Bisphenol-A Residue Viscosity Reduction via Dilution
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Solution Overview
Problem
Bisphenol-A residue streams become highly viscous due to the removal of phenol, making them difficult to handle and dispose of, as existing methods like thermal or catalytic cracking increase viscosity and result in a tarry aromatic waste with low phenol content.
Innovation Solution
Combining the bisphenol-A residue stream with a bottoms stream from an alkylaromatic production process, primarily composed of polyalkylated aromatic compounds, or a stream containing at least 90 wt% phenol, to reduce viscosity, creating a miscible liquid suitable for conventional handling and use as a boiler fuel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If phenol is removed from the residue stream by distillation to recover pure phenol, then phenol recovery is improved, but the viscosity of the residue stream increases making it difficult to handle
Solution Approach 1:
The patent introduces an intermediary substance (light cycle oil or phenol-containing stream) that acts as a mediator between the high-viscosity residue stream and the handling system. This intermediary dilutes the residue stream, reducing its viscosity to manageable levels while maintaining phenol recovery efficiency through the distillation process.
Solution Approach 2:
The patent changes the compositional parameters of the residue stream by adding light cycle oil or phenol-containing streams, which alters the physical properties (viscosity) of the mixture. This parameter change enables the residue stream to be handled at lower temperatures and with conventional equipment.
2Quantity of substance
If thermal or catalytic cracking is applied to the residue stream to recover phenol and IPP, then phenol and IPP recovery are enhanced, but the viscosity of the remaining residue stream increases further
Solution Approach 1:
The patent applies preliminary action by adding light cycle oil or phenol-containing streams to the residue stream before cracking occurs. This pre-dilution ensures that even after cracking increases viscosity, the overall mixture remains at manageable viscosity levels, enabling easier handling of the cracked residue.
Solution Approach 2:
The light cycle oil or phenol-containing stream serves as an intermediary that buffers the viscosity-increasing effect of cracking. This mediator maintains fluidity in the cracked residue stream, allowing conventional handling methods to be used despite the enhanced phenol and IPP recovery.
3Ease of operation
If the residue stream is maintained at high temperature (>130°C) to ensure flowability, then viscosity is reduced for handling, but energy consumption increases and safety risks arise
Solution Approach 1:
The patent changes the compositional parameters of the residue stream by adding light cycle oil or phenol-containing streams, which fundamentally alters the viscosity-temperature relationship. This allows the mixture to achieve acceptable flowability at lower temperatures, reducing energy consumption and safety risks associated with high-temperature maintenance.
4Ease of operation
If excessive phenol is used as viscosity-reducing diluent, then viscosity reduction is achieved, but economic value is lost since phenol is a higher value product
Solution Approach 1:
The patent substitutes expensive phenol with a cheaper alternative (light cycle oil or phenol-containing streams from other processes) as the viscosity-reducing diluent. This cheaper substance performs the same functional role of reducing viscosity without representing a significant economic loss, as it is either waste material or lower-value byproduct.
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 combined stream achieves significantly reduced viscosity, allowing for handling with conventional pumps and storage at lower temperatures, and is suitable for use as a boiler fuel, improving the manageability and disposal of bisphenol-A residue streams.
Implementation Method 1
combining the residue stream with at least one of (a) a bottoms stream comprising polyalkylaromatic compounds and remaining after the fractionation of an effluent from an aromatics alkylation process
Implementation Method 2
Combining the bisphenol-A residue stream with a bottoms stream from an alkylaromatic production process, primarily composed of polyalkylated aromatic compounds, or a stream containing at least 90 wt% phenol, to reduce viscosity
Implementation Method 3
combining the residue stream with at least one of (b) a stream containing at least 90 wt % phenol
Implementation Method 4
a stream containing at least 90 wt% phenol, to reduce viscosity, creating a miscible liquid suitable for conventional handling
Data Source
AI summary
In a method of reducing the viscosity of a residue stream from the production of bisphenol-A, the residue stream is combined with at least one of (a) a bottoms stream comprising polyalkylaromatic compounds and remaining after the fractionation of an effluent from an aromatics alkylation process to remove monoalkylaromatic compounds, (b) a stream containing at least 90 wt % phenol and (c) a mixture of phenol and said bottoms stream (a) to produce a combined stream.