Microwave-Dried Zeolite Catalyst for Low-Coke Alkane Aromatization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catalysts for aromatization of alkanes with 4 to 7 carbon atoms, particularly those with 5 carbon atoms, face challenges in achieving high conversion and selectivity of aromatics due to issues like coke formation and varying efficacy, especially when using zeolite catalysts modified with gallium.
Innovation Solution
A catalyst comprising zeolite, a transition metal from group VIII (e.g., platinum) and a group IIIA metal (e.g., gallium), prepared through a process involving microwave treatment and calcination, enhances aromatics production by improving catalyst stability and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If zeolite catalyst modified with gallium is used for aromatization of alkanes with 5 carbon atoms, then conversion and selectivity of aromatics can be improved, but coke formation increases and catalyst stability deteriorates
Solution Approach 1:
The patent uses a composite catalyst system combining zeolite (ZSM-5 or ZSM-11) with gallium and platinum metals. The zeolite provides the acidic sites for cracking and cyclization, while gallium promotes dehydrogenation and platinum enhances aromatization. This composite structure allows the catalyst to achieve high conversion and selectivity while maintaining stability by distributing the catalytic functions across multiple components, reducing coke formation compared to gallium-modified zeolite alone.
Solution Approach 2:
The patent optimizes specific parameters including the silica-to-alumina ratio of zeolite (20:1 to 80:1), gallium content (0.1-5 wt%), platinum content (0.1-2 wt%), and calcination temperature (300-650°C). By carefully controlling these parameters, the catalyst achieves the right balance between activity (conversion and selectivity) and stability (resistance to coke formation), resolving the contradiction between productivity and harmful byproducts.
2Ease of manufacture
If conventional drying method is used in catalyst preparation, then process simplicity is maintained, but catalyst performance and stability are insufficient
Solution Approach 1:
The patent replaces conventional thermal drying with microwave irradiation for drying the catalyst precursor. Microwave heating provides rapid, uniform heating that removes water more effectively than conventional methods, leading to better catalyst performance and stability. This substitution maintains relative process simplicity while significantly improving catalyst reliability, as microwave drying prevents overheating and localized damage that can occur with conventional high-temperature drying.
3Reliability
If calcination temperature is increased to improve catalyst stability, then catalyst performance improves, but energy consumption and risk of excessive coke formation increase
Solution Approach 1:
The patent optimizes the calcination temperature to a specific range (300-650°C), with preferred ranges of 400-600°C or 500-650°C. This parameter optimization achieves sufficient catalyst stability and performance without the excessive energy consumption and coke formation risks associated with higher temperatures. The presence of platinum and optimized zeolite composition allows effective catalyst activation at these moderate temperatures.
Solution Approach 2:
The composite catalyst system with platinum and optimized gallium content enables effective catalyst formation at lower calcination temperatures. The platinum component facilitates catalyst activation and stabilization without requiring high-temperature treatment, thereby reducing energy consumption while maintaining catalyst stability and minimizing coke formation during the calcination process.
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 catalyst achieves high conversion and selectivity of aromatics, such as benzene, toluene, and xylene, by reducing coke formation and stabilizing the catalyst performance.
Implementation Method 1
treating and drying the mixture obtained from step a) with a microwave at a power in a range from 400 to 1,000 watts
Implementation Method 2
calcining the mixture obtained from step d) at a temperature less than or equal to 650 °C
Implementation Method 3
catalyst for aromatization of alkanes having 4 to 7 carbon atoms
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a catalyst for aromatization of alkanes having 4 to 7 carbon atoms, especially alkanes having carbon atoms. Said catalyst has the efficacy in the aromatics production with high conversion and high selectivity of aromatics or high yield of aromatics, wherein said catalyst comprises zeolite, at least 1 transition metal from group VIII transition metal in a range of 0.1 to 2 % by weight based on the total weight of the catalyst, and at least 1 metal from group IIIA metal in a range of 0.1 to 5 % by weight based on the total weight of the catalyst. Said catalyst is treated and dried with a microwave at a power in a range from 400 to 1,000 watts after step of contacting with a solution comprising at least 1 transition metal salt from group VIII transition metal and after step of contacting with a solution comprising at least 1 group IIIA metal salt. Moreover, this invention also relates to a process for preparing said catalyst and a process of aromatics preparation using said catalyst.