Off-Gas Stripping for Cumene Hydroperoxide Waste Water

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for removing organic impurities, particularly methanol, from waste water streams in the cumene-to-phenol production process are inefficient, requiring significant energy input and costly materials like activated carbon, which is ineffective for methanol absorption.

Innovation Solution

Utilizing off-gases from the cumene oxidation to cumene hydroperoxide process, low in oxygen and rich in nitrogen, as a stripping agent to remove organic compounds from waste water streams, thereby reducing the chemical oxygen demand and recycling valuable cumene.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If activated carbon adsorption beds are used to remove organic impurities from waste water streams, then VOC emissions are prevented and cumene is recovered, but methanol removal is ineffective and significant energy input is required

Engineering Contradiction:

ImproveVOC emissionsVSAvoidmethanol removal effectiveness

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The invention changes the parameter of using steam (high temperature gas) instead of activated carbon for stripping organic impurities. This parameter change enables effective removal of methanol and other light organic compounds from waste water streams, overcoming the limitation of activated carbon which is ineffective for methanol absorption.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the physical adsorption mechanism of activated carbon with a thermal stripping mechanism using steam. This substitution allows for more effective removal of volatile organic compounds including methanol, while also reducing the need for costly activated carbon materials.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If steam stripping is used to remove organic compounds from waste water, then removal effectiveness is improved, but energy consumption increases significantly

Engineering Contradiction:

Improveorganic compound removal efficiencyVSAvoidenergy input

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention uses off-gases from the cumene oxidation process itself as the stripping medium. These off-gases, which would otherwise be wasted or require incineration, are redirected to strip organic impurities from waste water streams. This self-service approach eliminates the need for external steam generation, significantly reducing energy consumption while maintaining high removal efficiency.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention converts the harmful off-gases containing VOCs from the oxidation process into a useful stripping medium for waste water treatment. By using these off-gases for stripping, the system simultaneously treats waste water and prepares the off-gases for incineration or reuse, turning a potential environmental hazard into a beneficial resource.

Inventive Principle:

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

3Loss of energy

If off-gases from cumene oxidation are used as stripping agent, then energy consumption is reduced and valuable cumene is recovered, but the oxygen content must be controlled to prevent explosions

Engineering Contradiction:

Improveenergy consumptionVSAvoidexplosion risk

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The invention utilizes the nitrogen-rich, oxygen-depleted off-gases from the oxidation process as an inert stripping medium. By controlling the oxygen content to be low (typically less than 5-10% by volume), the system creates an inert atmosphere that prevents explosive conditions while still providing effective stripping of organic impurities from waste water streams.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The system incorporates monitoring and control mechanisms to maintain safe oxygen levels in the off-gases used for stripping. By continuously monitoring oxygen content and adjusting process parameters accordingly, the system ensures that the stripping operation remains within safe operational limits, preventing explosion risks while maximizing energy efficiency.

Inventive Principle:

Principle #23Feedback

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 method effectively reduces the organic load in waste water streams, decreases energy consumption, and recovers valuable cumene, making the process more efficient and cost-effective by using a freely available gas stream before incineration.

Implementation Method 1

contacting a waste water stream containing at least one organic compound formed during phenol production with off gas from step (i) so as to strip at least some of said at least one organic compound from said waste water stream and into said off gas

Methodology Applied

Scientific EffectStripping: Sparging

Data Source

PatentEP2657192B1Reducing organic impurities in waste water

Publication Date: 2019.03.20 BOREALIS AG

Figure 1
Figure 2

AI summary

Use of off gas from the oxidation of cumene to cumene hydroperoxide to strip at least one organic compound from a waste water stream containing said at least one organic compound, in particular to strip at least one organic compound from a waste water stream formed during phenol production.