Membrane-Based Acid and Alkali Recovery System

Product Overview

The membrane-based acid and alkali recovery system is a high-efficiency separation solution designed for the resource recovery of high-concentration alkaline solutions. It is widely used in viscose fiber production and related chemical processes.

Using advanced membrane separation technology, the system efficiently separates and recovers sodium hydroxide from impurities. This helps maintain product quality while significantly reducing raw material consumption and waste discharge, supporting cost reduction and sustainable production.

Working Principle

The system is mainly used to treat high-concentration sodium hydroxide solutions generated during viscose fiber production

• Alkali Steeping Process:
In the pulp steeping stage, cotton pulp or wood pulp is soaked in a sodium hydroxide solution with a concentration of 200–210 g/L. The cellulose reacts with the alkali to form alkali cellulose, while generating a large amount of spent caustic solution containing impurities such as hemicellulose

• Membrane Separation:
The spent caustic solution is treated using high-efficiency membrane filtration, which separates sodium hydroxide from hemicellulose and other dissolved impurities. The membrane system offers more than 10 times the efficiency of traditional dialysis processes, enabling rapid and effective purification

• Alkali Recovery and Reuse:

After membrane treatment, the recovered alkali solution has an average concentration of around 100 g/L, close to the original process requirement, and can be directly reused. The recovery rate can exceed 85%

If higher concentration is required, the solution can be further concentrated by evaporation or adjusted by adding a small amount of fresh caustic soda

Key Features

• High recovery efficiency: Sodium hydroxide recovery exceeds 85%, significantly reducing raw material consumption
• Superior separation performance: Membrane filtration is over 10 times more efficient than traditional dialysis, greatly improving processing speed
• Direct reuse capability: Recovered alkali (~100 g/L) can be reused directly, minimizing additional processing steps

• Environmentally friendly: Reduces discharge of concentrated alkaline waste, lowering environmental impact

• Stable product quality: Higher purity compared to conventional methods, helping improve final product quality

Applications

• Viscose fiber production: Recovery and recycling of caustic soda to improve efficiency and reduce costs
• Chemical processes: Suitable for various processes using sodium hydroxide, enabling alkali recovery and reuse

• Cellulose processing industries: Applied in pulp, paper, and textile sectors to optimize resource utilization
• Environmental protection and wastewater treatment: Serves as an effective solution for industrial waste liquid treatment and resource recovery, reducing pollution and enhancing sustainability