JPH1095603A - Recovery of sulfuric acid from waste sulfuric acid and apparatus for recovering sulfuric acid - Google Patents
Recovery of sulfuric acid from waste sulfuric acid and apparatus for recovering sulfuric acidInfo
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- JPH1095603A JPH1095603A JP8251751A JP25175196A JPH1095603A JP H1095603 A JPH1095603 A JP H1095603A JP 8251751 A JP8251751 A JP 8251751A JP 25175196 A JP25175196 A JP 25175196A JP H1095603 A JPH1095603 A JP H1095603A
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- JP
- Japan
- Prior art keywords
- sulfuric acid
- waste
- recovering
- decomposition
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、廃硫酸からの硫酸
回収方法および硫酸回収装置に係り、特に、メチルメタ
クリレート（ＭＭＡ）の製造プロセスにおけるアミド化
工程で発生する廃硫酸から硫酸を回収するのに好適な廃
硫酸からの硫酸回収方法および硫酸回収装置に関する。The present invention relates to a method and an apparatus for recovering sulfuric acid from waste sulfuric acid, and more particularly to a method for recovering sulfuric acid from waste sulfuric acid generated in an amidation step in a process for producing methyl methacrylate (MMA). The present invention relates to a method for recovering sulfuric acid from waste sulfuric acid and an apparatus for recovering sulfuric acid, which are suitable for the invention.
【０００２】[0002]
【従来の技術】産業廃棄物には各種廃硫酸があり、例え
ば、石油精製工業で発生する硫酸スラッジをはじめと
し、合成繊維工業、鉄鋼業、一般化学工業等においても
硫酸を消費すれば必ず廃硫酸が発生する。これらの廃硫
酸は、それぞれ工場内で硫安、芒硝、石膏等の形態で回
収されるか、中和処理後廃棄されるか、またはそのまま
河川もしくは海洋に廃棄されていた。2. Description of the Related Art Industrial wastes include various types of waste sulfuric acid. For example, sulfuric acid sludge generated in the petroleum refining industry, as well as the synthetic fiber industry, the steel industry, the general chemical industry, etc., if sulfuric acid is consumed, must be eliminated. Sulfuric acid is generated. These waste sulfuric acids have been recovered in the factory in the form of ammonium sulfate, sodium sulfate, gypsum, etc., or discarded after neutralization, or have been discarded directly in rivers or oceans.
【０００３】メチルメタクリレート（ＭＭＡ）の製造プ
ロセスにおいても廃硫酸が発生する。すなわちメチルメ
タクリレート（ＭＭＡ）は、例えばアセトンシアンヒド
リン法（ＡＣＨ法）により、ＡＣＨ合成工程、アミド化
工程およびエステル化工程を経て分離精製されるが、前
記アミド化工程において多量の濃硫酸が使用されるの
で、多量の廃硫酸が発生する。この廃硫酸の処理方法の
一例としては、図２に装置系統図を示したように、主と
して燃焼分解炉における廃硫酸分解工程、廃熱ボイ
ラによる分解ガスからの熱回収工程、増湿塔、冷却塔
および湿式集塵器等による分解ガスの冷却洗浄精製工程
および乾燥塔、転化器、吸収塔等によるＳＯ2 をＳＯ
3 に転化したのち吸収して濃硫酸を製造する工程とから
なる方法があげられる。[0003] Waste sulfuric acid is also generated in the process of producing methyl methacrylate (MMA). That is, methyl methacrylate (MMA) is separated and purified, for example, by an acetone cyanohydrin method (ACH method) through an ACH synthesis step, an amidation step and an esterification step, and a large amount of concentrated sulfuric acid is used in the amidation step. Therefore, a large amount of waste sulfuric acid is generated. As an example of this waste sulfuric acid treatment method, as shown in the apparatus system diagram in FIG. 2, a waste sulfuric acid decomposition step in a combustion cracking furnace, a heat recovery step from cracked gas by a waste heat boiler, a humidification tower, a cooling tower Cooling / cleaning process of decomposed gas by a tower and a wet dust collector, etc. and SO 2 by a drying tower, a converter, an absorption tower, etc.
And then absorbing and producing concentrated sulfuric acid.
【０００４】ＭＭＡ製造プロセスのアミド化工程で発生
した、例えば１０〜２０％の硫酸、３０〜５０％の酸性
硫安、数％の有機物、数１００ｐｐｍの無機塩類および
水からなる廃硫酸は、原料廃硫酸１１として燃焼分解炉
１に導入され、例えば液体燃料を燃焼して形成された還
元性の高温火柱状のガス流中に噴射されて分解し、例え
ば次式に示すようにＳＯ2 またはＳＯ3 を発生する。[0004] Waste sulfuric acid generated in the amidation step of the MMA production process, for example, consisting of 10 to 20% sulfuric acid, 30 to 50% acid ammonium sulfate, several percent of organic substances, several hundred ppm of inorganic salts and water is used as raw material waste. Sulfuric acid 11 is introduced into the combustion decomposition furnace 1, and is injected and decomposed into, for example, a reducing high-temperature column-shaped gas stream formed by burning a liquid fuel, for example, SO 2 or SO 3 as shown in the following equation. Occurs.
