burning means.
- reaction means for oxidizing the sulfur oxide (SOx) with a catalyst to generate a reaction gas containing sulfur trioxide (SO 3 ) has a denitrification function, wherein the catalyst is vanadium pentoxide (V 2 O 5 ). It is preferable to also serve as
- the catalyst of the reaction means is vanadium pentoxide (V 2 O 5 ), which also serves as a denitration function, so that the oxidation of sulfur oxides and the decomposition of nitrogen can be carried out at the same time.
- the reaction means preferably further comprises a denitration catalyst containing titanium oxide (TiO 2 ) as a co-catalyst in addition to the catalyst.
- the concentration of nitrogen e.g., undecomposed NH 3 , NO, NO 2 and other NOx
- a promoter is included in the absence of vanadium pentoxide.
- the conversion of sulfur oxides proceeds preferentially over the decomposition of nitrogen. Therefore, by providing the denitration catalyst containing the co-catalyst as described above, the nitrogen decomposition reaction can be prioritized over the conversion of sulfur oxides, and the nitrogen decomposition can proceed.
- the reaction means is provided with the catalysts arranged in multiple stages, and the air introduced from the outside is directly applied to the post-conversion gas whose temperature is raised by the exothermic reaction caused by the oxidation of the sulfur oxides by the catalysts in the preceding stages among the multiple stages. It is preferable to reduce the temperature of the post-conversion gas without relying on a heat exchanger by mixing and lowering the temperature to a temperature suitable for the subsequent catalytic reaction.
- the temperature can be lowered at the rear stage.
- the reaction is promoted by increasing the partial pressure of oxygen required for conversion.
- the gas flow capacity of the combustion furnace and boiler of the upstream equipment can be reduced by attracting the atmosphere and replenishing oxygen with the reaction means (converter) instead of the combustion means (combustion furnace) of the most upstream equipment. It is effective in reducing the size of the combustion furnace/boiler and reducing the combustion improver.
- the above configuration also serves to cool the gas after conversion in the converter, so that a heat exchanger for cooling can be omitted.
- reaction means may use both an indirect cooling means for indirectly cooling the converted gas with a heat exchanger and cooling by direct mixing of the atmosphere.
- the cooling is performed by the indirect cooling means, so that the gas temperature in the latter stage of the catalyst can be efficiently lowered to a temperature suitable for the catalytic reaction.
- the increase in the amount of gas can be suppressed by reducing the amount of mixed air.
- the combustion means supplies the oxygen-containing gas to the raw material of less than 5000 kJ/kg and burns it, and supplies the air to the raw material of 5000 kJ/kg or more to burn it.
- the combustion means supplies the oxygen-containing gas to the raw material of less than 5000 kJ / kg and burns it, and when the raw material of less than 5000 kJ / kg is small, the raw material of 5000 kJ / kg or more and the combustion improver (COG etc. ) may also be supplied with an oxygen-containing gas for combustion.
- the combustion can be stabilized by supplying an oxygen-containing gas with a high oxygen concentration for combustion.
- an oxygen-containing gas may be supplied.
- the oxygen-containing gas may be supplied to all the raw materials or to some of the raw materials depending on the supply ratio of the raw materials.
- the dilute sulfuric acid generating means adjusts the concentration of dilute sulfuric acid by controlling the temperature of the circulating sulfuric acid aqueous solution up and down.
- the concentration of the dilute sulfuric acid to be generated can be adjusted. can be raised to around 80° C., dilute sulfuric acid can be produced with a commercial value of around 70% by weight.
- sulfuric acid concentrating means for concentrating the dilute sulfuric acid generated by the dilute sulfuric acid generating means to a concentration of 70 to 80% by weight.
- dilute sulfuric acid generated by the dilute sulfuric acid generating means by concentrating the concentration of dilute sulfuric acid generated by the dilute sulfuric acid generating means to 70 to 80% by weight, dilute sulfuric acid of 70% or more that brings value as a trading commodity is generated, and carbon steel Diluted sulfuric acid of 70% or more (preferably around 75%) can be produced that can be used for corrosion resistance in the configured product line.
- the dilute sulfuric acid generating means uses part of the generated aqueous sulfuric acid solution to directly contact-cool the reaction gas, and does not have equipment for indirectly cooling the reaction gas.
- the cooling means is an exhaust heat boiler having a boiler
- the exhaust heat boiler is water supply means for supplying water into the boiler; It is preferable to provide heat exchange means for evaporating the water with the combustion gas to generate steam and cooling the combustion gas by heat exchange.
- outlet temperature adjusting means including a boiler bypass and a control valve for keeping the outlet temperature constant with respect to fluctuations in the outlet temperature of the boiler.
- the concentration of dilute sulfuric acid generated by the dilute sulfuric acid generating means is adjusted without adding water from the combustion means to the dilute sulfuric acid generating means by adjusting the water content of the raw material. preferably.
- the concentration of dilute sulfuric acid can be adjusted without adding water.
- the present invention includes a raw material supply step of supplying a raw material containing at least sulfur, nitrogen, and 40 to 80% by weight or more of water, and an oxygen-containing gas that produces an oxygen-containing gas having an oxygen concentration of 22 to 40% by volume. a gas generation step, and a combustion step of burning the raw material with the oxygen-containing gas to generate a combustion gas containing sulfur oxides (SOx, where 1 ⁇ x ⁇ 3) and 10% by volume or more of moisture.
- SOx sulfur oxides
- a cooling step of cooling the combustion gas a reaction step of oxidizing the sulfur oxides (SOx) with a catalyst to generate a reaction gas containing sulfur trioxide (SO 3 ); a dilute sulfuric acid producing step of producing sulfuric acid, and producing less than 90% by weight of dilute sulfuric acid only from the water content of the raw material without adding water at least from the combustion step to the dilute sulfuric acid producing step. It is a method for producing dilute sulfuric acid.
- a raw material containing sulfur and nitrogen as well as a large amount of water is used, and by burning the raw material with an oxygen-containing gas with a high oxygen concentration, sulfuric acid is produced in a state containing a certain amount or more of water. manufacturing. Therefore, the sulfuric acid to be produced is dilute sulfuric acid, and there is no need to install dehumidifying equipment or drying equipment to produce sulfuric acid as in the conventional method. Therefore, the cost for producing dilute sulfuric acid can be reduced as compared with the conventional method. Further, in the present invention, less than 90% by weight of dilute sulfuric acid can be produced only from the water content of the raw material without adding water from the raw material supply means to the dilute sulfuric acid producing means.
- the production cost of dilute sulfuric acid can be reduced without requiring a special device such as a water supply device.
- the raw material is burned with an oxygen-containing gas having an oxygen concentration of 22 to 40% by volume, the amount of NOx contained in the combustion gas can be reduced compared to when air is used.
- the amount of generated exhaust gas itself can be reduced.
- the combustion gas generated by the combustion means is oxidized with nitrogen.
- the amount of matter is less than the amount of nitrogen oxides in the combustion gas that would be produced if the raw materials were burned under the same conditions using air with an oxygen concentration of 21% by volume.
- Combusting the feedstock with oxygen-containing gas in this way reduces the amount of nitrogen oxides in the resulting combustion gases compared to burning the feedstock with normal air. be able to.
- the burning step burns the raw material at 900 to 1100°C.
- the oxygen concentration is high, it is possible to reduce the amount of raw materials and combustion improvers (COG, etc.) required to maintain combustion, thereby reducing combustion costs.
- COG combustion improvers
- NOx nitrogen oxides
- the amount of oxides is small, which makes it possible to reduce the environmental load. Therefore, the equipment for removing nitrogen oxides is unnecessary or can be minimized, so that the production cost of dilute sulfuric acid can be reduced.
- the combustion step burns the raw material at a temperature of 1050°C or less.
- the oxygen concentration of the oxygen-containing gas introduced from the oxygen-containing gas generation step is in the range of 22 to 30% by volume, and the oxygen concentration in the combustion gas generated in the combustion step is It is within the range of 2.0 to 7.0% by volume.
- the SO3 conversion rate is equivalent to the value without oxygen enrichment. can be maintained.
