Binderless Na-LSX Zeolite Synthesis for Higher Nitrogen Adsorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zeolite synthesis methods for nitrogen adsorption are limited in efficiency and purity, leading to suboptimal performance in nitrogen separation processes.
Innovation Solution
A binderless Na-LSX zeolite is synthesized with a specific molar gel composition of SiO2/Al2O3=2.0; (Na2O+K2O)/SiO2=3.0; Na2O/Na2O+K2O=0.77; H2O/Na2O+K2O=25, using a one-step crystallization process without gel ageing, followed by ion exchange and conversion to binderless forms like extrudates, spheres, and tablets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional zeolite synthesis methods are used, then the synthesis process is simpler, but the nitrogen adsorption capacity and purity are insufficient
Solution Approach 1:
The patent applies parameter changes by optimizing the molar gel composition ratios (SiO2/Al2O3=2.0, (Na2O+K2O)/SiO2=3.0, Na2O/Na2O+K2O=0.77, H2O/Na2O+K2O=25) and crystallization conditions (70-75°C for 17 hours) to achieve 100% crystallinity and enhanced nitrogen adsorption capacity of 9.64 ml/g, resolving the contradiction between adsorption performance and synthesis complexity
Solution Approach 2:
The patent employs preliminary action by conducting gel ageing at 50°C for 4 hours before crystallization to promote uniform gel formation and nuclei development, which ensures complete crystallization to the Na-LSX phase and achieves high nitrogen adsorption capacity without requiring complex multi-step procedures
2Stability of the object's composition
If gel ageing is performed to improve crystallinity, then the crystallization quality improves, but the synthesis time increases
Solution Approach 1:
The patent applies preliminary action by performing gel ageing at 50°C for 4 hours before crystallization to pre-form uniform gel structures and nuclei, which enables complete crystallization to the Na-LSX phase in a single 17-hour step at 70-75°C, achieving 100% crystallinity without requiring extended multi-stage treatment
Solution Approach 2:
The patent utilizes parameter changes by optimizing the gel composition ratios and ageing conditions (50°C for 4 hours) to create a homogeneous gel precursor that crystallizes completely to the desired Na-LSX phase in one step, eliminating the need for prolonged sequential treatments and reducing overall synthesis time
3Productivity
If high temperature crystallization is used to increase production rate, then the productivity improves, but the zeolite purity decreases due to formation of zeolite A
Solution Approach 1:
The patent applies parameter changes by optimizing the crystallization temperature to 70-75°C (rather than higher temperatures) and controlling the gel composition ratios to achieve complete crystallization to the Na-LSX phase in 17 hours, maintaining 100% purity while ensuring high productivity through efficient single-step crystallization
Solution Approach 2:
The patent employs preliminary action by pre-ageing the gel at 50°C for 4 hours to form uniform gel structures before crystallization, which enables complete and selective crystallization to the Na-LSX phase at moderate temperatures (70-75°C), preventing formation of unwanted zeolite A while maintaining high production rates
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 binderless Na-LSX zeolite achieves higher nitrogen adsorption capacity, with 100% crystallinity and improved purity, suitable for nitrogen separation in PSA/VPSA techniques.
Implementation Method 1
The binderless Na-LSX zeolite achieves higher nitrogen adsorption capacity... for higher N2 adsorption... Nitrogen is separated in order to obtain either nitrogen rich product or nitrogen less product
Implementation Method 2
a one-step crystallization process without gel ageing... transferring the obtained gel at step (c) into a 20L SS autoclave and crystallizing out at 70-75° C. for 17 h... with 100% crystallization
Implementation Method 3
subjecting the NaK-LSX thus obtained further for ion exchange using 2 M Sodium chloride solution... washing the excess salt with deionized water to remove chloride ions
Data Source
AI summary
The present invention relates to a process for the synthesis of binder-less Na-LSX zeolite without gel ageing, which shows higher N2 adsorption from air, which contains 21% N2 and 79% O2.