【０００５】Ｈ2 ＳＯ4 →Ｈ2 Ｏ＋ＳＯ3 ＮＨ4 ＨＳＯ4 →ＮＨ3 ＋Ｈ2 Ｏ＋ＳＯ3 （ＮＨ4 ）2 ＳＯ4 →２ＮＨ3 ＋Ｈ2 Ｏ＋ＳＯ3 ＮＨ4 ＨＳＯ3 →ＮＨ3 ＋Ｈ2 Ｏ＋ＳＯ2 （ＮＨ4 ）2 ＳＯ3 →２ＮＨ3 ＋Ｈ2 Ｏ＋ＳＯ2 ＳＯ2 、ＳＯ3 等を含有する分解ガスは、例えば１００
０〜１１００℃で後流の廃熱ボイラ２に導入され、ここ
で例えば４００℃まで冷却される。このとき、例えば５
０ｋｇ／ｃｍ2 Ｇ程度の高圧水蒸気１６が得られる。H 2 SO 4 → H 2 O + SO 3 NH 4 HSO 4 → NH 3 + H 2 O + SO 3 (NH 4 ) 2 SO 4 → 2NH 3 + H 2 O + SO 3 NH 4 HSO 3 → NH 3 + H 2 O + SO 2 (NH 4 ) The decomposition gas containing 2 SO 3 → 2NH 3 + H 2 O + SO 2 SO 2 , SO 3, etc. is, for example, 100
At 0 to 1100 ° C., it is introduced into the downstream waste heat boiler 2 where it is cooled to, for example, 400 ° C. At this time, for example, 5
High pressure steam 16 of about 0 kg / cm 2 G is obtained.
【０００６】熱回収された分解ガスは、順次、後流の増
湿塔４、冷却塔５および湿式集塵器６に導入されて常温
付近まで冷却されるとともに、除塵される。このときＳ
Ｏ3その他の成分を洗浄吸収した多量の凝縮水が発生
し、廃棄硫酸１４として系外に抜き取られる。この廃棄
硫酸１４は、原料廃硫酸１１の、例えば７０％程度の容
量を占め、硫酸濃度は、例えば３．５％程度であるが、
灰分、酸化鉄等のダストを多量に含んでいるので上質で
はないという理由から、硫酸回収されることなく、例え
ば中和沈殿処理される。The heat-recovered cracked gas is successively introduced into the downstream humidification tower 4, cooling tower 5, and wet dust collector 6, where it is cooled to near room temperature and is dust-removed. Then S
A large amount of condensed water generated by washing and absorbing O 3 and other components is generated, and is extracted out of the system as waste sulfuric acid 14. The waste sulfuric acid 14 occupies, for example, about 70% of the capacity of the raw material waste sulfuric acid 11, and the sulfuric acid concentration is, for example, about 3.5%.
Since it contains a large amount of dust such as ash and iron oxide, it is not of high quality.
【０００７】一方、洗浄された分解ガスは、後流の乾燥
塔７に流入して乾燥された後、転化器８に流入し、ここ
で分解ガスに含まれるＳＯ2 が、例えば五酸化バナジウ
ム触媒の存在下でＳＯ3 に転化する。ＳＯ3 含有分解ガ
スは、後流の吸収塔９に流入し、ここでＳＯ3 が濃硫酸
と接触して吸収され、回収硫酸１２として回収される。
吸収塔９から流出する排ガスは、別途洗浄、脱硫処理さ
れたのち大気に放出される。On the other hand, the washed cracked gas flows into a downstream drying tower 7 to be dried and then flows into a converter 8, where SO 2 contained in the cracked gas is converted into, for example, a vanadium pentoxide catalyst. To SO 3 in the presence of The SO 3 -containing cracked gas flows into the downstream absorption tower 9, where the SO 3 comes into contact with concentrated sulfuric acid, is absorbed, and is recovered as recovered sulfuric acid 12.
The exhaust gas flowing out of the absorption tower 9 is separately washed and desulfurized and then released to the atmosphere.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、上記従
来技術では、原料廃硫酸に含まれるダストの大部分が洗
浄精製工程から排出される廃棄硫酸と共に排出されるの
で、該廃棄硫酸の性状が粗悪となり、硫酸を回収するこ
となく廃棄するか、または多大な費用をかけて廃液処理
もしくは処分しなければならならず、硫酸回収率の向上
およびコストの低減を図るうえで大きな問題となってい
た。However, according to the above-mentioned prior art, most of the dust contained in the raw sulfuric acid is discharged together with the sulfuric acid discharged from the washing and refining process. In addition, the sulfuric acid must be discarded without being collected, or the waste liquid must be treated or disposed at a large cost, which has been a major problem in improving the sulfuric acid recovery rate and reducing the cost.
