采用Na AlO2和HCl两步法对ZSM-5分子筛进行改性,运用XRD、SEM、NH3-TPD、N2吸附-脱附、ICP-OES、TG等方法对改性前后的分子筛进行表征。结果表明:经Na Al O2改性后的ZSM-5分子筛中引入了介孔,且分子筛的晶型、酸性、微孔体积等保持较好...采用Na AlO2和HCl两步法对ZSM-5分子筛进行改性,运用XRD、SEM、NH3-TPD、N2吸附-脱附、ICP-OES、TG等方法对改性前后的分子筛进行表征。结果表明:经Na Al O2改性后的ZSM-5分子筛中引入了介孔,且分子筛的晶型、酸性、微孔体积等保持较好,并具有较高的固相收率;酸洗前通过中间焙烧有利于消除孔道覆盖和恢复酸性。将改性后的分子筛应用于甲醇芳构化反应中,在温度400℃、压力0.15 MPa、质量空速1.9h-1的反应条件下,经0.45 mol/L Na Al O2改性的分子筛反应效果最优,产物芳烃收率可达41.9%,BTX收率达32.7%;与原粉分子筛相比,产物芳烃收率提高了3.8百分点,BTX收率提高了4.4百分点;同时,其反应稳定性可达30 h,较原粉延长了1倍多。展开更多
A series of pseudo-boehmite samples with their sulfate radicals(SO2-4) concentration ranging from 0.9% to 3.0% were prepared by the reaction of Na Al O2 solution on Al2(SO4)3 solution. The existing form of sulfate rad...A series of pseudo-boehmite samples with their sulfate radicals(SO2-4) concentration ranging from 0.9% to 3.0% were prepared by the reaction of Na Al O2 solution on Al2(SO4)3 solution. The existing form of sulfate radicals was investigated. Results have shown that sulfates in pseudo-boehmite included two parts, the soluble sulfate radicals and the insoluble sulfate radicals, which accounted for 99% of the total amount of sulfate radicals. XRD, low-temperature N2-adsorption, and TEM were used to characterize the properties of these pseudo-boehmite samples. Results have shown that the relative crystallinity and crystal size of pseudo-boehmite decreased with the increase of sulfate radicals in the support. In the meanwhile, the bound water content in pseudo-boehmite increased. The TEM images of pseudo-boehmite indicated that the pseudoboehmite was prone to become amorphous hydrated alumina. However, the effect of sulfate content on the specific surface area and pore structure of aluminium oxide was insignificant.展开更多
Pseudo-boehmite (PB) and γ-Al2O3 support are prepared by neutralization ofNaAlO2 solution with CO2(mixed gases) on bench scale. PB, typically loosely packed, fibrous particle/aggregate, is obtained by adjustingconcen...Pseudo-boehmite (PB) and γ-Al2O3 support are prepared by neutralization ofNaAlO2 solution with CO2(mixed gases) on bench scale. PB, typically loosely packed, fibrous particle/aggregate, is obtained by adjustingconcentration and flow rate of CO2 and concentration of NaAlO2 solution at a pH level lower than that commonlyassumed during neutralization. After calcination at different temperatures, γ-Al2O3 supports with different pore vol-ume and different pore size are prepared at different conditions.展开更多
摘要采用Na AlO2和HCl两步法对ZSM-5分子筛进行改性,运用XRD、SEM、NH3-TPD、N2吸附-脱附、ICP-OES、TG等方法对改性前后的分子筛进行表征。结果表明:经Na Al O2改性后的ZSM-5分子筛中引入了介孔,且分子筛的晶型、酸性、微孔体积等保持较好,并具有较高的固相收率;酸洗前通过中间焙烧有利于消除孔道覆盖和恢复酸性。将改性后的分子筛应用于甲醇芳构化反应中,在温度400℃、压力0.15 MPa、质量空速1.9h-1的反应条件下,经0.45 mol/L Na Al O2改性的分子筛反应效果最优,产物芳烃收率可达41.9%,BTX收率达32.7%;与原粉分子筛相比,产物芳烃收率提高了3.8百分点,BTX收率提高了4.4百分点;同时,其反应稳定性可达30 h,较原粉延长了1倍多。
基金financially supported by the SINOPEC(Contact No.111010)
摘要A series of pseudo-boehmite samples with their sulfate radicals(SO2-4) concentration ranging from 0.9% to 3.0% were prepared by the reaction of Na Al O2 solution on Al2(SO4)3 solution. The existing form of sulfate radicals was investigated. Results have shown that sulfates in pseudo-boehmite included two parts, the soluble sulfate radicals and the insoluble sulfate radicals, which accounted for 99% of the total amount of sulfate radicals. XRD, low-temperature N2-adsorption, and TEM were used to characterize the properties of these pseudo-boehmite samples. Results have shown that the relative crystallinity and crystal size of pseudo-boehmite decreased with the increase of sulfate radicals in the support. In the meanwhile, the bound water content in pseudo-boehmite increased. The TEM images of pseudo-boehmite indicated that the pseudoboehmite was prone to become amorphous hydrated alumina. However, the effect of sulfate content on the specific surface area and pore structure of aluminium oxide was insignificant.
摘要Pseudo-boehmite (PB) and γ-Al2O3 support are prepared by neutralization ofNaAlO2 solution with CO2(mixed gases) on bench scale. PB, typically loosely packed, fibrous particle/aggregate, is obtained by adjustingconcentration and flow rate of CO2 and concentration of NaAlO2 solution at a pH level lower than that commonlyassumed during neutralization. After calcination at different temperatures, γ-Al2O3 supports with different pore vol-ume and different pore size are prepared at different conditions.