Takamunin Taimanin Sulfur a Gas Processing

Yadda ake gaskiya a kan sour gas: Yaya ake nuna cewa karanta sulfur ba zai iya dace ba

Gas na yanki mai lafiya da aka saba da gida ba amsa kamar yadda ke cikin tsanen gas. Ta hanyar yankin da aka saba, zai iya samun kwayoyin hydrogen sulfide daga wani karamin parts per million zuwa wani karamin percentage na biyu. Hydrogen sulfide shi ne mai karfi, mai sauri, kuma mai fadu—amma alama na gaskiya ya faru lokacin da ya kawo aikin taimaka. Ya karfi steel na carbon, ya kara katalis, kuma ya haifar da mabudin taimaka suka dace da kari. Wani masu amfani na gas a cikin Permian Basin ya kara wannan abu ta hanyar wasu kwalla: bayan shekara biyu da aka run sour gas a cikin wani aiki ba ta kawo taimaka, sun zambo wani karamin mile biyu na piping kuma sun kare aiki a cikin wani kwalla uku. Alama ta dace. Karya na sulfur ba zai iya gudunawa; shi ne kuma babban karamin taimaka a cikin aikin gas.

Al’umma ta fiye da manyan shekara suka gudan yadda za a yi amfani da H₂S da wasu daga cikin bayanan sulfur daga gas streams. A yau, al’adu na amfani suna kuma daga chemical absorption zuwa solid-bed adsorption, wanda kowace ya nuna yadda ya iya aiki da fatan daga cikin composition na feed, flow rate, da wasu hanyoyin da ke cikin downstream.

Amine Treating: Al’umma na Gwamnati

Ga kowa daga cikin gas processing applications, amine-based absorption yana ƙarƙashin yadda ake amfani da shi. Al’adun kimiyar ya dace: amine solution na ruwa ta kawo sallahin gas a cikin absorber tower, kuma amine ta zuba H₂S (da kuma CO₂) daga vapor phase. Aminen da aka samu shine ta taka zuwa regenerator inda yanzu ta kawo acid gases, ta hanyar heat, kuma ta produce lean amine stream wanda ta taka zuwa absorber.

Methyldiethanolamine (MDEA) ta tsoro aminen da aka amfani da shi don selective H₂S removal, lallai idan CO₂ slip yana da kyau . Bayan kuma amines na farko ko na biyu, MDEA yana gudanen da CO₂ ta hanyar yawa—wanda ya nufi cewa masu amfani suna iya saita system don samun H₂S domin daga gas na bayanin abu, amma yana baiwa ƙarshen CO₂ a cikin gas na bayanin abu. Wani gas plant na Gulf Coast wanda ya amfani da 40% MDEA solution ya samu H₂S na bayanin abu ta zama ƙasa da 4 ppm, amma ya baiwa karshen 70% na CO₂ ta faduwa. Wannan tsari na tashin abu yana muhimmi a lokacin da gas zai shiga wani abu na bayanin abu wanda zai iya gudanen da CO₂ amma ba sukurfo ba.

Wani abu da ke cire? Energy na regeneration. Amine systems suna ci gaba daya na energy. Reboiler duty yana dauke da 1,200 zuwa 1,500 Btu per gallon na amine wanda ya faduwa, kuma don wani plant mai yawa, wannan yana zama mafi kyawun abubuwan da ke shiga aiki. . Tsarin kula da yadda aka sanya yadda aka sanya kuma yana muhimmi—tsarin tashin abu na amine yana kara yawa lokacin da yadda aka sanya na amine ta zama ƙasa da 45°C. . A yankin da suka fiye da yadda aka sanya, wannan yana nufi cewa za a siyayi chillers, wanda zai kara abubuwan da ke shiga aiki da kuma karamin abubuwan da ke shiga aiki.

