Alkali Concentration

Alkali produced through the chlor-alkali process is initially in a diluted form containing a high percentage of water. To make it suitable for industrial and commercial applications, the solution is carefully concentrated by removing excess water through evaporation. This process ensures high purity, consistent quality, and the required strength for reliable performance across industries.

Spent Alkali Recovery

Alkali refers to water-soluble basic chemicals with high pH, widely used for cleaning, neutralization, processing, and chemical reactions. Common alkalis such as sodium hydroxide (NaOH) and potassium hydroxide (KOH) are generated in industries including textile mercerization, cleaning-in-place (CIP) systems, soap manufacturing, and dyeing processes.

Challenges

High boiling point and corrosive nature demand specialized materials of construction

Scaling and fouling risks due to impurities and salts

Energy consumption if not designed with heat recovery

Safety considerations while handling concentrated alkali

Maintaining consistent concentration and quality

"SED’s alkali concentration systems are engineered for high efficiency, corrosion resistance, and consistent performance. The systems concentrate caustic solutions up to 48 to 72%, making them suitable for direct reuse. "

SED Smart Solution

SED’s MVR based low temperature evaporator enables controlled water removal, ensuring the final alkali product consistently meets the desired concentration while preserving its quality and functional properties, delivering superior product performance with optimized energy efficiency.

Key Advantages

Vacuum based evaporation reduces boiling point.

Patented low-temperature evaporation design minimizes scaling, corrosion and fouling.

Increase alkali strength, converting dilute solutions into reusable, high-value chemicals.

Chemical cost reduction by reusing recovered alkali.

Lower effluent load & total dissolved solids, supporting zero liquid discharge compliance.

Reduced fresh alkali consumption.

Smaller storage & transport volumes.

Recovered condensate can be reused in the process, supporting sustainable operations and lower utility consumption.

Industry-wise Usage

Textiles

NaOH for scouring & mercerizing

Pulp & Paper

NaOH and Na₂CO₃ for pulping and recovery

Metal & Aluminium

NaOH for degreasing and etching

Chemical & Dyes

NaOH, KOH for reactions and pH control

Food & Pharma

NaOH for CIP cleaning systems

Sugar & Distillery

NaOH recovery & reuse