Pellet Catalyst Epoxidation Biphasic Medium Separation
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Solution Overview
Problem
The existing processes for manufacturing 1,2-epoxy-3-chloropropane (epichlorohydrin) using allyl chloride and hydrogen peroxide are complicated by the need for solvent and catalyst recovery, which increases process complexity and costs, while also affecting catalyst activity and selectivity.
Innovation Solution
A process using a solid catalyst with an external surface-to-volume ratio of less than or equal to 2.4 × 10^4 m^-1 in a biphasic reaction medium, allowing for easier catalyst separation and regeneration, reduced solvent contamination, and simplified solvent recycling, while maintaining high reaction rates and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a powder catalyst is used, then the catalyst activity and selectivity are improved, but the catalyst recovery operation becomes more complicated
Solution Approach 1:
The patent changes the physical parameter of the catalyst from powder form to pellet form with controlled porosity. This parameter change maintains the catalytic activity while enabling easier recovery through filtration or decantation, resolving the contradiction between catalyst performance and recovery complexity
Solution Approach 2:
The patent employs porous pellet-shaped catalysts with controlled pore structures. The porosity allows reactants to access active sites effectively (maintaining activity) while the pellet shape enables simple separation from the reaction mixture, solving both the activity and recovery issues simultaneously
2Reliability
If large quantities of solvent are used, then the catalyst activity and selectivity are improved, but the need for solvent separation, recovery and recycling increases process complexity
Solution Approach 1:
The patent changes the physical state parameter of the reaction system by forming a biphasic medium. This allows the reaction to proceed with reduced solvent quantities while the phase separation enables simple product isolation, resolving the contradiction between selectivity and process complexity
Solution Approach 2:
The patent utilizes phase separation in a biphasic reaction medium where the organic product layer separates from the aqueous phase. This phase transition enables easy product isolation without complex solvent recovery operations, maintaining selectivity while simplifying the process
3Productivity
If a catalyst with high surface area to volume ratio is used, then the reaction rate is improved, but the catalyst separation becomes more difficult
Solution Approach 1:
The patent optimizes the surface area to volume ratio parameter by using pellet-shaped catalysts with controlled porosity rather than fine powders. This maintains sufficient reaction rate while enabling easy separation through standard filtration or decantation operations
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
This approach significantly reduces the complexity and costs associated with solvent and catalyst recovery, enhances epichlorohydrin purity, and allows for continuous processing with minimal impact on reaction rate and selectivity, using catalysts like zeolites with specific shapes and structures.
Implementation Method 1
reaction between allyl chloride and hydrogen peroxide in the presence of a solid catalyst
Implementation Method 2
in an epoxidation medium comprising at least two liquid phases under the conditions of reaction
Data Source
AI summary
Process for the manufacture of 1,2-epoxy-3-chloropropane by reaction between allyl chloride and hydrogen peroxide in the presence of a solid catalyst and in the possible presence of at least one solvent in an epoxidation medium comprising at least two liquid phases under the conditions of reaction, wherein the catalyst exhibits an external surface to volume ratio lower than to 2.4 104 m−1.