Njira yatsopanoyi imatembenuza mpweya wa methane kukhala methanol wamadzimadzi.
Gulu la ofufuza lasintha bwino methane kukhala methanol pogwiritsa ntchito zitsulo zopepuka komanso zomwazika monga mkuwa munjira yotchedwa photo-oxidation. Zomwe zidachitika mpaka pano posintha gasi wa methane kukhala mafuta amadzimadzi pa kutentha kozungulira komanso kuthamanga (25 ° C ndi 1 bar, motsatana), malinga ndi kafukufuku wofalitsidwa m'magaziniyi. Chemical Communications.
Mawu akuti bar monga gawo lokakamiza amachokera ku liwu lachi Greek lotanthauza kulemera (baros). Mpiringidzo umodzi wofanana ndi 100,000 Pascals (100 kPa), pafupi ndi mpweya wokhazikika wa mumlengalenga pamtunda wa nyanja (101,325 Pa).
Zotsatira za kafukufukuyu ndi gawo lofunikira kwambiri pakupangitsa kuti gasi azitha kupezeka ngati gwero lamphamvu popanga mafuta ena osagwiritsa ntchito mafuta a petulo ndi dizilo. Ngakhale kuti gasi wachilengedwe ndi mafuta, kusinthidwa kwake kukhala methanol kumatulutsa mpweya wochepa wa carbon dioxide (CO2) kusiyana ndi mafuta ena amadzimadzi omwe ali m'gulu lomwelo.
Kusinthaku kunachitika chifukwa cha kutentha komanso kupanikizika, zomwe zingapangitse methane, mpweya wowonjezera kutentha, kugwiritsidwa ntchito kupanga mafuta. Ngongole: UFSCAR
Methanol ndi yofunika kwambiri popanga biodiesel komanso makampani opanga mankhwala ku Brazil, komwe amagwiritsidwa ntchito popanga zinthu zosiyanasiyana.
Kuphatikiza apo, kusonkhanitsa methane kuchokera mumlengalenga ndikofunikira kwambiri pakuchepetsa zotsatira zoyipa zakusintha kwanyengo popeza mpweya uli ndi kuthekera kochulukitsa ka 25 kothandizira kutentha kwa dziko monga CO2, mwachitsanzo.
“Pali mkangano waukulu pakati pa asayansi pankhani ya kukula kwa nkhokwe za methane padziko lapansi. Malinga ndi kuyerekezera kwina, atha kukhala ndi mphamvu kuwirikiza kawiri mphamvu zamafuta ena onse akaphatikiza. Pakusintha kwa zongowonjezera, tidzayenera kuyika methane iyi nthawi ina, "Marcos da Silva, wolemba woyamba wa nkhaniyi, adauza Agência FAPESP. Silva ndi Ph.D. wosankhidwa mu Dipatimenti ya Fizikisi ya Federal University of São Carlos (UFSCar).
Kafukufukuyu adathandizidwa ndi FAPESP, Bungwe la Higher Research Council (CAPES, bungwe la Unduna wa Zamaphunziro), ndi National Council for Scientific and Technological Development (CNPq, mkono wa Unduna wa Sayansi, Ukadaulo, ndi Kupanga zatsopano).
Malinga ndi Ivo Freitas Teixeira, pulofesa ku UFSCar, mlangizi wa thesis wa Silva komanso wolemba womaliza wa nkhaniyi, chithunzithunzi chomwe chinagwiritsidwa ntchito mu phunziroli chinali chinthu chatsopano. "Gulu lathu linapanga zatsopano kwambiri powonjezera oxidizing methane mu gawo limodzi," adatero. "M'makampani opanga mankhwala, kutembenuka kumeneku kumachitika kudzera mukupanga haidrojeni ndi CO2 mu magawo osachepera awiri komanso pansi pa kutentha kwambiri komanso kupanikizika. Kuchita bwino kwathu popeza methanol m'malo ocheperako, pomwe tikugwiritsanso ntchito mphamvu zochepa, ndi gawo lalikulu lopita patsogolo.
Malinga ndi Teixeira, zotsatilazi zimapanga njira yofufuzira m'tsogolomu pakugwiritsa ntchito mphamvu ya dzuwa pakusintha kumeneku, zomwe zingathe kuchepetsa kuwononga chilengedwe.
