10-Membered Ring Zeolite Surface Acid Site Control
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Solution Overview
Problem
Existing methods for producing aromatic hydrocarbons using zeolites face challenges with production efficiency and selectivity due to unselective reactions on zeolite surface acid sites, and previous solutions either remove surface acid sites, require multiple hydrothermal syntheses, or have stability issues at high temperatures.
Innovation Solution
A novel 10-membered ring pore zeolite with a specific average particle diameter and a controlled amount of Bronsted acid sites on the outer surface, selectively removing surface acid sites to enhance catalyst performance for producing aromatic hydrocarbons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If surface acid sites are removed to improve selectivity, then product selectivity is improved, but catalyst activity decreases
Solution Approach 1:
The patent applies local quality by creating different acid site distributions in different regions of the zeolite catalyst. The outer surface is modified to have reduced Bronsted acid sites (0.1-10.0 μmol/g) to improve selectivity, while the inner pores maintain sufficient acid sites for catalytic activity. This spatial differentiation of acid site concentration allows simultaneous optimization of both selectivity and activity.
2Productivity
If zeolite particle size is reduced to improve reaction efficiency, then productivity is improved, but mechanical strength decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size parameter within the range of 100 nm or less (preferably 5-100 nm). This specific size range optimizes the surface area to volume ratio for enhanced reaction efficiency while the controlled size distribution and surface modification maintain sufficient mechanical strength for practical application.
3Manufacturing precision
If Bronsted acid sites on outer surface are reduced to improve selectivity, then product selectivity is improved, but deactivation rate increases
Solution Approach 1:
The patent applies local quality by creating different acid site distributions in different regions of the zeolite catalyst. The outer surface is modified to have reduced Bronsted acid sites (0.1-10.0 μmol/g) to improve selectivity, while the inner pores maintain sufficient acid sites for catalytic activity. This spatial differentiation of acid site concentration allows simultaneous optimization of both selectivity and activity.
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 novel zeolite achieves excellent production efficiency and selectivity for aromatic hydrocarbons, maintaining stability at high temperatures and reducing side reactions.
Implementation Method 1
Zeolites are widely used industrially as the uses such as petrochemical catalysts... Methods for producing aromatic compounds by contacting aliphatic or alicyclic hydrocarbon raw materials with a catalyst mainly comprising a medium pore zeolite at a temperature of around 400° C. to around 800° C.
Implementation Method 2
Medium pore zeolites and zeolite complexes have been used as highly selective catalysts using pores in a size equivalent to aromatic compounds. The micropores of medium pore zeolites have an inlet size of around 0.5 nm, and it is considered that the micropores function as effective reaction sites of molecules having a molecular size approximate to this pore size.
Implementation Method 3
reactions on acid sites on the surface (outer surface) of zeolite are also known... A Bronsted acid amount on an outer surface is 0.1 to 10.0 μmol/g
Data Source
AI summary
Provided are: novel zeolite having an extremely small amount of specific Bronsted acid sites on the surface thereof, which is expected to be useful as a catalyst for the aromatization of a non-aromatic hydrocarbon typified by an aliphatic hydrocarbon; and a catalyst for use in the production of an aromatic hydrocarbon, which comprises the zeolite. Zeolite characterized by satisfying the following requirements (i) to (iii). (i) The zeolite has an average particle diameter of 100 nm or less. (ii) The zeolite is 10-membered ring microporous zeolite. (iii) The amount of the Bronsted acid sites on the outer surface of the zeolite is 0.1 to 10.0 μmol/g.