Study of boron behaviour in two spanish coal combustion power plants

• Published in: Journal of environmental management 2011-10, Vol.92 (10), p.2586-2589
• Main Authors: Ochoa-González, Raquel, Cuesta, Aida Fuente, Córdoba, Patricia, Díaz-Somoano, Mercedes, Font, Oriol, López-Antón, M. Antonia, Querol, Xavier, Martínez-Tarazona, M. Rosa, Giménez, Antonio
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Boron; Boron - analysis; Boron determination; Boron partitioning; Byproducts; Chemical pollution; Chemicals; Coal; Coal - analysis; Coal Ash; Coal combustion; Coal-fired power plants; Coke; Combustion; Comparative analysis; Computing time; Conservation of Natural Resources - methods; Conservation, protection and management of environment and wildlife; Electric power generation; Electric power plants; Environmental degradation; Environmental Monitoring - methods; Environmental protection; Fires; Fly ash; Fuels; Fundamental and applied biological sciences. Psychology; Gases; General aspects; Industrial Waste; Petroleum; Power Plants; Spain; Waste management; Waste water; Water Pollution
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2011.05.028

A full-scale field study was carried out at two Spanish coal-fired power plants equipped with electrostatic precipitator (ESP) and wet flue gas desulfurisation (FGD) systems to investigate the distribution of boron in coals, solid by-products, wastewater streams and flue gases. The results were obtained from the simultaneous sampling of solid, liquid and gaseous streams and their subsequent analysis in two different laboratories for purposes of comparison. Although the final aim of this study was to evaluate the partitioning of boron in a (co-)combustion power plant, special attention was paid to the analytical procedure for boron determination. A sample preparation procedure was optimised for coal and combustion by-products to overcome some specific shortcomings of the currently used acid digestion methods. In addition boron mass balances and removal efficiencies in ESP and FGD devices were calculated. Mass balance closures between 83 and 149% were obtained. During coal combustion, 95% of the incoming boron was collected in the fly ashes. The use of petroleum coke as co-combustible produced a decrease in the removal efficiency of the ESP (87%). Nevertheless, more than 90% of the remaining gaseous boron was eliminated via the FGD in the wastewater discharged from the scrubber, thereby causing environmental problems. ► The fate of Boron during coal combustion was investigated. ► A sample preparation procedure for B analysis in coal and by-products was optimised. ► 95% of the incoming boron was collected in the fly ashes. ► The co-combustion of pet-coke produces a decrease in the ESP B removal efficiency. ► The remaining gaseous boron was eliminated via the FGD in the wastewater.