Distilleries are among the most polluting industries due to the ethanol fermentation process, which results in the discharge of large quantities of high-strength liquid effluents. These effluents typically exhibit high concentrations of organic matter, high COD and BOD, TDS, sulfates, low pH, high temperature, dark brown color, and elevated salinity. The distillation process requires substantial amounts of water for molasses dilution, steam generation, and cooling tower makeup.

Key wastewater streams include Raw Spent Wash (RSW), spent lees, and yeast sludge generated after alcohol extraction via the distillation column. Additionally, process condensate water is produced from the evaporation of RSW or post-Biomethanated Distillery Effluent (PMDE). Low-strength effluents, such as cooling tower blowdown and boiler blowdown water, are also generated. During fermentation, yeast converts sugar into alcohol, producing carbon dioxide (CO₂) as a byproduct.

The industry faces challenges in treating RSW, spent lees, and process condensate water to achieve the Zero Liquid Discharge (ZLD) condition mandated by pollution control authorities. Additionally, recovering the CO₂ generated from the fermentation process poses another challenge.

We offer solutions for RSW treatment that include pre-treatment, biogas extraction via a biodigester, and technologies such as Concentrated Dissolved Residuals (CDRO), evaporation, and Agitated Thin Film Dryers (ATFD) to achieve ZLD in compliance with Pollution Control Board norms.

For the biogas generated, we provide viable options for its use as fuel in boilers, as a power source through gas engines after H₂S scrubbing, or for producing Compressed Biogas (CBG) following biogas upgrading.

We also offer treatment solutions for spent lees, cooling tower blowdown, boiler blowdown water, and process condensate water through a centralized treatment unit (CPU). This includes pre-treatment and biological treatment, followed by ultrafiltration (UF) and reverse osmosis (RO) to recycle the permeate as dilution water for the fermentation process and makeup water for cooling towers. The RO reject is processed in an evaporation plant to achieve ZLD.

Furthermore, we provide treatment for raw carbon dioxide (CO₂) generated during fermentation. Scrubbing or membrane-based treatment methods can be implemented to obtain food-grade CO₂, generating continuous revenue for the customer while preventing air pollution. Finally, yeast sludge is dried and utilized as organic fertilizer.