Phosphate-Modified Zeolite NaX Catalyst for Styrene Production
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Solution Overview
Problem
Current methods for producing styrene from ethylbenzene are energy-intensive and environmentally harmful, and existing zeolite catalysts for side-chain alkylation of toluene with methanol are expensive and complex to prepare.
Innovation Solution
A zeolite catalyst modified with Na3PO4 or Na2HPO4 supported on zeolite NaX, prepared through a simplified process involving immersion in a phosphate solution and calcination, which reduces production costs and extends catalyst life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CsX zeolite catalyst is used for side-chain alkylation of toluene with methanol, then catalytic activity is improved, but catalyst cost increases significantly
Solution Approach 1:
The invention modifies the zeolite NaX catalyst by changing its chemical composition parameters through phosphate modification. Specifically, Na3PO4 or Na2HPO4 is introduced to replace part of the sodium ions in the zeolite structure, creating Na3PO4/NaX or Na2HPO4/NaX catalysts. This parameter change transforms the low-cost zeolite NaX into a catalyst with enhanced performance comparable to expensive CsX catalysts, thereby resolving the contradiction between catalytic activity and catalyst cost.
2Reliability
If K3PO4/NaX catalyst is prepared using the method in CN109395767A, then catalytic performance is achieved, but preparation process complexity increases
Solution Approach 1:
The invention extracts and eliminates the complex multi-step ion exchange and washing procedures from the preparation process. Instead of the conventional three-time ion exchange with K3PO4 solution followed by three washing steps, the invention directly uses phosphate modification with Na3PO4 or Na2HPO4 solution, followed by simple filtration and drying. This extraction of unnecessary complexity steps while retaining the essential modification function resolves the contradiction between catalytic performance and preparation process complexity.
3Productivity
If conventional ethylbenzene dehydrogenation method is used for styrene production, then production capacity is maintained, but energy consumption and environmental harm increase
Solution Approach 1:
The invention changes the reaction pathway parameters by adopting side-chain alkylation of toluene with methanol instead of the conventional ethylbenzene dehydrogenation route. This parameter change in the chemical process enables styrene production with lower energy consumption and reduced environmental harm, while maintaining production capacity through the improved catalytic activity of the modified zeolite catalyst.
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 Na3PO4/NaX or Na2HPO4/NaX catalyst achieves higher selectivity and yield for styrene production, with yields up to 91% higher than K3PO4/NaX catalysts, while being more cost-effective and simpler to produce.
Implementation Method 1
A zeolite catalyst for side-chain alkylation of toluene with methanol and a process for preparing the same are provided
Implementation Method 2
immersing a zeolite NaX in trisodium phosphate aqueous solution (Na3PO4 aqueous solution) or dibasic sodium phosphate aqueous solution (Na2HPO4 aqueous solution)
Implementation Method 3
calcinating the solid obtained in step (2) in air at 400 to 600° C. for 3 h
Data Source
AI summary
The disclosure relates to a zeolite catalyst for side-chain alkylation of toluene with methanol, including a zeolite NaX and Na3PO4 or Na2HPO4 supported on the zeolite NaX. The zeolite catalyst can be effective for catalyzing the side-chain alkylation of toluene with methanol. The disclosure also relates to a process for preparing a zeolite catalyst for side-chain alkylation of toluene with methanol, which is simple, practical and cheap in cost.