Distillery Effluent

Distilleries have been generating huge quantities of high toxic effluents and in spite of the best efforts made so far a comprehensive treatment has not been possible. In most of the conventional technologies, the treated effluent also yields very high BOD, COD, TS and TDS level with black colored and odor effluent to rivers & natural water streams. Based on the above mentioned fact, a treatment by which it will be possible to overcome all the problems have been worked out. The basic thrust of the technology is to reduce the quantity by a maximum possible extent. The concept and the treatment is based on the belief that the entire BOD requirement should go down and the condensate coming out should not be polluted.

The technology is based on basic principle of reduction of quantity by concentrating the effluent and subsequently drying it to a Powder / Mixed Fuel form which can be used as an alternative fuel for boilers and as an organic / inorganic fertilizer for plant growth.

Distillery Effluent is fed to the vacuum evaporator to concentrate maximum up to 60% solids concentration. The total process is under vacuum and the vapors generated in the system are re-used to economize steam consumption. In order to reduce steam consumption in multiple effect evaporation system the thermal vapour recompression system is used. The thermal vapour recompression system use Vapours generated in the evaporator and compress it by steam and the compressed vapours are used as heating medium in the evaporator. Water recovered from the evaporator has low BOD value and can be recycled in the plant.

The resultant slurry (concentrate) is fed to the drying section for converting the liquid concentrate to powder / mixed fuel (mixing with Secondary Fuel e.g. Bagasse, rice husk etc.) form. The air heated by steam radiator or hot air generator is fed into the dryer. The whole system is designed to obtain the optimum results. The emissions from the dryer are within the norms specified by the Govt. of India. This powder / mixed fuel can be used as an alternative fuel to steam boilers.

The Basic thrust of the technology is to reduce the quantity of Effluent by a maximum possible extent in the first stage.

In many of this kind of processes foaming is a big problem, which carries away lot of suspended particles in the condensate water, which eventually increases the BOD of distillate. The SSP’s technology has taken care of this problem and the BOD levels are contained to an extent of 80 mg/l and the distillate produced is colorless and is reusable for other processes.

SSP has designed and supplied DDGS plants to various parties in India as well as abroad. In today's business scenario it is imperative for one to properly address his attention on the economic and environmental aspects that concern the grain-based alcohol producing industries in India vis-à-vis processing of stillage obtained as the by-product after distillation.

SSP is the pioneer in India to have indigenously developed a proven, fully integrated technology for manufacturing Distillers Dried Grains with Solubles (DDGS) from whole grain stillage which is the residue obtained after alcohol has been separated by distillation of the fermented mash of feed stock and water.

The grain stillage from the bottom of analyzer column of grain based distillery is introduced to a continuous decanter centrifuge. Suspended particles are separated as a wet cake from the decanter and thin liquor is further processed to the evaporation section.

The thin liquor from decanter is concentrated in multiple effects falling film vacuum evaporator to get maximum water evaporation per kg steam energy supplied. The total process is under vacuum and the vapours generated in the system are re-used to economize steam consumption. In order to reduce steam consumption in multiple effect evaporation system the thermal vapour recompression system is used. The thermal vapour recompression system use vapours generated in the evaporator and compress it by steam and the compressed vapours are used as heating medium in the evaporator. The concentrate obtained from the evaporator is stored and fed to the mixing section. The wet cake and the concentrate is mixed and blended to for a uniform mix. The so formed mix is fed to the spin flash dryer to dry the wet mix to get dried powder DDGS. Fraction of DDGS at 10% moisture content is re-circulated through the blending section so to reduce the water evaporation load on spin flash dryer.

The DDGS thus obtained is a high protein content product and can be used as catlle feed of good nutritional value.