- the SO 3 conversion in the combustion gas produced in the combustion process can be low, for example in the range of 1.0-3.0%.
- the acid dew point in the exhaust heat boiler downstream of the combustion furnace is not affected, and it can be handled in the same manner as in the case of air (without oxygen enrichment) combustion.
- a gas removal step for removing unreacted sulfur dioxide in the dilute sulfuric acid generation step.
- sulfur dioxide can be detoxified without being released into the environment.
- the unreacted sulfur dioxide and ammonia are reacted to produce ammonium sulfite ((NH 4 ) 2 SO 3 : ammonium sulfite), which is oxidized to form ammonium sulfate ((NH 4 ) 2 SO 4 : ammonium sulfate).
- the ammonia may absorb sulfur dioxide with ammonia water or with ammonia contained in the desulfurization waste liquid.
- the latter desulfurization waste liquid is reacted with the unreacted sulfur dioxide. It is preferable to recycle it later as the raw material.
- the desulfurization waste liquid as an ammonia source and recycling the desulfurization waste liquid after reaction with sulfur dioxide as a raw material, the desulfurization waste liquid can be effectively used.
- the combustion step employs a combustion furnace having a partially open grid-like brick inside.
- bricks have a heat retention effect when heated, so unburned raw materials can be post-burned.
- the lattice-like bricks have appropriate openings, which can improve the flow of raw materials, oxygen-containing gas, and combustion gas as a rectifying effect. Therefore, the raw material can be efficiently burned by the burning means.
- the catalyst is vanadium pentoxide (V 2 O 5 ), and it is preferable that it also has a denitration function.
- the catalyst in the reaction step is vanadium pentoxide (V 2 O 5 ), which also serves as a denitrification function, so that the oxidation of sulfur oxides and the decomposition of nitrogen can be performed at the same time.
- V 2 O 5 vanadium pentoxide
- the reaction step preferably further comprises a denitration catalyst containing titanium oxide (TiO 2 ) as a co-catalyst in addition to the catalyst.
- vanadium pentoxide without a promoter is used when the nitrogen content (e.g. NOx such as undecomposed NH 3 , NO, NO 2 ) in the feedstock is relatively high.
- the conversion of sulfur oxides proceeds preferentially over the decomposition of nitrogen. Therefore, by providing the denitration catalyst containing the co-catalyst as described above, the nitrogen decomposition reaction can be prioritized over the conversion of sulfur oxides, and the nitrogen decomposition can proceed.
- the catalyst is installed in a plurality of stages, and the air introduced from the outside is directly applied to the post-conversion gas whose temperature is raised by the exothermic reaction due to the oxidation of the sulfur oxide by the catalyst in the front stage among the plurality of stages. It is preferable to reduce the temperature of the post-conversion gas without relying on a heat exchanger by mixing and lowering the temperature to a temperature suitable for the subsequent catalytic reaction.
- an indirect cooling step of indirectly cooling the post-conversion gas with a heat exchanger and cooling by direct mixing of the atmosphere may be used together.
- the cooling by the indirect cooling process is performed, so that the gas temperature in the latter stage of the catalyst can be efficiently lowered to a temperature suitable for the catalytic reaction.
- the increase in the amount of gas can be suppressed by reducing the amount of mixed air.
- the raw material of less than 5000 kJ/kg is combusted by supplying the oxygen-containing gas, and the raw material of 5000 kJ/kg or more is combusted by supplying air.
- the oxygen-containing gas is supplied to the raw material of less than 5000 kJ / kg and burned, and when the raw material of less than 5000 kJ / kg is small, the raw material of 5000 kJ / kg or more and a combustion improver (COG etc. ) may also be supplied with an oxygen-containing gas for combustion.
- the combustion can be stabilized by supplying an oxygen-containing gas with a high oxygen concentration for combustion.
- an oxygen-containing gas may be supplied.
- the oxygen-containing gas may be supplied to all the raw materials or to some of the raw materials depending on the supply ratio of the raw materials.
- the concentration of dilute sulfuric acid is preferably adjusted by controlling the temperature of the circulating sulfuric acid aqueous solution up and down.
- the concentration of the dilute sulfuric acid produced can be adjusted. can be raised to around 80° C., dilute sulfuric acid can be produced with a commercial value of around 70% by weight.
- a sulfuric acid concentration step of concentrating the diluted sulfuric acid produced in the diluted sulfuric acid production step to a concentration of 70 to 80% by weight.
- dilute sulfuric acid of 70% or more that brings value as a trade commodity is generated, and carbon steel Diluted sulfuric acid of 70% or more (preferably around 75%) can be produced that can be used for corrosion resistance in the configured product line.
- the reaction gas is directly contact-cooled using the generated aqueous sulfuric acid solution, and it is preferable that there is no equipment for indirect cooling of the reaction gas.
- the cooling step uses a waste heat boiler having a boiler, and the waste heat boiler is a water supply step of supplying water into the boiler; and a heat exchange step of evaporating the water in the combustion gas to generate steam and cooling the combustion gas by heat exchange.
- an outlet temperature adjustment step including a boiler bypass and a control valve for keeping the outlet temperature constant with respect to fluctuations in the outlet temperature of the boiler.
- the concentration of dilute sulfuric acid generated in the dilute sulfuric acid generation step is adjusted without adding water from the combustion step to the dilute sulfuric acid generation step by adjusting the water content of the raw material. preferably.
- the concentration of dilute sulfuric acid can be adjusted without adding water.
- FIG. 3 is a schematic diagram showing an upstream process of the dilute sulfuric acid production apparatus of the present invention
- FIG. 3 is a schematic diagram showing a downstream process of the dilute sulfuric acid manufacturing apparatus of the present invention
- 1 is a schematic diagram showing an internal structure of a combustion means (combustion furnace) of the present invention
- FIG. 5 is a graph showing simulation results of the combustion furnace 51.
- FIG. 4 is a schematic diagram showing the internal structure of a converter 61.
- FIG. 1 is a schematic diagram showing the internal structure of an embodiment of a combustion means (combustion furnace) of the present invention
- FIG. 1 is a system diagram of equipment used in Examples.
- FIG. It is a figure which shows the result of an Example. It is a figure which shows the result of an Example.
- FIG. 1 is a schematic diagram showing an upstream process of a dilute sulfuric acid manufacturing apparatus 40
- FIG. 1 is a schematic diagram showing a case where an oxygen-containing gas is supplied to a raw material (here, desulfurization waste liquid/molten sulfur). Oxygen-containing gas and air may be supplied for purified COG.
- FIG. 2 is a schematic diagram showing downstream processes of the dilute sulfuric acid manufacturing apparatus 40. As shown in FIG.
- the "diluted sulfuric acid” of the present invention means an aqueous sulfuric acid solution having a sulfuric acid concentration of less than 90% by weight, and includes "diluted sulfuric acid” (sulfuric acid content 60 to 80% by weight) and “purified dilute sulfuric acid” defined in JIS K1321. ” (sulfuric acid content 27 to 50% by weight).
- the dilute sulfuric acid production apparatus 40 of this embodiment includes means for supplying raw materials.
- the raw material of this embodiment consists of molten sulfur, desulfurization waste liquid, and purified COG as a combustion improver.
- the raw material supply means is means for supplying these raw materials to the combustion furnace 51 .
- the dilute sulfuric acid production apparatus 40 of the present embodiment includes a pipeline 41a for supplying molten sulfur as a raw material. Molten sulfur is obtained by melting sulfur collected from oil refineries and the like.
- a pump 41b is connected to the pipeline 41a, whereby the raw material is transferred to the pipeline 41c and supplied into the combustion furnace 51. As shown in FIG.
- the dilute sulfuric acid manufacturing apparatus 40 also includes a pipeline 42 for supplying desulfurization waste liquid as a raw material.
- a desulfurization waste liquid is a waste liquid from a desulfurization facility installed for the purpose of removing dust, organic matter, sulfur compounds, and the like in exhaust gas (crude COG) discharged from a coke oven facility or the like.
- the desulfurization effluent contains components such as free sulfur, free NH3 , NH4SCN , ( NH4 ) 2S2O3 , H2O . Of these, water (H 2 O) is often 50% by weight or more of the entire desulfurization waste liquid, although it is not specified.
