Mohan Breweries & Distilleries Limited, Chengalpet, Tamil Nadu, India

Cane Molasses Distillery Effluent Treatment System

Mohan Breweries and Distilleries Ltd. (MBDL), earlier known as Vorion Chemicals & Distilleries Ltd., is operating a 40 KL per day capacity distillery at Chengalpet (near Chennai) in Tamil Nadu.

The distillery uses Sugar Cane Molasses as a raw material to make alcohol, using continuous fermentation technology. During the distillation process, a large quantity of wastewater (called spent wash), approximately 13 - 15 times the quantity of alcohol produced, is produced. The spent wash has a very high BOD/COD.

UEM was awarded the job to install a complete effluent treatment system to treat the spent wash and bring down the BOD to the required levels while simultaneously generating biogas to be used as source of energy. The system was designed to treat 600 M3/day of spent wash with a BOD of 50,000 mg/l and a COD of 100,000 mg/l. The effluent treatment system incorporates a large volume (16,800 M3) Low Rate Anaerobic Digester followed by Secondary & Tertiary Aerobic Activated Sludge Treatment System using Fine Bubble Air Diffusers. The amount of biogas generated from this process is approximately 21,000 M3/day. The overall ETP system has been functioning satisfactorily since its completion.