Cyclohexanone Production Heat Integration and Purification
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Solution Overview
Problem
Conventional processes for producing cyclohexanone from phenol have high net energy and steam consumption, resulting in a negative environmental impact and increased production costs, with the product often requiring additional purification to achieve high purity levels.
Innovation Solution
A continuous industrial-scale process involving high per-pass phenol conversion, optimized cyclohexanone to cyclohexanol ratios, and extensive heat integration, combined with a multi-step distillation purification process to achieve high cyclohexanone purity with reduced energy and steam consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional phenol hydrogenation process is used, then cyclohexanone can be produced, but net energy and steam consumption are high
Solution Approach 1:
The patent changes key process parameters including operating at lower temperatures (50-150°C), using specific catalyst compositions (Pt or Pd on support with promoters), and optimizing H2/phenol ratios (0.5-2.0 mol/mol) to reduce energy consumption while maintaining production efficiency
Solution Approach 2:
The patent converts the exothermic hydrogenation reaction heat, which was previously a energy loss requiring cooling, into a beneficial source for steam generation and process heating needs, thereby reducing net energy consumption while maintaining productivity
2Loss of energy
If conventional phenol hydrogenation process is used, then cyclohexanone can be produced, but steam consumption is high
Solution Approach 1:
The patent utilizes the exothermic heat from phenol hydrogenation to generate steam in-situ, converting what was previously a waste heat requiring energy-intensive cooling into a valuable steam source for process needs, thereby reducing steam consumption while maintaining production rates
Solution Approach 2:
The patent merges the hydrogenation reaction function with steam generation function in the same reactor system, allowing simultaneous product formation and steam production, which reduces overall steam consumption while maintaining cyclohexanone productivity
3Manufacturing precision
If conventional separation process is used, then cyclohexanone can be recovered, but product purity is insufficient for high-grade nylon
Solution Approach 1:
The patent achieves high purity (≥99.5 wt%) by optimizing reaction parameters to maximize selectivity for cyclohexanone over cyclohexanol, and by implementing a simplified distillation sequence that exploits the boiling point differences of components, reducing the need for complex multi-stage purification while meeting high-grade nylon specifications
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 a cyclohexanone purity of at least 99.5 wt% with significantly lower net energy and steam consumption, improving the carbon footprint and reducing production costs while meeting high-grade nylon specifications.
Implementation Method 1
hydrogenating phenol in a phenol hydrogenation reactor in a phenol hydrogenation reaction section with gaseous hydrogen, in the presence of platinum and/or palladium comprising catalyst
Implementation Method 2
hydrogenating phenol in a phenol hydrogenation reactor in a phenol hydrogenation reaction section with gaseous hydrogen
Implementation Method 3
whereby reaction heat is produced
Implementation Method 4
separating cyclohexanone from said hydrogenated product stream in a separation and purification section by multiple-steps comprising: i. removing in a first distillation section, components with a boiling point lower than cyclohexanone; ii. removing in a second distillation section cyclohexanone
Implementation Method 5
wherein at least some of the reaction heat produced in the phenol hydrogenation reaction section is applied for the production of steam
Data Source
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AI summary
An industrial scale continuous process for the production and recovery of cyclohexanone from phenol and hydrogen, said process comprising: hydrogenating phenol in a phenol hydrogenation reactor; separating cyclohexanone from a hydrogenated product stream in a separation and purification section [II] comprising at least 4 distillation sections; wherein at least some of the reaction heat produced in the phenol hydrogenation reaction section [I] is applied for the production of steam; and wherein the molar ratio of cyclohexanone to phenol that is charged to said phenol hydrogenation reactor is from 0.02 to 0.10; and/or wherein the molar ratio of cyclohexanol to phenol that is charged to said phenol hydrogenation reactor is from 0.001 to 0.10.