Cire ƙazanta masu cutarwa a cikin iskar gas da abubuwan da za su iya taurarewa yayin aikin cryogenic. Kamar hydrogen sulfide, carbon dioxide, ruwa, babban hydrocarbon da mercury. Iskar gas ɗin da nau'ikan tsire-tsire na LNG daban-daban ke sarrafawa ya bambanta, don haka hanyoyin magani da hanyoyin magance su ma sun bambanta.
Iskar acid gabaɗaya tana nufin H2S, CO2, cos, RSH da sauran ƙazanta na yanayin iskar gas. Cire iskar acid galibi ana kiranta desulfurization da decarbonization, ko kuma desulfurization a al'ada. Lokacin tsarkake iskar gas, ana iya cire H2S da CO2 a lokaci guda, saboda ana iya cire waɗannan abubuwan guda biyu tare a cikin hanyar alcohol amine da tsarkakewar molecular sieve.
2.3.2 Zaɓin hanyar cire sulfur
A cikin sashin shaye-shayen iskar gas, akwai hanyoyi guda uku na tsarkakewa, wato hanyar amine ta alcohol, hanyar hot potash (benfied) da kuma hanyar sulfonol amine.
Mercury: kasancewar mercury na iya lalata kayan aikin aluminum sosai. Idan akwai mercury (gami da sinadarai masu kama da mercury, ions na mercury da mahaɗan mercury na halitta), aluminum zai yi aiki da ruwa don samar da samfuran lalata farin foda, wanda zai lalata halayen aluminum sosai. Ƙaramin adadin mercury ya isa ya haifar da mummunar illa ga kayan aikin aluminum, kuma Mercury zai kuma haifar da gurɓataccen muhalli da lahani ga ma'aikata yayin gyarawa. Saboda haka, ya kamata a iyakance yawan sinadarin mercury. Cire mercury ya dogara ne akan amsawar mercury da sulfur a cikin wani abu mai kama da catalytic reactor.
Babban sinadarin hydrocarbon: yana nufin hydrocarbons sama da C5 +. A cikin hydrocarbons, lokacin da nauyin kwayoyin halitta ya canza daga ƙanana zuwa babba, zafin tafasarsa yana canzawa daga ƙasa zuwa babba. Saboda haka, a cikin zagayowar iskar gas mai narkewa, manyan hydrocarbons koyaushe ana tarawa da farko. Idan ba a raba babban sinadarin hydrocarbon da farko ba, ko kuma a raba shi bayan narkewa, babban sinadarin hydrocarbon na iya daskarewa ya toshe kayan aiki. Ana cire manyan hydrocarbons ta hanyar sieve na kwayoyin halitta da sauran masu shaye-shaye yayin bushewa, sauran kuma ana raba su ta hanyar rabuwar cryogenic.
Cos: Ana iya jika shi da ɗan ƙaramin ruwa don samar da H2S da CO2, wanda ke haifar da tsatsa ga kayan aikin. Yana da sauƙin haɗawa da propane da aka dawo da shi. Yawanci ana cire shi tare da H2S da CO2 yayin cire acidity.
Helium: Iskar gas ita ce babbar hanyar samun helium kuma ya kamata a raba ta a yi amfani da ita. Tana da babban amfani ta hanyar haɗakar rabuwar membrane da rabuwar cryogenic.
Nitrogen: ƙaruwar abun da ke cikinsa zai sa fitar da iskar gas ta halitta ya fi wahala. Ana amfani da hanyar walƙiya ta ƙarshe gabaɗaya don cirewa daga LNG.
Babban sinadarin iskar gas shine methane (CH4), kuma matsakaicin zafinsa shine 111k (- 162 ℃).
Yawan methane mai ruwa a wurin tafasa na yau da kullun shine 426kg / m3, kuma yawan methane mai iskar gas a yanayin da aka saba shine 0.717kg / m3, tare da bambanci kusan sau 600. Babban bambanci a cikin girma shine babban dalilin adanawa da jigilar iskar gas mai ruwa.
Lokacin Saƙo: Disamba-03-2021