Gradient Catalyst Bed for Low-Byproduct Propylene Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for producing acrolein and acrylic acid from propylene result in high levels of byproducts, such as maleic anhydride, which complicate and increase the cost of the production process due to the need for additional steps like distillation and extraction to remove these byproducts.
Innovation Solution
A reactor design with a catalyst bed comprising a molybdenum and bismuth-based mixed oxide catalyst gradient, where the catalyst closest to the inlet produces a lower amount of maleic anhydride relative to acrolein and acrylic acid compared to the catalyst closer to the outlet, minimizing byproduct formation through controlled catalyst composition and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional molybdenum and bismuth based mixed oxide catalyst is used for propylene oxidation, then acrolein and acrylic acid are produced, but high amounts of maleic anhydride byproducts are formed requiring additional purification steps
Solution Approach 1:
The catalyst bed is designed with spatially varying properties: the catalyst closest to the inlet produces lower maleic anhydride relative to acrolein and acrylic acid compared to the catalyst closest to the outlet. This local quality variation in catalyst performance along the reactor length reduces overall byproduct formation while maintaining production efficiency
Solution Approach 2:
The invention changes the operational parameters of the catalyst system by controlling the relative amounts of maleic anhydride produced at different positions in the catalyst bed. By adjusting catalyst composition or activity parameters along the bed, the selectivity toward desired products is improved while minimizing harmful byproducts
2Manufacturing precision
If additional purification steps like distillation and extraction are added to remove byproducts, then product purity is improved, but process complexity and cost increase
Solution Approach 1:
The catalyst bed is designed to preliminarily minimize byproduct formation during the oxidation reaction itself. By optimizing catalyst properties before the reaction occurs, the system prevents harmful substances from forming in the first place, eliminating the need for subsequent purification 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
Reduces the formation of maleic anhydride byproducts, simplifying the process and reducing costs by minimizing the need for additional purification steps, while maintaining comparable propylene conversion efficiency.
Implementation Method 1
a catalyst bed disposed between the inlet and the outlet. The catalyst bed comprises a molybdenum and bismuth based mixed oxide catalyst
Implementation Method 2
oxidizing propylene in a reactor
Data Source
AI summary
A reactor for producing acrolein and/or acrylic acid from propylene comprises an inlet for propylene to enter the reactor, an outlet for reaction products to exit the reactor, and a catalyst bed disposed between the inlet and the outlet. The catalyst bed comprises a molybdenum and bismuth based mixed oxide catalyst. The catalyst closest to the inlet of the reactor, CATinlet, produces a lower amount of maleic anhydride to the total amount of acrolein and acrylic acid compared to the catalyst closest to the outlet of the reactor, CAToutlet.