Catalyst Composition for Oxychlorination Reducing Stickiness
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Solution Overview
Problem
Fluidized bed oxychlorination catalysts used in the production of 1,2-dichloroethane often experience 'catalyst sticking' or 'stickiness,' leading to reactor failure and significant economic losses due to inappropriate operational conditions or catalyst properties, particularly high Cl/C ratio, low O/C ratio, and low operation temperature.
Innovation Solution
A catalyst composition comprising copper, alkali metals, alkaline earth metals, and transition metals such as manganese or rhenium, impregnated on high surface area alumina supports, with specific weight percentages and BET surface areas to reduce stickiness and enhance performance, allowing for improved HCl conversion and EDC selectivity while maintaining fluidization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalyst compositions are used to achieve high HCl conversion, then productivity is improved, but catalyst sticking occurs leading to reactor failure
Solution Approach 1:
The patent modifies the chemical composition parameters of the catalyst by incorporating specific promoters (alkali metals, alkaline earth metals, and transition metals) in optimized ratios. This changes the catalyst's chemical properties to reduce stickiness while maintaining high HCl conversion activity, directly resolving the contradiction between productivity and reliability
Solution Approach 2:
The patent creates a composite catalyst system combining copper chloride (active component) with multiple promoter chlorides (alkali, alkaline earth, and transition metals) on a support material. This composite structure synergistically maintains high conversion while preventing catalyst sticking, thereby improving both productivity and reliability simultaneously
2Manufacturing precision
If operational conditions are optimized for high EDC selectivity, then manufacturing precision is improved, but catalyst stickiness increases causing operational failures
Solution Approach 1:
The patent enhances the local chemical environment at the catalyst active sites by introducing specific promoter elements. This creates localized modifications that maintain high EDC selectivity while the overall catalyst composition resists sticking, resolving the contradiction between manufacturing precision and ease of operation
3Ease of manufacture
If catalyst composition is simplified to reduce manufacturing complexity, then ease of manufacture is improved, but catalyst performance and resistance to stickiness deteriorate
Solution Approach 1:
The patent establishes specific compositional parameters and ratios for the catalyst components. By defining precise parameter ranges for copper chloride, alkali metal chlorides, alkaline earth metal chlorides, and transition metal chlorides, the patent achieves reliable anti-sticking performance while maintaining manufacturability through systematic formulation
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 composition demonstrates high resistance to stickiness, maintaining high HCl conversion and EDC selectivity across a range of temperatures, reducing the risk of reactor failure and improving operational efficiency.
Implementation Method 1
catalyst for the oxychlorination of ethylene with HCl and oxygen (or an oxygen containing gas) to form 1,2-dichloroethane
Implementation Method 2
impregnated on high surface area alumina supports
Data Source
AI summary
This invention relates to a catalyst containing from about 2 up to about 8% by wt. of copper, zero up to about 0.6 moles/kg of one or more alkali metal(s), from about 0.08 up about 0.85 moles/kg of one or more alkaline earth metals and from about 0.09 up to about 0.9 moles/kg of one or more transition metals selected from the group consisting of Mn, Re and mixtures thereof, where all the metals are impregnated in form of their chlorides or other water soluble salts on a fluidizable support with a BET surface area of from about 80 up to about 220 m2/g. A process for the oxychlorination of ethylene to form 1,2-dichloroethane using such a catalyst having good activity, good selectivity and low tendency to stickiness in fluidized bed oxychlorination reactions.