Maitiro Ekugadzira Sulfuric Acid
Sulfuric acid (H₂SO₄) ndeimwe yemakemikari akakosha kwazvo pasi rose. Inowanzonzi "musimboti weindasitiri yemakemikari" nekuda kwekushandiswa kwayo kwakasiyana-siyana: kubva pakugadzira mafetiraiza ephosphate neammonium sulfate, kuburikidza nekugadzira petroleum, kunatsa simbi, kugadzira mabhatiri e lead-acid, kusvika kumaindasitiri emachira nemishonga. Kudiwa kukuru kwesulfuric acid kwakaita kuti pave nekugadzirwa kwemaitiro ekugadzira anoshanda, asingadhuri, uye asina njodzi kune zvakatipoteredza. Parizvino, nzira inonyanya kushandiswa mumaindasitiri ndeyeContact Process, inotsiva nzira dzekare dzakadai seLead Chamber Process.
Pfupiso yeKugadzirwa kweSulfuric Acid
Kazhinji, kugadzirwa kwesulfuric acid kuburikidza neContact Process kunosanganisira matanho makuru akati wandei: (1) kuumbwa kwesulfur dioxide (SO₂), (2) kucheneswa nekuomeswa kwegasi, (3) oxidation yeSO₂ kuita sulfur trioxide (SO₃) ine catalyst, (4) kunyudzwa kweSO₃ mu concentrated sulfuric acid kuti igadzire oleum, uye (5) kusanganiswa kweoleum kuita sulfuric acid nehuwandu hwaunoda. Danho rega rega rinoda kudzora zvakanyanya tembiricha, kumanikidzwa, uye kuumbwa kwegasi kuti uwane goho rakakura uye kuderedza kuburitswa kwegasi rine njodzi.
1. Kuumbwa kweSulfur Dioxide (SO₂)
Zvinhu zvikuru zvinoshandiswa mukugadzira sulfuric acid zvinogona kuva elemental salfa, H₂S gasi rinobva mumafuta anocheneswa, kana metal sulfide ores (semuenzaniso, pyrite FeS₂). Nzira inonyanya kushandiswa ndeyekupisa elemental salfa mumhepo yakaoma:
S(s) + O₂(g) → SO₂(g) + simba
Izvi zvinoitwa ne exothermic (zvinoburitsa kupisa). Kupisa kunobva kwaitwa kunowanzo shandiswa kugadzira utsi, saka zvirimwa zve sulfuric acid zvinowanzo batanidzwa nemasisitimu ekudzoreredza simba. Kana chikafu chiri sulfide ore, dombo rinogochwa kuti ribudise SO₂. Zvisinei, kushandiswa kwe elemental sulfur kunowanzo buritsa gasi rakachena uye kunoita kuti nzira yekuchenesa ive nyore.
2. Kuchenesa uye Kuomesa Gasi
Magasi anobvira haangove neSO₂ neN₂ chete kubva mumhepo, asiwo anogona kutakura guruva, utsi hwemvura, nezvimwe zvinhu zvisina kuchena zvakaita searsenic compounds kana catalyst particulates kana zvichibva muore. Tsvina iyi ine njodzi nekuti inogona kukuvadza catalyst panguva ye oxidation stage. Saka, gasi rinofanira kugadziriswa kuburikidza ne cleansing unit, semuenzaniso:
- Dutu rinoparadzanisa kana electrostatic precipitator yekubata guruva/zvidimbu zvidiki
- Kukwesha kuderedza tsvina inonyunguduka
– Muchina wekuomesa (shongwe yekuomesa) unoshandisa sulfuric acid yakawanda kuti utore utsi hwemvura
Kuomesa gasi kwakakosha zvikuru nekuti kuvapo kwemvura kunogona kukonzera kuumbwa kweacid mhute, kukanganisa maitiro ekunyudzwa kweSO₃, uye kuwedzera ngura mumidziyo.
3. Kuoxidation kweSO₂ kuenda kuSO₃ (Chikamu Chinokosha Chekubata)
Danho guru reKubatana nderekusanganiswa kwesulfur dioxide kuita sulfur trioxide:
2 SO₂ (g) + O₂ (g) ⇌ 2 SO₃ (g)
Kuita uku kunobva ku exothermic uye inzira ye equilibrium. Mupfungwa, tembiricha yakaderera inobatsira kuumbwa kweSO₃ (nekuti nzira yacho inobva ku exothermic). Zvisinei, tembiricha yakaderera inoderedza reaction rate. Nokudaro, indasitiri inosarudza mamiriro akakodzera: tembiricha inosvika 400–450°C uye kumanikidzwa kuri pedyo nekumanikidzwa kwemhepo (kana kuti kwakakwira zvishoma). Kuti kukurumidzise reaction, vanadium(V) oxide (V₂O₅) catalyst inoshandiswa, inoiswa mu catalyst bed mu converter.
MaConverter anowanzova nemibhedha yakawanda ye catalyst ine system ye intercooling. Izvi zvinoita kuti tembiricha irambe iri mukati mehuwandu hwakakodzera: kana kukanyanya kupisa, equilibrium inodzokera ku SO₂, nepo catalyst ichigonawo kuona kushanda kwakaderera pakupisa kwakanyanya.
