Konewar kwal a wuraren samar da wutar lantarki yana samar da sharar gida mai ƙarfi, kamar tokar ƙasa da ƙura, da kuma iskar gas da ake fitarwa zuwa sararin samaniya. Ana buƙatar masana'antu da yawa su cire hayakin SOx daga iskar gas ta amfani da tsarin desulfurization na iskar gas (FGD). Manyan fasahohin FGD guda uku da ake amfani da su a Amurka sune gogewar ruwa (85% na kayan aiki), gogewar busasshe (12%), da allurar sorbent busasshe (3%). Masu gogewar ruwa yawanci suna cire fiye da kashi 90% na SOx, idan aka kwatanta da masu gogewar busasshe, waɗanda ke cire kashi 80%. Wannan labarin yana gabatar da fasahohin zamani don magance ruwan sharar da datti ke samarwa ta hanyar datti.Tsarin FGD.
Tushen FGD Mai Riga
Fasahar Wet FGD tana da alaƙa da sashin sinadarin slurry reactor da kuma sashin da ke cire ruwa mai ƙarfi. An yi amfani da nau'ikan abubuwan shaye-shaye iri-iri, ciki har da hasumiyoyin da aka cika da tire, masu goge venturi, da masu goge feshi a cikin sashin reactor. Masu goge-shaye suna kawar da iskar acidic ta hanyar amfani da alkaline slurry na lemun tsami, sodium hydroxide, ko limestone. Saboda dalilai da dama na tattalin arziki, sabbin masu goge-shaye suna amfani da limestone slurry.
Lokacin da dutse mai laushi ya yi aiki da SOx a cikin yanayin rage yawan shan ruwa, SO2 (babban bangaren SOx) yana canzawa zuwa sulfite, kuma ana samar da wani sinadari mai wadataccen sinadarin calcium sulfite. Tsarin FGD na baya (wanda aka fi sani da oxidation na halitta ko tsarin oxidation da aka hana) yana samar da samfurin calcium sulfite. SabonTsarin FGDamfani da na'urar hada iskar shaka wadda ake canza sinadarin calcium sulfite slurry zuwa calcium sulfate (gypsum); ana kiran waɗannan da tsarin FGD na dutse mai ƙarfi (LSFO).
Tsarin FGD na zamani na LSFO FGD yana amfani da ko dai mai feshi mai ɗaukar hasumiyar feshi tare da na'urar haɗa iskar shaka a cikin tushe (Hoto na 1) ko tsarin kumfa mai jet. A cikin kowannensu iskar gas ɗin tana shawagi a cikin ruwan dutse a ƙarƙashin yanayin rashin iskar shaka; sannan slurry ɗin ya wuce zuwa wurin haɗa iskar shaka ko yankin amsawar iskar shaka, inda ake canza sulfite zuwa sulfate, kuma gypsum ya faɗi. Lokacin riƙe ruwa a cikin na'urar haɗa iskar shaka yana kimanin mintuna 20.
1. Tsarin FGD na fesawa na dutse mai ƙarfi (LSFO). A cikin ruwan gogewa na LSFO, slurry yana wucewa zuwa wani reactor, inda ake ƙara iska don tilasta iskar oxygen na sulfite zuwa sulfate. Wannan iskar oxygen yana canza selenite zuwa selenate, wanda ke haifar da matsalolin magani daga baya. Tushe: CH2M HILL
Waɗannan tsarin yawanci suna aiki da daskararrun da aka dakatar daga kashi 14% zuwa 18%. Daskararrun da aka dakatar sun ƙunshi daskararrun gypsum masu kyau da kauri, tokar tashi, da kayan da ba su da aiki da aka haɗa da farar ƙasa. Lokacin da daskararrun suka kai ga iyakar sama, ana tsaftace daskararrun. Yawancin tsarin LSFO FGD suna amfani da tsarin rabuwa da daskararrun injina da tsarin cire ruwa don raba gypsum da sauran daskararrun daga ruwan tsarkakewa (Hoto na 2).
2. Tsarin tsarkake gypsum na FGD. A cikin tsarin tsarkake gypsum na yau da kullun, ana rarraba barbashi a cikin tsarkakewa, ko kuma a raba su, zuwa ƙananan juzu'i masu kauri da ƙanana. Ana raba ƙananan barbashi a cikin ambaliya daga hydroclone don samar da ruwa mai zurfi wanda ya ƙunshi galibin manyan lu'ulu'u na gypsum (don siyarwa mai yuwuwa) wanda za'a iya cire shi zuwa ƙarancin danshi tare da tsarin cire bel ɗin tsotsa. Tushe: CH2M HILL
Wasu tsarin FGD suna amfani da na'urorin kauri ko tafkuna masu daidaita nauyi don rarrabawa da kuma cire ruwa daga datti, wasu kuma suna amfani da na'urorin centrifuges ko na'urorin cire ruwa daga datti na rotary vacuum, amma yawancin sabbin tsarin suna amfani da hydroclones da bel ɗin injin tsabtace ruwa. Wasu na iya amfani da hydroclones guda biyu a jere don ƙara cire datti daga tsarin cire ruwa daga datti. Wani ɓangare na kwararar ruwa daga datti za a iya mayar da shi zuwa tsarin FGD don rage kwararar ruwan sharar gida.
Ana iya fara tsarkakewa idan akwai tarin sinadarin chloride a cikin sinadarin FGD, wanda ya zama dole sakamakon iyakokin da aka sanya sakamakon juriyar tsatsa na kayan gini na tsarin FGD.
Halayen Ruwan Sharar Gida na FGD
Abubuwa da yawa masu canzawa suna shafar tsarin ruwan sharar gida na FGD, kamar su kwal da dutse mai daraja, nau'in gogewa, da tsarin cire ruwa daga gypsum da ake amfani da shi. Kwal yana ba da iskar gas mai guba - kamar chlorides, fluorides, da sulfate - da kuma karafa masu canzawa, gami da arsenic, mercury, selenium, boron, cadmium, da zinc. Kwal din yana ba da gudummawar ƙarfe da aluminum (daga ma'adanai na yumbu) zuwa ruwan sharar gida na FGD. Yawanci ana niƙa dutse mai daraja a cikin injin niƙa mai danshi, kuma zaizayar ƙasa da tsatsa na ƙwallon suna ba da gudummawar ƙarfe ga slurry na dutse mai daraja. Tukwane suna ba da gudummawa ga takin da ba shi da amfani, wanda shine ɗayan dalilan da yasa ake tsarkake ruwan sharar gida daga mai tsafta.
Daga: Thomas E. Higgins, PhD, PE; A. Thomas Sandy, PE; da Silas W. Givens, PE.
Email: caroline@rbsic-sisic.com
Lokacin Saƙo: Agusta-04-2018