- the pipeline 42 communicates with the combustion furnace 51, and the desulfurization waste liquid is also supplied into the combustion furnace 51 as a raw material.
- the dilute sulfuric acid production device 40 is provided with a pipeline 43 for supplying refined COG as a combustion improver.
- Refined COG is a gas generated in the process of producing coke used in iron manufacturing and the like.
- Purified COG generally contains components such as H 2 , N 2 , O 2 , CO, CO 2 , CH 4 , C 2 H 6 and trace amounts of sulfur compounds.
- the conduit 43 also communicates with the combustion furnace 51, and the purified COG is also supplied into the combustion furnace 51 as a combustion improver.
- the pipeline 41a, the pump 41b, the pipeline 41c, the pipeline 42, and the pipeline 43 correspond to the material and combustion improver supply means of the present invention, and these means realize the combustible material supply process.
- the desulfurization waste liquid contains sulfur alone and sulfur content (10 to 40% by weight) such as (NH 4 ) 2 S 2 O 3 , It contains nitrogen content (5-25% by weight) such as NH 3 and water (40-80% by weight).
- the water content is obtained by mixing the water in each raw material and the combustion improver. Defined as quantity.
- a pipeline 44a for supplying compressed air, which is a spray medium, is connected to the pipeline 41c and the pipeline 42.
- a steam heater 44b is provided in the pipeline 44a, and heated air is supplied to the pipeline 41c to perform fine atomization for increasing the combustion efficiency of these raw materials.
- the dilute sulfuric acid manufacturing apparatus 40 is provided with a pipeline 45a for supplying air. The air supplied from the pipeline 45a is transferred to the pipeline 45c via the blower 45b.
- the pipeline 45c is provided with an oxygen gas generator (PVSA 45d: vacuum type pressure swing adsorption method), and high-concentration oxygen is supplied from the PVSA 45d.
- the PVSA 45d is an apparatus that uses an adsorbent such as zeolite to adsorb and remove nitrogen in the air under pressure to efficiently obtain high-purity oxygen. PVSA45d can generate oxygen with a purity of 90% by volume or more. This oxygen is mixed with the air in the conduit 45a and supplied into the combustion furnace 51 as air with a high oxygen concentration.
- a PSA method pressure swing adsorption method
- oxygen may be supplied by branching from an existing oxygen gas pipe.
- the line 45e was used for the oxygen-containing gas to the desulfurization waste liquid
- the line 45f was used for the oxygen-containing gas to the molten sulfur.
- the pipeline 45a, the blower 45b, the PVSA 45d, the pipeline 45c, the pipeline 45e, and the pipeline 45f correspond to the oxygen-containing gas generating means of the present invention, and these means realize the oxygen-containing gas generating step.
- Line 45c may use air instead of oxygen-containing gas and is indicated by a dotted line.
- the oxygen-containing gas supplied to the combustion furnace 51 is adjusted to have an oxygen concentration of 22 to 40% by volume, preferably 22 to 30% by volume, more preferably 25 to 30% by volume.
- the combustion furnace 51 (combustion means) performs a combustion process of burning raw materials with an oxygen-containing gas to generate combustion gas containing sulfur oxides (SOx) and 10% by volume or more of moisture.
- FIG. 3 is a schematic diagram showing the internal structure of the combustion furnace 51. As shown in FIG. As shown in this figure, a supply port 51a for supplying raw materials and an oxygen-containing gas is provided upstream of a combustion furnace 51, and the raw materials are burned inside and combustion gas is discharged from a downstream outlet 51b. Ejected. In this embodiment, molten sulfur is supplied from the upper supply port 51a in the figure, desulfurization waste liquid is supplied from the middle supply port 51a, and purified COG is supplied from the lower supply port 51a. In addition to supplying raw materials from separate supply ports for each type of raw material as in the present embodiment, raw materials may be supplied to the combustion furnace 51 in a state in which some or all of the raw materials are mixed in advance.
- a moisture evaporation zone On the raw material supply side of the combustion furnace 51, there is a moisture evaporation zone, where mainly molten sulfur and refined COG are burned and moisture in the desulfurization waste liquid is evaporated.
- the downstream stream is a combustible combustion zone, where combustible substances in the desulfurization waste liquid are combusted. A boundary is formed between them.
- a lattice-like brick 51c is provided between the combustible combustion area and the discharge port 51b.
- the lattice-like bricks 51c are made by arranging cubic heat-resistant bricks in a lattice and partially opening them.
- the aperture ratio of the grid bricks 51c is preferably around 50%.
- the lattice bricks 51c are often provided in multiple stages.
- the oxygen concentration of the oxygen-containing gas introduced into the combustion furnace 51 is in the range of 22 to 40% by volume, preferably 22 to 30% by volume, and the oxygen concentration in the combustion gas generated in the combustion furnace 51 is 2.0. It is more preferable that the SO 3 conversion rate in the combustion gas generated in the combustion furnace 51 is within the range of 1.0 to 3.0%.
- the grid-like bricks 51c are physically separated from the air so that the combustibles do not blow through in an unburned state even if the mixture of the air and the combustibles in the combustible combustion zone is inadequate. It has the function of promoting re-mixing with combustible materials and promoting re-combustion by the heat possessed by bricks. For this purpose, it is preferable to install a plurality of stages of grid bricks 51c. In addition, the stepped openings of the plurality of steps of grid bricks 51c are mutually staggered. As a result, the dust in the gas adheres to and grows on the surface of the bricks and falls, so it is preferable to install a plurality of stages of grid bricks 51c for accumulating falling dust without providing an opening at the bottom.
- FIG. 6 is a schematic diagram of an embodiment of means for supplying an oxygen-containing gas to the combustion furnace 51.
- the burner at the sulfur supply port 51a is provided with means for supplying an oxygen-containing gas from a pipeline 45f, and the burner at the desulfurization waste liquid supply port 51a is equipped with a pipeline 45e.
- means for supplying an oxygen-containing gas from the In the route for supplying the purified COG to the combustion furnace 51 as shown in (b) of the figure, the burner of the supply port 51a of the purified COG is provided with means for supplying an oxygen-containing gas from a pipe line 45c.
- the calorific value of desulfurization waste liquid is as low as less than 5000 kJ/kg, so that it is difficult to burn, but the combustion is promoted by supplying an oxygen-containing gas containing 22 to 40% by volume of oxygen to the burner.
- an oxygen-containing gas containing 22 to 40% by volume of oxygen to the burner.
- purified COG may only be supplied with air. It is preferable that the combustion of the two be controlled independently.
- the combustion temperature for burning the raw material in the combustion furnace 51 is preferably within the range of 900 to 1100°C.
- the upper limit of the combustion temperature is preferably 1050°C or less.
- the combustion temperature is preferably low, for example 1025° C. or lower, more preferably 100° C. or lower. This is because the NOx concentration increases as the combustion temperature increases, as shown in FIG. 15, which will be described later.
- the generated combustion gas is greater than when the raw material is burned under the same conditions using normal air (oxygen concentration 21% by volume).
- NOx (rich) is the amount of NOx contained in the combustion gas when the raw material is burned with an oxygen-containing gas with an oxygen concentration of 22 to 40% by volume, and the same raw material is used under the same conditions using air with an oxygen concentration of 21% by volume.
- NOx (air) is the amount of NOx contained in the combustion gas when is burned
- the NOx reduction rate shown by the following formula can be 50 to 95%.
- the NOx reduction rate tends to decrease as the oxygen concentration increases, and can be about 80% at an oxygen concentration of 25% by volume and about 60% at an oxygen concentration of 30% by volume.
- the combustion gas generated in the combustion furnace 51 is transferred to a waste heat boiler (WHB) 52 (cooling means).
- the waste heat boiler (1) 52 performs a cooling process of supplying chemically adjusted water into the boiler, evaporating with the combustion gas to generate steam, and cooling the combustion gas by heat exchange. Thereby, the temperature of the combustion gas is cooled to 380 to 460.degree. C., preferably about 420.degree.
- the exhaust heat boiler (1) 52 has a boiler, and cools the combustion gas in this boiler.