【０００９】[0009]
【課題を解決するための手段】本発明の目的は、上記従
来技術の問題点を解決し、硫酸回収率を向上させるとと
もに、系外に排出する総廃棄物量を低減して総コストの
低減を図ることができる、廃硫酸からの硫酸回収方法お
よび硫酸回収装置を提供することにある。上記目的を達
成するため、本願で特許請求する発明は以下のとおりで
ある。 （１）廃硫酸を熱分解する廃硫酸燃焼分解工程と、分解
生成ガスの熱量を回収する熱回収工程と、熱回収後の分
解ガスを清浄する洗浄精製工程と、清浄後の分解ガスに
含まれるＳＯ2 をＳＯ3 に転化したのち硫酸で吸収する
硫酸製造工程とを有する廃硫酸からの硫酸回収方法にお
いて、前記熱回収後の分解ガスを乾式集塵器に導入して
同伴固形分を除去したのち後流の洗浄精製工程に送ると
ともに、該洗浄精製工程から排出される硫酸含有排液を
濃縮したのち後流の硫酸製造工程に導入するか、または
前記廃硫酸燃焼分解工程にリサイクルすることを特徴と
する廃硫酸からの硫酸回収方法。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, improve the sulfuric acid recovery rate, and reduce the total amount of waste discharged outside the system to reduce the total cost. An object of the present invention is to provide a method for recovering sulfuric acid from waste sulfuric acid and a device for recovering sulfuric acid, which can be achieved. To achieve the above object, the invention claimed in the present application is as follows. (1) Waste sulfuric acid combustion and decomposition step for thermally decomposing waste sulfuric acid, heat recovery step for recovering the calorie of the decomposition product gas, cleaning and purification step for cleaning the decomposition gas after heat recovery, and the cleaning gas contained in the purified gas the SO 2 in the sulfate process for recovering from a waste sulfuric acid having a sulfuric acid production process of absorption with sulfuric acid after conversion to SO 3 that is, remove entrained solids by introducing decomposition gas after the heat recovery in a dry dust collector After that, it is sent to the downstream washing and purification step, and the sulfuric acid-containing effluent discharged from the washing and purification step is concentrated and then introduced into the downstream sulfuric acid production step, or recycled to the waste sulfuric acid combustion decomposition step. A method for recovering sulfuric acid from waste sulfuric acid, comprising:
【００１０】（２）前記硫酸含有排液を前記熱回収工程
で発生する水蒸気を用いて間接加熱して濃縮したのち後
流の硫酸製造工程に導入するか、または前記廃硫酸燃焼
分解工程にリサイクルすることを特徴とする上記（１）
記載の廃硫酸からの硫酸回収方法。 （３）メチルメタクリレート（ＭＭＡ）製造工程から排
出される廃硫酸を原料廃硫酸として用い、かつ回収され
た硫酸を前記ＭＭＡ製造工程に用いることを特徴とする
上記（１）または（２）記載の廃硫酸からの硫酸回収方
法。(2) The sulfuric acid-containing effluent is concentrated by indirect heating using steam generated in the heat recovery step and then introduced into a downstream sulfuric acid production step, or recycled to the waste sulfuric acid combustion and decomposition step. (1) characterized in that:
The method for recovering sulfuric acid from waste sulfuric acid as described in the above. (3) The method according to the above (1) or (2), wherein the waste sulfuric acid discharged from the methyl methacrylate (MMA) production step is used as a raw material waste sulfuric acid, and the recovered sulfuric acid is used in the MMA production step. Method for recovering sulfuric acid from waste sulfuric acid.
【００１１】（４）廃硫酸を熱分解する燃焼分解手段
と、分解生成ガスの熱量を回収する熱回収手段と、熱回
収後の分解ガスを清浄する洗浄精製手段と、清浄後の分
解ガスに含まれるＳＯ2 をＳＯ3 に転化したのち硫酸で
吸収する硫酸製造手段とを有する廃硫酸からの硫酸回収
装置において、前記熱回収手段の後流に熱回収後の分解
ガスに含まれる同伴固形分を除去したのち後流の洗浄精
製手段に送る乾式集塵手段を設けるとともに、前記洗浄
精製手段から排出された硫酸含有排液を濃縮して後流の
硫酸製造手段に導入するかまたは前記廃硫酸燃焼分解手
段にリサイクルする硫酸濃縮手段を設けたことを特徴と
する廃硫酸からの硫酸回収装置。 （５）前記硫酸濃縮手段が、前記硫酸含有排液を前記熱
回収手段で発生した水蒸気を用いて間接加熱して濃縮す
るものであることを特徴とする上記（４）記載の廃硫酸
からの硫酸回収装置。(4) Combustion decomposition means for thermally decomposing waste sulfuric acid, heat recovery means for recovering the calorie of the decomposition product gas, cleaning and purifying means for cleaning the decomposition gas after heat recovery, in sulfuric acid recovery apparatus from waste sulfuric acid having a sulfuric acid production unit the SO 2 is absorbed in sulfuric acid after converted to SO 3 contained, entrained solids contained in the decomposed gas after heat recovery on the downstream of the heat recovery means Is provided, and a sulfur-containing wastewater discharged from the cleaning and purifying means is concentrated and introduced into the downstream sulfuric acid producing means, or the waste sulfuric acid is removed. An apparatus for recovering sulfuric acid from waste sulfuric acid, wherein sulfuric acid concentrating means for recycling is provided in the combustion decomposition means. (5) The sulfuric acid concentrating means is for indirectly heating and concentrating the sulfuric acid-containing effluent using steam generated by the heat recovery means, wherein Sulfuric acid recovery device.
【００１２】本発明において、熱回収後の分解ガスを清
浄する洗浄精製手段としては、例えば水をスプレーする
冷却塔および湿式集塵器が好適に用いられる。また冷却
塔は、例えば廃熱回収後の、例えば４００℃の分解ガス
を、例えば８０℃まで冷却する増湿塔と、該増湿塔出口
分解ガスを、例えば４０℃まで冷却する冷却塔とで構成
される。湿式集塵器としては、ヒューム状の硫酸を確実
に捕集することができる、例えばミストコットレル等の
湿式電気集塵装置が用いられる。In the present invention, for example, a cooling tower for spraying water and a wet dust collector are preferably used as cleaning and purifying means for purifying decomposed gas after heat recovery. Further, the cooling tower is, for example, a humidification tower that cools the decomposition gas at, for example, 400 ° C. after waste heat recovery to, for example, 80 ° C., and a cooling tower that cools the decomposition gas at the humidification tower outlet to, for example, 40 ° C. Be composed. As the wet dust collector, for example, a wet electric dust collector such as a mist cotter, which can surely collect fume-like sulfuric acid, is used.
