Investigation of a NOx emission from coal power plants in Texas, United States and its impact on the environment

Texas is the largest state by area in the US after Alaska, and one of the top states in the production and consumption of electricity with many coal-fired plants. Coal-fired power plants emit greater than 70% of pollutants in the energy sector. When coal is burned to produce electricity, nitrogen oxides (NO_x) are released into the air, one of the main pollutants that threaten human health and lead to a large number of premature deaths. The key to effective air quality management is the strict compliance of all plants with emission standards. However, not all Texas coal plants have the environmental equipment to lower pollutant emissions. Nitrogen dioxide (NO₂) observations from the TROPOspheric Monitoring Instrument (TROPOMI) were used to evaluate the emissions for Texas power plants. Data from both the Emissions and Generation Resource Integrated Database (EGRID) and the Emissions Database for Global Atmospheric Research (EDGAR) were used to examine emissions. It was found that NO_x emissions for Texas power plants range from 1.53 kt/year to 10.99 kt/year, with the Martin Lake, Limestone and Fayette Power Project stations being the top emitters. WA Parish and Martin Lake stations have the strongest NO_x fluxes, with both exhibiting significant seasonal variability. Comparisons of bottom-up inventories for EDGAR and EGRID show a high correlation (r=0.956) and a low root mean square error (0.766). A more reasonable control policy would lead to much reduced NO_x emissions.