- the waste heat boiler (1) 52 includes water supply means (water supply step) for supplying water into the boiler, and water from the water supply means is evaporated with combustion gas to generate steam, and the combustion gas is transferred by heat exchange. and heat exchange means for cooling (heat exchange step).
- the exhaust heat boiler (1) 52 of the present embodiment includes outlet temperature adjusting means (outlet temperature adjusting means) for adjusting the outlet temperature of the converter 61 of the boiler to the temperature required for generating the reaction gas in the converter 61. step), and constant temperature means (constant temperature step) including a boiler bypass and a control valve for keeping the outlet temperature constant with respect to fluctuations in the boiler outlet temperature.
- the outlet temperature adjusting means includes a bypass duct of the boiler and a bypass gas amount adjusting valve, adjusts the amount of high-temperature bypass gas, and mixes it with the low-temperature gas at the boiler outlet to obtain combustion gas at a predetermined temperature.
- the exhaust heat boiler (1) 52 may be provided with recycling means (recycling step) for recovering the steam generated by the heat exchange means and reusing it as water for the water supply means.
- the combustion gas cooled by the exhaust heat boiler (1) 52 is introduced into the converter 61 (reaction means).
- the combustion gas cooled by the exhaust heat boiler (1) 52 contains a small amount of nitrogen (for example, undecomposed NH3 and NOx such as NO and NO2).
- the converter 61 reacts and oxidizes sulfur dioxide (SO 2 ) in the combustion gas with oxygen by means of catalysts installed in multiple stages (three stages in the figure) to produce a reaction gas containing sulfur trioxide (SO 3 ). (reaction step). More specifically, the converter 61 directly mixes the post-conversion gas whose temperature is raised by the oxidation (exothermic reaction) of sulfur oxides (SOx) and oxygen by the catalyst in the preceding stage among the multiple stages, with the atmosphere attracted from the outside. Sulfur dioxide is converted to sulfur trioxide (SO 3 ) with high efficiency by lowering the temperature to a temperature suitable for the subsequent catalytic reaction.
- FIG. 5 is a schematic diagram showing the internal structure of the converter 61, in which (a) is a side view, (b) is a cross-sectional view along line AA' of (a), and (c) is a dashed line of (b). It is an enlarged view of circle.
- the converter 61 includes a main air pipe 61a that takes in air from the atmosphere, branch air pipes 61b that branch off from the main air pipe 61a inside the device, and air that is sent into the device from the branch air pipes 61b. and an air port 61d to enter.
- a known catalyst used for producing sulfuric acid can be used, such as vanadium pentoxide (V 2 O 5 ).
- Vanadium pentoxide has a denitrification function, reacting NH 3 and NOx to decompose into nitrogen (N 2 ) and water (H 2 O). Therefore, the catalyst can simultaneously produce sulfur trioxide and decompose nitrogen ( NH3 and NOx). At this time, NH 3 may be injected for denitration. Since 60 to 80% of sulfur dioxide (SO 2 ) is oxidized in the first stage of the converter 61, the gas temperature after the reaction is 500 to 600°C, preferably about 540°C.
- the remaining sulfur dioxide (SO 2 ) is oxidized to sulfur trioxide (SO 3 ) in the second and third stages of the converter 61, and the inlet temperature of each stage can be 410 to 440°C.
- the air is directly mixed with the outlet gas of the preceding stage to control the temperature.
- a denitration catalyst may be arranged upstream of the first stage of the converter 61 (inflow side of the combustion gas from the exhaust heat boiler (1) 52). can be used.
- co-catalysts include titanium oxide (TiO 2 ) and the like, or mixtures thereof.
- TiO 2 titanium oxide
- the decomposition reaction of nitrogen content proceeds preferentially over the conversion of sulfur oxides, and the nitrogen content is reduced. decomposed.
- sulfur oxides can be efficiently converted by vanadium pentoxide that does not contain a promoter, in a state that is not easily affected by nitrogen.
- the converter 61 can use both direct cooling and indirect cooling means (not shown) for indirectly cooling the converted gas through heat exchange.
- Direct cooling is different from the above-mentioned method of directly cooling the post-conversion gas by mixing air drawn from the outside into the post-conversion gas. It means cooling without contact.
- the indirect cooling means is a device that performs a step of indirect cooling (indirect cooling step). From the viewpoint of preventing the acid dew point of the heat transfer surface, the indirect cooling means is preferably a heat exchanger or a boiler using steam on the low temperature side.
- the reaction gas produced in the converter 61 is transferred to the waste heat boiler (2) 62 and cooled.
- the waste heat boiler (2) 62 can use the same device as the waste heat boiler (1) 52 described above.
- the reaction gas is cooled to a temperature of about 280-300.degree. It should be noted that although installation of the waste heat boiler (2) 62 is recommended from the viewpoint of effective use of energy, it is not an essential device in the present invention and can be installed arbitrarily.
- the reaction gas cooled by the exhaust heat boiler (2) 62 is transferred to the bottom of a dilute sulfuric acid tower 71 (diluted sulfuric acid generating means) that performs a dilute sulfuric acid generating step.
- the dilute sulfuric acid tower 71 is a device that absorbs H 2 O and SO 3 in the reaction gas into a circulating sulfuric acid aqueous solution (dilute sulfuric acid) to produce dilute sulfuric acid as a product, and is also called an absorption tower.
- the dilute sulfuric acid tower 71 is filled with packings, and an aqueous sulfuric acid solution is sprayed from the top of the tower toward the packings. 2 O and SO 3 are absorbed in the aqueous sulfuric acid solution.
- the sulfuric acid aqueous solution that has absorbed SO 3 is transferred to a tank 73 (diluted sulfuric acid generating means), cooled by a heat exchanger 74 (diluted sulfuric acid generating means) with cooling water from a cooling tower (not shown), and then produced as a final product. It is stored in tank 75 . In the tank 75, the temperature of the aqueous sulfuric acid solution has dropped to about 50-60.degree.
- the sulfuric acid concentration of the sulfuric acid aqueous solution stored in the tank 75 as the final product is mostly in the range of 50 to 70% by weight depending on the raw material containing sulfuric acid, nitrogen and 40 to 80% by weight or more of water. ing. In this embodiment, it is possible to increase the concentration of sulfuric acid to 70% by weight or more in order to bring value as a commodity to the dilute sulfuric acid as the final product.
- the heat exchanger 74 (temperature control means) of this embodiment can control the temperature of the circulating sulfuric acid aqueous solution from the dilute sulfuric acid tower 71 up and down.
- the degree of cooling in the heat exchanger 74 is moderated, and the temperature of the sulfuric acid aqueous solution sprayed from the top of the dilute sulfuric acid tower 71 is changed from about 50-60°C to 80-100°C. degree, preferably around 80°C.
- the amount of water entrained in the outlet gas of the dilute sulfuric acid column 71 can be increased, and the sulfuric acid concentration of the sulfuric acid aqueous solution stored in the tank 75 can be increased to 70% by weight or more.
- the temperature of the aqueous sulfuric acid solution in the tank 75 rises to 80-100.degree.
- a sulfuric acid concentration device for concentrating the aqueous sulfuric acid solution stored in the tank 75 .
- the sulfuric acid contained in the aqueous sulfuric acid solution can be concentrated to increase the concentration (sulfuric acid concentration step).
- the sulfuric acid concentrator include a device that evaporates and condenses the water contained in the sulfuric acid aqueous solution by heating or the like.
- FIG. 19 is a diagram showing the corrosiveness of sulfuric acid to carbon steel (SS400 material).
- the horizontal axis indicates the concentration of sulfuric acid (% by weight), and the vertical axis indicates the corrosion rate. From this figure, it can be seen that the corrosion of carbon steel is reduced when the sulfuric acid concentration is around 70 to 80% by weight, and that the corrosion rate is greatly reduced by lowering the temperature. That is, carbon steel can be applied by lowering the temperature of product sulfuric acid having a concentration of 70 to 80% by weight by any of the above methods.
- a gas containing sulfuric acid mist, unreacted SO 2 and the like is discharged from the top of the dilute sulfuric acid tower 71 .