【００１３】本発明において、熱回収手段の後流に設け
られる乾式集塵手段としては、例えば乾式電気集塵器が
好適に用いられる。乾式電気集塵器で捕集された、例え
ば灰分、酸化鉄分等の固形物は回収ダストとして系外に
排出され、例えば別途埋め立て等に利用される。本発明
において、洗浄精製工程から排出される硫酸含有排液を
濃縮する硫酸濃縮手段としては、例えば前記硫酸含有排
液を、減圧下に水蒸気によって、例えば３段階に間接加
熱する間接加熱装置があげられ、例えば硫酸濃度５％の
希硫酸は硫酸濃度９７％の濃硫酸に濃縮される。硫酸含
有排液を間接加熱する水蒸気としては、熱回収手段とし
ての廃熱回収ボイラで生成された高圧水蒸気を用いるこ
とが好ましい。In the present invention, as the dry dust collecting means provided downstream of the heat recovery means, for example, a dry electric dust collector is preferably used. Solid matter, such as ash and iron oxide, collected by the dry electric precipitator is discharged out of the system as collected dust, and is used, for example, separately for landfill. In the present invention, examples of the sulfuric acid concentrating means for concentrating the sulfuric acid-containing effluent discharged from the washing and purifying step include, for example, an indirect heating device that indirectly heats the sulfuric acid-containing effluent with steam under reduced pressure, for example, in three stages. For example, dilute sulfuric acid having a sulfuric acid concentration of 5% is concentrated into concentrated sulfuric acid having a sulfuric acid concentration of 97%. As the steam for indirectly heating the sulfuric acid-containing effluent, it is preferable to use high-pressure steam generated by a waste heat recovery boiler as heat recovery means.
【００１４】本発明方法および装置は、ダスト等の不純
物含有量が比較的少ない廃硫酸から硫酸を回収するのに
好適であり、例えばＭＭＡ製造プロセスにおけるアミド
化工程から排出される廃硫酸からの硫酸の回収に適して
いる。The method and apparatus of the present invention are suitable for recovering sulfuric acid from waste sulfuric acid having a relatively low content of impurities such as dust. For example, sulfuric acid from waste sulfuric acid discharged from an amidation step in an MMA production process is suitable. Suitable for collecting
【００１５】[0015]
【発明の実施の形態】次に本発明を実施例によりさらに
詳細に説明する。図１は、本発明の一実施例である廃硫
酸からの硫酸回収方法を示す装置系統図である。この装
置が図２の従来技術と異なるところは、廃熱ボイラ２
と、増湿塔４、冷却塔５および湿式集塵器６からなる洗
浄精製装置との間に乾式集塵手段として乾式電気集塵器
３を設け、かつ前記増湿塔４、冷却塔５および湿式集塵
器６からなる洗浄精製装置から排出される硫酸含有排液
（以下、希硫酸１５ともいう）を濃縮して後流の、乾燥
塔７、転化器８および吸収塔９からなる硫酸製造装置に
導入するか、または燃焼分解炉１にリサイクルする硫酸
濃縮装置１０を設けた点である。Next, the present invention will be described in more detail by way of examples. FIG. 1 is an apparatus system diagram showing a method for recovering sulfuric acid from waste sulfuric acid according to one embodiment of the present invention. This device differs from the prior art of FIG.
A dry electric precipitator 3 is provided as a dry precipitator between the humidifying tower 4, the cooling tower 5 and the washing / purifying device including the wet precipitator 6, and the humidifying tower 4, the cooling tower 5 and The sulfuric acid-containing effluent (hereinafter, also referred to as dilute sulfuric acid 15) discharged from the washing and purifying apparatus including the wet dust collector 6 is concentrated to produce sulfuric acid comprising a drying tower 7, a converter 8, and an absorption tower 9 in the downstream. The point is that a sulfuric acid concentrating device 10 is provided to be introduced into the device or recycled to the combustion cracking furnace 1.
【００１６】このような構成において、例えばＨ2 Ｏ：
３２％、Ｈ2 ＳＯ4 ：１２％、ＮＨ 4 ＨＳＯ4 ：４２
％、（ＮＨ4 ＳＯ3 Ｈ2 Ｃ）2 ＣＯ：１０％および有機
物４％を含む、ＭＭＡ製造プロセスのアミド化工程から
排出された原料廃硫酸１１は、燃焼分解炉１に導入さ
れ、例えば液体燃料として重油を燃焼して形成された還
元性の火柱状のガス流中に噴射されて分解し、例えば
４．３％のＳＯ2 と０．１８％のＳＯ3 の他酸素、炭酸
ガス、窒素、Ｈ2 Ｏ、アンモニウム塩等を含む、例えば
１０００〜１１００℃の分解ガスとなる。In such a configuration, for example, HTwoO:
32%, HTwoSOFour: 12%, NH FourHSOFour: 42
%, (NHFourSOThreeHTwoC)TwoCO: 10% and organic
From the amidation step of the MMA production process containing 4%
The discharged raw material sulfuric acid 11 is introduced into the combustion cracking furnace 1.
