Wastewater discharged from chemical plants containing sulfolane typically has a high concentration. Direct discharge not only causes serious environmental pollution but also results in the loss of valuable resources. Traditional distillation methods consume significant energy, and high temperatures can easily lead to side reactions such as sulfolane ring-opening. Although biological treatment can reduce wastewater pollution, sulfolane is biodegraded and cannot be recovered, leading to resource loss.
To address the challenges of high energy consumption, poor economics, and low recovery efficiency associated with conventional technologies, the solvent extraction process is adopted. By integrating the CWL-M centrifugal extractor developed by Zhengzhou Tiei Extraction, sulfolane wastewater can be treated efficiently with low energy consumption, achieving both resource recovery and wastewater purification. The recovered sulfolane purity exceeds 99%, while the sulfolane content in treated wastewater is reduced to below 50 mg/L. The treated water can be reused, enabling near-zero wastewater discharge.
Process Flow for Sulfolane Wastewater Treatment
1.Extraction: Sulfolane-containing wastewater and the extractant (preferably dichloroethane) are fed into the CWL-M centrifugal extractor for counter-current extraction. Wastewater enters from the heavy-phase inlet of the first stage, while the extractant can be introduced at multiple stages. The CWL-M centrifugal extractor provides more than three theoretical stages and operates continuously in series. The sulfolane-rich extract phase is discharged from the light-phase outlet, while the water-rich raffinate phase is discharged from the heavy-phase outlet.
2.Distillation: The extract phase is sent to a distillation unit, where the extractant and high-purity sulfolane are separated and recovered based on boiling point differences.
3.Solvent Recycling: The recovered extractant is cooled and recycled back to the extraction section, with minimal loss.
4.Wastewater Reuse: The raffinate wastewater can be sent to a biological treatment unit or directly reused in production, enabling near-zero wastewater discharge.
Advantages of the Centrifugal Extraction Process
Simple Process Flow: Low equipment investment and easy operation
High Recovery Rate: Both the sulfolane extraction efficiency and recovery purity exceed 99%
Compliant Effluent Quality: Sulfolane concentration in treated wastewater is reduced to below 50 mg/L
Solvent Recycling: Dichloroethane can be recovered and regenerated, resulting in low operating costs
Significant Reduction in Energy Consumption
Traditional distillation for separating the sulfolane-water system requires extremely high energy consumption. Centrifugal extraction introduces an extractant to transform the separation from sulfolane-water separation into sulfolane-solvent separation. Since extraction is carried out under normal temperature and pressure, and the latent heat of vaporization of the extractant is far lower than that of water, overall energy consumption is greatly reduced.
Taking 100 t/h of sulfolane wastewater as an example:
Traditional four-effect distillation process: Energy consumption is approximately 2779 kg/h of standard oil equivalent
Centrifugal extraction (using dichloroethane as extractant): Energy consumption is approximately 697 kg/h of standard oil equivalent
Approximately 75% reduction
Core Equipment: CWL-M Centrifugal Extractor
As the core liquid-liquid extraction equipment, the CWL-M centrifugal extractor demonstrates significant advantages in sulfolane wastewater treatment:
1.High Mass Transfer Efficiency
The centrifugal force field enhances mixing, achieving an extraction efficiency of over 99%.
2.Complete Phase Separation
Millisecond-level separation effectively eliminates phase entrainment.
3.Corrosion-Resistant Design
All wetted parts are manufactured with special corrosion-resistant materials to withstand long-term exposure to organic solvents.
4.Automated Operation
The system supports continuous operation, enabling unattended extraction process control.
Practical applications have proven that the extraction-distillation process for sulfolane wastewater treatment can significantly reduce energy consumption while efficiently recovering sulfolane. This technology offers substantial industrial value and broad application prospects.
Email: sales@tieiextraction.com
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