A typical 300 MW ultralow emission coal-fired power plant: source, distribution, emission, and control of polycyclic aromatic hydrocarbons

Abstract

• The LLT-ESP presents the best effect on the control of PAHs. • The APCDs have selectivity for the removal of PAHs with different phases and ring numbers. • Blending coal species guides the source reduction technology of PAHs. • The concentration of PAHs is effectively reduced by adsorbent injection coupled with an LLT-ESP. Polycyclic aromatic hydrocarbons (PAHs) are one of the dominant contributors to toxic organic pollutants emitted from coal combustion. In this study, the PAHs and condensable particulate matter (CPM) were sampled from a 300 MW ultralow emission coal-fired power plant. The effect of air pollution control devices (APCDs) on PAHs migration regularity and the influence of coal species changes on the emission of PAHs were studied. Note that the APCDs have definite selectivity for the removal of PAHs with different phases and ring numbers. The low-low temperature electrostatic precipitator (LLT-ESP) presented the best removal effect on PAHs (PAHs in flue gas, 29.92%; PAHs in CPM, 94.76%). The concentrations of PAHs were reduced at the outlet of the furnace (PAHs in flue gas, decreased from 3.318 to 2.850 μg/Nm 3 ) and at the stack (PAHs in flue gas, decreased from 4.737 to 3.008 μg/Nm 3 ; PAHs in CPM, decreased from 0.554 to 0.429 μg/Nm 3 ) by replacing bituminous coal with blended coal (lower volatiles) as fuel. The adsorbent injection coupled with LLT-ESP had a preferable removal effect on the PAHs (decreased from 4.949 to 1.451 μg/Nm 3 ), which was nearly 40% higher than the efficiency without the spray adsorbent.