For example, the return formed by burning heavy oil as liquid fuel
Injected into the original fire column gas flow and decomposed, for example
4.3% SOTwoAnd 0.18% SOThreeOther oxygen and carbonic acid
Gas, nitrogen, HTwoIncluding O, ammonium salts, etc., for example
It becomes a decomposition gas at 1000 to 1100 ° C.
【００１７】分解ガスは、廃熱回収ボイラ２に流入し、
ここで、熱回収されて、例えば４００℃まで冷却され
る。このとき、回収した熱によって、例えば４０〜６０
ｋｇ／ｃｍ2 Ｇ程度の高圧水蒸気１６が生成される。熱
回収された分解ガスは、後流の乾式電気集塵器３に流入
し、ここで灰分、酸化鉄等の固形分がダスト１３として
分離されて系外に排出される。固形分が除去された分解
ガスは、次いで、洗浄精製装置の一部である増湿塔４に
流入し、例えばスプレー水によって洗浄されて、例えば
８０℃まで冷却されたのち冷却塔５に流入する。冷却塔
５に流入した分解ガスは、例えば同じくスプレー水によ
ってさらに洗浄、冷却されて、例えば４０℃となったの
ち、後流の湿式集塵器６としての、例えばミストコット
レルに流入し、ここで、例えばヒューム状の硫酸分が除
去され、不純物をほとんど含まないＳＯ2 含有ガスとな
る。このとき、洗浄排液として希硫酸１５が得られる。The cracked gas flows into the waste heat recovery boiler 2,
Here, heat is recovered and cooled to, for example, 400 ° C. At this time, for example, 40-60
High-pressure steam 16 of about kg / cm 2 G is generated. The heat-recovered decomposition gas flows into the downstream dry electrostatic precipitator 3 where solids such as ash and iron oxide are separated as dust 13 and discharged out of the system. The decomposed gas from which the solid content has been removed then flows into the humidification tower 4 which is a part of the washing and purifying apparatus, and is washed with, for example, spray water, cooled to, for example, 80 ° C., and then flows into the cooling tower 5. . The decomposed gas that has flowed into the cooling tower 5 is further washed and cooled by, for example, spray water, and reaches, for example, 40 ° C., and then flows into, for example, a mist cotrel as a downstream wet dust collector 6, where , for example, fume-like sulfuric acid content is removed, the SO 2 containing gas containing almost no impurities. At this time, dilute sulfuric acid 15 is obtained as a washing waste liquid.
【００１８】固形分、ＳＯ3 分等が除去された洗浄精製
装置出口の分解ガスは、後流の硫酸製造装置の一部とし
ての乾燥塔７に流入し、例えば濃硫酸と接触して乾燥さ
れた後、転化器８に流入し、ここで、例えば五酸化バナ
ジウム触媒等の酸化触媒の存在下でＳＯ2 がＳＯ3 に転
化される。次いでＳＯ3 を含む分解ガスは後流の吸収塔
９に流入し、濃硫酸と接触して吸収、回収される。濃硫
酸の一部は回収硫酸１２として系外に抜き出されるが、
他の一部は乾燥塔７に循環されて、例えば転化前の分解
ガスの乾燥に使用される。The decomposed gas at the outlet of the washing and purifying apparatus from which solids, SO 3 and the like have been removed flows into a drying tower 7 as a part of a downstream sulfuric acid producing apparatus, and is dried by contacting with, for example, concentrated sulfuric acid. after it flows into the converter 8, wherein, SO 2 is converted to SO 3 in the presence of an oxidation catalyst such as, for example, vanadium pentoxide catalyst. Next, the cracked gas containing SO 3 flows into the absorption tower 9 downstream, and is absorbed and recovered by contact with concentrated sulfuric acid. Part of the concentrated sulfuric acid is extracted out of the system as recovered sulfuric acid 12,
The other part is circulated to the drying tower 7 and used, for example, for drying cracked gas before conversion.
【００１９】増湿塔４、冷却塔５および湿式集塵器６か
らなる洗浄精製装置から排出された、希硫酸１５（例え
ば硫酸濃度５％）は、硫酸濃縮装置１０に流入し、例え
ば５０〜６０Ｔｏｒｒの減圧下、前記廃熱回収ボイラ２
で生成された高圧水蒸気１６を、例えば１５８℃、５ｋ
ｇ／ｃｍ2 Ｇ程度に調整した蒸気によって、例えば３段
階で間接加熱されて例えば９７％の濃硫酸１７となる。
得られた濃硫酸１７は、後流の硫酸製造装置の一部であ
る、例えば乾燥塔７に導入され、分解ガスの乾燥および
ＳＯ3 の吸収に供される。Dilute sulfuric acid 15 (for example, sulfuric acid concentration of 5%) discharged from the washing and purifying apparatus including the humidifying tower 4, the cooling tower 5, and the wet dust collector 6 flows into the sulfuric acid concentrating apparatus 10 and, for example, 50 to 50%. Under reduced pressure of 60 Torr, the waste heat recovery boiler 2
High-pressure steam 16 generated at 158 ° C., 5 k
The steam adjusted to about g / cm 2 G is indirectly heated in, for example, three stages to give 97% concentrated sulfuric acid 17, for example.
The obtained concentrated sulfuric acid 17 is introduced into, for example, a drying tower 7 which is a part of a downstream sulfuric acid producing apparatus, and is subjected to drying of a decomposition gas and absorption of SO 3 .
