Propene Oxidation Catalyst Temperature Control
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Solution Overview
Problem
The existing processes for long-term operation of heterogeneously catalyzed partial gas phase oxidation of propene to acrolein face challenges in maintaining catalyst quality and selectivity over extended periods, with previous methods either reducing catalyst life or compromising acrolein formation selectivity.
Innovation Solution
A process involving a fixed catalyst bed with multimetal oxide comprising Mo, Fe, and Bi, arranged in two temperature zones (A and B) where the reaction gas mixture flows through in the sequence 'first A' then 'B', with initial temperature differences ΔTBA > 0°C, and increasing at least one temperature over time to maintain catalyst quality and selectivity, ensuring ΔTBA increases with operating time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fixed catalyst bed is operated for extended periods, then productivity is maintained, but catalyst quality degrades and service life is reduced
Solution Approach 1:
The patent applies dynamics by making the temperature profile adjustable and time-dependent. Instead of a static temperature distribution, the system dynamically adapts the temperature difference between zones A and B over time to compensate for catalyst degradation, extending service life while maintaining productivity
Solution Approach 2:
The patent changes the temperature parameter profile over time. By increasing the temperature difference ΔTBA with operating time, the system compensates for catalyst quality degradation, allowing prolonged operation without premature loss of performance
2Duration of action of stationary object
If the temperature difference ΔTBA is increased to counteract catalyst degradation, then service life is extended, but selectivity for acrolein formation may be compromised
Solution Approach 1:
The patent applies local quality by maintaining different temperature characteristics in different zones. Zone A operates at a lower temperature to preserve selectivity, while zone B operates at a higher temperature to drive conversion, and the controlled difference ΔTBA extends service life without compromising overall selectivity
Solution Approach 2:
The catalyst bed is segmented into two temperature zones with different temperature levels. This segmentation allows simultaneous optimization: zone A maintains conditions for high selectivity while zone B provides the temperature boost needed for conversion and extended operation
3Productivity
If the reaction gas mixture flows through temperature zones A and B in sequence, then propene conversion is optimized, but temperature control complexity increases
Solution Approach 1:
The temperature control system is segmented into two independent zones that can be controlled separately. This allows optimized propene conversion through sequential flow while managing complexity by treating each zone as an independent control unit with specific temperature targets
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 extends the service life of the catalyst bed while maintaining high acrolein selectivity and propene conversion, allowing for prolonged operation without premature degradation or loss of selectivity.
Implementation Method 1
heterogeneously catalyzed partial gas phase oxidation of propene to acrolein over a freshly charged fixed catalyst bed
Implementation Method 2
partial gas phase oxidation of propene to acrolein
Implementation Method 3
The chemical reaction proceeds when the reaction gas mixture flows through the fixed catalyst bed, during the residence time of the reaction gas mixture therein
Data Source
AI summary
A process for long-term operation of a heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, in which the propene present in the reaction gas input mixture is partially oxidized as this gas mixture passes through the fixed catalyst bed which is accommodated in two spatially successive temperature zones A, B, and, in long-term operation, as a measure to counteract the reduction in the quality of the fixed catalyst bed, the temperature of at least one of the two temperature zones is increased such that the difference TB−TA becomes increasingly greater, where TB is the temperature of temperature zone B, and TA the temperature of temperature zone A.