By 2015 expenditures will rise to just under $5 billion annually. Part of this increase will be due to new hazardous air pollutant standards slated to be issued in the U.S. in June of this year. These standards are likely to result in over 100 scrubbers for HCl removal. An equal number of new baghouses will be needed to meet the toxic metal and particulate limits.
At present the number is uncertain but the rules could force most plants to install regenerative thermal oxidizers to meet the total hydrocarbon limits. Settlements of lawsuits are also resulting in the first selective catalytic reduction (SCR) units for NOx control. This approach is much more capital intensive than the selective, non-catalytic approach (SNCR) which involves only injection of urea or ammonia into the hot zones of the system.
SNCR is being used on a number of plants around the world. SCR has been applied only to a few plants.
Fabric filters have become the choice for new cement plants to control emissions from the kiln as well as the various transfer and grinding operations. With 50 percent of the world's production of cement and continuous expansion of infrastructure, China has become a very large market for fabric filters.
Europe continues to steadily reduce allowable emissions of acid gases and NOx. As a result, there are more HCl removal systems on cement plants in Europe than in any other continent. This is despite the relatively small cement production. Germany produces only 1.3 percent of the world's cement compared to 1.9 percent in Italy and 2.1 percent in Spain.
The location of the cement production will be shaped by the regulations. The Portland Cement Association predicts that without the new toxic standards, cement imports to the U.S. will be 18 percent of the total in 2020. With the regulations, the imports will rise to 33 percent.
Mercury control expenditures are likely to rise. It is estimated that Chinese mercury emissions from cement plants are 75 tons per year. Chinese coal-fired power plants emit close to 100 tons/yr of mercury. This contrasts to U.S. cement plants which emit approximately 15 tons and U.S. coal plants with emissions of 50 tons. Elemental mercury represents a significant portion of total cement plant mercury emissions. In the elemental state, mercury travels on an intercontinental basis making it a global problem.
A number of cement plants operate electrostatic precipitators for particulate removal. With the passage of more stringent emission limits, these plants are investing in upgrades. One such upgrade involves replacing the conventional transformer-rectifiers with switch mode power supplies. In addition to the upgrades, the supply of replacement rappers and other components is a significant business for the pollution control industry. The trend to replace electrostatic precipitators with baghouses is continuing with substantial activity in the Ukraine and other former Soviet countries as well as in Asia.
There is a big opportunity for innovative technology. The variation, in the level of pollutants from one plant to another, dictates that solutions be tailored to individual plant needs. One plant may need to remove 99 percent of the mercury due to the fact that the local limestone has unusually high mercury content. Importing limestone from some distance would not be economical. Therefore a new approach will be needed. One may be the two-stage scrubber system. The first stage is the HCl scrubber and the second stage is the SO2 scrubber. Incinerators in Europe are making commercial hydrochloric acid with this technology. At the same time, they are achieving very high mercury removal.
With the climate change initiatives there is interest in alternative fuels for cement plants. European cement producers are pursuing renewable biomass sources such as switchgrass. The fuel selection will impact the cost and performance of the air pollution control equipment.