【００２０】本実施例によれば、廃熱回収ボイラ２の後
流に分解ガス中の固形分を分離、除去する乾式電気集塵
器３を設けたことにより、増湿塔４、冷却塔５および湿
式集塵器６からなる洗浄精製装置から排出される硫酸含
有排液がダストを含まない清澄な希硫酸１５となるの
で、該希硫酸１５を濃縮装置１０で濃縮することによ
り、濃硫酸として回収することができる。従って廃棄硫
酸１４として廃棄していた従来技術に較べて硫酸回収率
が著しく向上する。硫酸回収率の向上幅は、分解ガスに
含まれる全ＳＯｘ量に対するＳＯ3 に相当する分だけ、
すなわち、例えば３〜５％向上となる。According to the present embodiment, the humidification tower 4 and the cooling tower 5 are provided by providing the dry electric precipitator 3 for separating and removing solids in the decomposed gas downstream of the waste heat recovery boiler 2. And the sulfuric acid-containing effluent discharged from the cleaning and refining device comprising the wet dust collector 6 becomes clear dilute sulfuric acid 15 containing no dust. Can be recovered. Therefore, the sulfuric acid recovery rate is remarkably improved as compared with the prior art which was discarded as the waste sulfuric acid 14. The improvement in the sulfuric acid recovery rate is equivalent to SO 3 with respect to the total SOx amount contained in the cracked gas,
That is, for example, the improvement is 3 to 5%.
【００２１】本実施例によれば、洗浄精製工程で生じる
硫酸含有排液（希硫酸１５）を濃縮して濃硫酸１７とし
て回収することができるので、従来必要であった廃棄硫
酸１４の処理設備およびコストが不要となるうえ、全工
程がほぼクローズド化され、系外に排出されるのは、乾
式電気集塵器３で捕集されたダスト１３だけとなる。ま
た、乾式電気集塵器３から排出されるダスト量は、例え
ば３０ｋｇ／ｈｒであり、従来技術において洗浄精製工
程から排出されていた廃棄硫酸１４（例えば１５ｔ／ｈ
ｒ）に較べて著しく減量されるので、廃棄物処理設備を
含む全プロセスの小型化および低コスト化を実現するこ
とができる。According to the present embodiment, the sulfuric acid-containing effluent (dilute sulfuric acid 15) generated in the washing and purifying process can be concentrated and recovered as concentrated sulfuric acid 17, so that the conventional equipment for treating waste sulfuric acid 14 is required. In addition to eliminating the cost, the entire process is almost closed, and only the dust 13 collected by the dry electric precipitator 3 is discharged out of the system. The amount of dust discharged from the dry electrostatic precipitator 3 is, for example, 30 kg / hr, and the waste sulfuric acid 14 (for example, 15 t / h) discharged from the cleaning and refining process in the related art.
Since the weight is remarkably reduced as compared with r), downsizing and cost reduction of the entire process including the waste treatment facility can be realized.
【００２２】本実施例によれば、廃熱回収ボイラ２で得
られた高圧水蒸気１６を硫酸濃縮装置１０の加熱源とし
て使用したことにより、熱利用率が向上し、別途加熱源
を設ける必要はない。According to this embodiment, since the high-pressure steam 16 obtained in the waste heat recovery boiler 2 is used as a heating source of the sulfuric acid concentrator 10, the heat utilization rate is improved, and it is not necessary to provide a separate heating source. Absent.
【００２３】[0023]
【発明の効果】本願の請求項１記載の発明によれば、熱
回収後の分解生成ガスに含まれる固形分を除去したのち
洗浄精製工程に送ることにより、分解ガス中の固形分を
あらかじめ除去して洗浄精製装置から排出される硫酸含
有排液中への固形物の混入を防止することができるの
で、前記硫酸含有排液を濃縮して濃硫酸として回収する
ことができる。従って硫酸回収率が向上するとともに、
廃棄硫酸の処理が不要となりプロセス全体をほぼクロー
ズド化することができる。According to the first aspect of the present invention, the solid content in the decomposition gas after the heat recovery is removed and then sent to the washing and purifying step to remove the solid content in the decomposition gas in advance. As a result, it is possible to prevent the solid matter from being mixed into the sulfuric acid-containing waste liquid discharged from the washing and purifying apparatus, so that the sulfuric acid-containing waste liquid can be concentrated and recovered as concentrated sulfuric acid. Therefore, the sulfuric acid recovery rate is improved,
The treatment of waste sulfuric acid becomes unnecessary, and the entire process can be made almost closed.
【００２４】本願の請求項２記載の発明によれば、硫酸
含有排液の加熱源として熱回収装置で発生する高圧水蒸
気を用いることにより、上記発明の効果に加え、熱利用
率が著しく向上する。本願の請求項３記載の発明によれ
ば、原料廃硫酸としてメチルメタクリレート（ＭＭＡ）
製造工程から排出される廃硫酸を用い、かつ回収された
硫酸を前記ＭＭＡ製造工程に使用するようにしたことに
より、ＭＭＡ製造プロセスにおけるアミド化工程から排
出される廃硫酸から効率よく硫酸を回収して再度ＭＭＡ
製造プロセスのアミド化工程に使用することができるの
で、硫酸消費量が著しく低減し大幅なコストダウンを図
ることができる。According to the second aspect of the present invention, by using high-pressure steam generated in the heat recovery device as a heating source for the sulfuric acid-containing waste liquid, the heat utilization factor is significantly improved in addition to the effect of the above-mentioned invention. . According to the invention of claim 3 of the present application, methyl methacrylate (MMA) is used as the raw material waste sulfuric acid.