Kuti vawedzere kushanda zvakanaka uye kudzora kuburitswa kwemhepo, mafekitori mazhinji emazuva ano anoshandisa chirongwa cheDouble Contact Double Absorption (DCDA). Muchimiro ichi, gasi rinopfuura nemuchinoshandura, uko imwe SO₃ inonyudzwa, uye gasi rinodzoserwa kuchinoshandura kuti riwedzere kuoxidation risati ranyudzwa kekupedzisira. Mugumisiro wacho ndewekuti SO₂ inonyudzwa zvakanyanya uye kuburitswa kwemhepo kushoma.
4. Kunyudzwa kweSO₃ uye Kuumbwa kweOleum
Danho rinotevera nderekubata SO₃. Pakutanga, zvinoita sezviri nyore kungopindura SO₃ nemvura:
SO₃ (g) + H₂O (l) → H₂SO₄ (l)
Zvisinei, mumaindasitiri, kusangana kwakananga nemvura kunokonzera dambudziko guru: SO₃ inokurumidza kuita zvinhu uye inogadzira mhute ye sulfuric acid iyo inonetsa kuumba nekupinza, zvichiita kuti pave nenjodzi yekurasikirwa nezvigadzirwa uye kuburitsa zvinhu zvinosvibisa. Saka, SO₃ hainyudzwe nemvura, asi ne sulfuric acid yakawanda (kazhinji 98%) kuti igadzire oleum (sulfuric acid inodarika SO₃):
SO₃ (g) + H₂SO₄ (l) → H₂S₂O₇ (l)
Oleum (H₂S₂O₇) inonziwo pyrosulfuric acid. I "mhando yekuchengetera" yeSO₃ iri nyore kubata mu liquid systems. Kupinza SO₃ mu concentrated sulfuric acid kunobatsirawo kudzivirira kuumbwa kweacid mhute uye kunowedzera kushanda zvakanaka kweabsorption.
5. Kusanganiswa kweOleum muSulfuric Acid
Kana oleum yagadzirwa, danho rekupedzisira nderekugadzira sulfuric acid pahuwandu hwakakodzera kudiwa pamusika, senge 98% yekushandiswa mumaindasitiri kana huwandu hwakaderera hwekushandiswa kwakatarwa. Kusanganiswa kunowanikwa nekuwedzera mvura nenzira yakarongwa:
H₂S₂O₇ (l) + H₂O (l) → 2 H₂SO₄ (l)
Kusanganiswa uku kunokonzerwawo ne exothermic reaction, saka kunofanirwa kuitwa nekutonga kwakasimba kwekupisa uye nzira dzekuchengetedza. Imwe nzira inozivikanwa yekuchengetedza ndeyekuwedzera acid mumvura, kwete zvakasiyana, kudzivirira kupararira kwemvura nekuda kwekupisa kamwe kamwe. Padanho remaindasitiri, masisitimu ekusanganisa akagadzirwa nema chillers, stirrers, uye tembiricha sensors kudzora kuburitswa kwekupisa kubva mu reaction.
Kuchengetedzeka uye Zvakatipoteredza
Kugadzirwa kwesulfuric acid kunosanganisira magasi ane njodzi (SO₂, SO₃) anogona kukonzera kutsamwa kukuru kwekufema uye kukonzera mvura ine acid kana ikaburitswa mumhepo. Saka, chirimwa ichi chinoshandisa:
1. Sisitimu yeDCDA uye unit yekunyudza kuti iwedzere kushandurwa kweSO₂ kuita SO₃ uye kuderedza kuburitswa kwemhepo.
2. Muchina wekubvisa mhute kuti ubate mhute ine acid kubva mugasi usati waburitswa nemuchimney.
3. Zvinhu zvisingapindi ngura (semuenzaniso simbi dzakati wandei, ma alloys chaiwo, kana ma coatings ekudzivirira) nekuti H₂SO₄ inoparadza zvakanyanya, kunyanya pahuwandu hwakati uye tembiricha.
4. Kugara uchitarisa kuburitswa kwemhepo kuti uve nechokwadi chekuti nharaunda inoenderana nemitemo.
Pamusoro pezvo, kupisa kwemaitiro ekunze kunowanzo shandiswa muhurongwa hwekudzoreredza simba, zvichiita kuti maitiro acho ave anoshanda nesimba zvakanyanya uye kuderedza kukanganiswa kwekabhoni.
Penutup
Maitiro emazuva ano ekugadzira sulfuric acid anotongwa neContact Process nekuda kwekushanda kwayo kwepamusoro, mhando yakanaka yezvigadzirwa, uye kuburitswa kwemhepo kunodzorwa netekinoroji dzakadai seDCDA. Matanho makuru anosanganisira kupisa sulfur kuti ibudise SO₂, kuchenesa nekuomesa gasi, catalytic oxidation kuSO₃, kunyudzwa kweSO₃ mu sulfuric acid yakakora kuti igadzire oleum, uye kusanganiswa kweoleum kuita sulfuric acid sezvinodiwa. Nezviyero zvekushanda zvinodzorwa, dhizaini yakakodzera yemiti, uye masisitimu akasimba ekuchengetedza uye ezvakatipoteredza, indasitiri inogona kugadzira sulfuric acid yakawanda yakavimbika kutsigira zvikamu zvakasiyana-siyana zvehupfumi.
Kana muchida, ndinogona kugadzira chinyorwa chino chine chimiro chedzidzo (nemashoko ekuti "sumo-nzira-mhedzisiro-hurukuro") kana kuwedzera chati yemafambiro enyaya kuti zvive nyore kunzwisisa.
