Study On Isomerization Performance Of Catalysts For Catalytic Cracking And Producing Isomerized Hydrocarbon

This article mainly uses Y,ZSM-35,SAPO-11,ZSM-5,β-type molecular sieves as raw materials,and selects sodium hydroxide,magnesium chloride,ferric chloride,chromium chloride,manganese chloride,and diammonium hydrogen phosphate as modifications.For raw materials,a series of modified molecular sieves and catalytic cracking catalysts were prepared by ion exchange method and impregnation method.The isomerization performance of the catalyst was investigated and a series of characterizations were performed.The activity of the above molecular sieves and catalysts was tested using a micro-reactive device,and the performance of the catalyst was evaluated by ACE evaluation device.(1)The catalyst was prepared by using NaY as raw material,metal and phosphorus as modifiers.The study found that loading metal and phosphorus elements can enrich the pore structure of the catalyst,increase the mesopore volume,and effectively adjust the amount of acid.The micro-reaction activity of the catalyst loaded with metal elements was reduced,while the activity of the catalyst loaded with phosphorus elements was increased.The ACE evaluation results show that the catalyst conversion rate of 0.6% Mg and 6% Mn is increased compared with the blank sample,while the catalyst conversion rate of 0.9% Fe,3% Cr and 1% P is reduced,indicating that 0.6% Mg and 6% Mn can effectively improve the catalytic cracking performance of the catalyst.The catalyst isomerization index loaded with 0.6% Mg,0.9% Fe,and 3% Cr increased by 0.15,0.04,and 0.03 percentage points,and the catalyst isomerization index loaded with 6% Mn and 1% P decreased by 0.13 and 0.02 percentage point.It can be seen that the loading of 0.6% Mg,0.9% Fe and 3% Cr can improve the isomerization performance of the catalyst,while the loading of 6% Mn and 1% P does not improve the isomerization performance of the catalyst.Considering from the aspects of catalytic cracking performance and isomerization performance,under the existing experimental conditions,0.6% of Mg is the best loading amount and the best loading metal element.(2)The catalyst was prepared with NaY as the raw material and NaOHas the modifier.The results showed that NaOH modification can enrich the pore structure of the catalyst,effectively increase the specific surface area,mesopore volume and average pore size,but the effect of NaOH modification on isomerization small.(3)Catalysts were prepared with Y,ZSM-35,SAPO-11,ZSM-5,andβ-type molecular sieves.The study found that the loading of metal elements had a certain modulation effect on the pore structure and acid content of the composite catalyst.The ACE results show that the catalytic cracking performance of the composite catalyst HS-0 is relatively good when no metal elements are loaded,but the isomerization performance of the composite catalyst HZ35-0 and the composite catalyst HS-0 is very similar.After 0.6% Mg loading,the conversion rate of the composite catalyst decreased by 1.22 percentage points,indicating that the catalytic cracking performance of the catalyst after the loading of metallic magnesium elements was reduced,but the isomerization index increased by 0.02 percentage points.This shows that the loading of 0.6% metal element magnesium has little effect on the isomerization performance of the composite catalyst HZ35-2,and the cracking performance has not improved.