Izisefu zemolekyulizisetyenziswa ngokubanzi kumashishini ekhemikhali kunye nepetrochemical kwiinkqubo ezahlukeneyo zokwahlula kunye nokucoca. Esinye sezicelo zabo ezibalulekileyo kukuhlanjululwa kwegesi ye-hydrogen. I-Hydrogen isetyenziswa kakhulu njenge-feedstock kwiinkqubo ezahlukeneyo zemizi-mveliso, ezifana nokuveliswa kwe-ammonia, i-methanol, kunye nezinye iikhemikhali. Noko ke, ihydrogen eveliswa ngeendlela ezahlukahlukeneyo ayisoloko inyulu ngokwaneleyo ukuze isetyenziswe kwezi zinto, yaye ifuna ukucocwa ukuze kususwe ukungcola okunjengamanzi, ikharbon diokside nezinye iigesi. Iisefu zemolekyuli zisebenza kakhulu ekususeni obu kungcola kwimijelo yegesi yehydrogen.

I-Sieves ye-molekyuli zizinto ezixubileyo ezikwaziyo ukukhetha iimolekyuli ze-adsorb ngokusekelwe kubukhulu kunye nokumila kwazo. Ziquka isakhelo se-cavities edibeneyo okanye ii-pores ezinobungakanani obufanayo kunye nokumila, ezivumela ukuba zikhethe ngokukhetha iimolekyuli ezihambelana nale mibhobho. Ubungakanani bemigodi bunokulawulwa ngexesha lokuhlanganiswa kwe-molecular sieve, okwenza kube lula ukulungelelanisa iimpawu zabo kwizicelo ezithile.

Kwimeko yokuhlanjululwa kwe-hydrogen, iisefu ze-molecular zisetyenziselwa ukukhetha ngokukhetha amanzi kunye nobunye ukungcola kumjelo wegesi ye-hydrogen. I-molecular sieve ibhengeza iimolekyuli zamanzi kunye nobunye ukungcola, ngelixa ivumela iimolekyuli zehydrogen ukuba zidlule. Ukungcola kwe-adsorbed kunokuhlanjululwa kwi-molecular sieve ngokuyifudumeza okanye ngokuyicoca ngomjelo wegesi.

Eyona isetyenziswa kakhului-molecular sieveukuhlanjululwa kwe-hydrogen luhlobo lwe-zeolite ebizwa ngokuba yi-3A zeolite. Le zeolite inobungakanani be-pore ye-3 angstroms, evumela ukuba ikhethe ngokukhetha amanzi kunye nokunye ukungcola okunomlinganiselo omkhulu we-molecular kune-hydrogen. Ikwakhetha kakhulu amanzi, nto leyo eyenza ukuba asebenze kakhulu ekususeni amanzi kumsinga wehydrogen. Ezinye iintlobo ze-zeolite, ezifana ne-4A kunye ne-5A zeolites, zingasetyenziselwa ukuhlanjululwa kwe-hydrogen, kodwa azikhethi kakhulu emanzini kwaye zinokufuna amaqondo obushushu aphezulu okanye uxinzelelo lokuchithwa.

Ukuqukumbela, iisefu zemolekyuli zisebenza kakhulu ekucoceni igesi ye-hydrogen. Zisetyenziswa ngokubanzi kumashishini ekhemikhali kunye nepetrochemical ukuveliswa kwegesi ye-hydrogen ecocekileyo kakhulu kwizicelo ezahlukeneyo. I-3A zeolite yeyona nto isetyenziswa ngokuqhelekileyo i-molecular sieve yokuhlanjululwa kwe-hydrogen, kodwa ezinye iindidi ze-zeolite nazo zingasetyenziswa ngokuxhomekeke kwiimfuno ezithile zesicelo.

Ngaphandle kwee-zeolites, ezinye iintlobo ze-molecular sieves, ezifana ne-activated carbon kunye ne-silica gel, zingasetyenziselwa ukuhlanjululwa kwe-hydrogen. Ezi zixhobo zinendawo ephezulu kunye nomthamo ophezulu we-pore, obenza ukuba basebenze kakhulu ekubhengezeni ukungcola okuvela kwimijelo yegesi. Nangona kunjalo, abakhethi kakhulu kunezeolites kwaye banokufuna amaqondo obushushu aphezulu okanye uxinzelelo lokuvuselelwa.

Ukongeza kokuhlanjululwa kwe-hydrogen,iisefu zemolekyulizikwasetyenziswa kwezinye izicelo zokwahlula igesi kunye nokucoca. Zisetyenziselwa ukususa ukufuma kunye nokungcola emoyeni, initrogen, kunye neminye imijelo yegesi. Zikwasetyenziselwa ukwahlula iigesi ngokusekwe kubungakanani bazo bemolekyuli, njengokuhlukana kweoksijini kunye nenitrogen emoyeni, kunye nokwahlulwa kweehydrocarbons kwigesi yendalo.

Ngokubanzi, i-molecular sieves zizinto eziguquguqukayo ezinoluhlu olubanzi lwezicelo kumashishini ekhemikhali kunye nepetrochemical. Zibalulekile kwimveliso yeegesi ezicocekileyo, kwaye zibonelela ngeenzuzo ezininzi kwiindlela zokwahlula ngokwesiko, njengokusetyenziswa kwamandla aphantsi, ukukhetha okuphezulu, kunye nokusebenza ngokulula. Ngokunyuka kwemfuno yeegesi ezicocekileyo kwiinkqubo ezahlukeneyo zamashishini, ukusetyenziswa kweesefu zemolekyuli kulindeleke ukuba kukhule kwixesha elizayo.