Identification and Quantification of Environmental Issues of Aging Coal-Based Power Plant—Case Study

Abstract

This research has focused on three environmental issues: (1) fugitive dust emissions; (2) water management; and (3) operational parameters (such as thermal efficiency) of aging coal-based thermal power plants, using a case study. Regarding dust emissions, it was observed that the identified sources are fugitive in nature and contribute to a significant loss of raw material and particulate emissions. These sources include coal dust emissions from a wagon tippler area, ball mill operations, and leakage from the ash hoppers of electrostatic precipitators. In situ measurements of air quality and meteorological measurements were undertaken to estimate the emissions from a wagon tippler area, and a mass balance technique was applied across other operations to estimate the emissions. These fugitive emissions were about 98% of the total particulate emissions and the remaining 2% emissions were from the stack. The losses of water in various unit operations were also examined. The sources of water losses include the clariflocculator, the demineralization plant, and auxiliary water cooling of motors and pumps. The operational parameters such as auxiliary power requirement and thermal efficiency that indirectly affect the environment were also studied. The auxiliary power requirement was estimated as 9 MW against the accepted requirement of 7 MW. The thermal efficiency of the plant was estimated to be 26%, against the acceptable level of 32% of such plants in India. This study suggests that a significant reduction in cost and improvements in the environment could be achieved if the plant could be operated at rated efficiencies. It was observed that nonpoint (fugitive) sources, although significant, are ignored.