By using the waste sulfuric acid discharged from the production step and using the recovered sulfuric acid in the MMA production step, sulfuric acid can be efficiently recovered from the waste sulfuric acid discharged from the amidation step in the MMA production process. MMA again
Since it can be used in the amidation step of the production process, the consumption of sulfuric acid is significantly reduced, and the cost can be significantly reduced.
【００２５】本願の請求項４記載の発明によれば、燃焼
分解手段の後流に乾式集塵手段を設けるとともに、洗浄
精製手段から排出される硫酸含有排液を濃縮して後流の
硫酸製造手段に導入する硫酸濃縮手段を設けたことによ
り、硫酸回収率が向上し、プロセス全体をほぼクローズ
ド化して系外への廃棄物量を著しく低減するとともに、
従来必要であった廃棄硫酸処理設備が不要となる。According to the fourth aspect of the present invention, a dry dust collecting means is provided downstream of the combustion decomposition means, and the sulfuric acid-containing effluent discharged from the washing and purifying means is concentrated to produce the downstream sulfuric acid. By providing sulfuric acid concentrating means to be introduced into the means, sulfuric acid recovery rate is improved, the entire process is almost closed and the amount of waste out of the system is significantly reduced,
The waste sulfuric acid treatment equipment that was conventionally required becomes unnecessary.
【００２６】本願の請求項５記載の発明によれば、熱回
収手段としての廃熱ボイラで回収した高圧水蒸気を、硫
酸濃縮手段における加熱源として使用することにより、
上記発明の効果に加え、熱利用率が大幅に向上する。According to the fifth aspect of the present invention, by using high-pressure steam recovered by a waste heat boiler as heat recovery means as a heating source in sulfuric acid concentrating means,
In addition to the effects of the above invention, the heat utilization rate is greatly improved.
【図１】本発明の一実施例を示す装置系統図。FIG. 1 is a system diagram showing an embodiment of the present invention.
【図２】従来技術を示す説明図。FIG. 2 is an explanatory view showing a conventional technique.
１…燃焼分解炉、２…廃熱ボイラ、３…乾式電気集塵
器、４…増湿塔、５…冷却塔、６…湿式集塵器、７…乾
燥塔、８…転化器、９…吸収塔、１０…硫酸濃縮装置、
１１…原料廃硫酸、１２…回収硫酸、１３…ダスト、１
４…廃棄硫酸、１５…希硫酸、１６…高圧水蒸気、１７
…濃硫酸。DESCRIPTION OF SYMBOLS 1 ... Combustion decomposition furnace, 2 ... Waste heat boiler, 3 ... Dry electric precipitator, 4 ... Humidification tower, 5 ... Cooling tower, 6 ... Wet precipitator, 7 ... Drying tower, 8 ... Converter, 9 ... Absorption tower, 10 ... sulfuric acid concentrator,
11: raw sulfuric acid, 12: recovered sulfuric acid, 13: dust, 1
4 ... Waste sulfuric acid, 15 ... Dilute sulfuric acid, 16 ... High pressure steam, 17
... concentrated sulfuric acid.
Claims (5)
と、分解生成ガスの熱量を回収する熱回収工程と、熱回
収後の分解ガスを清浄する洗浄精製工程と、清浄後の分
解ガスに含まれるＳＯ2 をＳＯ3 に転化したのち硫酸で
吸収する硫酸製造工程とを有する廃硫酸からの硫酸回収
方法において、前記熱回収後の分解ガスを乾式集塵器に
導入して同伴固形分を除去したのち後流の洗浄精製工程
に送るとともに、該洗浄精製工程から排出される硫酸含
有排液を濃縮したのち後流の硫酸製造工程に導入する
か、または前記廃硫酸燃焼分解工程にリサイクルするこ
とを特徴とする廃硫酸からの硫酸回収方法。1. A waste sulfuric acid combustion decomposition step for thermally decomposing waste sulfuric acid, a heat recovery step for recovering the calorific value of a decomposition product gas, a cleaning and purifying step for cleaning the decomposition gas after heat recovery, and a decomposed gas after cleaning in sulfuric acid recovery method from waste sulfuric acid having a sulfuric acid production step of SO 2 absorbed in sulfuric acid after converted to SO 3 contained in the entrained solids by introducing decomposition gas after the heat recovery in a dry dust collector And then sent to the downstream cleaning and purification step, and the sulfuric acid-containing effluent discharged from the cleaning and purification step is concentrated and then introduced into the downstream sulfuric acid production step, or recycled to the waste sulfuric acid combustion and decomposition step. A method for recovering sulfuric acid from waste sulfuric acid.
生する水蒸気を用いて間接加熱して濃縮したのち後流の
硫酸製造工程に導入するか、または前記廃硫酸燃焼分解
工程にリサイクルすることを特徴とする請求項１記載の
廃硫酸からの硫酸回収方法。2. The sulfuric acid-containing effluent is concentrated by indirect heating using steam generated in the heat recovery step and then introduced into a downstream sulfuric acid production step or recycled to the waste sulfuric acid combustion decomposition step. The method for recovering sulfuric acid from waste sulfuric acid according to claim 1, wherein:
程から排出される廃硫酸を原料廃硫酸として用い、かつ
回収された硫酸を前記ＭＭＡ製造工程に用いることを特
徴とする請求項１または２記載の廃硫酸からの硫酸回収
方法。3. The waste according to claim 1, wherein waste sulfuric acid discharged from the methyl methacrylate (MMA) production step is used as raw material waste sulfuric acid, and recovered sulfuric acid is used in the MMA production step. Method for recovering sulfuric acid from sulfuric acid.
