Core-Shell Catalyst for Simultaneous MTBE and TBA Conversion
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Solution Overview
Problem
Current methods for producing isobutylene from a mixture of MTBE and TBA face challenges due to differing catalyst requirements and reaction conditions between MTBE cracking and TBA dehydration, leading to inefficient separation processes and lower conversion rates and selectivity for high-purity isobutylene production.
Innovation Solution
A catalyst with a core-shell structure, comprising amorphous silica-alumina as the core and aluminum oxide containing silicon and tin as the shell, is developed to facilitate simultaneous MTBE cracking and TBA dehydration reactions, optimizing the weight ratio and elemental content for enhanced conversion and selectivity of isobutylene production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate catalysts and reaction conditions are used for MTBE cracking and TBA dehydration, then each reaction can proceed optimally, but the device complexity and operational costs increase due to requiring separate installations
Solution Approach 1:
The patent combines two separate catalytic functions into a single core-shell catalyst structure. The amorphous silica-alumina core provides MTBE cracking activity while the aluminum oxide shell provides TBA dehydration activity, allowing both reactions to occur simultaneously in one reactor, thereby reducing device complexity and operational costs
Solution Approach 2:
The dual-function catalyst achieves multi-functionality by incorporating both MTBE cracking and TBA dehydration capabilities in one catalyst particle. This universal catalyst can handle mixed feeds containing both MTBE and TBA, eliminating the need for separate specialized catalysts and reactors
2Device complexity
If a single catalyst is used for both MTBE cracking and TBA dehydration, then device complexity is reduced, but achieving high conversion rates and selectivity for both reactions simultaneously becomes difficult
Solution Approach 1:
The catalyst is segmented into distinct core and shell regions with different compositions and functions. The amorphous silica-alumina core is optimized for MTBE cracking while the aluminum oxide shell is optimized for TBA dehydration, allowing each segment to independently optimize its reaction while working together in the same particle
Solution Approach 2:
The patent uses composite material structure combining amorphous silica-alumina and aluminum oxide in a core-shell configuration. This composite structure leverages the complementary catalytic properties of both materials, achieving high selectivity and conversion for both reactions simultaneously through the synergistic interaction of the composite components
3Quantity of substance
If conventional separation processes are used for MTBE and TBA mixtures, then pure components can be obtained, but the loss of time and operational costs increase
Solution Approach 1:
The patent changes the reaction parameters by using a dual-function catalyst that enables both MTBE cracking and TBA dehydration to proceed under the same temperature and pressure conditions. This parameter unification eliminates the need for separate reaction and separation stages, directly producing high-purity isobutylene without time-consuming separation processes
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 conversion rates of 99.0% or higher for both MTBE and TBA, with selectivity for isobutylene exceeding 99.5%, reducing the need for separate installations and lowering operational costs by enabling simultaneous reaction in a single apparatus.
Implementation Method 1
the main reaction is MTBE cracking into isobutylene and methanol under the action of a catalyst
Implementation Method 2
The reaction of TBA dehydration for preparing isobutylene
Data Source
AI summary
The present invention relates to the field of isobutylene preparation. Disclosed are a catalyst and preparation method thereof, and method for preparing isobutylene by applying the same; the catalyst has a core-shell structure, the core an amorphous silica-alumina particle and/or an aggregate molding thereof, and the shell aluminum oxide comprising silicon and tin; the weight ratio of aluminum oxide comprising silicon and tin to amorphous silica-alumina is 1:60-1:3; in the aluminum oxide comprising silicon and tin, on basis of the weight of aluminum oxide comprising silicon and tin, the content of silicon is 0.5-2 wt %, and of tin is 0.2-1 wt %. The catalyst of the present invention is used to catalyze a mixture of MTBE and TBA to prepare isobutylene, enabling the MTBE cleavage and TBA dehydration reactions to be conducted simultaneously to generate isobutylene, achieving higher conversion rates of TBA and MTBE, and higher selectivity for generating isobutylene.