Titanium Silica Catalyst Epoxidation Solvent Selection
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Solution Overview
Problem
Current epoxidation processes using titanium silica catalysts face issues with ring opening byproducts when using small molecule solvents like methanol, which reduce propylene oxide yield and require additional buffers to minimize these byproducts, but these buffers also decrease catalytic performance.
Innovation Solution
The method employs a titanium silica catalyst with a silica zeolite framework, using 1-phenylethyl alcohol and acetophenone as solvents, along with hydrogen peroxide as the oxidizing agent, and a buffer to enhance peroxide conversion and selectivity while minimizing ring opening byproducts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If small molecule solvents like methanol are used with titanium silica catalysts, then the catalytic reaction can proceed, but ring opening byproducts are formed which reduce propylene oxide yield
Solution Approach 1:
The patent changes the solvent parameter from small molecules (methanol, water) to large molecules (1-phenylethyl alcohol, acetophenone). This parameter change prevents ring opening byproducts because the large solvent molecules are too bulky to attack the epoxide ring, thereby maintaining high propylene oxide yield without forming unwanted byproducts.
2Object-generated harmful factors
If buffers are added to reduce ring opening byproducts, then the amount of byproducts decreases, but catalytic performance is significantly reduced
Solution Approach 1:
The patent introduces large molecule solvents as intermediary substances that mediate between the catalyst and the epoxide product. These solvents physically block the approach of nucleophiles to the epoxide ring without interfering with the catalytic cycle, thus reducing ring opening byproducts while maintaining high catalytic performance.
3Adaptability or versatility
If a wider range of solvents is used to improve process flexibility, then solvent selection becomes more versatile, but maintaining high catalytic efficacy becomes more difficult
Solution Approach 1:
The patent establishes a new parameter regime by using large molecule solvents with specific molecular size and structure characteristics. This parameter change expands solvent versatility while maintaining catalytic efficacy, as the key parameter is the large molecular size rather than specific chemical functionality, allowing multiple solvent options without sacrificing performance.
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 achieves high peroxide conversion and selectivity to epoxide with reduced ring opening byproducts, maintaining high catalytic efficacy and allowing for the use of a wider range of solvents, thus improving the commercial viability of the epoxidation process.
Implementation Method 1
the epoxidation of propylene with an oxidizing agent in the presence of a catalyst
Implementation Method 2
the direct epoxidation of an olefin with oxygen in the presence of a catalyst
Data Source
Figure 1
AI summary
The present disclosure relates to a method of epoxidizing an olefin to form an epoxide, the method comprising contacting an alkene,(C≤12) or aralkene(C≤12) with a titanium silica catalyst, a peroxide, a buffer, and one or more organic solvents in a reaction mixture, wherein the one or more organic solvents comprise a first organic solvent selected from: R1-OH (I), R2-CN (II), R3-C(O)-R4 (III) or R5-O-R6 (IV) wherein: R1 is alkyl(C≤12), aryl(C≤12), aralkyl(C≤12)or a substituted version of any of these groups; R2 is alkyl(C≤12), aryl(C≤12), aralkyl(C≤12) or a substituted version of any of these groups; R3 is hydrogen, alkl(C≤6) or substituted alkyl(C≤6); and R4, R5, and R6 are each independently selected from alkyl(C≤12), aryl(C≤12), aralkyl(C≤12) or a substituted version of any of these groups, or are taken together are alkoxydiyl(C≤12), alkanediyl(C≤12), substituted alkoxydiyl(C≤12) or substituted alkanediyl(C≤12).