An Indian process engineering firm has come up with a new technology that would help produce potash from boiler ash, a waste byproduct generated in copious amounts by ethanol-making distilleries.
The waste-to-wealth technology developed by the Faridabad-based SSP Pvt Ltd, in fact, has a twin advantage: Apart from safely disposing of a dangerous waste product, it helps the country save precious foreign exchange spent on importing potash fertilisers. India meets its entire potash requirement through imports currently.
Waste disposal challenge
“Disposal of boiler ash is a major headache for most molasses-based distilleries. More so, after the Central Pollution Control Board started insisting on its safe disposal,” said Saibal Ghosh, CEO of the SSP Pvt Ltd, which developed the technology.
“For instance, a distillery producing 100 kilolitres of ethanol per day will generate nearly 60 tonnes of boiler ash. The technology that we have developed can produce 34 per cent potash, which is 97 per cent pure. This is in the first stage. The cake left behind after the first stage can be further treated to produce an additional 16 per cent of potash,” Ghosh told BusinessLine.
Since purity of potash used as fertiliser is nearly 60 per cent, the quantity of fertiliser-grade potash available through the SSP process would be much higher, said Ashish Banerjee, Director of SSP.
SSP was established in 1977 by Ashish’s father RP Banerjee to help Varghese Kurien, the Father of White Revolution, with machineries required for milk chilling and processing. Of late, the firm has diversified into developing different process technologies, which are currently used in 47 countries. For instance, SSP accounts for more than 90 per cent coffee processing equipment used in the country.
India currently produces 4.5 billion litres of ethanol and this leads to generation of 3 million tonnes of boiler ash. Considering that nearly 50 per cent of this can be converted into potash, India would be able to meet nearly half the potash requirement domestically. Last year, it imported nearly 4 million tonnes of potash.
“Imagine the kind of forex savings that it can have,” Banerjee said.
Currently, most ethanol distilleries give away boiler ash to farmers as soil enhancers. But it is seldom useful to farmers as the fine ash clogs pores in the soil, preventing water penetration, Ghosh said.
According to him, the cost of setting up a plant that can treat 60 tonnes of boiler ash per day is around ₹20 crore. This includes not just the capital expenditure, but interest on investment as well as operating costs. Distilleries setting up this plant can break even within one and a half years of operation.