He aha ka Silica Alumina Ratio o Zeolite Molecular Sieve

He aha ka Silica Alumina Ratio o Zeolite Molecular Sieve?

ʻO ka ratio silica alumina (SiO₂/AlO₃molar ratio) he ʻāpana hoʻoponopono koʻikoʻi no ka hana koʻikoʻi o nā kānana molekole zeolite, e hoʻopili pololei ana i ko lākou paʻa paʻa, ka hāʻawi ʻana i ka pae waikawa, a me ka topology pore. E aʻo kākou e pili ana i ke ʻano-ʻano, hoʻolālā-pili hana o nā kānana molekala zeolite me nā lākiō alumini silika like ʻole, a me ko lākou hoʻopili pono ʻana i nā petrochemicals, pale kaiapuni, etc.

Wehewehe o Silica Alumina Ratio

• ʻO ka lakio alumina silica e pili ana i ka ratio molar a i ʻole lākiō ʻātoma (Si/Al) o ke silikona-oxygen tetrahedron (SiO₄) i ka alumini -oxygen tetrahedron (AlO₄) i loko o ka molecular sieve framework. A ʻo kāna waiwai e hoʻoholo ai i ka nui o ka uku o ka anga, a me ke ʻano o ka uku cation.
• Haʻahaʻa silica alumina lākiō molecular kānana he kiʻekiʻe maikaʻiʻole hoʻopaʻa 'ia i loko o ka anga, a koi i ka nui o ka cation uku. ʻO ke kiʻina o ka silica alumina ratio molecular sieve e hoʻomalu ʻia e nā kaula Si-O-Si ikaika, a ʻo kona ʻano topological he paʻa wela loa. Hoʻoponopono ka silica alumina ratio i ka ikaika o ka waikawa, ka nui o ka pore a me ka hydrophobicity o ka molecular sieve, e kūpono ana ia no nā ʻano ʻoihana like ʻole.

Hoʻohui ʻia ʻo Zeolite Molecular Sieve

Ka Mechanism Hooponopono O Silica Alumina Ratio

• ʻO ka hoʻoponopono Acidity: ʻO nā ʻātoma alumina ke kumu o nā kahua ʻakika Brønsted, a ʻo ka silica alumina ratio pili pono i ka nui o ka waikawa a me ka ikaika: Ke piʻi ka silica alumina ratio mai 20 a 150, ʻo ka nui o nā wahi waikawa nāwaliwali (desorption ma 120 desorption) a me nā wahi waikawa ikaika (desorption ma 400 degere) o HZSM05%. ʻO ka hapa o nā wahi ʻakika ikaika i ka lakio silica alumina kiʻekiʻe (e like me ZSM-5-300) e emi iho ana, e kāohi ana i ka hoʻololi ʻana o ka hydrogen, a piʻi ka propylene selectivity i 81.5%.
• ʻO ka hana pore a me ka hana adsorption: Ke piʻi ka silica alumina ratio o ZSM-22 molecular sieve mai 40 a 130, piʻi mua ka nui o ka pore i 0.25 cm.³/g a emi iho i ka 0.18 knm³/g, because the framework shrinkage is aggravated under high silicon conditions. ZSM-5 molecular sieve with a silica alumina ratio of >Loaʻa iā 100 ka mana adsorption o 41 mg / g no toluene, ʻo ia ka 70% kiʻekiʻe ma mua o ka ZSM-5 me ka silica alumina ratio o 38, no ka mea, ʻo ka hydrophobicity i hoʻonui ʻia e hōʻemi i ka adsorption hoʻokūkū o nā mole wai.
• Paʻa wela a me ka lōʻihi o ka wai wela: ʻano haʻahaʻa -silicon Y-(SiO₂/Al₂O₃=2) e hāʻule ana ka iwi iwi ma 660 degere, ʻoiai ke kiʻekiʻe-silicon ZSM-5 (SiO₂/Al₂O₃>30) hiki ke pale i nā mahana a hiki i 900 degere. Ke piʻi ka silica alumina lākiō ma ka Cu / SSZ-13 catalyst mai ka 6 a hiki i ka 16, ke piʻi aʻe ka nui o ka mālama ʻana o ka hana SCR mai 45% a i 85% ma hope o ka mālama ʻana i ka hydrothermal ma 800 degere / 16h, ma muli o ka emi ʻana o ka uku dealumination.

Silica Alumina Ratio Adaptation Strategy I loko o nā noi ʻoihana

• Fluid catalytic cracking (FCC): Inā he 6-8 ka lākiō silica alumina o USY molecular sieve, e emi ana ke koho coke ma 2.5 pakeneka a piʻi ka hua aila māmā i 3%.
• Methanol i olefins (MTO): Ke 0.3-0.5 ka lakene silica alumina o SAPO-34 molecular sieve, hiki i ka ethylene/propylene selectivity i 80%. ʻO ke kiʻekiʻe kiʻekiʻe o ka silica alumina ratio e hoʻolalelale i ka waiho kalapona o polycyclic aromatic hydrocarbons a hoʻopau i ka hana.
• VOCs adsorption: ʻO ka mana adsorption o ZSM-5 molecular sieve me ka silica alumina ratio o 300 no ka benzene series he 120 mg / g, a ua hoʻonui ʻia ka manawa komo i 66 min, ʻoi aku ka maikaʻi ma mua o ka 40 mg / g o ka carbon activated.
• NOx ka wehe 'ana: I ka lakiona silica alumina o Cu/LTA catalyst he 16-23, ka NOx huli ana i ka helu ma 90% ma hope hydrothermal aging ma 600 degere, nona ka hana kiʻekiʻe a me ka lōʻihi.
• Hoʻokuʻu ʻia ka lāʻau lapaʻau i hoʻopaʻa ʻia: ʻO ka ratio silica alumina haʻahaʻa (1.5~2.0) ʻano A zeolite molecular sieve e hoʻokō i ka hoʻokuʻu mau ʻana o ka ibuprofen ma o ka hoʻoponopono ʻana i ka nui o ka pore, me ka helu hoʻokuʻu 24h o 95%.
• CO₂hopu: Amine-mea hana X zeolite molecular sieve (silica alumina ratio 2.5) mālama i ka CO₂hiki i ka adsorption o 12 wt% ma lalo o nā kūlana humid, a hoʻonui ʻia kona kūpaʻa wai e 3 mau manawa.