CHA Zeolite Synthesis via TABA-TACHA Salt Merging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing CHA-type zeolites using TABA or TACHA salts as organic structure-directing agents result in lower yields and reduced production efficiency, making them unsuitable for mass production due to higher costs and difficulty in controlling production conditions compared to methods using ADA salts.
Innovation Solution
A method involving the use of a combination of ADA and TACHA salts with specific molar ratios and alkali sources to produce a highly crystalline CHA-type zeolite with enhanced heat resistance and crystallinity, suitable for industrial production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TABA salt or TACHA salt is used as OSDA to reduce cost, then unit price of OSDA is reduced, but yield and production efficiency are lower
Solution Approach 1:
The patent combines TABA salt and TACHA salt in specific molar ratios (TABA salt: 0.01-0.1 mol, TACHA salt: 0.01-0.1 mol relative to silica) to achieve synergistic effects. This combination resolves the contradiction by merging the cost advantage of TABA salt with the structural directing capability of TACHA salt, resulting in high yield (≥70%) and production efficiency while maintaining lower OSDA costs compared to using ADA salt alone.
2Reliability
If TACHA salt is used to reduce OSDA cost, then production cost is reduced, but production conditions are difficult to control
Solution Approach 1:
The patent optimizes specific parameters including the molar ratio of TABA salt to TACHA salt (1:9 to 9:1), crystallization temperature (100-200°C), and crystallization time (1-7 days) to achieve easy process control. By establishing these precise parameter ranges, the patent resolves the contradiction between reduced production cost and ease of operation, making the process suitable for industrial mass production.
3Productivity
If ADA salt is used alone to achieve high yield, then production efficiency is high, but production cost increases
Solution Approach 1:
The patent replaces the expensive ADA salt with cheaper TABA salt and TACHA salt combinations that achieve comparable or superior performance. The OSDA molecules serve their structure-directing function during crystallization and are then removed, allowing the use of cost-effective alternatives without compromising the high yield (≥70%) and production efficiency of ADA salt-based methods.
4Ease of manufacture
If existing CHA-type zeolite is used to achieve basic catalytic function, then production is simple, but heat resistance and crystallinity are insufficient
Solution Approach 1:
The patent produces composite CHA-type zeolite materials with optimized SiO2/Al2O3 ratios (10-100) and controlled crystallinity (≥80%). The specific compositional control and crystallization conditions create a composite structure that maintains production simplicity while significantly improving heat resistance (stable at ≥600°C) and crystallinity compared to conventional CHA-type zeolites.
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 a CHA-type zeolite with higher crystallinity and heat resistance, matching or exceeding the yield of existing methods using ADA salts alone, while reducing production costs and improving process control, making it more suitable for industrial applications.
Implementation Method 1
a crystallization step of crystallizing a composition containing an alumina source, a silica source, an alkali source, water, an N,N,N-trialkyladamantylammonium salt and an N,N,N-trialkylcyclohexylammonium salt
Data Source
AI summary
A CHA-type zeolite has a molar ratio of silica to alumina of 10.0 or more and less than 20.0 and a molar ratio of silanol groups to silicon of 0.15×10−2 or more and 0.50×10−2 or less, a molar ratio of silica to alumina of 20.0 or more and 35.0 or less and a molar ratio of silanol groups to silicon of 0.15×10−2 or more and 1.10×10−2 or less, a molar ratio of silica to alumina of more than 35.0 and 45.0 or less and a molar ratio of silanol groups to silicon of 0.15×10−2 or more and 1.65×10−2 or less, or a molar ratio of silica to alumina of more than 45.0 and 55.0 or less and a molar ratio of silanol groups to silicon of 0.15×10−2 or more and 1.80×10−2 or less.