In industries such as chemical fiber production, polyimide film manufacturing, pharmaceuticals, and electronic materials, Dimethylacetamide (DMAC) is widely used as an excellent solvent due to its strong polarity and high boiling point. However, DMAC is completely miscible with water at any ratio and has a boiling point as high as 165–167°C, making it difficult to separate and recover directly from aqueous solutions. Large volumes of high-concentration DMAC wastewater, if discharged without effective treatment, not only result in significant waste of valuable resources but also impose substantial environmental and operational cost pressures on enterprises.
Zhengzhou Tiei Extraction provides an innovative, economical, and environmentally friendly solution for efficient DMAC wastewater recovery and resource reutilization through the CWL-M series centrifugal extractor.

Three Major Challenges in DMAC Wastewater Recovery

1.Extremely High Energy Consumption in Traditional Distillation: Because DMAC and water form a high-boiling mixture, traditional distillation requires large amounts of steam and electricity. Processing each ton of DMAC wastewater entails high energy costs, and the purity of the recovered DMAC is difficult to meet the requirements for reuse.
2.Escalating Treatment Costs: The direct outsourcing of high-COD and high-nitrogen DMAC wastewater treatment is prohibitively expensive; conversely, companies that opt ​​to construct their own biochemical treatment systems face significant challenges, including high technical barriers, substantial land requirements, and difficulties in consistently meeting discharge standards.
3.Increasingly Strict Environmental Regulations: As emission standards continue to tighten, traditional distillation and biological treatment methods often struggle with low recovery efficiency and difficult handling of by-product salts. Many enterprises face the risk of production restrictions or shutdowns due to environmental compliance challenges.

These issues are not only cost burdens but also major obstacles to sustainable industrial development. The emergence of centrifugal extraction technology provides a new pathway for closed-loop DMAC wastewater recycling.

Centrifugal Extraction Process: An Efficient, Energy-Saving, and Precise Separation Solution

Unlike traditional distillation towers or mixer-settler systems, the CWL-M centrifugal extractor utilizes a high-gravity centrifugal field to intensify mass transfer and phase separation, simplifying the DMAC recovery process into three main stages: extraction, stripping, and distillation.

1.Precise DMAC Extraction: Pretreated DMAC wastewater and a proprietary extractant are continuously fed into the centrifugal extractor at a controlled ratio. The extractant demonstrates high selectivity for DMAC, rapidly binding with DMAC molecules in the wastewater.

2.Rapid Mixing and Separation: Under a centrifugal force of up to 800–1200G, the two liquid phases are instantly dispersed into micron-sized droplets, increasing the mass transfer interface area by hundreds of times. DMAC molecules are efficiently transferred from the aqueous phase to the organic phase within seconds. Subsequently, the strong centrifugal field enables rapid and clear phase separation, with extractant carryover lower than 0.1%.

3.Stripping and Solvent Regeneration: The organic phase loaded with DMAC enters the stripping stage, where it contacts a small amount of stripping agent. DMAC is transferred back into the aqueous phase to obtain a high-concentration DMAC solution, while the extractant is regenerated and recycled with minimal loss.

4.Distillation Purification and Wastewater Compliance: The concentrated DMAC solution can then be purified through a simple distillation process to obtain DMAC with a purity of ≥99.5%, suitable for direct reuse in production lines. Meanwhile, the raffinate wastewater experiences a COD reduction of more than 90%, allowing it to be easily integrated into biological treatment systems or discharged in compliance with environmental standards.

Core Advantages of CWL-M Centrifugal Extractors in DMAC Recovery

1.Breaking the Azeotropic Limitation for Higher Recovery and Purity
Traditional distillation processes are limited by the DMAC-water azeotropic system, with recovery rates typically remaining around 80% and product purity often below 95%. As a physical separation process, centrifugal extraction is completely unaffected by azeotropic limitations. The DMAC recovery rate can exceed 99%, while product purity remains consistently above 99.5%, truly transforming “waste liquid into reusable raw material.”

2.More Than 60% Reduction in Energy Consumption
The extraction process operates at ambient temperature without the need to evaporate large amounts of water. The primary energy consumption comes only from motor operation, and the overall energy consumption per ton of wastewater is only one-third to one-fourth that of traditional distillation.

3.Compact Equipment Design with Fast Return on Investment
The CWL-M series centrifugal extractor integrates mixing, reaction, and separation into a single compact unit. Each equipment occupies only 1–3 square meters, and even multi-stage systems require far less space than traditional extraction columns or distillation units. Its modular design can flexibly accommodate treatment capacities ranging from 1 to 100 m³/h, allowing easy production expansion without major infrastructure modifications. In most cases, the investment payback period is only 6–14 months.

4.Fully Enclosed Operation for Reliable Environmental Compliance
The equipment adopts a fully sealed structure, effectively preventing organic vapor emissions and improving the working environment. In addition, the biodegradability of the raffinate is significantly enhanced, solving the challenges associated with high-salt and high-COD wastewater treatment and helping enterprises comply with increasingly stringent environmental regulations.

Real Industrial Cases: Transforming Wastewater into Valuable Resources

Case Study 1: A Polyimide Film Manufacturer
Challenge: The DMAC wastewater concentration was approximately 25%, with a daily discharge volume of 40 tons. The existing distillation unit suffered from high energy consumption and a recovery rate of only 82%, while the disposal of evaporation residues presented significant difficulties.
Solution: Implementation of the CWL-350M centrifugal extractor unit (three stages of counter-current extraction + one stage of stripping).
Results: The DMAC recovery rate increased to 98.6%, achieving a product purity of 99.7% and an annual DMAC recovery volume of approximately 3,000 tons. Energy consumption per ton of treated water dropped from 0.6 tons of steam to 0.15 tons of steam; furthermore, the wastewater COD level was reduced from 120,000 mg/L to 8,000 mg/L, thereby significantly reducing the load on subsequent biochemical treatment processes.

Case Study 2: An Acrylic Fiber Manufacturer
Challenge: Wastewater containing DMAC exhibited an extremely high COD level of up to 200,000 mg/L; outsourced treatment costs exceeded 5 million RMB annually, and the facility faced the risk of restricted acceptance by the industrial park's wastewater treatment system.
Solution: CWL250-M Centrifugal Extractor (four stage counter-current extraction).
Results: DMAC recovery rate reached 99.2%, and the COD of the raffinate was reduced to below 5,000 mg/L, allowing it to be discharged directly into the industrial park's centralized wastewater treatment plant.

Zhengzhou Tiei Extraction CWL-M centrifugal extractor utilizes highly efficient continuous separation technology, ultra-low operating costs, and flexible engineering integration to help enterprises achieve resource recycling and reutilization of DMAC wastewater. Whether you are a manufacturer in the chemical fiber, membrane material, pharmaceutical, or electronic chemical industries, Tiei Extraction can provide customized centrifugal extraction solutions tailored to your process requirements.
Bid farewell to traditional processing methods characterized by high energy consumption and low recovery rates. Choose Tiei Extraction to truly transform your DMAC wastewater into a valuable resource, while driving green and sustainable development for your business.
Email: sales@tieiextraction.com
Whatsapp: +86 19069612820