Ukushiswa kwamalahle ezindaweni zokukhiqiza ugesi kukhiqiza imfucuza eqinile, njengomlotha ongaphansi nowempukane, kanye negesi yomoya ekhishwa emoyeni. Izitshalo eziningi ziyadingeka ukususa ukukhishwa kwe-SOx kugesi yomoya kusetshenziswa izinhlelo zokususa i-flue gas desulfurization (FGD). Ubuchwepheshe obuthathu obuhamba phambili be-FGD obusetshenziswa e-US ukuhlafuna ngamanzi (85% wezinto ezifakiwe), ukuhlafuna ngamanzi (12%), kanye nokujova nge-sorbent eyomile (3%). Ama-scrubbers amanzi avame ukususa ngaphezu kuka-90% we-SOx, uma kuqhathaniswa nama-scrubbers omoya, asusa u-80%. Lesi sihloko sinikeza ubuchwepheshe besimanje bokwelapha amanzi angcolile akhiqizwa ngamanzi amanzi.Izinhlelo ze-FGD.
Izisekelo ze-Wet FGD
Ubuchwepheshe be-Wet FGD bufana nesigaba se-slurry reactor kanye nesigaba sokukhipha amanzi esiqinile. Kusetshenziswe izinhlobo ezahlukene zezinciphisi, okuhlanganisa imibhoshongo epakishiwe kanye ne-tray, izinciphisi ze-venturi, kanye nezinciphisi zokufafaza esigabeni se-reactor. Izinciphisi ziqeda amagesi ane-acidic nge-alkaline slurry ye-lime, i-sodium hydroxide, noma i-limestone. Ngenxa yezizathu eziningana zomnotho, izinciphisi ezintsha zivame ukusebenzisa i-limestone slurry.
Uma i-limestone isabela ne-SOx ezimweni zokunciphisa ze-absorber, i-SO 2 (ingxenye eyinhloko ye-SOx) iguqulwa ibe yi-sulfite, bese kukhiqizwa i-slurry ecebile nge-calcium sulfite. Izinhlelo ze-FGD zangaphambilini (ezibizwa ngokuthi i-oxidation yemvelo noma izinhlelo ze-oxidation ezivinjelwe) zakhiqiza umkhiqizo ongaphansi kwe-calcium sulfite. OkushaIzinhlelo ze-FGDsebenzisa i-reactor ye-oxidation lapho i-calcium sulfite slurry iguqulwa khona ibe yi-calcium sulfate (gypsum); lezi zibizwa ngokuthi izinhlelo ze-limestone forced oxidation (LSFO) FGD.
Izinhlelo zesimanje ze-LSFO FGD ezijwayelekile zisebenzisa i-spray tower absorber ene-integral oxidation reactor esisekelweni (Isithombe 1) noma uhlelo lwe-jet bubbler. Kuyo ngayinye igesi imuncwa ku-limestone slurry ngaphansi kwezimo ze-anoxic; i-slurry bese idlulela ku-aerobic reactor noma indawo yokusabela, lapho i-sulfite iguqulwa ibe yi-sulfate, bese i-gypsum ivuvukala. Isikhathi sokubamba i-hydraulic ku-oxidation reactor singaba yimizuzu engama-20.
1. Uhlelo lwe-FGD lwekholomu ye-limestone oluphoqelelwe ukuxiliswa (LSFO). Ku-LSFO scrubber slurry idlulela ku-reactor, lapho umoya wengezwa khona ukuphoqa ukuxiliswa kwe-sulfite ibe yi-sulfate. Lokhu kuxiliswa kubonakala sengathi kuguqula i-selenate ibe yi-selenate, okuholela ezinkingeni zokwelapha kamuva. Umthombo: CH2M HILL
Lezi zinhlelo zivame ukusebenza ngezinto eziqinile ezilengayo ezingu-14% kuya ku-18%. Izinto eziqinile ezilengayo zakhiwa izinto eziqinile ze-gypsum ezincane neziqinile, umlotha ompukane, kanye nezinto ezingasebenzi kahle ezifakwe ne-limestone. Lapho izinto eziqinile zifinyelela umkhawulo ophezulu, i-slurry iyahlanzwa. Iningi lezinhlelo ze-LSFO FGD zisebenzisa izinhlelo zokuhlukanisa izinto eziqinile zemishini kanye nokukhipha amanzi ukuze zihlukanise i-gypsum nezinye izinto eziqinile emanzini okuhlanza (Isithombe 2).
2. Uhlelo lokususa amanzi lwe-gypsum lokuhlanza i-FGD. Kuhlelo lokususa amanzi lwe-gypsum olujwayelekile, izinhlayiya eziku-purge zihlukaniswa, noma zihlukaniswe, zibe yizingxenyana eziqinile nezincane. Izinhlayiya ezincane zihlukaniswa ekuchichimeni okuvela ku-hydroclone ukuze kukhiqizwe ukugeleza okungaphansi okuqukethe ikakhulukazi amakristalu amakhulu e-gypsum (okungathengiswa) angasuswa amanzi abe ngumswakama ophansi ngohlelo lokususa amanzi ngebhande le-vacuum. Umthombo: CH2M HILL
Ezinye izinhlelo ze-FGD zisebenzisa ama-gravity thickeners noma amachibi okuxazulula izinkinga ukuze kuhlukaniswe futhi kukhishwe amanzi, kanti ezinye zisebenzisa ama-centrifuge noma izinhlelo zokukhipha amanzi ze-rotary vacuum drum, kodwa izinhlelo eziningi ezintsha zisebenzisa ama-hydroclone namabhande e-vacuum. Ezinye zingasebenzisa ama-hydroclone amabili alandelanayo ukwandisa ukususwa kwezinto eziqinile ohlelweni lokukhipha amanzi. Ingxenye yokugcwala kwe-hydroclone ingabuyiselwa ohlelweni lwe-FGD ukuze kuncishiswe ukugeleza kwamanzi angcolile.
Ukuhlanza kungase kuqalwe nalapho kukhona ukunqwabelana kwama-chloride ku-slurry ye-FGD, okudingwa yimingcele ebekwa ukumelana nokugqwala kwezinto zokwakha zesistimu ye-FGD.
Izici Zamanzi Angcolile ze-FGD
Izinto eziningi eziguquguqukayo zithinta ukwakheka kwamanzi amdaka e-FGD, njengokwakheka kwamalahle kanye ne-limestone, uhlobo lwe-scrubber, kanye nesistimu yokususa amanzi e-gypsum esetshenziswayo. Amalahle anikela ngamagesi ane-acidic - njenge-chloride, i-fluoride, ne-sulfate - kanye nezinsimbi eziguquguqukayo, okuhlanganisa i-arsenic, i-mercury, i-selenium, i-boron, i-cadmium, ne-zinc. I-limestone inikela ngensimbi ne-aluminium (kusukela kumaminerali obumba) emanzini amdaka e-FGD. I-limestone ivame ukugaywa emshinini webhola omanzi, kanti ukuguguleka kanye nokugqwala kwamabhola kunikeza insimbi edakeni le-limestone. Ubumba luvame ukufaka ama-inert fines, okuyisinye sezizathu ezenza amanzi amdaka akhishwe ku-scrubber.
Kusukela ku: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; kanye noSilas W. Givens, PE.
Email: caroline@rbsic-sisic.com
Isikhathi sokuthunyelwe: Agasti-04-2018