Distillery Spent Wash...
is the main effluent generated from molasses based distilleries. The distillery industry consumes significant quantities of fresh water and generates large volumes of Spent Wash (vinasse) having very high pollution load. The quantity of spent wash generated can vary from 10 to 15 litres per litre of alcohol produced, depending upon the type of fermentation process used in the distillery. There are currently 356 molasses based distilleries, with a combined, installed capacity of 4230 million litres per annum, in India today.
Problems with DSW disposal...
are centred around the high biological and chemical oxygen demand (BOD and COD) associated with the inorganic salts inherent to DSW. These, along with other minor sugar decomposition products and xenobiotic compounds render the effluent severely recalcitrant. The toxic nature of DSW has resulted in distilleries being classified as “Red Category” among all highly polluting industries by CPCB. For every distillery in the country it is now mandatory to achieve near ‘Zero Spent Wash discharge’ as per CPCB.
Eutrophication of waterbodies...
occurs if untreated DSW is released in natural water bodies. The highly coloured compounds in spent wash reduce sunlight penetration into water bodies, decreasing both photosynthetic activity and dissolved oxygen concentration affecting aquatic life in the water body. These combined with the unpleasant odour of the effluent, associated with sulphur compounds, necessitates efficient DSW treatment to prevent harm to environment and human health.
Conventional DSW treatment…
is cost intensive and encounters several problems associated with limited life in-use, frequent cleaning and in certain cases flue gas emissions which require additional financial investments. Some of these methods include the multiple effect evaporation (MEE) system, RO (reverse osmosis), incineration system and others. Besides these, the bio-methanation process, particularly at scales appropriate for large distilleries, results in secondary effluents, which are more toxic than DSW itself.
Our Solution
Our affiliates have developed a novel, first-of-its-kind technology for the effective and economical conversion of DSW into bio-oil, a high-density liquid fuel, biogas and water recycled from the effluent. The technology coverts half of the COD content of DSW into liquid fuel, and the other half into biogas. The liquid fuel recovered from the process, is a high density boiler fluid which can be used as a power/heat source in the distillery.
