Phenol Hydrogenation Heat Integration for Cyclohexanone Production

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Solution Overview

Problem

The conventional process for preparing a mixture of cyclohexanone and cyclohexanol from phenol requires high energy consumption and significant use of cooling water, leading to increased costs and carbon footprint due to the need for extensive heating and cooling.

Innovation Solution

The introduction of additional in-process heat exchange steps to transfer heat from the hydrogenation product stream to other parts of the process stream that require heating, reducing the need for steam heating and cooling water usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional heating and cooling processes are used in the phenol hydrogenation process, then the process can be operated, but energy consumption and cooling water usage increase significantly

Engineering Contradiction:

Improveenergy consumptionVSAvoidenergy loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent combines the cooling function and heating function into a single integrated heat exchange system. The hot hydrogenation product stream is cooled while simultaneously heating the cooling water that will be used elsewhere in the process, merging two separate thermal processing steps into one mutually beneficial operation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent converts the harmful waste heat from the hot hydrogenation product stream into a beneficial resource by using it to preheat cooling water. This transforms what would normally be wasted energy (a harmful thermal polluting the system) into a useful heating source, reducing overall energy consumption.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Quantity of substance

If conventional heating and cooling processes are used in the phenol hydrogenation process, then the process can be operated, but cooling water consumption increases

Engineering Contradiction:

Improvecooling water consumptionVSAvoidthermal pollution

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The hot hydrogenation product stream serves a dual function: it is cooled to the required temperature while simultaneously providing heat to preheat the cooling water. The system essentially heats itself by utilizing its own thermal energy, reducing the need for external heating sources and cooling water consumption.

Inventive Principle:

Principle #25Self-service

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 reduces energy consumption and cooling water usage, thereby lowering the process's energy costs and carbon footprint while maintaining the production of high-purity cyclohexanone and cyclohexanol.

Implementation Method 1

hydrogenating phenol with gaseous hydrogen, in the presence of platinum or palladium, in a hydrogenation reactor

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 2

heat transferred from the hydrogenation product stream as it is cooled is transferred to another part of the process stream which requires heating

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentUS9388107B2Process for the production of a mixture comprising cyclohexanone and cyclohexanol from phenol

Publication Date: 2016.07.12 CAP III

AI summary

The present invention provides a process for continuously preparing a mixture of cyclohexanone and cyclohexanol comprising, a) hydrogenating phenol with gaseous hydrogen, in the presence of platinum or palladium, in a hydrogenation reactor, to produce a hydrogenation product stream comprising cyclohexanone, cyclohexanol, phenol and hydrogen; b) cooling the hydrogenation product stream to a temperature such that the fraction of phenol by mass in a first gas phase is lower than the fraction of phenol by mass in a first liquid phase; c) separating the first gas phase from the first liquid phase; d) returning at least part of the first gas phase to the hydrogenation reactor; e) heating the first liquid phase; f) purifying the first liquid phase by distillation; characterized in that heat is transferred from the hydrogenation product stream in step b) to another part of the process by means of in-process heat exchange; a mixture of cyclohexanone and cyclohexanol obtained by the process; and a chemical plant suitable for continuously preparing mixture of cyclohexanone and cyclohexanol according to the process.