Solid Bed Adsorption: Lokacin da tsarin tashin abu yana muhimmi

Don ƙarfi na amfani da H₂S zuwa wani yawa ta ƙasa daga ppm—sannan kuma amsa suka gano sabon tashin LNG ko amfani da fuel cell—sistem na amine ba su iya samun hanyar daidai ba. Wannan ne kamar yadda solid bed adsorption za a amfani da ita. ZnO beds suna da fahimta ta musamman: H₂S ya zama da ZnO don samun zinc sulfide, wanda ya kare a cikin bed don yadda ya faru kafin ya rufe. Algori ta yawa ta zama babu wani abu da ke nufin, ba ta bukata kuma kuma yadda ya ke amfani da abubuwan da suka tsara, kuma ta bayyana H₂S na gaba ta ƙasa daga 1 ppm kafin ya rufe.

Amma akwai wani abu da ke ciki. Solid beds suna da yawa ta kawo abubuwa da suka rufe. Bayan ZnO ya rufe daga kowane siffa, bed ya kamata a saita ko a saita shi kafin ya rufe, wanda zai nufin yadda ya ke rufe. Wani mahallin da ke bayar da LNG a Qatar ya amfani da mahaɗin ZnO guard beds a sama, ya saita su a juna ta amfanin da suka rufe don haka yadda liquefaction train ba ta gane kuma yadda sulfur ya rufe. Alhamdulillah, aljebra ta rufe idan yadda gas da aka saita ta nufin ya rufe kafin ya rufe abubuwan da suka rufe—amma don abubuwan da suka rufe a yawa ta kawo abubuwa da suka rufe, amine treating ya rufe a yawa ta kawo abubuwa da suka rufe.

Farko na Mabuwa da Yadda Mai Tsoro

Sistemu na mabuwa suka ƙara alama a cikin farko na kuma sullubu na sulfur, amma a cikin yadda suka dace da CO₂ wanda ke nuna farko na pressure ya zama babban sabon farko. Mabuwa na polymer wanda suka cika gaba daya za su iya kuma H₂S daga wasu nisba na % zuwa ƙarshen 100 zuwa 200 ppm a cikin yadda mai sau daya. Alama na farko ne shine yadda ta fuskanci: ba a amfani da kimiyar ba, ba a amfani da hanyar yin abin tsaki ba, kuma ba a amfani da abubuwan da suka yi ayyana ba. Wani masu amfani na Permian wanda ya amfani da mabuwa a cikin yadda mai sau daya a 30 MMscfd ya bayyana cewa yadda ya yi ayyana ya kasance 40% ƙasa don amfani da amine unit wanda ya sauya.

Amma, mabuwa ba su kuma babban halin da ke taka da dukkan abubuwa. Su ke kusurci a cikin hydrocarbons mai yawa wanda za su iya kuma ko kuma matrix na polymer. Ayyinin farko na amfani da mabuwa don kare abubuwan da suka dace da ruwa da abubuwan da suka dace da kwayoyi suna da muhimci, kuma yadda mabuwa suka yi ayyana ya kasance ƙasa a lokacin da za su iya kuma gaba daya na mabuwa wanda ke dace da farko.

Taimanin Tashin Kasa: Yana Zama Ƙaramin 99.9%

Wannan lamba ta nuna abin da ke kusanci a lota: wani tashin sulfur na Claus mai zuwa biyu zuwa uku na sarrafa yana samun ƙaramin sulfur daga 93 zuwa 98% . Wannan sulfur da ya kashe a tashin kasa ba ta fadu na al'umma kuma—yana kuma ta zama abin da aka lost. Tashin tashin kasa (TGTUs) yana gudanar da wannan shugaban da yake tsayayen sulfur masu zuwa H₂S, sannan yana gudanar da wannan tashin a cikin amine absorber mai tsari .

Lambobi suna da muhimmanci. Daga wani TGTU da ke cikin, karamin sulfur na sarrafa zai iya zama ƙaramin 99.9%. Wani refinery a Gulf Coast na Amurka ya saita tashin Claus ta da ake amfani da shi da TGTU kuma ya rage SO₂ emissions da over 90% sannan ya samun ƙaramin 12 tons na sulfur kafin rana—abinci da ya kashe a cikin stack. Waqtar da aka samu shine ta zama ƙaramin 18 months, wanda ya haifar da shugaban sulfur da aka sale da kuma abubuwan da aka lost na emissions.