解生成ガスの熱量を回収する熱回収手段と、熱回収後の
分解ガスを清浄する洗浄精製手段と、清浄後の分解ガス
に含まれるＳＯ2 をＳＯ3 に転化したのち硫酸で吸収す
る硫酸製造手段とを有する廃硫酸からの硫酸回収装置に
おいて、前記熱回収手段の後流に熱回収後の分解ガスに
含まれる同伴固形分を除去したのち後流の洗浄精製手段
に送る乾式集塵手段を設けるとともに、前記洗浄精製手
段から排出された硫酸含有排液を濃縮して後流の硫酸製
造手段に導入するかまたは前記廃硫酸燃焼分解手段にリ
サイクルする硫酸濃縮手段を設けたことを特徴とする廃
硫酸からの硫酸回収装置。4. Combustion decomposition means for thermally decomposing waste sulfuric acid, heat recovery means for recovering the calorific value of the decomposition product gas, cleaning and purifying means for cleaning the decomposition gas after heat recovery, and the cleaning gas contained in the purified gas in sulfuric acid recovery apparatus from waste sulfuric acid having a sulfuric acid production unit the SO 2 is absorbed in sulfuric acid after conversion to SO 3 that is, the entrained solids contained in the decomposed gas after heat recovery on the downstream of the heat recovery means A dry dust collecting means is provided after removal and sent to a downstream cleaning and purifying means, and a sulfuric acid-containing effluent discharged from the cleaning and purifying means is concentrated and introduced into a downstream sulfuric acid producing means or the waste sulfuric acid combustion is performed. An apparatus for recovering sulfuric acid from waste sulfuric acid, wherein sulfuric acid concentrating means for recycling is provided in the decomposition means.
を前記熱回収手段で発生した水蒸気を用いて間接加熱し
て濃縮するものであることを特徴とする請求項４記載の
廃硫酸からの硫酸回収装置。5. The waste sulfuric acid according to claim 4, wherein the sulfuric acid concentrating means is for indirectly heating and concentrating the sulfuric acid-containing effluent using steam generated by the heat recovery means. Sulfuric acid recovery equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25175196A JP3846942B2 (en) | 1996-09-24 | 1996-09-24 | Method and apparatus for recovering sulfuric acid from waste sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25175196A JP3846942B2 (en) | 1996-09-24 | 1996-09-24 | Method and apparatus for recovering sulfuric acid from waste sulfuric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1095603A true JPH1095603A (en) | 1998-04-14 |
| JP3846942B2 JP3846942B2 (en) | 2006-11-15 |
Family
ID=17227389
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25175196A Expired - Fee Related JP3846942B2 (en) | 1996-09-24 | 1996-09-24 | Method and apparatus for recovering sulfuric acid from waste sulfuric acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3846942B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008284435A (en) * | 2007-05-16 | 2008-11-27 | Mitsubishi Rayon Co Ltd | Gas compressing method and method of manufacturing (meth)acrolein and/or (meth)acrylic acid and method of manufacturing methylmethacrylate using it |
| CN110054165A (en) * | 2018-12-12 | 2019-07-26 | 湘潭大学 | A kind of method of waste sulfuric acid solution reclaiming clean |
| CN111533092A (en) * | 2020-05-09 | 2020-08-14 | 山东合生固废处置工程有限公司 | Method for treating and recycling sulfur-phosphorus-containing organic waste |
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1996
- 1996-09-24 JP JP25175196A patent/JP3846942B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008284435A (en) * | 2007-05-16 | 2008-11-27 | Mitsubishi Rayon Co Ltd | Gas compressing method and method of manufacturing (meth)acrolein and/or (meth)acrylic acid and method of manufacturing methylmethacrylate using it |
| CN110054165A (en) * | 2018-12-12 | 2019-07-26 | 湘潭大学 | A kind of method of waste sulfuric acid solution reclaiming clean |
| CN111533092A (en) * | 2020-05-09 | 2020-08-14 | 山东合生固废处置工程有限公司 | Method for treating and recycling sulfur-phosphorus-containing organic waste |
| CN112897474A (en) * | 2021-02-06 | 2021-06-04 | 岷山环能高科股份公司 | Sulfur trioxide purifying device |
| CN112897474B (en) * | 2021-02-06 | 2023-09-29 | 岷山环能高科股份公司 | Device for purifying sulfur trioxide |
| WO2022172864A1 (en) * | 2021-02-10 | 2022-08-18 | 日本管機工業株式会社 | Apparatus for producing dilute sulfuric acid and method for producing dilute sulfuric acid |
| WO2022172354A1 (en) * | 2021-02-10 | 2022-08-18 | 日本管機工業株式会社 | Dilute sulfuric acid production device and dilute sulfuric acid production method |
| CN115535971A (en) * | 2021-06-29 | 2022-12-30 | 杭州瑞佑科技有限公司 | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution |
| CN115535971B (en) * | 2021-06-29 | 2024-02-09 | 杭州瑞佑科技有限公司 | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution |
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| Publication number | Publication date |
|---|---|
| JP3846942B2 (en) | 2006-11-15 |
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