- Sulfuric acid mist is collected from this exhaust gas by a wet electrostatic precipitator 76 or a mist eliminator, transferred to the tank 73, and reused as an aqueous sulfuric acid solution. be transported.
- the exhaust gas from the wet type electrostatic precipitator 76 or the mist eliminator is transferred to the bottom of the detoxification tower 81a and comes into contact with aqueous ammonia also introduced from the bottom of the tower. Unreacted SO 2 in the exhaust gas reacts with ammonia to produce ammonium sulfite ((NH 4 ) 2 SO 3 : ammonium sulfite). Most of the waste liquid containing ammonium sulfite is circulated and returned to the detoxification tower 81a by the pump 82, and a part of it is air-oxidized by the oxidizing air from the blower 83 via an in-line mixer or the like, and is passed through the gas-liquid separator 84.
- ammonium sulfate (NH 4 ) 2 SO 4 : ammonium sulfate).
- the gas and entrained mist from the detoxification tower 81a are washed by the circulating liquid of the detoxification tower 81b by the pump 86, and the gas is discharged from the detoxification tower 81b.
- the exhaust gas after detoxification does not contain SO 2 , and contains only N 2 , O 2 , CO 2 and NOx within regulation values.
- the desulfurization waste liquid as an absorbing and neutralizing agent for unreacted sulfur dioxide (SO2) gas treatment (flue gas desulfurization), and react ammonia and sulfur dioxide contained in the desulfurization waste liquid.
- SO2 gas treatment flue gas desulfurization
- the desulfurization waste liquid after SO2 absorption is removed from the pipeline 89 and returned to the pipeline 42 ("desulfurization waste liquid return" in the figure), so that the desulfurization waste liquid can be recycled as a raw material.
- the desulfurization waste liquid can be effectively used.
- the exhaust gas is sucked/pressurized by the blower 87 and discharged into the atmosphere through the chimney 88.
- the blower 87 has a function of making all the individual units of the dilute sulfuric acid manufacturing apparatus 40 negative pressure. This prevents hot and harmful gases from leaking into the atmosphere.
- the converter 61 also has a function of attracting air from the atmosphere without providing special equipment. As described above, dilute sulfuric acid production and exhaust gas treatment are performed.
- water Dilute sulfuric acid with a concentration of less than 90% by weight can be produced only from the water contained in the raw material without adding steam (including water vapor). Therefore, the water supply facility required for producing dilute sulfuric acid becomes unnecessary, and the cost for producing dilute sulfuric acid can be reduced.
- the results of the above simulation are shown in the table below.
- the "item" row of the table shows the numerical values enclosed by the diamonds in FIGS. 1 and 2, and the rows below it show the results such as temperature and components at the position of the item.
- the amount of exhaust gas can be reduced by about 25% by increasing the oxygen concentration of the oxygen-containing gas to 25% by volume using PVSA 45d as in the present invention.
- the necessary amount of catalyst is calculated under the condition that the reciprocal of the time that the gas contacts the catalyst layer per unit time, that is, the space velocity SV (unit: 1/hr) is almost constant. Therefore, by reducing the gas amount by 25%, the necessary catalyst amount can be reduced by 25%.
- the components at the inlet of the combustion furnace 51 were set to the values shown in the table below.
- the calculation conditions of the combustion furnace 51 set the following numerical values.
- the simulation results (graph) are shown in FIG.
- the amount of NO produced at the furnace outlet in the case without PVSA was set to 1 and compared with the case with PVSA. As indicated by NO in this figure, it can be seen that the amount of NOx produced is smaller in the case with PVSA. It was found that in the case without PVSA, NOx was generated by combustion of COG gas (CH 4 , H 2 , CO) on the combustion furnace inlet side. The reason why the amount of NOx produced is lower with PVSA is presumed to be that the production of NOx derived from COG gas is suppressed in the case with PVSA.
- Experimental Results (1) List of Experimental Results Table 14 shows the experimental results. In this test, even though the raw material was completely combusted, the oxygen concentration in the exhaust gas did not match the calculated value, and it was assumed that air leaked in due to the aging of the furnace. The experimental results were organized by correcting the amount of combustion air so that the measured concentrations would match. 8 to 14 show temperature distributions in the furnace.
- FIG. 17 shows the experimental results organized by the oxygen concentration of the exhaust gas regardless of the oxygen enrichment rate. From this figure, the higher the oxygen concentration of the exhaust gas, the higher the SO 3 conversion rate, which is explained by the above two equations. Experimental results suggest that the exhaust gas temperature and oxygen concentration in the latter region of the combustion furnace affect the conversion of SO 3 rather than the oxygen partial pressure in the combustion zone. In other words, the oxygen enrichment rate does not affect the SO3 conversion rate , but the exhaust gas temperature and oxygen concentration at the furnace outlet affect the SO3 conversion rate.
- the SO 3 conversion rate is represented by the following formula.
- SO3 conversion ( SO3 /SOx) x 100 (Here , SO3 is the volume concentration of SO3 contained in the exhaust gas , and SOx is the volume concentration of SOx contained in the exhaust gas).
- Equation 3 For the above chemical equilibrium constant (Kp), the Bodenstein and Pohl formula has been proposed, and the experimental results were evaluated using this formula. Regarding the partial pressure of each gas component obtained in the experiment, it was found that the actually measured value and the value obtained by Equation 3 approximately matched by correcting the exhaust gas temperature in Equation 3 above.
- FIG. 18 shows the measured values at an oxygen concentration of around 6% and the equilibrium curve in Equation 3.
- Table 15 shows the relationship between oxygen enrichment and exhaust gas amount (Wet) at an exhaust gas temperature of 950°C. As shown in the table, it was confirmed that the amount of exhaust gas can be reduced as the oxygen enrichment rate is increased. In actual equipment, it is expected that the exhaust gas flow rate can be reduced by about 30%.
