Izinteknoloji Zokususa Isulfur Kukusebenza Kwegasi

Umthwalo Wokusebenza Kwegasi Elibomvu: Kungani Ukususa Isulfur Kungabikho Nokubhekana Nayo

Umgas wokuphuma ngokodwa kwezindawo zokugcina akakhathali kuzoba nesikhundla sokuthi sithathele kwezindawo zokugcina. Ngokwesibonelo sesikhundla, kungakhiwa ukuthi kunezinkomba zokuthi kune-“hydrogen sulfide” ezihamba kusukela kubili baparts per million kuze kubili bapercents. I-“hydrogen sulfide” iyadlula izinkambo, iyabutha, futhi iyabulala—kepha isibophezelo esikhulu sibegqoka lapho isebenzisa amachini okusebenza. Iyadlula izinkambo zokuthi zingamandla, iyabutha amacatalyst, futhi iyagqoka izibhalo zokuhlela ukuthi zibe yizinye zezinkinga. Umsebenzisi wokuthi wasebenza emuva kwezindawo zokugcina e-Permian Basin wafunda lokhu ngendlela enkulu: emva kokuthi kusebenzise isigas esisilungile ngokwesibonelo ngeminyaka yomzuzu, wabuyisela izinkambo eziningi kwezindawo zokugcina zokuthi zingaphezu kwezindawo ezimbili zokuthi zingamandla, futhi wabulala ukusebenza ngeminyaka yomzuzu yeshumi kanye. Lokhu kwakuyisifundo esikhulu. Ukukhipha isulfur akakwazi ukuvalelwa; kukhona kuyisibophelo esikhathele kwezindawo zokusebenza kwegas.

Industriya yayispende iminyaka eminingi ekuthuthukiseni indlela yokukhupha i-H₂S nezinye izinkokhelo zezilwane zokushisa kusuka kwezindawo zokushisa. Isikhundla sokusebenza saseyadala sisebenzisa ukuthwabha kwemithambo yamanani, ukuthwabha kwezinkokhelo zokushisa, ngokuzenzakalelayo kubonakala kubona isikhundla sokusebenza ngokwesibonelo, ubungakanani bezindawo zokushisa, ubungakanani bewayini, nokuthandekile kwezinye izinhlangano.

Ukuthwabha kwe-Amine: Umsebenzi wokusebenza kwezindustria

Kubalulekile kakhulu kwezindawo zokusebenza kwezindawo zokushisa, ukuthwabha kwe-amine kuyisikhundla sokusebenza sokwesibonelo. Ukuchaza kwesayensi kuyisibonelo: isayensi yamanini ayenqaba kusuka kwezindawo zokushisa ezingasiza kwi-tower yokuqondisa, futhi amine ayikhipha i-H₂S (kanye noma i-CO₂) kusuka kwezindawo zokushisa. Amine esihlukile ayedlula ku-remover apho isayensi iyathwabha izinkokhelo zokushisa ngokusebenzisa isayensi esisheshayo esiyadlula kwi-absorber.

I-Methyldiethanolamine (MDEA) ibecoshwa yisayensi esifunekayo sokukhipha i-H₂S ngokugcina, ikakhulu lapho ukukhipha kwe-CO₂ kuyisifundo sokufuna . Ngaphandle kwezinye izinkolelo zokuphakanyisa okanye zokuphakanyisa kwesibili, i-MDEA isenzeka ngokushibiya ngokukhula kwe-CO₂—okuthi amasipheki akwazi ukugcina isisiko ukuze abulele i-H₂S ngelona lelihloko ngaphansi kwe-CO₂ ezingeni eliphezulu le-gas. Indawo yegas yaseGulf Coast eyisebenzisa isilungu se-MDEA sokuphakanyisa-40% sifuna i-H₂S esingaphansi kwe-4 ppm emgubeni wokuphuma, futhi isibonelo sokuphuma kwe-CO₂ esingaphezulu kwe-70% esingena. Lokho kukhomba ukuthi ukukhetha kuyinto ebalulekile uma igas iphambili ekupheleni kwezinhlangano ezinamandla e-CO₂ kodwa akayikwazi ukulindela isulfur.

Ukubuyiselwa kwenza? I-energy yokubuyisela. Izinhlangano zama-amine ziyizithembiso zokusebenza. I-reboiler duty isebenza phakathi kwe-1,200 ne-1,500 Btu ngaligallon lama-amine asenziwa, futhi kwindawo enkulu lokho kuyabuyisa izindlela zokusebenza ezikhulu. ukudibanisa kwesilinganiso se-temperature siphambili—ukukhetha kwe-amine kufadile ngokushibiya uma isilinganiso se-lean amine siphinda phezu kwe-45°C. kumazwe othando wekhanda, lokhu kusuka kubhalwa kwe-chillers, okuyabuyisa izindlela zokubuyisela nokuhlelwa kwezinhlangano.

