Nano-sized Mesoporous Zeolite Beta Synthesis via Desilication
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Solution Overview
Problem
Conventional beta zeolites have small pore sizes that hinder the diffusion and reaction of large molecules in heavy oil conversion processes, leading to low catalytic activity and potential catalyst deactivation.
Innovation Solution
A process for synthesizing nano-sized mesoporous zeolite beta using desilication without drying and calcination, eliminating the need for a structure directing agent like CTAB, to enhance pore sizes and catalytic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional beta zeolites are used with small pore sizes, then the zeolite structure is stable, but the diffusion of large molecules is hindered leading to low catalytic activity
Solution Approach 1:
The patent applies porous materials by creating mesoporous zeolite beta with a dual pore structure. The desilication process generates mesopores (2-50 nm) within the zeolite crystal structure, while maintaining the original micropores. This hierarchical porosity allows large heavy oil molecules to access active sites through mesopores while the micropores maintain shape selectivity and catalytic function, resolving the contradiction between structural stability and molecular diffusion.
Solution Approach 2:
The patent introduces another dimension to the pore structure by creating a hierarchical system with both micropores and mesopores. The desilication process adds a mesoporous dimension to the traditional microporous zeolite structure, enabling molecules to diffuse through multiple pathways and access active sites more efficiently while maintaining the original zeolite framework stability.
2Manufacturing precision
If ion exchange and separation steps are added to obtain H-form zeolite product, then the desired zeolite form is achieved, but the yield of final products decreases
Solution Approach 1:
The patent extracts and eliminates the problematic ion exchange and separation steps from the conventional synthesis process. By using a direct hydrothermal synthesis method with controlled pH and specific precursors, the process directly produces H-form zeolite beta without requiring subsequent ion exchange to remove template molecules or adjust proton content, thereby eliminating material losses and reducing process complexity.
Solution Approach 2:
The synthesis process is designed to self-produce the desired H-form zeolite directly during crystallization. The controlled hydrothermal conditions and precursor selection enable the system to automatically form the correct protonated form without requiring external intervention through ion exchange steps, improving both yield and process efficiency.
3Shape
If alkaline treatment with NaOH is used, then the mesoporous structure is created, but sodium ions must be removed requiring additional ion exchange steps
Solution Approach 1:
The patent changes the chemical parameters of the treatment solution by using ammonium hydroxide instead of sodium hydroxide. This parameter change allows the creation of mesoporous structure through desilication while introducing ammonium ions that can be easily removed as ammonia gas during drying and calcination, eliminating the need for complex back-ion exchange steps required when using sodium hydroxide.
Solution Approach 2:
The patent employs a treatment approach where the ammonium ions introduced during mesopore formation are easily discarded as ammonia gas during the drying and calcination processes. This eliminates the need for additional ion exchange steps to remove sodium ions, simplifying the overall synthesis process while maintaining mesoporous structure.
4Loss of substance
If drying and calcination steps are added to treat zeolite beta, then the template is removed, but the synthesis cost and process complexity increase
Solution Approach 1:
The patent merges the template removal function with the existing drying and calcination steps that are already required for product formulation. By designing the synthesis process to produce a wet gel that can be directly formulated into final product form, the template removal occurs concurrently with the necessary drying and calcination processes, eliminating the need for separate additional treatment steps.
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 synthesized nano-sized mesoporous zeolite beta exhibits improved crystallinity, mesoporosity, and catalytic performance in heavy oil conversion processes, such as hydrocracking and fluid catalytic cracking, while reducing synthesis costs and complexity.
Implementation Method 1
The process may synthetize a nano-sized zeolite beta without the use of a structure directing agent (SDA) such as cetrimonium bromide (CTAB). The meso-nano zeolite beta may be used as a catalyst in heavy oil conversion processes such as hydrocracking and fluid catalytic cracking.
Implementation Method 2
heating the aluminosilicate fluid gel for at a first temperature for a first time period to form a zeolite beta product
Implementation Method 3
calcinating the treated zeolite beta product at a fourth temperature for a fourth time period after the drying to produce the nano-sized mesoporous zeolite beta composition
Data Source
AI summary
A nano-sized mesoporous zeolite beta composition and processes for the synthesis and use of the nano-sized mesoporous zeolite beta. The nano-sized mesoporous zeolite beta is synthesized using desilication without the addition of a structure directing agent (SDA). A process for hydrocracking a hydrocarbon feedstock using the nano-sized mesoporous zeolite beta is also provided.