Photocatalysts
Mu labotale, asayansi apanga crystalline carbon nitride mu mawonekedwe a polyheptazine imide (PHI), pogwiritsa ntchito zitsulo zosakhala zolemekezeka kapena zapadziko lapansi, makamaka zamkuwa, kuti apange ma photocatalysts owoneka bwino.
Kenako adagwiritsa ntchito ma photocatalysts mu methane oxidation reactions ndi hydrogen peroxide ngati zoyambitsa. Chothandizira cha mkuwa-PHI chinapanga zinthu zambiri zamadzimadzi zomwe zimakhala ndi okosijeni, makamaka methanol (2,900 micromoles pa gramu ya zinthu, kapena µmol.g-1 mu maola anayi).
"Tinapeza chothandizira chabwino kwambiri ndi zinthu zina zofunika kwambiri pakupanga mankhwala, monga kugwiritsa ntchito madzi ochuluka komanso ochepa a hydrogen peroxide, omwe ndi oxidizing agent," adatero Teixeira. "Masitepe otsatirawa akuphatikizapo kumvetsetsa zambiri za malo amkuwa omwe akugwira ntchito muzinthuzo komanso momwe amachitira. Tikukonzekeranso kugwiritsa ntchito oxygen mwachindunji kupanga hydrogen peroxide muzochita zokha. Ngati zikuyenda bwino, izi zipangitsa kuti ntchitoyi ikhale yotetezeka komanso yothandiza pazachuma. ”
Mfundo ina yomwe gulu lipitiliza kufufuza zokhudzana ndi mkuwa. "Timagwira ntchito ndi mkuwa wobalalika. Pamene tinkalemba nkhaniyi, sitinkadziwa ngati tikulimbana ndi maatomu akutali kapena magulu. Tsopano tikudziwa kuti ndi magulu,” adatero.
Phunziroli, asayansi adagwiritsa ntchito methane yoyera, koma m'tsogolomu, adzachotsa mpweya kuchokera kuzinthu zongowonjezeranso monga biomass.
Malinga ndi bungwe la United Nations, methane mpaka pano yachititsa pafupifupi 30% ya kutentha kwa dziko kuyambira nthawi ya mafakitale isanayambe. Kutulutsa kwa methane kuchokera ku zochitika za anthu kutha kuchepetsedwa ndi 45% m'zaka khumi zikubwerazi, kupewa kukwera pafupifupi 0.3 ° C pofika 2045.
Njira yosinthira methane kukhala mafuta amadzimadzi pogwiritsa ntchito photocatalyst ndi yatsopano komanso yosapezeka pamalonda, koma kuthekera kwake posachedwa ndikofunikira. “Tidayamba kafukufuku wathu zaka zinayi zapitazo. Tsopano tili ndi zotsatira zabwino kwambiri kuposa za Pulofesa Hutchings ndi gulu lake mu 2017, zomwe zidalimbikitsa kafukufuku wathu, "adatero Teixeira, ponena za kafukufuku yemwe adasindikizidwa m'magaziniyi. Science ndi ofufuza ogwirizana ndi mayunivesite ku United States ndi United Kingdom, motsogozedwa ndi Graham Hutchings, pulofesa pa University of Cardiff ku Wales.
Zothandizira:
"Selective methane photooxidation into methanol pansi pazikhalidwe zofatsa zomwe zimalimbikitsidwa ndi ma atomu a Cu omwazika kwambiri pa crystalline carbon nitrides" ndi Marcos AR da Silva, Jéssica C. Gil, Nadezda V. Tarakina, Gelson TST Silva, José BG Filho, Klaus Krambrock, Markus Antonietti Caue Ribeiro ndi Ivo F. Teixeira, 31 May 2022, Chemical Communications.
DOI: 10.1039/D2CC01757A
"Aqueous Au-Pd colloids imathandizira kusankha CH4 oxidation ku CH3O ndi O2 under mild conditions” ndi Nishtha Agarwal, Simon J. Freakley, Rebecca U. McVicker, Sultan M. Althahban, Nikolaos Dimitratos, Qian He, David J. Morgan, Robert L. Jenkins, David J. Willock, Stuart H. Taylor, Christopher J. Kiely ndi Graham J. Hutchings, 7 September 2017, Science.
DOI: 10.1126/science.aan6515
