Beta Zeolite Seed Crystal Route for High-Purity OSDA-Free Synthesis
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Solution Overview
Problem
Existing methods for producing beta zeolite using organic structure-directing agents (OSDA) are costly and environmentally harmful, with the need for high-temperature calcination and limited composition ranges, and result in impurities and high production costs.
Innovation Solution
A method for producing beta zeolite using a seed crystal synthesized without OSDA, characterized by specific particle size distribution and acid-treated to enhance purity and reduce environmental impact, allowing for a wider composition range and reduced impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If tetraethylammonium ion is used as an organic structure-directing agent to synthesize beta zeolite, then the beta zeolite can be produced with controlled composition, but the production cost increases and environmental load increases due to expensive compounds and decomposition issues
Solution Approach 1:
The invention extracts and removes the organic structure-directing agent (tetraethylammonium ion) from the synthesis system entirely. By using a seed crystal method without OSDA, the patent eliminates the need for expensive organic compounds while still achieving controlled beta zeolite synthesis through the template effect of the seed crystal.
Solution Approach 2:
The invention replaces expensive, non-reusable organic compounds with a reusable seed crystal. The seed crystal can be used multiple times in successive syntheses, making the process more economical and sustainable compared to single-use organic structure-directing agents.
2Reliability
If tetraethylammonium ion is used as an organic structure-directing agent, then beta zeolite crystallization can be achieved, but calcination is required to remove incorporated ions which creates environmental pollution and requires additional chemicals for detoxification
Solution Approach 1:
The invention extracts and eliminates the organic structure-directing agent from the system by using a seed crystal method. This prevents the incorporation of organic ions into the crystal structure, thereby eliminating the need for calcination and the associated environmental pollution from exhaust gases and detoxification chemicals.
Solution Approach 2:
The invention converts the harmful role of organic structure-directing agents into a beneficial seed crystal approach. The seed crystal provides the necessary template effect for crystallization without the harmful side effects of organic compound decomposition and pollution.
3Reliability
If a narrow composition range is used for sodium aluminosilicate reaction mixture as disclosed in prior art, then beta zeolite synthesis can be achieved, but the SiO2/Al2O3 ratio is limited to a restricted range which does not meet various demands
Solution Approach 1:
The invention changes the key parameter of composition range from narrow to wide. By using a seed crystal without OSDA, the patent enables synthesis of beta zeolite across a broad range of SiO2/Al2O3 ratios (5-100), providing versatility to meet different application demands while maintaining reliable crystallization.
4Reliability
If conventional synthesis methods are used without stirring, then beta zeolite can be produced, but establishment of conditions allowing synthesis by stirring is desired for industrial mass production efficiency
Solution Approach 1:
The invention introduces dynamic stirring conditions to the synthesis process. The seed crystal method is particularly suitable for stirred reactors, allowing efficient mass production through continuous mixing and heat transfer, thereby enhancing productivity for industrial applications while maintaining reliable beta zeolite production.
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 method achieves high-purity beta zeolite production with reduced environmental load and costs, enabling efficient and cost-effective synthesis with shorter production times.
Implementation Method 1
a hydrothermal treatment is performed, and thereby crystallization is performed
Implementation Method 2
acid-treated seed crystal
Data Source
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AI summary
Provided is a production method with which it is possible to produce beta zeolite at high purity by suppressing the generation of impurities by a seed crystal addition method that can reduce the environmental burden as much as possible, without using an organic structure-directing agent. This method for producing beta zeolite having a step that mixes and heats an organic-compound-free reaction mixture comprising a silica source, alumina source, alkali source, and water with beta zeolite seed crystals, wherein (I) beta zeolite synthesized without using an organic structure-directing agent and having 90% or more by volume of particles 10 µm or less in diameter in the particle size distribution by a laser diffraction scattering-type particle size distribution measurement method is used, (III) acid-treated zeolite in which the SiO2/Al2O3 ratio is 150 or less is prepared by (II) contact treatment with an acidic aqueous solution, and the acid-treated zeolite is used as the beta zeolite seed crystals.