Stripper Column Control for Nitrobenzene Wastewater Purity
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Solution Overview
Problem
Existing methods for treating wastewater contaminated with nitrobenzene in stripper columns are inefficient in terms of energy consumption and require excessive manual intervention, failing to meet stringent purity requirements for biological treatment plants without compromising operational efficiency.
Innovation Solution
A method involving continuous operation of a stripper column with controlled feeding of stripping gas based on linear mathematical relationships to maintain nitrobenzene concentration within a defined range, allowing for automatic adjustments to ensure compliance with wastewater treatment plant specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the flow rate of stripping gas is increased to reduce nitrobenzene concentration in wastewater, then the purity of treated wastewater is improved, but the energy consumption increases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the flow rate of stripping gas based on measured nitrobenzene concentrations. The system modifies operational parameters (gas flow rate) in response to changing conditions to optimize both purification effectiveness and energy efficiency, avoiding excessive energy consumption while maintaining required purity standards.
Solution Approach 2:
The patent implements feedback control by continuously measuring the nitrobenzene concentration in the treated wastewater and using this information to adjust the stripping gas flow rate. The control system compares measured concentrations with target values and automatically modifies operational parameters to maintain optimal performance, resolving the contradiction between achieving high purity and minimizing energy use.
2Manufacturing precision
If manual adjustment of stripping gas flow rate is used to meet purity requirements, then the purity of treated wastewater is improved, but the operational complexity and manual intervention increase
Solution Approach 1:
The patent applies self-service by implementing an automated control system that performs measurements and adjustments without requiring manual intervention. The system autonomously monitors nitrobenzene concentrations and regulates the stripping gas flow rate to maintain purity requirements, eliminating the need for continuous manual operation while ensuring consistent performance.
Solution Approach 2:
The automated feedback control system continuously measures nitrobenzene concentration and automatically adjusts the stripping gas flow rate based on deviations from target values. This closed-loop control eliminates manual intervention while maintaining the required purity standards, resolving the contradiction between achieving high precision and ensuring ease of operation.
3Use of energy by moving object
If the flow rate of stripping gas is reduced to save energy, then the energy consumption is decreased, but the nitrobenzene concentration in treated wastewater increases
Solution Approach 1:
The patent applies dynamics by transitioning from static, fixed gas flow rates to dynamic, variable flow rates that adapt to changing wastewater conditions. The system continuously adjusts the stripping gas flow rate based on real-time measurements of nitrobenzene concentration, enabling energy-efficient operation while maintaining purity standards through responsive parameter modification.
Solution Approach 2:
The system modifies the operational parameter of gas flow rate in response to measured concentration levels. When concentrations are low, the gas flow rate is reduced to save energy; when concentrations approach limits, the flow rate is increased to maintain purity. This dynamic parameter adjustment resolves the contradiction between energy consumption and purification effectiveness.
4Reliability
If continuous monitoring and adjustment of stripping gas flow rate is implemented, then the compliance with purity requirements is improved, but the device complexity increases
Solution Approach 1:
The patent implements feedback control with continuous monitoring of nitrobenzene concentration and automatic adjustment of stripping gas flow rate. This closed-loop system ensures reliable compliance with purity requirements by automatically responding to concentration changes, accepting the necessary increase in device complexity as a trade-off for achieving consistent regulatory compliance.
Solution Approach 2:
The patent replaces manual mechanical adjustment with automated electronic control and measurement systems. By substituting human operation with instrumental measurement and automatic control mechanisms, the system achieves reliable continuous compliance while the complexity is managed through automation rather than manual procedures.
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
Achieves efficient energy use and reduced manual intervention while ensuring the wastewater meets purity requirements, allowing for consistent operation and compliance with legal limits.
Implementation Method 1
stripping of the wastewater stream AW1 with a stripping gas SG1 in a continuously operated stripper column to obtain a wastewater stream AW2 containing nitrobenzene in a reduced concentration
Data Source
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AI summary
The present invention relates to a method for cleaning a wastewater stream AW1 contaminated with nitrobenzene, comprising (I) stripping the wastewater stream AW1 with a stripping gas SG1 in a continuously operated stripping column in order to obtain a wastewater stream AW2, which contains nitrobenzene at a reduced concentration (cNB,AW2) in comparison with AW1, (II) additionally cleaning the wastewater stream AW2 in a wastewater treatment installation, a target value (cNB,AW2,SOLL) being defined for the concentration of nitrobenzene in the wastewater stream AW2, which target value is greater than zero but is based on the requirements of the wastewater treatment installation for the maximum nitrobenzene content of the wastewater streams fed to the wastewater treatment installation, a system of linear mathematical relations of the type ṁSG1 = x ∙ ṁAW1 being stored in a database for at least one combination of given constraints for (a) the nitrobenzene concentration in AW1, for (b) the temperature of AW1 and for (c) the temperature of SG1, which linear mathematical relations define a range of concentrations of nitrobenzene in AW2, the system containing, in addition to a mathematical relation (0) corresponding to the target value cNB,AW2,SOLL, at least a first linear mathematical relation (1) for a first value of cNB,AW2, said first value corresponding to 98% of the target value cNB,AW2,SOLL, and a second linear mathematical relation (2) for a second value of cNB,AW2, said second value corresponding to 102% of the target value cNB,AW2,SOLL, and the rate of flow of the stripping gas being adapted to the rate of flow of the wastewater AW1 such that the rate of flow of AW1 lies within a value range (AB), which is spanned by the first mathematical relation (1) and by the second mathematical relation (2) for the particular rate of flow of AW1, and controlling the concentration of nitrobenzene in AW2 (cNB,AW2) by adjusting the rate of flow of stripping gas SG1 accordingly in the event of a measured actual value of the concentration of nitrobenzene in AW2 which lies outside of an interval of > 98% to < 102% of the target value.