Ukubhala Kwesolid Bed: Uma Ukukhetha Kuyinto Ebalulekile

Kukhona izinkinga ezidinga ukuthi i-H₂S ibe ngaphezulu kwe-sub-ppm—bheka ukuthi kuyisikhathi sokuvula kwesikhathi sokugcina kwe-LNG noma izinkinga zokusebenzisa i-fuel cell—izinhlelo zama-amine zingathola isikhathi esihle. Lokhu kukuphela ukuthi izinhlelo zokuthwala okusodwa ziyakwenzeka. Izinhlelo zokuthwala ngokwesolid bed ziyisikhathi sokubaluleka: i-H₂S ithwala ne-ZnO ukuze kube yizinc sulfide, okungabili kulesolid bed kusukela kuqeda. Umsebenzi uyisikhathi esisheshayo, akadinga ukusebenzisa amanzi, futhi uyathumela i-H₂S yokuphuma ngaphezulu kwe-1 ppm ngokuphambili.

Kodwa kukhona isibopho. Izinhlelo zokuthwala ngokwesolid bed ziyachithwa. Uma i-zinc oxide iqeda kabusha ukuthwala i-sulfur, lesolid bed kufanele ikhutshazwe noma ikhululwe, okubangela ukuthi umsebenzi usetshenziswa. Indawo enkulu yokuthumela i-LNG e-Qatar iyasebenza izinhlelo eziningi zokuthwala ngokwesolid bed zama-ZnO ngokwesibonelo, zibuyisana ngokwesikhathi sokubuyisana ukuze umkhumbi wokuthuluzwa awube nesikhathi sokuthwala kwe-sulfur. Ukuthengisa kwenza uma ivali yegas ekuthululweyo iyathuthukisa ukuthengisa kwe-media—kepha kuzinkinga ozinca, ukuthengisa ngokwama-amine kuyadlula ngokwesikhathi sokusebenza.

Ukuthwabha kwe-Membrane nezinye izindlela ezitsha

Izisistemu zesikhumba zazisakaza isikhundla esithile kulemvelo yokususa isulfur, ikakhulukazi kumizimba eyisemthwakathini yama-CO₂ apho umphumela wokuphakanyisa kwekuphakanyisa kuyasebenza ukusungula. Izikhumba zesipolimeri nezinye izinyathelo ezilungile zingasusa i-H₂S kusukela kumbili okungu-100 ku-200 ppm ngomlando wodwa. Umphilo wawo uyisibonelo sokugcina: akukho izinkambo, akukho ukuthakatha, nokuncitshwa kwamaphetha okuncitshwa. Umsebenzisi we-Permian osebenzisa isikhumba sesikhumba kumizimba yoku-30 MMscfd wabona ukuthi izindlela zokusebenza ziyagcina ngokuphakeme kwe-40% kunye nesikhumba se-amine esayishintsha.

Kodwa, izikhumba azikwazi ukwenza konke. Zihlukene ngezinhlobo ezingabiyo zezinhlobo eziningi ezinokubangela ukuthi isipolimeri sifanane noma sifadile. Ukuvula kwesikhundla sokufaka kufuneka ukususa amanzi namakhanda, futhi ukusebenza kwesikhumba kuhlela ngokuphakeme njengoba isikhumba sokuzilungisa sifadile. Kunezinhlobo zonke, izikhumba zisebenza ngempela njengeqembu lokuvula phambi kokuvula kwesikhumba se-amine noma isikhumba sokuvula.

Ukusebenzisa I-Tail Gas Ukuthuluzela: Ukuthula Okungafanele Kwe-Sulfur Ngaphezu Kwama-99.9%

Lokhu kubhalwe ngokugcwele: i-Claus sulfur recovery unit eyodwa noma ezimbili engeyona yezinkambo eziyodwa noma ezintathu ziyakwenzela ukuthula kwe-sulfur okungama-93 ku-98% . Lokhu sasikhiya sasulfur esinguqukileyo kwi-tail gas akuyi nje indlela yokwenza ingqayizivele—kuyi impahla esisilungileyo. I-Tail Gas Treating Units (TGTUs) izimela lokho ngokuhlanganisa ama-sulfur okungafanele ngokubuyisa kwi-H₂S, emva koko ukubhala leli umsindo ngokusebenzisa i-selective amine absorber .

Amaphuzu ayigcwele. Noma kunye ne-TGTU, ukuthula kwesulfur ngokwesibonelo kungafika kuma-99.9%. Umkhumbi wepetroli waseGulf Coast yase-United States wabuyekeza i-Claus unit yakhe ngokusebenzisa i-TGTU futhi wabeka isikhundla sokuphatha i-SO₂ ngaphezu kwe-90% ngokuthula kwe-sulfur ezingama-12 tons ngosuku—impahla esingathuli kakhulu kusuka kumkhumbi. Isikhathi sokubuyisela kufika ngaphezu kwe-18 months, okwenzelwa ngokukhetha ukuthula kwe-sulfur nokuvikela amacredit yokuphatha.