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Abstract
Description
SO3転換率 = (SO3/SOx)×100
(ここで、SO3は前記燃焼ガス中に含まれるSO3の体積濃度、SOxは前記燃焼ガス中に含まれるSOxの体積濃度である)。
これにより、燃焼炉後流の排熱ボイラでの酸露点に影響を及ぼさず空気(酸素富化無し)供給の場合と同等に扱うことができる。
また、最上流設備の燃焼手段(燃焼炉)ではなく、反応手段(転化器)で大気を誘引して酸素を補充することにより、上流設備の燃焼炉やボイラの通ガス容量をより小さくおさえることができ、燃焼炉・ボイラのサイズダウン及び燃焼炉助燃剤の低減に効果がある。さらに、上記の構成によって、転化器での転化後ガスの冷却も兼ねるため、冷却のための熱交換器を省略することができる。
あるいは、前記燃焼手段は、5000kJ/kg未満の原料に前記酸素含有ガスを供給して燃焼し、前記5000kJ/kg未満の原料が少ない場合には、5000kJ/kg以上の原料及び助燃剤(COG等)にも酸素含有ガスを供給して燃焼させてもよい。
このように、酸素含有ガスを原料ごとに振り分けることで、原料の燃焼を効率的に行うことができる。
前記ボイラ内に水を供給する給水手段と、
前記燃焼ガスで前記水を蒸発させて蒸気を発生させて熱交換により前記燃焼ガスを冷却する熱交換手段と、を備えることが好ましい。
また、本発明では、酸素濃度が22~40体積%の酸素含有ガスで原料を燃焼しているため、空気を使用した場合よりも燃焼ガスに含まれるNOxの量を少なくすることができる。このような高い酸素濃度の酸素含入ガスを使うことで、生成する排ガスの量自体も少なくすることができる。
これにより、燃焼炉後流の排熱ボイラでの酸露点に影響を及ぼさず空気(酸素富化無し)燃焼の場合と同等に扱うことができる。
あるいは、前記燃焼工程は、5000kJ/kg未満の原料に前記酸素含有ガスを供給して燃焼し、前記5000kJ/kg未満の原料が少ない場合には、5000kJ/kg以上の原料及び助燃剤(COG等)にも酸素含有ガスを供給して燃焼してもよい。
このように、酸素含有ガスを原料ごとに振り分けることで、原料の燃焼を効率的に行うことができる。
前記ボイラ内に水を供給する給水工程と、
前記燃焼ガスで前記水を蒸発させて蒸気を発生させて熱交換により前記燃焼ガスを冷却する熱交換工程と、を備えることが好ましい。
以下、図1~図3を参照して、本発明の一実施形態に係る希硫酸製造装置及び希硫酸製造方法について説明する。図1は、希硫酸製造装置40の上流側工程を示す模式図であり、図1は、酸素含有ガスを原料(ここでは脱硫廃液・溶融硫黄)に供給する場合を示す摸式図である。精製COG用には酸素含有ガスを供給する場合と空気を供給する場合がある。
図2は、希硫酸製造装置40の下流側工程を示す模式図である。なお、本発明の「希硫酸」とは、硫酸濃度が90重量%未満の硫酸水溶液を意味し、JIS K1321で規定される「薄硫酸」(硫酸分60~80重量%)や「精製希硫酸」(硫酸分27~50重量%)を含む。
SO3転換率 = (SO3/SOx)×100
(ここで、SO3は前記燃焼ガス中に含まれるSO3の体積濃度、SOxは前記燃焼ガス中に含まれるSOxの体積濃度である)。
NOx減少率: NOx(rich)/NOx(air) ×100(%)
NOx減少率は、酸素濃度を上げるにつれて減少する傾向にあり、酸素濃度が25体積%では約80%、酸素濃度が30体積%では約60%とすることができる。
(1)希硫酸製造装置全体のシミュレーション
図1、図2の希硫酸製造装置40について、表1に示す設定値に基づき、電解質シミュレータ 「OLI Flowsheet: ESP」(OLI systems社)、汎用プロセスシミュレータ PRO/IITM(AVEVA社)、及び計算ソフトを使用し、シミュレーションを行った。
図3の燃焼炉51について、化学反応シミュレーションソフト「CHEMKIN」(ANSYS社)を使用し、シミュレーションを行った。条件は以下のとおりである。
<計算条件>
・液体の物質はすべて気体に置き換える。
・Sを含む化学種については不活性物質としてN2に置き換える。
・燃焼炉内はプラグフロー流れとする。
・燃焼に伴う発熱は考慮しない。
・PVSAありとPVSAなしのケースで解析を実施した。
(本発明の用語:実施例中の用語)
・原料(脱硫廃液):燃焼液
・COG:COG (コークス炉ガスとも記載)
・酸素含有ガス:酸素冨化空気
・燃焼ガス:排ガス(燃焼排ガスなどとも記載)
・燃焼手段:炉(円筒炉、燃焼炉などとも記載)
・原料に溶融硫黄は用いていない。
各実験の運転条件は記載のとおり。
実施例と記載の実験は、酸素含有ガス中の酸素濃度を変化させたケースであり、比較例は空気を供給したケースを示す。なお、下記表の酸素濃度は一次燃焼空気中の酸素濃度を、また排ガス温度は目標値を示す。
コールドスタートではCOG専焼運転により、暖気した。
2)本実験
上記「(5)実験概要」に従って、運転条件を変えて燃焼実験を実施した。具体的には、COG専焼により炉内が十分暖気されたことを確認後、燃焼液を徐々に供給し、実機で計画されている溶融硫黄については、相当する発生熱量分のCOGを供給した。運転条件設定後、排ガス組成を、自動分析計及びガスサンプリング/中和滴定分析にて測定した。
(1)実験結果一覧
実験結果を表14に示す。なお、本試験を通じて、原料は完全燃焼していたにも関わらず排ガスの酸素濃度が計算値と一致せず炉の老朽化による空気の漏れ込みがあったと想定され、投入酸素に対し排ガスの酸素濃度測定値を一致させるよう、燃焼空気量を補正して実験結果を整理した。また、図8~図14に、炉内温度分布を示す。
分析値は滴定法定量下限より小さく、アンモニア濃度は1ppm以下(検出限界以下)であることを確認した。なお排ガス温度条件は、アンモニア燃焼上、一番厳しい条件と考えられる900℃にて確認した。
(1)NOx生成量の評価
排ガス中のNOx濃度は、上記の表14(a),(b),(c)のとおりである。図15のとおり、排ガス温度が高いほどNOx値は高くなるが、いずれの結果においても、NOxは環境規制値よりも十分低いことを確認した。
・1000℃,950℃では、酸素富化によるNOx生成量の低下がみられる。この結果はシミュレーションとも一致する。
これは、酸素冨化によるCOG低減によるものであると推測される。
・900℃では、そもそものNOx生成量が少なく、酸素濃度による顕著な有意差は見られなかった。
SO2からSO3への転換は、一般に下記の酸化反応式(発熱)及び化学平衡式にて論ぜられる。
Kp : 化学平衡定数
pX : 各成分Xの分圧
これらの式が表すところは、以下の2点である。
1)温度が高いほど、SO3/SO2比が小さくなる
2)酸素濃度が高いほど、SO3/SO2比が大きくなる
実験結果によれば、燃焼ゾーンでの酸素分圧よりも、燃焼炉後半の領域における排ガスの温度及び酸素濃度がSO3の転換率に影響を及ぼすと考えられる。つまり酸素富化率はSO3転換率には影響を及ぼさず、炉出口における排ガスの温度や酸素濃度がSO3転換率に影響を及ぼしている。このように、燃焼ゾーンだけでなく炉出口の排ガスでSO3転換率を評価することが適切であることを確認した。
なお、SO3転換率は下記の式で表される。
SO3転換率 = (SO3/SOx)×100
(ここで、SO3は前記排ガス中に含まれるSO3の体積濃度、SOxは前記排ガス中に含まれるSOxの体積濃度である)。
排ガス中のアンモニアについては検出されず、脱硫廃液の完全燃焼かつ、アンモニア濃度が環境規制値より低いことを確認した。
1)酸素富化による燃焼排ガス量の低減
・実験でも酸素富化による排ガス量の低減効果を確認した。
2)酸素富化によるNOx量の低下
・酸素富化燃焼において、NOx濃度は環境規制値を満足する低い値であることを確認した。
・1000℃,950℃では、酸素富化によるNOx生成量の低下がみられる。この結果はシミュレーションとも一致する。
3)アンモニア濃度
・酸素富化燃焼において、アンモニア濃度は、環境規制値を満足する低い値であることを確認した。
4)酸素富化によるSO3転換率
・酸素富化により、炉出口での排ガス中SO3転換率は影響がないことを確認した。排ガス中の酸素濃度によるSO3転換率への影響を確認した。
・排ガス中の酸素濃度を調整することで、酸素富化により排ガス流量を低減しつつSO3転換率を空気燃焼時と同等にすることができる。
Claims (44)
- 硫黄分と、窒素分と、40~80重量%以上の水分とを少なくとも含む原料を供給する原料供給手段と、
酸素濃度が22~40体積%の酸素含有ガスを生成する酸素含有ガス生成手段と、
前記酸素含有ガスで前記原料を燃焼して硫黄酸化物(SOx:ここで、1≦x<3)と10体積%以上の水分とを含む燃焼ガスを生成する燃焼手段と、
前記燃焼ガスを冷却する冷却手段と、
前記硫黄酸化物(SOx)を触媒により酸化して三酸化硫黄(SO3)を含む反応ガスを生成する反応手段と、
