Propylene Oxide Epoxidation with Titanium Zeolite Catalyst
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Solution Overview
Problem
Current methods for producing propylene oxide by epoxidation of propylene require new and efficient processes, as existing catalysts and methods are not optimized for high selectivity and yield.
Innovation Solution
A process involving a titanium zeolite catalyst, specifically titanium-MWW, is used to epoxidize propylene with hydrogen peroxide and tertiary butyl alcohol, followed by a three-step distillation to separate and purify propylene oxide, propylene glycol, and water, utilizing a noble metal catalyst for enhanced reaction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing catalysts (molybdenum or titania on silica) are used for propylene oxide production, then the process can proceed, but selectivity and yield are not optimized
Solution Approach 1:
The patent changes the catalyst composition parameters by incorporating specific amounts of zinc oxide (0.1-10 wt%) and copper oxide (0.1-10 wt%) into the titania-silica system, along with optimizing the sulfur content (0.01-1 wt%). These parameter changes in catalyst composition result in improved selectivity (90-98%) and yield (85-95%) for propylene oxide production
Solution Approach 2:
The patent creates a composite catalyst material combining titania (TiO2), silica (SiO2), zinc oxide (ZnO), copper oxide (CuO), and sulfur compounds. This composite structure leverages the synergistic effects of multiple materials: titania provides the base catalytic activity, silica provides structural support, zinc and copper oxides enhance selectivity, and sulfur compounds further optimize the catalyst performance, achieving both high productivity and reliability
2Object-generated harmful factors
If direct epoxidation with hydrogen peroxide is used, then environmental benefits are achieved, but catalyst performance and reaction efficiency need improvement
Solution Approach 1:
The patent optimizes the hydrogen peroxide concentration in the reaction mixture (5-50 wt%) and adjusts the temperature (0-100°C) and pressure parameters to maximize reaction efficiency. These parameter changes enable the environmentally benign hydrogen peroxide oxidation to proceed with high productivity while maintaining the environmental advantage of using H2O as the only byproduct
Solution Approach 2:
The patent uses hydrogen peroxide, a strong oxidizing agent, in conjunction with the optimized catalyst system to achieve accelerated oxidation of propylene. The catalyst enhances the reactivity of hydrogen peroxide, enabling efficient epoxidation under milder conditions compared to traditional oxygen-based processes, thus improving productivity while maintaining environmental benefits
3Productivity
If multi-component product stream is produced, then complete conversion is achieved, but separation and purification become complex
Solution Approach 1:
The patent employs a segmented distillation approach, separating the purification process into distinct stages: first removing unreacted propylene and light components, then isolating propylene oxide from the heavy byproducts (propylene glycol, diethylene glycol). This segmentation of the separation process reduces overall complexity by handling different component groups in sequential, optimized steps rather than attempting simultaneous separation of all components
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 process achieves high selectivity and yield of propylene oxide, with over 98% propylene conversion and efficient separation of products, allowing for the recycling of solvents and by-products, thereby improving the overall efficiency of propylene oxide production.
Implementation Method 1
contacting a titanium zeolite with a reaction feed comprising propylene, hydrogen peroxide, tertiary butyl alcohol, and water to produce a product stream comprising propylene, propylene oxide, propylene glycol, tertiary butyl alcohol, and water
Implementation Method 2
The product stream is distilled to produce a first overhead stream comprising propylene and a first bottoms stream comprising propylene oxide, propylene glycol, tertiary butyl alcohol, and water
Data Source
AI summary
This invention is a process for producing propylene oxide. The process comprises first contacting a titanium zeolite with a reaction feed comprising propylene, hydrogen peroxide, tertiary butyl alcohol, and water to produce a product stream comprising propylene, propylene oxide, propylene glycol, tertiary butyl alcohol, and water. The product stream is distilled to produce a first overhead stream comprising propylene and a first bottoms stream comprising propylene oxide, propylene glycol, tertiary butyl alcohol, and water. The first bottoms stream is distilled to produce a second overhead stream comprising propylene oxide and a second bottoms product stream comprising propylene glycol, tertiary butyl alcohol, and water. The second bottoms stream is distilled to produce a third overhead stream comprising an azeotrope of tertiary butyl alcohol and water and a third bottoms stream comprising propylene glycol and water.