FCC Catalyst Y Zeolite Pentasil Olefin Yield
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Solution Overview
Problem
Current FCC technologies face limitations in achieving high yields of propylene and LPG, as excessive ZSM-5 based additives dilute base catalyst activity and reduce unit conversion, while existing methods for increasing olefin yields often compromise gasoline yields.
Innovation Solution
Developing a catalyst composition with specific formulations of Y-type zeolite and pentasil, where Y-type zeolite and pentasil are present in separate particles, and the catalyst includes a high surface area matrix with controlled rare earth content, to enhance light olefin production without significantly reducing gasoline yields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ZSM-5 based additives are used to increase light olefin yields, then propylene and LPG production is improved, but base catalyst activity is diluted and unit conversion is reduced
Solution Approach 1:
The patent applies local quality by creating distinct functional zones within the catalyst particle: a core region containing Y-type zeolite for hydrocarbon cracking and a surface region containing pentasil crystals for light olefin production. This spatial separation allows different catalytic functions to operate simultaneously without mutual interference, resolving the contradiction between increasing light olefin yield and maintaining base catalyst activity.
Solution Approach 2:
The patent uses composite materials by combining Y-type zeolite and pentasil in a specific weight ratio range (Y-type zeolite: 70-90 wt%, pentasil: 10-30 wt%) within a unified catalyst particle structure. This composite approach enables synergistic effects where the Y-type zeolite provides framework stability and the pentasil enhances light olefin selectivity, achieving both high productivity and maintained reliability.
2Productivity
If ZSM-5 based additives are increased to enhance olefin yields, then propylene production is improved, but gasoline yields are compromised
Solution Approach 1:
The patent segments the catalytic functions by separating the cracking function (Y-type zeolite core) from the olefin production function (pentasil surface layer). This segmentation allows the Y-type zeolite to maintain gasoline production while the pentasil on the surface converts some gasoline-range hydrocarbons to light olefins, achieving both objectives simultaneously.
Solution Approach 2:
The patent applies parameter changes by optimizing the weight ratio of Y-type zeolite to pentasil within specific ranges (Y-type zeolite: 70-90 wt%, pentasil: 10-30 wt%) and controlling particle size (20-200 microns). These parameter optimizations enable the catalyst to achieve high olefin yields while preserving gasoline production, resolving the contradiction through quantitative control.
3Productivity
If catalyst particle size is reduced to improve mixing and reaction efficiency, then conversion is improved, but attrition resistance is reduced
Solution Approach 1:
The patent uses composite materials with a dual-phase structure where the Y-type zeolite core provides mechanical strength and the pentasil surface layer provides catalytic functionality. This composite structure allows the particle to maintain adequate strength for attrition resistance even at reduced sizes (20-200 microns), while still achieving improved mixing and reaction efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly increases propylene and LPG yields while maintaining gasoline yields, achieving levels not previously attainable with standard FCC catalysts, and provides enhanced attrition resistance for improved catalyst retention.
Implementation Method 1
Catalysts used in FCC processes are in particle form... In the reactor, hydrocarbon feed contacts hot, regenerated catalyst which vaporizes and cracks the feed
Implementation Method 2
hydrocarbon feed contacts hot, regenerated catalyst which vaporizes and cracks the feed at about 400° C. to 700° C.
Implementation Method 3
The cracking reaction deposits carbonaceous hydrocarbons or coke on the catalyst
Implementation Method 4
The coked catalyst is stripped of volatiles, usually with steam, in a catalyst stripper
Implementation Method 5
The catalyst regenerator burns coke from the catalyst with oxygen containing gas, usually air
Data Source
AI summary
A catalyst composition comprising at least about 10% by weight pentasil, at least about 12% by weight Y-type zeolite at a pentasil to Y zeolite ratio of at least 0.25, and wherein the pentasil and Y zeolite comprise at least about thirty-five percent of the catalyst have been shown to optimize light olefin yields and LPG from FCC processes. Embodiments having matrix surface areas greater than 25 m2/g, phosphorous and rare earth are preferred. The compositions of this invention are particularly useful in typical fluid catalytic cracking (FCC) processes.