Quality testing of ash from Bidadi plant under way; to be used in making construction materials  

Testing ash quality for construction use by IISc at WtE plant in Bidadi, Karnataka, with potential revenue from cement factories.

Around 10,621 tonnes of ash has been generated at the Karnataka Power Corporation Limited’s (KPCL) first of its kind waste-to-energy (WtE) plant in Bidadi until the end of April. While this ash, which remains after the incineration of waste for energy is being disposed of into landfills so far, the KPCL plans to generate some revenue by selling this ash to cement factories.

Among the ash generated at the plant, 9,214 tonnes have been categorised as bottom ash, which is collected, and 1,407 tonnes have been categorised as fly ash, which is released into the atmosphere after treatment. The ash generated in coal plants is generally used in cement factories. Now, tests are being conducted to find out if the ash from the WtE plant can be used for the same purpose.

A sample of ash from the plant is being tested by the Indian Institute of Science (IISc) to analyse if its quality is suitable for being used in the making of construction materials.

“The sample has been taken by the IISc team. If the quality is equivalent to that of coal ash, then it can be used by cement factories,” said Satish Kumar H., executive engineer (Bidadi), KPC Gas Power Corporation Limited.

Ever since the plant was commissioned, residents nearby and others have raised concerns about the hazardous nature of the ash, especially fly ash. Clarifying on this, Mr. Kumar said: “In the evaporation cooler of the plant, we douse the ash with lime, ammonia, and activated carbon. All the gases that are hazardous to the atmosphere are nullified in this process. The officials from the National Green Tribunal (NGT) recently visited and checked all the parameters and confirmed it was not hazardous.”

A scientist from IISc said that the testing is still in the initial stage. “We have collected the sample as part of a systematic study of technologies like the WtE in Bidadi across India. We will explore how the ash can be used through the study,” said Prakash Singh, from the Centre for Sustainable Technologies, IISc.

Gaurav Gupta, Additional Chief Secretary, Energy Department and the managing director of KPCL, said that while the testing is under way, the logistics for the transportation of the ash is yet to be figured out.