Catalytic Destruction of a Surrogate Organic Hazardous Air Pollutant as a Potential Co-benefit for Coal-Fired Selective Catalytic Reduction Systems

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• 作者：Chun Wai Lee ; Yongxin Zhao ; Shengyong Lu ; William R. Stevens
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：March 17, 2016
• 年：2016
• 卷：30
• 期：3
• 页码：2240-2247
• 全文大小：303K
• ISSN：1520-5029

文摘

Catalytic destruction of benzene (C₆H₆), a surrogate for organic hazardous air pollutants (HAPs) produced from coal combustion, was investigated using a commercial selective catalytic reduction (SCR) catalyst for evaluating the potential co-benefit of the SCR technology for reducing organic HAP emissions. Bench-scale experiments were performed using simulated coal combustion flue gases under a broad range of SCR reaction conditions. C₆H₆ was added at 1 or 17 ppm into the flue gas mixtures with different concentrations of sulfur dioxide (SO₂), nitrogen oxide (NO), hydrogen chloride (HCl), and ammonia (NH₃) to simulate the combustion of bituminous and sub-bituminous coals. The destruction of the C₆H₆ across the catalyst was measured by a total hydrocarbon analyzer and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI–TOFMS) for the experiments with high (17 ppm) and low (1 ppm) concentrations of C₆H₆, respectively. The operating parameters of the SCR process, including the space velocity, temperature, and concentration of C₆H₆, were found to have a significant impact on the destruction of C₆H₆. The constituents of the flue gas had very little impact on the destruction, suggesting that the significant additional co-benefit of destruction of trace organic HAPs provided by the SCR process may be applicable to a wide variety of coals under different firing conditions. Destruction of C₆H₆ with high efficiencies is likely to occur concurrently with the reduction of NO during the SCR process without indication of carbon deposition on the catalyst.