前記反応ガスを冷却して希硫酸を生成する希硫酸生成手段と、を含み、前記燃焼手段から前記希硫酸生成手段までにおいて水を添加することなく、前記原料の水分のみで90重量%未満の希硫酸を生成することを特徴とする希硫酸製造装置。 - 前記酸素含有ガス生成手段で生成した酸素濃度が22~40体積%の前記酸素含有ガスを使用して前記原料を燃焼することで、前記燃焼手段で生成する前記燃焼ガスの窒素酸化物の量を、酸素濃度21体積%の空気を使用して同一の条件で前記原料を燃焼したと仮定したときに生成する燃焼ガスの窒素酸化物の量よりも少なくすることを特徴とする請求項1に記載の希硫酸製造装置。
- 少なくとも前記燃焼手段と前記反応手段との間において脱硝のための設備を有していないことを特徴とする請求項1に記載の希硫酸製造装置。
- 前記燃焼手段が900~1100℃で前記原料を燃焼することを特徴とする請求項1に記載の希硫酸製造装置。
- 前記燃焼手段が1050℃以下で前記原料を燃焼することを特徴とする請求項4に記載の希硫酸製造装置。
- 前記燃焼手段は、
前記酸素含有ガス生成手段から導入される前記酸素含有ガスの酸素濃度が22~30体積%の範囲内であり、
前記燃焼手段で生成した前記燃焼ガス中の酸素濃度が2.0~7.0体積%の範囲内であることを特徴とする請求項1に記載の希硫酸製造装置。 - 前記希硫酸生成手段における未反応の二酸化硫黄を除去するガス除去手段を更に備えることを特徴とする請求項1に記載の希硫酸製造装置。
- 前記ガス除去手段は、前記未反応の二酸化硫黄とアンモニアとを反応させて亜硫酸アンモニウム((NH4)2SO3:亜硫安)を生成させ、酸化により硫酸アンモニウム((NH4)2SO4:硫安)として回収することを特徴とする請求項7に記載の希硫酸製造装置。
- 前記アンモニアは、アンモニア水で二酸化硫黄を吸収する場合と、脱硫廃液中に含まれるアンモニアで二酸化硫黄を吸収する場合があり、後者の脱硫廃液を前記未反応の二酸化硫黄との反応後少なくとも一部を前記原料としてリサイクルさせることを特徴とする請求項8に記載の希硫酸製造装置。
- 前記燃焼手段は、一部が開口した格子状レンガを内部に備えた燃焼炉であることを特徴とする請求項1に記載の希硫酸製造装置。
- 前記反応手段は、前記触媒が五酸化バナジウム(V2O5)であり、脱硝機能を兼ねることを特徴とする請求項1に記載の希硫酸製造装置。
- 前記反応手段は、前記触媒に加えて助触媒として酸化チタン(TiO2)を含む脱硝触媒を更に備えることを特徴とする請求項11に記載の希硫酸製造装置。
- 前記反応手段は、複数段に設置した前記触媒を備え、複数段のうち前段の前記触媒による前記硫黄酸化物の前記酸化による発熱反応で昇温する転化後ガスに、外部から誘引した大気を直接混合させて、後段の触媒反応に適する温度にまで降下させることで、熱交換器に依らずに前記転化後ガスの温度を低下させることを特徴とする請求項1に記載の希硫酸製造装置。
- 前記反応手段は、前記転化後ガスを熱交換器により間接的に冷却する間接冷却手段と前記大気の直接混合による冷却を併用することを特徴とする請求項13に記載の希硫酸製造装置。
- 前記燃焼手段は、5000kJ/kg未満の原料に前記酸素含有ガスを供給して燃焼し、5000kJ/kg以上の原料及び助燃剤を供給する場合には当該助燃剤に空気を供給して燃焼することを特徴とする請求項1に記載の希硫酸製造装置。
- 前記燃焼手段は、5000kJ/kg未満の原料に前記酸素含有ガスを供給して燃焼し、前記5000kJ/kg未満の原料が少ない場合には、5000kJ/kg以上の原料や助燃剤であっても、酸素含有ガスを供給して燃焼することを特徴とする請求項1に記載の希硫酸製造装置。
- 前記希硫酸生成手段は、硫酸水溶液の温度を上下に制御することで希硫酸の濃度を調整することを特徴とする請求項1に記載の希硫酸製造装置。
- 前記希硫酸生成手段で生成された希硫酸の濃度を70~80重量%に濃縮する硫酸濃縮手段を更に備えることを特徴とする請求項1に記載の希硫酸製造装置。
- 前記希硫酸生成手段は、生成した硫酸水溶液を使用して前記反応ガスを直接接触冷却しており、前記反応ガスを間接冷却するための設備を有していないことを特徴とする請求項1に記載の希硫酸製造装置。
- 前記冷却手段は、ボイラを有する排熱ボイラであり、該排熱ボイラは、
前記ボイラ内に水を供給する給水手段と、
前記燃焼ガスで前記水を蒸発させて蒸気を発生させて熱交換により前記燃焼ガスを冷却する熱交換手段と、を備えることを特徴とする請求項1に記載の希硫酸製造装置。 - 前記排熱ボイラは、
前記ボイラの出口温度の変動に対して前記出口温度を一定にするためのボイラバイパスと調節弁とを含む出口温度調整手段と、を更に備えることを特徴とする請求項20に記載の希硫酸製造装置。 - 前記希硫酸生成手段において、原料の水分量を調整することで前記燃焼手段から前記希硫酸生成手段までにおいて水を添加することなく、前記希硫酸生成手段で生成する希硫酸の濃度を調整することを特徴とする請求項1に記載の希硫酸製造装置。
- 硫黄分と、窒素分と、40~80重量%以上の水分とを少なくとも含む原料を供給する原料供給工程と、
酸素濃度が22~40体積%の酸素含有ガスを生成する酸素含有ガス生成工程と、
前記酸素含有ガスで前記原料を燃焼して硫黄酸化物(SOx:ここで、1≦x<3)と10体積%以上の水分とを含む燃焼ガスを生成する燃焼工程と、
前記燃焼ガスを冷却する冷却工程と、
前記硫黄酸化物(SOx)を触媒により酸化して三酸化硫黄(SO3)を含む反応ガスを生成する反応工程と、
前記反応ガスを冷却して希硫酸を生成する希硫酸生成工程と、を含み、少なくとも前記燃焼工程から前記希硫酸生成工程までにおいて水を添加することなく、前記原料の水分のみで90重量%未満の希硫酸を生成することを特徴とする希硫酸製造方法。 - 前記酸素含有ガス生成工程で生成した酸素濃度が22~40体積%の前記酸素含有ガスを使用して前記原料を燃焼することで、前記燃焼手段で生成する前記燃焼ガスの窒素酸化物の量を、酸素濃度21体積%の空気を使用して同一の条件で前記原料を燃焼したと仮定したときに生成する燃焼ガスの窒素酸化物の量よりも少なくすることを特徴とする請求項23に記載の希硫酸製造方法。
- 少なくとも前記燃焼工程と前記反応工程との間において脱硝のための設備を有していないことを特徴とする請求項23に記載の希硫酸製造方法。
- 前記燃焼工程が900~1100℃で前記原料を燃焼することを特徴とする請求項23に記載の希硫酸製造方法。
- 前記燃焼工程が1050℃以下の温度で前記原料を燃焼することを特徴とする請求項26に記載の希硫酸製造方法。
- 前記燃焼工程は、
前記酸素含有ガス生成工程から導入される前記酸素含有ガスの酸素濃度が22~30体積%の範囲内であり、
前記燃焼工程で生成した前記燃焼ガス中の酸素濃度が2.0~7.0体積%の範囲内であることを特徴とする請求項23に記載の希硫酸製造方法。 - 前記希硫酸生成工程における未反応の二酸化硫黄を除去するガス除去工程を更に備えることを特徴とする請求項23に記載の希硫酸製造方法。
- 前記ガス除去工程は、前記未反応の二酸化硫黄とアンモニアとを反応させて亜硫酸アンモニウム((NH4)2SO3:亜硫安)を生成させ、酸化により硫酸アンモニウム((NH4)2SO4:硫安)として回収することを特徴とする請求項29に記載の希硫酸製造方法。
- 前記アンモニアは、アンモニア水で二酸化硫黄を吸収する場合と、脱硫廃液中に含まれるアンモニアで二酸化硫黄を吸収する場合があり、後者の脱硫廃液を前記未反応の二酸化硫黄との反応後前記原料としてリサイクルさせることを特徴とする請求項30に記載の希硫酸製造方法。
- 前記燃焼工程は、一部が開口した格子状レンガを内部に備えた燃焼炉を使用することを特徴とする請求項23に記載の希硫酸製造方法。
- 前記反応工程は、前記触媒が五酸化バナジウム(V2O5)であり、脱硝機能を兼ねることを特徴とする請求項23に記載の希硫酸製造方法。
- 前記反応工程は、前記触媒に加えて助触媒として酸化チタン(TiO2)を含む脱硝触媒を更に備えることを特徴とする請求項33に記載の希硫酸製造方法。
- 前記反応工程は、複数段に設置した前記触媒を備え、複数段のうち前段の前記触媒による前記硫黄酸化物の前記酸化による発熱反応で昇温する転化後ガスに、外部から誘引した大気を直接混合させて、後段の触媒反応に適する温度にまで降下させることで、熱交換器に依らずに前記転化後ガスの温度を低下させることを特徴とする請求項23に記載の希硫酸製造方法。
- 前記反応工程は、前記転化後ガスを熱交換器により間接的に冷却する間接冷却工程と前記大気の直接混合による冷却を併用することを特徴とする請求項23に記載の希硫酸製造方法。
- 前記燃焼工程は、5000kJ/kg未満の原料に前記酸素含有ガスを供給して燃焼し、5000kJ/kg以上の原料及び助燃剤を供給する場合には当該助燃剤に空気を供給して燃焼することを特徴とする請求項23に記載の希硫酸製造方法。
