Kedu ihe bụ Silica Alumina Ratio nke Zeolite Molecular Sieve

Kedu ihe bụ Silica Alumina Ratio nke Zeolite Molecular Sieve?

Oke silica alumina (SiO₂/ AlO₃molar ratio) bụ isi ihe nhazi usoro maka isi arụmọrụ nke zeolite molecular sieves, na-emetụta kpọmkwem nkwụsi ike ha, nkesa saịtị acid, na pore topology. Ka anyị mụta maka ụdị - njirimara, nhazi -mmekọrịta arụmọrụ nke zeolite molecular sieves nwere silicon dị iche iche{3}}aluminom ruru, yana ngwa ha ndakọrịta na petrochemicals, gburugburu ebe obibi, wdg.

Nkọwa nke Silica Alumina Ratio

• Oke silica alumina na-ezo aka na molar ratio ma ọ bụ atomiki (Si/Al) nke silicon-oxygen tetrahedron (SiO)₄) na aluminom -oxygen tetrahedron (AlO₄) na molekụla sieve kpuchie. Na uru ya na-ekpebi njupụta ụgwọ nke usoro ahụ, na ụzọ nke ịkwụ ụgwọ cation.
• Silica alumina ratio molecular sieve nwere nnukwu njupụta ụgwọ na-adịghị mma na usoro ahụ, ma na-achọ nnukwu ụgwọ nkwụghachi ụgwọ cation. Ọkpụkpụ nke silica alumina ratio molecular sieve bụ nke siri ike Si{{1}O-Si bond na-achị, na usoro topological ya kwụsiri ike nke ukwuu. The silica alumina ratio na-achịkwa acid ike, pore nkesa nkesa na hydrophobicity nke molekụla sieve, na-eme ka ọ dabara maka dị iche iche ụlọ ọrụ ndapụta.

Nkewa nke Zeolite Molecular Sieve

Usoro iwu nke Silica Alumina Ratio

• Usoro nke acidity: Aluminom atom bụ isi iyi nke saịtị Brønsted acid, na silica alumina ratio na-emetụta kpọmkwem njupụta acid na ike: Mgbe silica alumina ratio na-abawanye site na 20 ruo 150, ngụkọta nke saịtị acid na-adịghị ike (desorption na 120 degrees ) na ebe acid siri ike (desorption) na-ebelata site na 4000% site na 4000 SM. Ọnụ ọgụgụ nke saịtị acid siri ike na oke silica alumina (dị ka ZSM-5-300) na-ebelata, na-egbochi mmeghachi omume nke ikuku hydrogen, na propylene selectivity na-abawanye ruo 81.5%.
• Ọdịdị pore na arụmọrụ adsorption: Mgbe nha silica alumina nke ZSM-22 molecular sieve na-abawanye site na 40 ruo 130, ụda pore na-ebu ụzọ na-abawanye ruo 0.25 cm³/ g wee na-agbada ruo 0.18 cm³/g, because the framework shrinkage is aggravated under high silicon conditions. ZSM-5 molecular sieve with a silica alumina ratio of >100 nwere ikike mgbasa ozi nke 41 mg / g maka toluene, nke dị 70% dị elu karịa nke ZSM-5 na silica alumina ratio nke 38, n'ihi na mmụba nke hydrophobicity na-ebelata mgbasa ozi asọmpi nke mkpụrụ ndụ mmiri.
• Nkwụsi ike nke okpomọkụ na ịdịte aka hydrothermal: Ụdị dị ala-silicon Y- (SiO₂/Al₂O₃=2) na-ada n'ọkpụkpụ ọkpụkpụ na ogo 660, ebe elu{2}}silicon ZSM-5 (SiO)₂/Al₂O₃>30) nwere ike iguzogide okpomọkụ ruo ogo 900. Mgbe silica alumina ratio na Cu / SSZ-13 catalyst na-abawanye site na 6 ruo 16, ọnụ ọgụgụ njigide ọrụ SCR na-abawanye site na 45% ruo 85% mgbe ọgwụgwọ hydrothermal gasịrị na 800 degrees / 16h, n'ihi mbelata nke nkwekọrịta nkwekọrịta.

Silica Alumina Ratio adaptation Strategy na Ngwa nrụpụta

• Fluid catalytic cracking (FCC): Mgbe silica alumina ratio nke USY molecular sieve bụ 6-8, coke selectivity na-ebelata site na pasent 2.5 na mmanụ ọkụ na-abawanye site na 3%.
• Methanol ka olefins (MTO): Mgbe nha silica alumina nke SAPO-34 molecular sieve bụ 0.3-0.5, ethylene / propylene selectivity ruru 80%. Oke silica alumina dị elu na-eme ka mkpokọ carbon nke polycyclic aromatic hydrocarbons wee bute nkwụsị.
• VOCs adsorption: ikike mgbasa ozi nke ZSM-5 molecular sieve na silica alumina ratio nke 300 maka usoro benzene bụ 120 mg / g, na oge ntinye na-agbatị ruo 66 min, nke dị mma karịa 40 mg / g nke carbon arụ ọrụ.
• Mwepụ NOx: Mgbe ọnụọgụ silica alumina nke Cu / LTA catalyst bụ 16-23, ọnụọgụ ntụgharị NOx na-anọgide na 90% mgbe ịka nká hydrothermal na ogo 600, nke nwere ma ọrụ dị elu na ogologo oge.
• Ntọhapụ ọgwụ a na-achịkwa: obere silica alumina ratio (1.5 ~ 2.0) ụdị A zeolite molecular sieve na-enweta ntọhapụ nke ibuprofen na-adịgide adịgide site na nhazi nha nha, yana ọnụego ntọhapụ 24h nke 95%.
• CO₂ijide: Amine{0}}ụdị X zeolite molecular sieve arụrụ ọrụ (silica alumina ratio 2.5) na-ejigide CO₂ikike adsorption nke 12 wt% n'okpuru ọnọdụ iru mmiri, a na-abawanye nguzogide mmiri ya ugboro 3.