一种分子筛催化剂其制备方法和应用

一种用于烯烃芳构化反应的改性分子筛催化剂，由分子筛与粘接剂组成，其中粘接剂占催化剂重量的20～80％。将所用的分子筛置于浓度为 0.01-5M的碱溶液中，室温～100℃下处理0.1-50小时；经洗涤、干燥，与粘接剂挤条成型，经氨交换，干燥，400～1000℃下焙烧，得目标产物。与普通未处理的催化剂相比，本发明的改性分子筛催化剂表现出很好的混合烯烃芳构化反应稳定性。带填

水合氧化锆的晶化方式对Pt/WO_3-ZrO_2异构化活性的影响

采用不同方法制备了一系列具有一定晶相结构的水合ZrO2,考察了制备方法对水合ZrO2晶化方式及Pt/WO3-ZrO2催化剂催化正己烷异构化活性的影响.采用X射线衍射,Raman光谱和NH3-程序升温脱附对催化剂进行了表征.结果表明,水合ZrO2的晶化方式与制备时氧气的存在与否有关,也大大影响了催化剂的异构化活性.以无氧条件下制备的水合ZrO2为载体时,Pt/WO3-ZrO2催化剂具有较高的异构化活性,而以在空气气氛中制得的水合ZrO2为载体时,Pt/WO3-ZrO2几乎无异构化活性

studyonthermodynamicsofbutenecatalyticcrackingtopropeneandethene

By analyzing the reaction process and calculating the thermodynamics of each reaction in butene catalytic cracking combining the factual product distribution, the formation mechanism of each product and its influence factors have been studied. The calculated equilibrium constants showed that high temperature favored C4H8 cracking to C3H6 and C2H4, but relatively low temperature and high pressure were needed in order to increase the molar ratio of C3H6/C2H4 in the products. The equilibrium constants of alkene hydrogen transfer and oligomerization-dehydrocyclization-aromatization reaction were 10 similar to 1000 times as high as those of C4H8 cracking to C3H6, which implied that it was favorable to form aromatics and low carbon alkanes under the cracking conditions compared with C3H6 and C2H4 production. In order to suppress the formation of aromatics and low carbon alkanes dynamically, it was very important to develop catalysts with high selectivity for C3H6 and C2H4, and to optimize reaction conditions such as relatively high WHSV and high temperature. In the mean time, the amount of C5+ hydrocarbons was in a low level under the catalytic cracking conditions. The thermodynamics result was confirmed and supplemented by its application in catalyst design and reaction condition optimization during butene catalytic cracking to C3H6 and C2H4

effectsofsteamtreatmentonacidityofzsm5anditscatalyticperformanceinbutenecracking

Propylene is one of the fastest growing petrochemicals, driven primarily by the high growth rate of polypropylene. The traditional methods to produce propylene cannot satisfy its demand. To increase the production of propylene, the catalytic cracking of low value C4+ hydrocarbons, by-products of petrochemical industry, to propylene and ethylene was investigated. The ZSM-5 zeolite was modified by steam treatment at different temperatures and for different time, and its acidity was measured by NH3-TPD technique. With increasing treatment temperature and time, the acid density and the acid strength of ZSM-5 decreased. When used as a catalyst for butene cracking, the ZSM-5 with low acid density and weak acid strength was favorable to enhance the yield of propylene plus ethylene, besides decreased the production of aromatics and low carbon paraffins. By leaching out the non-skeletal Al produced by the steam treatment with citric acid, the pore volume of ZSM-5 was enlarged and had a better capacity of accommodating the carbon deposit so that the catalyst life was prolonged. The yield of propylene plus ethylene could be enhanced if the reaction conditions were properly selected, as well as the yield of aromatics and paraffins could be decreased. The optimum conditions were as follows: WHSV = 3.5similar to8.8 h(-1), p = 0.06similar to0.1 MPa and theta = 600similar to620 degreesC

effectsofsteamtreatmentonacidityofzsm5anditscatalyticperformanceinbutenecracking

Propylene is one of the fastest growing petrochemicals, driven primarily by the high growth rate of polypropylene. The traditional methods to produce propylene cannot satisfy its demand. To increase the production of propylene, the catalytic cracking of low value C4+ hydrocarbons, by-products of petrochemical industry, to propylene and ethylene was investigated. The ZSM-5 zeolite was modified by steam treatment at different temperatures and for different time, and its acidity was measured by NH3-TPD technique. With increasing treatment temperature and time, the acid density and the acid strength of ZSM-5 decreased. When used as a catalyst for butene cracking, the ZSM-5 with low acid density and weak acid strength was favorable to enhance the yield of propylene plus ethylene, besides decreased the production of aromatics and low carbon paraffins. By leaching out the non-skeletal Al produced by the steam treatment with citric acid, the pore volume of ZSM-5 was enlarged and had a better capacity of accommodating the carbon deposit so that the catalyst life was prolonged. The yield of propylene plus ethylene could be enhanced if the reaction conditions were properly selected, as well as the yield of aromatics and paraffins could be decreased. The optimum conditions were as follows: WHSV = 3.5similar to8.8 h(-1), p = 0.06similar to0.1 MPa and theta = 600similar to620 degreesC

ptso42zro2al2o3在正己烷异构化反应中的催化行为

采用连续流动的固定床微反装置考察了Pt/SO42-/ZrO2-Al2O3（PSZA）在正己烷异构化反应中的催化行为。采用NH3-TPD、H2-TPR及TG表征了催化剂的酸性、还原性能及硫物种含量。结果表明，PSZA的初始异构化催化活性几乎不受反应温度的影响，而稳定性则与反应温度密切相关。低温下反应，催化剂在短时间内迅速失活，而提高反应温度可大大提高PSZA的反应稳定性。PSZA具有良好的再生性能，与新鲜催化剂相比，多次再生后的催化剂异构化催化活性基本没有变化。PSZA在低温下的快速失活与其催化活性中心产生的机理有关，而与其硫损失或硫物种的还原无关。在异构化反应过程中，催化剂通过氢溢流可产生强酸活性中心，并在反应过程中不断被消耗；在高温下通过氢溢流不断产生新的强酸中心，使催化活性保持稳定；而低温下氢溢流难以发生，消耗的强酸活性中心不能及时补充，使催化活性下降。

ptso42zro2al2o3在正己烷异构化反应中的催化行为

采用连续流动的固定床微反装置考察了Pt/SO42-/ZrO2-Al2O3（PSZA）在正己烷异构化反应中的催化行为。采用NH3-TPD、H2-TPR及TG表征了催化剂的酸性、还原性能及硫物种含量。结果表明，PSZA的初始异构化催化活性几乎不受反应温度的影响，而稳定性则与反应温度密切相关。低温下反应，催化剂在短时间内迅速失活，而提高反应温度可大大提高PSZA的反应稳定性。PSZA具有良好的再生性能，与新鲜催化剂相比，多次再生后的催化剂异构化催化活性基本没有变化。PSZA在低温下的快速失活与其催化活性中心产生的机理有关，而与其硫损失或硫物种的还原无关。在异构化反应过程中，催化剂通过氢溢流可产生强酸活性中心，并在反应过程中不断被消耗；在高温下通过氢溢流不断产生新的强酸中心，使催化活性保持稳定；而低温下氢溢流难以发生，消耗的强酸活性中心不能及时补充，使催化活性下降。