Gutwika amakara mu bigo bitanga amashanyarazi bibyara imyanda ikomeye, nk'ivu ryo hasi n'iry'umukungugu, hamwe n'imyuka isohoka mu kirere. Inganda nyinshi zisabwa gukura imyuka ya SOx muri gazi isohoka hakoreshejwe sisitemu yo gukuraho gazi isohoka mu kirere (FGD). Ikoranabuhanga ritatu rikomeye rya FGD rikoreshwa muri Amerika ni ugusukura amazi (85% by'ibikoresho), gusukura amazi (12%), no gutera sorbent y'umukungugu (3%). Imashini zisukura amazi zisanzwe zikuraho arenga 90% bya SOx, ugereranije n'imashini zisukura amazi zisanzwe, zikuraho 80%. Iyi nkuru igaragaza ikoranabuhanga rigezweho ryo gutunganya amazi yanduye aturuka mu mazi.Sisitemu za FGD.
Ibintu by'ibanze bya FGD byoroshye
Ikoranabuhanga rya Wet FGD rifite igice cy’urutare rw’amazi n’igice cyo gukuramo amazi mu buryo bw’ibinure. Hakoreshejwe ubwoko butandukanye bw’ibikoresho bikuramo amazi, harimo iminara ipakiye n’iy’amasahani, imashini zisukura amazi, n’ibikoresho byo gusukura amazi mu gice cy’urutare rw’amazi. Ibi bikoresho bikuramo amazi bigabanya imyuka ihumanya ikoresheje urutare rwa alkaline rw’ishwagara, sodiyumu hidroksidi, cyangwa ishwagara. Kubera impamvu nyinshi z’ubukungu, ibikoresho bishya bikuramo amazi bikunze gukoresha urutare rw’amazi.
Iyo limestone ihuye na SOx mu gihe cy’igabanuka ry’umuyoboro w’amazi, SO2 (igice kinini cya SOx) ihinduka sulfite, hanyuma hagakorwa urusenda rukungahaye kuri sulfite ya kalisiyumu. Sisitemu za FGD za kera (zitwaga oxidation karemano cyangwa sisitemu za oxidation zabujijwe) zakoze umusaruro wa sulfite ya kalisiyumu. IbishyaSisitemu za FGDKoresha icyuma gitunganya ogisijeni aho sulfure ya kalisiyumu ihinduka sulfure ya kalisiyumu (gypsum); ibi byitwa sisitemu za FGD zikoreshwa mu gutwika limestone (LSFO).
Sisitemu zisanzwe za LSFO FGD zikoresha agakoresho ko kumishaho imirasire gafite icyuma gikingira umwuka mu gice cyo hasi (Ishusho ya 1) cyangwa sisitemu yo gukaraba umwuka. Muri buri gasegereti, umwuka winjizwa mu gishishwa cy'amabuye y'agaciro mu gihe cy'umwuka udafite umwuka; icyo gishishwa gihita kijya mu gice cy'umwuka cyangwa ahantu hakorerwa ibikorwa, aho sulfite ihinduka sulfate, hanyuma gypsum igahita itera. Igihe cyo gufunga hydraulic muri icyuma gikingira umwuka ni iminota 20.
1. Sisitemu ya FGD iterwa n'ingufu za limestone zikoresheje ingufu za oxidation (LSFO). Muri LSFO scrubber slurry inyura mu cyuma gitera umwuka, aho umwuka wongerwamo kugira ngo oxidation ya sulfite ibe sulfate. Iyi oxidation isa nkaho ihindura selenite muri selenate, bigatera ingorane mu kuvura nyuma. Inkomoko: CH2M HILL
Ubusanzwe izi sisitemu zikora n'ibintu bikomeye bihagaze hagati ya 14% na 18%. Ibintu bikomeye bihagaze bigizwe n'ibintu bikomeye kandi binini bya gypsum, ivu ry'umukungugu, n'ibikoresho bidafite ishingiro byinjijwe muri limestone. Iyo ibintu bikomeye bigeze ku rugero rwo hejuru, ibintu bitonyanga birasukurwa. Sisitemu nyinshi za LSFO FGD zikoresha uburyo bwo gutandukanya ibintu bikomeye no kubikuramo amazi kugira ngo zitandukanye gypsum n'ibindi bintu bikomeye n'amazi yo gusukura (Ishusho ya 2).
2. Sisitemu yo gukuramo amazi ya gypsum muri FGD. Mu buryo busanzwe bwo gukuramo amazi ya gypsum, uduce duto two mu isukura dushyirwa mu byiciro bikomeye n'ibito. Uduce duto dutandukanywa mu isukura ry'amazi ya hydroclone kugira ngo habeho amazi aturuka ku ruganda runini rwa gypsum (ashobora kugurishwa) ashobora kuvamo amazi kugeza ku bushyuhe buke hakoreshejwe sisitemu yo gukuramo amazi ya vacuum belt. Inkomoko: CH2M HILL
Sisitemu zimwe na zimwe za FGD zikoresha ibikoresho bigabanya ubukana bw'amazi cyangwa ibidendezi byo guturamo kugira ngo habeho gushyira mu byiciro ibintu bikomeye no kubikuramo amazi, ndetse zimwe zigakoresha centrifuges cyangwa sisitemu zo gukuramo amazi zizunguruka, ariko sisitemu nyinshi nshya zikoresha hydroclones na vacuum belts. Zimwe zishobora gukoresha hydroclones ebyiri zikurikiranye kugira ngo zongere gukuramo ibintu bikomeye muri sisitemu yo gukuramo amazi. Igice cy'amazi menshi ashobora gusubizwa muri sisitemu ya FGD kugira ngo agabanye amazi atemba.
Gusukura bishobora kandi gutangira iyo hari chloride nyinshi mu gishanga cya FGD, bitewe n'imipaka ishyirwaho n'ubudahangarwa bw'ibikoresho by'ubwubatsi bya sisitemu ya FGD.
Ibiranga Amazi Yanduye ya FGD
Ibintu byinshi bigira ingaruka ku miterere y'amazi yanduye ya FGD, nk'imiterere y'amakara n'amabuye y'agaciro, ubwoko bw'imashini yo gusukura, n'uburyo bwo gukura amazi muri gypsum. Amakara atanga imyuka ihumanya - nka kloride, fluoride, na sulfate - ndetse n'ibyuma bihindagurika, harimo arsenic, mercure, selenium, boron, cadmium, na zinc. Limestone itanga icyuma na aluminium (biva mu mabuye y'ibumba) mu mazi yanduye ya FGD. Limestone ikunze gusya mu ruganda rutose, kandi isuri n'ingufu by'amabara bituma icyuma gitera ubushyuhe bw'amabuye y'agaciro. Ibumba rikunze gutanga ubushyuhe butagira amazi, ari na imwe mu mpamvu zituma amazi yanduye akurwa mu imashini yo gusukura.
Kuva kuri: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; na Silas W. Givens, PE.
Email: caroline@rbsic-sisic.com
Igihe cyo kohereza: Kanama-04-2018