Binder-converted Zeolite X for Low LTA Contamination
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Solution Overview
Problem
Conventional zeolite adsorbents used in separating para-xylene from mixed xylenes often contain detectable levels of contaminant LTA-type zeolite, which diminishes their adsorption performance, and existing methods to reduce these levels are not cost-effective due to the resulting loss in adsorbent efficacy.
Innovation Solution
A zeolitic binder-converted composition is developed using a low or no detectable LTA-containing X-type zeolite with a particle size not greater than 2.7 microns, achieved by converting a binder material into zeolite, resulting in a composition with improved purity and enhanced adsorptive separation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to reduce LTA-type zeolite contaminant levels, then purity is improved, but manufacturing cost increases and adsorbent efficacy is reduced
Solution Approach 1:
The invention applies preliminary action by carefully controlling the synthesis conditions from the beginning to prevent LTA-type zeolite formation. The specific molar ratios of reactants (Na2O:SiO2:Al2O3:H2O = 3.94-4.05:2.96-3.34:1.00:200.1-202.8) and synthesis parameters (temperature 38-48°C, time 18-72 hours) are optimized in advance to ensure low LTA content without requiring costly post-synthesis purification steps.
2Reliability
If LTA-type zeolite contaminant levels are reduced beyond customary levels, then adsorption performance is improved, but the point of return diminishes and becomes less cost-effective
Solution Approach 1:
The invention applies parameter changes by precisely adjusting the synthesis parameters to achieve optimal LTA content levels. The specific ranges for reactant molar ratios (particularly Na2O:SiO2 between 3.94-4.05 and SiO2:Al2O3 between 2.96-3.34) and synthesis conditions (temperature 38-48°C, time 18-72 hours) are optimized to achieve the desired balance between adsorption performance and cost-effectiveness, eliminating the need for expensive post-synthesis purification.
3Manufacturing precision
If binder material is converted to zeolite, then composition purity is improved, but the conversion process complexity increases
Solution Approach 1:
The invention applies merging by combining the binder material conversion with the existing zeolite synthesis process. The binder material (containing SiO2 and Al2O3) is converted to zeolite X in-situ during the hydrothermal synthesis process by adjusting the alkaline conditions, eliminating the need for separate conversion steps and reducing overall process complexity while improving composition purity.
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 zeolitic binder-converted composition effectively separates high purity para-xylene from mixed xylenes with improved efficiency and reduced contaminant zeolite content, enhancing the adsorbent's performance and reducing the amount of desorbent required in the separation process.
Implementation Method 1
synthetically prepared are used in various industrial processes. Synthetic zeolites are prepared via hydrothermal synthesis employing suitable sources of Si, Al and structure directing agents
Implementation Method 2
In adsorbent materials, zeolites can separate components of either multi-component gas mixtures or liquid mixtures
Data Source
AI summary
A zeolitic binder-converted composition comprising (a) a zeolite X composition having at least a first zeolite X having a mean diameter not greater than 2.7 microns, and a second zeolite X, wherein the second zeolite X is obtained by converting a binder material to the second zeolite X and the binder material is in a range from 5 to 50 wt % of the zeolite X composition; and (b) an unconverted binder material content, after conversion to the second zeolite X is complete, in a range from 0 to 3 wt % of the zeolite X composition. The zeolite X composition has an average Si/Al framework mole ratio in a range from 1.0 to 1.5, and a relative LTA intensity not greater than 1.0, as determined by x-ray diffraction (XRD).