- 前記燃焼工程は、5000kJ/kg未満の原料に前記酸素含有ガスを供給して燃焼し、前記5000kJ/kg未満の原料が少ない場合には、5000kJ/kg以上の原料や助燃剤であっても、酸素含有ガスを供給して燃焼することを特徴とする請求項23に記載の希硫酸製造方法。
- 前記希硫酸生成工程は、硫酸水溶液の温度を上下に制御することで希硫酸の濃度を調整することを特徴とする請求項23に記載の希硫酸製造方法。
- 前記希硫酸生成工程で生成された希硫酸の濃度を70~80重量%に濃縮する硫酸濃縮工程を更に備えることを特徴とする請求項23に記載の希硫酸製造方法。
- 前記希硫酸生成工程は、生成した硫酸水溶液を使用して前記反応ガスを直接接触冷却しており、前記反応ガスを間接冷却するための設備を有していないことを特徴とする請求項23に記載の希硫酸製造方法。
- 前記冷却工程は、ボイラを有する排熱ボイラを使用し、該排熱ボイラは、
前記ボイラ内に水を供給する給水工程と、
前記燃焼ガスで前記水を蒸発させて蒸気を発生させて熱交換により前記燃焼ガスを冷却する熱交換工程と、を備えることを特徴とする請求項23に記載の希硫酸製造方法。 - 前記排熱ボイラは、前記ボイラの出口温度の変動に対して前記出口温度を一定にするためのボイラバイパスと調節弁とを含む出口温度調整工程と、を更に備えることを特徴とする請求項42に記載の希硫酸製造方法。
- 前記希硫酸生成工程において、原料の水分量を調整することで前記燃焼工程から前記希硫酸生成工程までにおいて水を添加することなく、前記希硫酸生成工程で生成する希硫酸の濃度を調整することを特徴とする請求項23に記載の希硫酸製造方法。
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Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4411781B1 (ja) * | 1965-12-22 | 1969-05-29 | ||
JPS4723391A (ja) * | 1971-03-02 | 1972-10-12 | ||
JPS5547210A (en) * | 1978-09-26 | 1980-04-03 | Hitachi Zosen Corp | Production of sulfuric acid |
JPS5717410A (en) * | 1980-07-02 | 1982-01-29 | Hitachi Zosen Corp | Feeding method for oxygen in manufacturing process for sulfuric acid |
JPS5727135A (en) * | 1980-07-25 | 1982-02-13 | Mitsubishi Heavy Ind Ltd | Waste gas treating catalyst |
JPH01160809A (ja) | 1987-12-17 | 1989-06-23 | Mitsubishi Heavy Ind Ltd | 硫酸製造方法 |
JP2519691B2 (ja) | 1985-09-30 | 1996-07-31 | ザ・ビ−オ−シ−・グル−プ・ピ−エルシ− | 硫酸製造の方法および装置 |
JPH1095603A (ja) * | 1996-09-24 | 1998-04-14 | Mitsui Eng & Shipbuild Co Ltd | 廃硫酸からの硫酸回収方法および硫酸回収装置 |
JPH1135958A (ja) * | 1997-07-18 | 1999-02-09 | Ebara Corp | 低品質炭の有価物製造法 |
CN103172087A (zh) * | 2011-12-26 | 2013-06-26 | 宁波科新化工工程技术有限公司 | 煤气湿式氧化脱硫硫浆制硫酸或制硫铵的方法 |
JP2013539006A (ja) * | 2010-09-30 | 2013-10-17 | ハルドール・トプサー・アクチエゼルスカベット | 廃熱ボイラー |
CN109384200A (zh) * | 2018-12-27 | 2019-02-26 | 中冶焦耐(大连)工程技术有限公司 | 处理焦炉煤气脱硫产低纯硫磺及副盐废液的工艺及装置 |
CN110282606A (zh) | 2019-07-05 | 2019-09-27 | 科洋环境工程(上海)有限公司 | 含水硫膏和脱硫废液的湿法处理系统和工艺 |
JP2021031305A (ja) * | 2019-08-14 | 2021-03-01 | 日本管機工業株式会社 | 希硫酸製造装置及び希硫酸製造方法 |
-
2021
- 2021-02-10 WO PCT/JP2021/004925 patent/WO2022172354A1/ja active Application Filing
-
2022
- 2022-02-04 WO PCT/JP2022/004391 patent/WO2022172864A1/ja active Application Filing
- 2022-02-04 JP JP2022580603A patent/JPWO2022172864A1/ja active Pending
- 2022-02-04 EP EP22752691.0A patent/EP4292980A1/en active Pending
- 2022-02-04 KR KR1020237030661A patent/KR20230142786A/ko unknown
- 2022-02-04 CN CN202280014193.9A patent/CN116917229A/zh active Pending
- 2022-02-10 TW TW111104921A patent/TW202246168A/zh unknown
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4411781B1 (ja) * | 1965-12-22 | 1969-05-29 | ||
JPS4723391A (ja) * | 1971-03-02 | 1972-10-12 | ||
JPS5547210A (en) * | 1978-09-26 | 1980-04-03 | Hitachi Zosen Corp | Production of sulfuric acid |
JPS5717410A (en) * | 1980-07-02 | 1982-01-29 | Hitachi Zosen Corp | Feeding method for oxygen in manufacturing process for sulfuric acid |
JPS5727135A (en) * | 1980-07-25 | 1982-02-13 | Mitsubishi Heavy Ind Ltd | Waste gas treating catalyst |
JP2519691B2 (ja) | 1985-09-30 | 1996-07-31 | ザ・ビ−オ−シ−・グル−プ・ピ−エルシ− | 硫酸製造の方法および装置 |
JPH01160809A (ja) | 1987-12-17 | 1989-06-23 | Mitsubishi Heavy Ind Ltd | 硫酸製造方法 |
JPH1095603A (ja) * | 1996-09-24 | 1998-04-14 | Mitsui Eng & Shipbuild Co Ltd | 廃硫酸からの硫酸回収方法および硫酸回収装置 |
JPH1135958A (ja) * | 1997-07-18 | 1999-02-09 | Ebara Corp | 低品質炭の有価物製造法 |
JP2013539006A (ja) * | 2010-09-30 | 2013-10-17 | ハルドール・トプサー・アクチエゼルスカベット | 廃熱ボイラー |
CN103172087A (zh) * | 2011-12-26 | 2013-06-26 | 宁波科新化工工程技术有限公司 | 煤气湿式氧化脱硫硫浆制硫酸或制硫铵的方法 |
CN109384200A (zh) * | 2018-12-27 | 2019-02-26 | 中冶焦耐(大连)工程技术有限公司 | 处理焦炉煤气脱硫产低纯硫磺及副盐废液的工艺及装置 |
CN110282606A (zh) | 2019-07-05 | 2019-09-27 | 科洋环境工程(上海)有限公司 | 含水硫膏和脱硫废液的湿法处理系统和工艺 |
JP2021031305A (ja) * | 2019-08-14 | 2021-03-01 | 日本管機工業株式会社 | 希硫酸製造装置及び希硫酸製造方法 |
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EP4292980A1 (en) | 2023-12-20 |
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