Cyclohexanone Purification via Sorbent Bed Poison Removal
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Solution Overview
Problem
Current processes for producing cyclohexanone from phenol and cyclohexylbenzene face challenges due to catalyst poisoning and yield loss, as they involve hydrogenating mixtures containing phenol, cyclohexanone, and cyclohexylbenzene, which results in the formation of cyclohexanol and other impurities, leading to inefficient production of cyclohexanone.
Innovation Solution
A process that includes a series of distillation and hydrogenation steps, utilizing sorbent beds to remove catalyst poisons and optimize the conversion of phenol to cyclohexanone, achieving high purity cyclohexanone compositions with reduced impurities, such as using Amberlyst® A21 and A26 ion exchange resins to treat the feed before hydrogenation, and managing heat transfer in hydrogenation reactors to maintain optimal reaction conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrogenation of phenol/cyclohexanone/cyclohexylbenzene mixture is performed to produce more cyclohexanone, then cyclohexanone yield increases, but catalyst poisoning and formation of unwanted byproducts (cyclohexanol, bicyclohexane) occur
Solution Approach 1:
The patent applies preliminary action by removing catalyst poison components from the feed stream before hydrogenation. A sorbent bed containing materials like activated alumina, activated carbon, or silica gel is positioned upstream of the hydrogenation catalyst to adsorb sulfur-containing and other poisonous impurities. This preliminary purification protects the hydrogenation catalyst from poisoning, maintaining its activity and enabling sustained high cyclohexanone production without catalyst deactivation.
Solution Approach 2:
The patent extracts harmful components (catalyst poisons) from the reaction mixture before it reaches the hydrogenation catalyst. The sorbent bed selectively removes sulfur-containing compounds and other poisonous impurities through adsorption, separating these harmful substances from the phenol/cyclohexanone/cyclohexylbenzene mixture. This extraction prevents catalyst poisoning while allowing the desired hydrogenation reactions to proceed efficiently.
2Productivity
If hydrogenation of phenol/cyclohexanone/cyclohexylbenzene mixture is performed to produce more cyclohexanone, then cyclohexanone yield increases, but formation of cyclohexanol and bicyclohexane leads to yield loss
Solution Approach 1:
The patent applies local quality by creating different functional zones in the reaction system. The sorbent bed zone selectively removes catalyst poisons, while the hydrogenation zone performs the main conversion. Additionally, by controlling hydrogenation conditions (temperature, pressure, catalyst type) in the local reaction zone, the process favors cyclohexanone formation over cyclohexanol and bicyclohexane byproducts, minimizing unwanted side reactions.
Solution Approach 2:
The patent employs parameter changes by optimizing hydrogenation conditions including temperature, pressure, and catalyst composition to favor cyclohexanone production. By adjusting these parameters, the process minimizes the formation of cyclohexanol and bicyclohexane byproducts. The use of specific catalysts and controlled reaction conditions changes the selectivity of the hydrogenation reaction to maximize desired product while reducing unwanted byproducts.
3Ease of manufacture
If conventional hydrogenation process is used to convert phenol to cyclohexanone, then production is achieved, but catalyst poisoning from S-containing components reduces process efficiency
Solution Approach 1:
The patent applies segmentation by dividing the processing system into distinct functional units: a sorbent bed unit for poison removal positioned upstream, and a hydrogenation unit for main conversion. This segmentation allows each unit to perform its specific function optimally - the sorbent bed protects against poisoning while the hydrogenation unit maintains production efficiency. The modular design adds minimal complexity while significantly improving overall process 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
The process achieves cyclohexanone compositions with at least 99 wt% purity and minimal impurities, improving yield and reducing catalyst poisoning, thereby enhancing the efficiency and effectiveness of cyclohexanone production.
Implementation Method 1
removing at least a portion of catalyst poison components from a phenol/cyclohexanone/cyclohexylbenzene mixture
Implementation Method 2
hydrogenation of phenol to cyclohexanone
Implementation Method 3
processes for making cyclohexanone by phenol hydrogenation
Data Source
AI summary
Disclosed are processes for making such cyclohexanone compositions from a mixture comprising phenol, cyclohexanone, and cyclohexylbenzene. Such cyclohexanone compositions comprise at least 99 wt % cyclohexanone, at most 0.15 wt % water, and at most 500 wppm combined of certain cyclohexanone impurities selected from the group consisting of: benzene, cyclohexene, pentanal, cyclopentanol, cyclohexanol, and phenol.