Emissions Monitoring

The production process of cement involves the release of certain gases into the atmosphere. These emissions are monitored and disclosed in accordance with applicable local, national, and, in some cases, international regulations. Various effective methods are employed to ensure compliance with emission limits.

Measurement and disclosure systems vary by company and country. To address this variability, the Cement Sustainability Initiative (CSI) developed a protocol for monitoring emissions. Particulate matter (PM), nitrogen oxides (NOx), and sulfur oxides (SOx) were identified as major pollutants due to their volume. Participating companies also committed to monitoring emissions of other substances, including dioxins, furans, volatile organic compounds, and heavy metals such as mercury, cadmium, and thallium. Additionally, emissions of other heavy metals, such as antimony, arsenic, lead, chromium, cobalt, copper, manganese, nickel, and vanadium, will also be monitored.

As part of this initiative, each company set individual goals and pledged to monitor and publish annual emissions data starting in 2006, based on common performance indicators agreed upon by CSI members. This effort provides cement industry stakeholders with clear and reliable information about emissions, their impacts, and the actions being taken to reduce them.

NOx Reduction in Canada

The companies of Votorantim Cimentos North America (VCNA) achieved an expressive reduction in NOx (carbon oxide) emissions at their facilities. With the use of SNCR (Selective Non-Catalytic Reduction), a method which injects ammonia or urea into clinker kiln exhausts, NOx levels were cut by as much as 40%.

Ammonia and NOx react chemically to form a water and nitrogen vapor. The release of the pollutant is monitored continuously, enabling the facility to adjust the amount of ammonia injected into the kilns. In this manner, VCNA companies managed to avoid releasing nearly six thousand metric tons of gas into the atmosphere.

In use at Votorantim Cimentos since 2004, the method is a new arrival to the cement industry. The system was chosen for being more economical and more efficient than SCR (Selective Catalytic Reduction), the method most commonly used in the sector. SNCR enabled the Canada-based company to bring its NOx emissions within Ontario’s provincial regulations. Suwannee, located in Branford, Florida (USA) was the first Votorantim plant to adopt the method.

SOx Reduction in the United States

The St. Marys cement plant reduced its SOx emissions by 56.5% in 2006. Faced with the initial target of a 49% decrease, the unit installed a lime injection system toward the end of 2005. Lime reacts with SOx to form calcium sulphide, which either remains in solid form or is collected by the sleeve filters.  

This measure enabled the facility to exceed its initial target and achieve a 56.5% drop in comparison with rates for the first nine months of 2006 and the same period of 2005. The system became operational in January 2006.

Commitments individually assumed by CSI companies

Implement the recommendations outlined in the Emissions Monitoring and Reporting Protocol.
Make data on emissions available and accessible to stakeholders by 2006.
Set emission reduction targets for all relevant pollutants and make the results public.

Results obtained by Votorantim Cimentos:

Based on CSI directives, VC established corporate guidelines for Emissions Monitoring and Reporting in December 2005;
Reduction targets: targets for reducing emissions in Votorantim Cimentos were defined internally in the year 2000, shortly after the accession of the company CSI. The targets were defined as: 5% reduction in emissions of NOx, Sox, and particulate matter (PM) in 2012, compared with the data of 2000. By 2011, there were declines of 7.7% in NOx and 1.7% in SOx. The main initiatives implemented in VC to obtain these results were: NOx reductions in Canada and SOx reductions in the USA.