India: According to the latest data from the Gujarat Pollution Control Board (GPCB), the utilisation of hazardous waste as an alternative fuel and raw material (AFR) in cement kilns has increased by a factor of 35 since 2009 – 2010 from 15,693t/yr to 543,569t/yr in 2013 - 2014.
This follows the GPCB's measures to strike a balance between the disposal of toxic hazardous wastes, environmental protection and economic interests. Safe disposal of toxic hazardous waste posed a major challenge before the state pollution regulator took up disposal through cement kilns under controlled conditions.
In 2011 Gujarat State generated 109Bnt/yr of incinerable waste, 1107Bnt/yr of land-fillable waste and 577Bnt/yr of recyclable hazardous waste. These included plastic waste, spent carbon, tar, mixed waste liquid, pharmaceutical waste, tyre chips, agricultural waste, solid waste, chemical gypsum, iron sludge, copper slag and fly ash.
The GPCB encouraged major industrial clusters and cement plants to provide waste collection centres and pre-processing facilities for hazardous waste for co-processing. "It is a recovery of energy and material from waste," said Hardik Shah, member secretary of the GPCB. "The challenging task was to convince the top management of cement plants." The GPCB facilitated cement makers with access to its data on the waste generated in the State via Extended Green Node (XGN) software, which ensured the supply of suitable wastes.
"This involves some additional investment, but in the long run it repays as there are savings on fuel costs," said an Ambuja Cement spokesperson. Ambuja has invested US$16.7m to set up a pre-processing facility of solid/semi-solid waste at its Ambujanagar plant in Junagadh District, Gujarat State.
Similarly, Sanghi Industries is in the trial phase for using hazardous waste. "From a legal standpoint, we need to get clearance from the GPCB for co-processing any new waste material in our plant," said Alok Sanghi, director of Sanghi. "We have submitted the results of the trials conducted and are awaiting clearance from them." Sanghi has been doing trials for last 18 months.
"The use of alternative fuel in Indian cement industries has been limited," said GPCB's Shah. "The thermal substitution rate (TSR) in the cement industry is less than 1% in India as against 10% in Japan and 40% in European nations. The GPCB has set a target of three years to achieve a TSR of 10% by using AFR."