Co-Processing of Distillery Spent Wash Concentrate in the Cement Industry
Draft Guidelines for Co-processing of Distillery spent wash concentrate in Cement Industry
Central Pollution Control Board (Ministry of Environment & Forests, Govt. of India)
Parivesh Bhawan East Arjun Nagar, Delhi
1. Background
Co-processing of wastes in cement kiln is emerging as one of the environment friendly alternative disposal method in the recent years. Distillery spent wash has high organic content and dissolved inorganic solids which require careful handling and proper disposal to avoid damage to the environment. Presently it is being used on to land to provide nutrient value, though it contaminates both the ground water and surface water sources, as most often it is practiced in non-scientific manner. The adverse effect of spent wash disposal, via bio-composting is magnified during the rainy season. Concentration of spent wash in multiple effect evaporators and its subsequent incineration is also being practiced. However, it is not found technically and economically feasible in majority of cases. Hence, Central Pollution Control Board (CPCB) proposed, co-processing of concentrated spent wash in cement kiln. There are around 400 distillery units in India, with a total production capacity of about 3800 million litres of alcohol. Average generation of spent wash is around 812 litres / litre of alcohol produced, depending on continuous or batch process and quality of molasses used etc. Thus the co-processing of spent wash concentrate in cement kiln has following benefits: (a) wastes are destroyed at a higher temperature of around 1200-1400 C and longer residence time, (b) inorganic content gets fixed with the clinker apart from using the energy content of the wastes leaving no residue behind (c) the acidic gases, if any generated during co-processing gets neutralized, since the raw material in cement kiln is alkaline in nature, and (d) such phenomenon also reduces resource requirement. While in case of incineration, residuals require to be disposed
Central Pollution Control Board (Ministry of Environment & Forests, Govt. of India)
Parivesh Bhawan East Arjun Nagar, Delhi
1. Background
Co-processing of wastes in cement kiln is emerging as one of the environment friendly alternative disposal method in the recent years. Distillery spent wash has high organic content and dissolved inorganic solids which require careful handling and proper disposal to avoid damage to the environment. Presently it is being used on to land to provide nutrient value, though it contaminates both the ground water and surface water sources, as most often it is practiced in non-scientific manner. The adverse effect of spent wash disposal, via bio-composting is magnified during the rainy season. Concentration of spent wash in multiple effect evaporators and its subsequent incineration is also being practiced. However, it is not found technically and economically feasible in majority of cases. Hence, Central Pollution Control Board (CPCB) proposed, co-processing of concentrated spent wash in cement kiln. There are around 400 distillery units in India, with a total production capacity of about 3800 million litres of alcohol. Average generation of spent wash is around 812 litres / litre of alcohol produced, depending on continuous or batch process and quality of molasses used etc. Thus the co-processing of spent wash concentrate in cement kiln has following benefits: (a) wastes are destroyed at a higher temperature of around 1200-1400 C and longer residence time, (b) inorganic content gets fixed with the clinker apart from using the energy content of the wastes leaving no residue behind (c) the acidic gases, if any generated during co-processing gets neutralized, since the raw material in cement kiln is alkaline in nature, and (d) such phenomenon also reduces resource requirement. While in case of incineration, residuals require to be disposed