FCC Additive Composition for Light Olefin Yield Enhancement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current FCC catalyst technologies struggle to achieve propylene yields significantly above 10 wt% and LPG yields above 30 wt%, as excessive ZSM-5 based additives dilute base catalyst activity and reduce unit conversion, limiting the production of light olefins like propylene, isobutylene, and LPG.
Innovation Solution
A fluid catalytic cracking additive composition comprising 1-50 wt% pentasil zeolite, 0.01-5 wt% medium pore zeolite (5.4-7.7 Å), 0-15 wt% alumina, 5-20 wt% colloidal silica, and 10-60 wt% kaolin clay, with a silica-alumina ratio of 8 to 500, bonded with a clay-phosphate-silica-alumina binder, enhancing the cracking function to convert gasoline range hydrocarbons to light olefins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ZSM-5 based additives are used to increase light olefin production, then propylene and LPG yields are improved, but base catalyst activity is diluted and unit conversion is reduced
Solution Approach 1:
The invention uses a composite binder system comprising phosphate, colloidal silica, and alumina that forms a synergistic matrix supporting high concentrations of ZSM-5 additive (up to 60 wt% or more) while preserving base catalyst activity. This composite structure allows the additive to be effectively dispersed and anchored, preventing aggregation and maintaining both cracking function and light olefin selectivity.
Solution Approach 2:
The binder system creates a porous matrix structure that facilitates mass transfer and maintains accessibility to active sites. The phosphate-silica-alumina combination forms a hierarchical pore structure that allows reactants to reach ZSM-5 additive sites while maintaining overall catalyst porosity and preventing diffusion limitations that would otherwise reduce unit conversion.
2Productivity
If high concentration of ZSM-5 additive is used to enhance propylene selectivity, then light olefin production increases, but gasoline yield decreases
Solution Approach 1:
The invention creates local zones of high ZSM-5 concentration within the catalyst particle, surrounded by a phosphate-silica-alumina binder matrix that maintains overall catalyst functionality. This local quality approach allows intensive propylene production in specific regions while the surrounding binder preserves base catalyst activity for gasoline-range hydrocarbon formation, achieving both high propylene selectivity and maintained gasoline yield.
Solution Approach 2:
The catalyst is segmented into distinct functional zones: ZSM-5 additive regions for light olefin production and binder-supported base catalyst regions for general cracking. This segmentation allows independent optimization of each function, with the phosphate-silica-alumina binder providing structural support and maintaining porosity throughout the segmented structure.
3Productivity
If ZSM-5 additive is integrated into catalyst particle to increase light olefin yield, then propylene and iso-butylene production are enhanced, but attrition resistance may be compromised
Solution Approach 1:
The phosphate-silica-alumina binder forms a mechanically robust composite matrix that encapsulates and protects ZSM-5 additive crystals. This composite structure provides mechanical strength and attrition resistance while maintaining the high surface area and porosity needed for light olefin production. The binder acts as a protective shell that prevents additive crystal fracture during handling and regeneration cycles.
Solution Approach 2:
The binder system forms a flexible yet mechanically strong shell around ZSM-5 additive particles, allowing the catalyst to withstand mechanical stress and attrition. This thin film structure provides protective coverage while maintaining porosity and accessibility to active sites, balancing mechanical strength with catalytic functionality.
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
The additive composition achieves propylene selectivity up to 12 wt%, LPG selectivity up to 28 wt%, and iso-butylene selectivity up to 5 wt%, significantly improving light olefin yields while maintaining catalyst activity and reducing bottom yields.
Implementation Method 1
a fluid catalytic cracking additive composition comprising 1-50 wt% pentasil zeolite, 0.01-5 wt% medium pore zeolite (5.4-7.7 Å), 0-15 wt% alumina, 5-20 wt% colloidal silica, and 10-60 wt% kaolin clay, with a silica-alumina ratio of 8 to 500, bonded with a clay-phosphate-silica-alumina binder, enhancing the cracking function to convert gasoline range hydrocarbons to light olefins
Implementation Method 2
0-15 wt% alumina, 5-20 wt% colloidal silica, and 10-60 wt% kaolin clay, with a silica-alumina ratio of 8 to 500, bonded with a clay-phosphate-silica-alumina binder
Data Source
AI summary
The present invention relates to a fluid catalytic cracking additive composition for cracking of heavy hydrocarbon feed stocks and process for preparing the additive. The additive is suitable for enhancing yields of light olefins such as propylene, isobutylene, LPG and reduces the bottom yields. The invention specifically relates to a fluid catalytic cracking additive composition comprising a pentasil zeolite, zeolites having pore size in a range of 5.4-7.7 Å, alumina, colloidal silica, kaolin clay, and phosphate, wherein the zeolites having pore size in the range of 5.4-7.7 Å is present in an amount of 1 to 10 wt % with respect to the total amount of the pentasil zeolite and zeolite having the pore size in the range of 5.4-7.7 Å.