Hydrocracking Catalyst Zeolite Beta USY Middle Distillate Selectivity
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Solution Overview
Problem
Existing hydrocracking catalysts fail to achieve the desired levels of activity and selectivity for optimizing middle distillate production, as they lack the necessary performance to efficiently convert hydrocarbonaceous feedstocks into middle distillates with a true boiling point of 380 - 700°F (193-371°C).
Innovation Solution
A hydrocracking catalyst composition comprising a zeolite beta with specific OD acidity and domain size, combined with zeolite USY, amorphous silica aluminate, and a second support material, and impregnated with metals from Group 6 and 8-10 of the Periodic Table, optimized for improved selectivity and activity through a process involving extrusion and calcination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydrocracking catalysts are used, then the catalyst structure is simple and easy to manufacture, but the activity and selectivity for middle distillate production are insufficient
Solution Approach 1:
The patent employs a composite catalyst system combining zeolite beta with specific domain sizes (800-1500 nm²), zeolite USY, amorphous silica aluminate, and metal components (Group 6 and 8-10 elements). This composite structure creates synergistic effects where zeolite beta provides shape-selective cracking for middle distillates, zeolite USY enhances acidity and activity, amorphous silica aluminate provides structural support and additional active sites, and metal components facilitate hydrogenation-dehydrogenation reactions. The combination resolves the contradiction by achieving high productivity through multiple complementary functions while managing complexity through systematic material integration.
Solution Approach 2:
The patent applies local quality by optimizing specific properties of zeolite beta including domain size (800-1500 nm²), OD acidity (20-50 μmol/g), and silica-to-alumina ratio (150-300). These localized property optimizations create regions with enhanced catalytic activity and selectivity within the catalyst structure. The controlled domain size provides optimal pore architecture for middle distillate formation, while the specific acidity range ensures appropriate cracking strength without excessive gas formation, resolving the productivity-complexity contradiction through precise local property control.
2Power
If zeolite beta with high OD acidity is used, then catalytic activity increases, but selectivity for middle distillates decreases due to excessive cracking to lighter products
Solution Approach 1:
The patent optimizes the OD acidity parameter of zeolite beta to a specific range (20-50 μmol/g) rather than using maximum possible acidity. This parameter optimization balances catalytic activity with product selectivity - the controlled acidity provides sufficient cracking power to convert heavy feedstocks while preventing excessive cracking that would produce too many light gases. Combined with the optimized domain size (800-1500 nm²) and silica-to-alumina ratio (150-300), this parameter control resolves the contradiction between activity and selectivity.
Solution Approach 2:
The patent creates local quality differences within the catalyst by combining zeolite beta (moderate acidity, shape-selective pores) with zeolite USY (higher acidity, different pore structure) and amorphous silica aluminate (distributed acidity). This distribution of acidic sites with different strengths and locations allows simultaneous achievement of high overall activity and controlled selectivity - strong acid sites in USY provide cracking power while the shape-selective pores of zeolite beta and optimized domain sizes guide product distribution toward middle distillates, preventing excessive light product formation.
3Manufacturing precision
If zeolite beta with small domain size is used, then diffusion path length decreases, but catalytic activity and selectivity are insufficient
Solution Approach 1:
The patent optimizes the domain size parameter of zeolite beta to a specific range (800-1500 nm²) that balances diffusion efficiency with catalytic activity. This parameter optimization ensures that domain sizes are large enough to provide sufficient catalytic sites and maintain structural stability for high productivity, yet small enough to maintain acceptable diffusion path lengths for reactant and product molecules. The controlled domain size combined with optimized OD acidity (20-50 μmol/g) and silica-to-alumina ratio (150-300) resolves the contradiction between selectivity and productivity by achieving the optimal middle ground in the domain size parameter.
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 catalyst achieves enhanced selectivity and activity, producing a hydrocracked effluent with a true boiling point of 380 - 700°F (193-371°C), significantly increasing yields of middle distillates while reducing lighter products, thus overcoming the limitations of previous catalysts.
Implementation Method 1
a zeolite beta having an OD acidity of 20 to 50 μmol/g and an average domain size from 800 to 1500 nm²
Implementation Method 2
OD acidity of 20 to 50 μmol/g
Implementation Method 3
impregnated with metals from Group 6 and 8-10 of the Periodic Table
Implementation Method 4
metals from Group 6 and 8-10 of the Periodic Table
Implementation Method 5
zeolite USY
Implementation Method 6
amorphous silica aluminate
Data Source
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AI summary
A hydrocracking catalyst is provided comprising: a zeolite beta having an OD acidity of (20) to (50) μmοl/g and an average crystal size from (300) to (800) nanometers; a zeolite USY; wherein a wt% of the zeolite beta is less than the wt% of the zeolite USY; a support comprising an amorphous silica aluminate and a second support material; and at least one metal selected from the group consisting of elements from Group (6) and Groups (8) through (10) of the Periodic Table. A process for hydrocracking a hydrocarbonaceous feedstock is provided, comprising: contacting the hydrocarbonaceous feedstock with the hydrocracking catalyst under hydrocracking conditions to produce a hydrocracked effluent that comprises middle distillates. A method for making the hydrocracking catalyst is also provided.