Read part four of the article here.
Ambient air quality
The revised National Ambient Air Quality Standards (NAAQS) 2009 were released by the MoEF. As per these norms, both residential and industrial areas will have the same standards. The new standards include limits for benzene, ozone, benzo(a) pyrene, arsenic, nickel and ammonia, which were not covered in earlier standards notified in 1994.
These rules are a little more stringent than the earlier standards; however the cement industry has made it possible to achieve these limits. Though there are limits for 12 pollutants, four criteria pollutants namely particulate matter (PM10 and PM2.5), sulfur dioxide and nitrogen dioxide are required to be monitored regularly.
Monitoring requirements for cement plants
The cement plants in India are required to monitor ambient air quality and stack emissions on their premises. The exact location of ambient air quality monitoring stations and the sampling ports in the stacks shall be decided by the concerned cement plants in consultation with the respective SPCB. Cement plants shall have sampling ports built into the stack. A permanent sampling platform and approach shall also be provided to the stack sampling station. The State Board may prescribe more rigorous monitoring requirements depending on the location of the industry, especially if it is in a protected area.
The environmental parameters to be regularly monitored at cement plants are particulate matter (PM10/PM2.5), sulfur dioxide and nitrogen dioxide in ambient air and particulate matter, SO2 and NOX emissions in the kiln stack.
There are two types of fugitive dust: one is process related, such as material handling, size reduction operations, etc. The other is non-process related, such as vehicular traffic inside the plant. Fugitive emissions also occur from limestone excavations in quarries. CPCB has developed guidelines for the prevention and control of fugitive dust emissions in cement plants. However, cement plants are taking various measures to reduce fugitive emissions comparable to the “best practice” elsewhere in the world.
Emissions of greenhouse gases like CO2, generated from decomposition of the carbonate raw material (calcination of limestone), burning of fossil or alternate fuel (coal, lignite, etc.) and use of grid or captive power is a major environmental issue for the cement industry. There is no limit for CO2 emissions from cement plants in India. However, the industry has been working on the issue of its GHG emissions and has brought the CO2 emission level down from 1.05 t of CO2/t of cement in 1994 to 0.719 t of CO2/t of cement in 2010. The approximate contributions of each of the three main sources of CO2 emissions are calcinations 50 to 55%; fuel combustion 35 to 45%; electricity up to 10%.
The various environmental acts/rules/regulations discussed above, enacted in India and implemented by regulatory agencies such as the MoEF/CPCB/SPCBs applicable to the Indian cement industry, cover different aspects of environment protection. The Indian cement industry is proactive and is taking voluntary steps, such as the utilisation of alternate fuel, modernisation of APCE, reduction of water consumption and rainwater harvesting in used quarries, and the use of treated waste water for dust suppression and green belt development. Some of the cement plants have incorporated waste heat recovery plants to generate energy.
Especially over the last decade, the importance of environmental impact has been well recognised by the cement industry and it has been clearly understood that the improvement of the environment is everybody’s business. The Indian cement industry has come a long way in achieving technological upgradation, enhanced production, higher energy efficiency and improved environmental condition, conforming to policies and regulation of statutory/ regulatory bodies under government administration.
This article is abridged from the original, which was included as ‘Keynote: Environmental Regulations in India’ in the October 2013 issue. The issue is available for subscribers to download by signing in here.
Read the article online at: https://www.worldcement.com/asia-pacific-rim/09102013/environmental_regulations_in_indian_cement_industry5_277/