FCC轻汽油醚化改性β沸石催化剂的成型条件研究

Study on shaping condition of modified β zeolite catalyst for FCC light gasoline etherification

采用等体积浸渍法、不同的浸渍次序制备了二元改性P-Mo/Hβ分子筛活性组分;在连续小型固定床反应器上醇烯摩尔比1.05条件下考察了P-Mo/Hβ在挤条成型过程中各因素对其醚化性能的影响以及β沸石成型后再浸渍的催化剂活性。结果表明:同步浸渍法均比分步浸渍法改性效果好;添加扩孔剂聚乙二醇(PEG)有利增大催化剂比表面积,PEG的不同种类和用量、HNO3用量对催化剂醚化活性影响很大,-γAl2O3用量影响不显著;通过比较,最佳的工艺成型条件为:w(PEG-4000)=10%,w(γ-Al2O3)=20%,w(浓HNO3)=10%,P-Mo/Hβ挤条成型经水热稳定化后,70℃时总叔碳烯烃转化率达54.33%,接近阳离子交换树脂催化剂水平,且有良好的再生性能。

A etherification catalyst P-Mo/H β was prepared and the influence of the preparation factors(pore-expanding agent PEG,peptizing agent HNO_3,binderγ-Al_2O_3 and hydrothermal treatment)on etherification performance of the catalyst were investigated in a continuous fixed-bed reactor with methanol and tert-olefins molar ratio 1.05.It was shown that impregnating-meanwhile was superior to impregnating-respectively.The appropriate addition of PEG could effectively increase surface area of the catalyst.Addition of PEG and HNO_3 and hydrothermal treatment had significantly affected the etherification activity whileγ-Al_2O_3 inversely.By comparison,the optimal shaping condition was PEG-4000(10%),γ-Al_2O_3(20%),HNO_3(10%) and after hydrothermal treatment the total conversion of tert-olefins was up to 54.33% at 70?℃,which was comparable with resin catalyst,and the shaped catalyst had good regeneration.