Ethanol distillation from sweet sorghum
Work was carried out on the development of a solar powered ethanol distillation plant between 1985 and 1987.
A pilot distillation plant was set up on the Institute campus and was capable of distilling 50 l/day of 94% (v/v) ethanol from MADHURA sweet sorghum hybrid developed at NARI. The solar collector area was 38 sq. m. About 70% of the energy for distillation came from solar energy. This was perhaps the first such pilot plant anywhere in the world.
Based on the work at NARI on sweet sorghum to produce fuel, food and fodder from the same piece of land yearly production of food, fuel and fodder from 1 ha of ‘Madhura’ yields:
– 60-80 tons of stripped stalks
– 21-28 tonnes of bagasse
– 2000-3000 liters of ethanol ( 95% v/v)
– 2-4 tons of good quality grain
Ethanol can be used as a substitute for kerosene for household lighting and cooking energy needs. Fruthermore it can be mixed with diesel and petrol to help reduce pollution as well as foreign exchange outflow in importing petroleum products. At NARI suitable stoves and lanterns have been developed to run on low concentration (50% and above) of ethanol/water mixtures.
Solar detoxification of distillery waste
Between 2001 and 2003 NARI developed technology for solar detoxification of distillery waste using photocatalysts. The distillery waste is rendered odorless and completely colorless through this process. The chemical oxygen demand (COD) is also reduced drastically. A pilot plant was set up and ran for 2 years at NARI campus. It could clean 200 liters of diluted distillery waste in two days. The chemical used could be recycled and the waste water had 90% transmittance and hence was fit for discharge in waterways.
Details of the pilot plant are given here.