Kadanin tushen TGTU shi ne amsa na solvants. MDEA mai tsari ya zama, amma amsa mai gaskiya da aka buƙata don yadda suka yi aminin tail gas suna ƙara H₂S kuma a yawan yarwa—da hanyar 50°C lean amine—wanda ya ƙare ayyukan chillers da ke kara abu. don wasu ƙwarai na yankin ƙafin ko wasu da ke da ƙananan al'ada na yadda, wannan shi ne ayyukan da ke cire.

Yi wani ra'ayi: Al'amarun da suka dace don amsa

Amsa teknikin kuskuren sulfur ba ta zama amsa “maki” na opsiyon ba—amma ta zama amsa tekniki da ke dace da yadda da ayyukan da suka ci gaba. Wannan shine da ke sauyi ayyukan:

1. Kadarin sulfur na feed. H₂S mai yawa (ta ƙasa 5%) yana nufin amine treating da Claus unit don kuskuren sulfur. H₂S mai gashi (ta ƙasa 100 ppm) zai iya haɗa da adsorber mai gashi.

2. Yadda na flow. Amsa na amine zai ƙara a matsayin ekonomi; membranes da solid beds suna da abubuwan da suka dace da yadda na capacity.

3. CO₂ co-absorption. Idan CO₂ slip yana da kimyar, sistemai na MDEA suna da ƙarfin. Idan CO₂ kuma ya kamata ku cire, amine mai tsaya ko solvent na fizikal zai iya zama mafi kyau.

4. Takwasin bayani na abu. LNG feed yana bukatar H₂S a tsaki da ppm. Gas na pipeline zai iya gaskiya 4 zuwa 10 ppm. Idan takwasin bayani ta zama ƙarami, kuna zauna kadan.

5. Sarari na gida. A yankin da suka yi amfani da sarari na SO₂, kominshin na Claus + TGTU zai iya amincewa ne a matsayin wajib.

Wani abu da suka bayyana su masu amfani: kada ka sao kalmomi na solushin. Wani gas plant na wasu daga West Texas ya dauki shekara biyu don rarraba sistem na amine-da-membrane, amma ya sanya shi bayan sauya saboda composition na feed ta zama mafi kyau da aka san. Wani MDEA unit mai yawa zai iya aiki a kadan da kudin kasa. Kadan lokaci teknoliji mafi kyau shine wanda aka bayyana a shekara hudu.

Kwalitas da Aiki suna da muhimmi kamar teknoliji

Alkimiya ta fahimtar sosai. Alatun da suka cire a gida ne. Wani abu ne da ke farka tsarin samun sulfur daga project na suka kara yawa da wadanda suka shiga karamin kuɗi—yadda aka sanya alatu, yadda aka gina alatu, da tattalin arziki na masu amfani da alatu. Alatu mai ƙarfi ba ta tabbata da amine ba ta zama a gas na gaba ba. Alatu mai ƙarfi ba ta tabbata da reboiler ba ta tabbata da yadda aka gina amine ba ta tabbata da yadda aka gina amine ba ta tabbata da H₂S zuwa gaba ba. Wadannan ba su abubuwan teori ba; suna zuwa a lokacin gudunmawa a cikin al'umma kowace shekara.

Don kuma yawan al’umma da suka yi amfani da wani abu da ke nufin gudunawa wadannan ƙarfin yadda ake amfani da shi, ake iya gudunawa wani abu da ke fahimci dukkanin tashin gas—from inlet separation to sulfur recovery—yana zama babbar farko. Al’umma kamar GreenFir suna ba da fasaha na amfani da kayan aikin da suka dawo da kuma tsarin kiyaye mai kyau don kayan aikin tashin gas da ke cikin wani kusur, kuma suka taimaka wadansu masu aiki na project don gudunawa wadannan al’alame da suka samu a lokacin da aka ci gaba da wani abu da ke cikin wani kusur da ke cikin wani kusur. Idan kusurin kiyaye sulfur ya zo da ke gudunawa, ya zama mafi kyau don gudunawa, kuma gas yana kai da mahallin da ke cikin shari’a daga rabi day