Isiphumo sokusebenza kwe-TGTU sibonakala kuukwahlwa kwezinkqubo. I-MDEA engenabizo ibenza, kodwa izinkqubo ezisemthethweni ezenziwe ngokupheleleyo ukusebenza kwezinyathelo zokugcina isulfur ziyasebenza ngokuphambuka kwe-H₂S nakwesikhathi esiphakeme—kufika ku-50°C yamini eyenkulu—okunqamisa ukunqamula kwezinkqubo zokuchitha izinkambo. kumazikhulu okuphakeme kwezinsizwa noma kwezinye izilwanyana ezingenasiphelo sokusebenza, lokhu kuyinto enkulu yokubuyeza.

Ukuzilungela Okupheleleyo: Izindlela Zokukhetha Ezinconywa

Ukukhetha indlela yokususa isulfur akuyiyo ukukhetha indlela "enkhulu" — kuyiyo ukulungiselela indlela ekhethweyo ngokupheleleyo kwezinkqubo zokufaka nokusebenza. Lokhu okuthi kuyisibonelo sokukhetha:

1. Ukukhanya kwe-sulfur kwesifundo. I-H₂S ephezulu (ngaphezulu kwe-5%) kusho ngokubhekiselela kwezinkqubo zokuhlanjwa ngamini ne-Claus unit yokubuyisela isulfur. I-H₂S emphezulu (ngaphansi kwe-100 ppm) kungafanele ukusebenzisa isikhumbuzo sesolid-bed esingcono.

2. Ukuvulwa kwesifundo. Izinkqubo zokuhlanjwa ziyascale ngokupheleleyo; izimembreni nezinkqubo zesolid-bed zinezindlela zokuthengiselwa eziningi ngalunye lwesilinganiso sokusebenza.

3. Ukuthatha kwe-CO₂ kunye. Ukuthi i-CO₂ isikhalipho esibalulekile, izisitemu ezisebenzisa i-MDEA zinabantu abanamandla. Uma i-CO₂ kufanele ibuyiselwe, izisitemu zesilika esihlanganisiwe noma isilika esenzeka ngokwesibonelo singasemthwakathini.

4. Isiphequluli sesithu. I-LNG ifuna i-H₂S engaphezulu kwe-sub-ppm. I-gas yepipeline ingatholakala ngokwesibonelo kwe-4 ku-10 ppm. Okuphakeme ukusipekula, okuphakeme ukuthi uzobuya kubhenta.

5. Imigomo yezinhlanhla. Kwizindawo ezenza izimilingo zesi-SO₂ zingaphansi kakhulu, izinkombination zesi-Claus + TGTU ziyisikhumbuzo esifanayo.

Into eyodwa abasebenzi abanempilo baza kuzibona: ungakhethi isiphumo esikhulu kakhulu. Isithuthi sezinye izinkampani zegaz eNtshona Texas sasenya iminyaka miyane ema-2 ukuthatha isiphumo sesilika-esihlanganisiwe-noma-isilika esenzeka ngokwesibonelo, kodwa sasenya ngokuphela emva kokusuka kakhulu ngoba isimo sesilika sasenqaba kakhulu kunokwenzeka. Isilika se-MDEA esisheshayo siza kwenza umsebenzi ngokuphela kwesikhundla sesikhundla sokuthengiswa. Ngokushesha, isitayile esihle kakhulu siyoyinto ephendulwe ngokuphela ngeminyaka emashumi amahlanu.

Ubukhulu nokwenza kungafana nesitayile

Ukuchemistri kuyaziwa kahle. Izinguquko ziyisikhundla esiphambili. Lokho okuthi kuhlanganisa izindlela zokususa isulfur ezenzekayo kanye nezozilinganisa amasimu akhona kuyisisekelo—ukwenza i-“fabrication” ngobunzima, ukwenza ukulungiswa kwezinto ngokuphelele, nokufundisa abasebenzisi. Umkhosi ongavaliwe ngokuphelele ungathwala isilungu se-amine kumugqa wokuphuma. Umkhosi ongakwazi ukubhekana ngokuphelele ungakhelwa ngokuphelele, futhi isilungu se-amine sibekela, sithwala i-H₂S ku-“outlet”. Lezi azingazange zibe ngamathethelelo; kuzoba kubonwa eminyakeni yokuqala yezinhlangano zonke ngonyaka.

Kubantu abasebenzisa abafuna ukujikwa kwezinkinga zokusebenzisa lezi, ukusebenzana ne-‘fabricator’ oyazi umgqa wokusebenza kwemithambo yegesi—kushukela kusukela kwe-‘inlet separation’ ku-‘sulfur recovery’—kuyenza umphumela omubi. Izinhlangano ezinsuku zika-GreenFir zinakho ukwenza izinto ngokuphathelene nokugcina ubunzima bezimali kwezinkampani zokusebenza kwezimithambo yegesi ekhuluma ngokuphathelene nesikhathi, kusiza amaphrojekthi ukuvula izinkinga zokuhlanganisa eziphatha izinhlangano eziningi zokuthenga. Uma iskhidi yokususa isulfur ibuya iyisibonelo sokusebenza, ukuguqula kufanele kufanele kufanele, futhi izinga lezinye zegesi liyabona isibonelo esifanele kusukela ngesonto yokuqala.