Emission Characteristics of Hazardous Atmospheric Pollutants from Ultra-low Emission Coal-fired Industrial Boilers in China

Abstract

This study comprehensively investigated the emission characteristics of primary air pollutants (PM, SO 2 and NO x ) and trace elements (As, Cd, Cr, Hg and Pb) from twelve coal-fired industrial boilers, nine of which were ultra-low emission (ULE) and three of which were non-ULE, based on field measurements. The concentrations, release ratios and relative enrichment factors (REFs) of the trace elements in both the coal and the bottom ash were obtained. Furthermore, the influence of atmospheric pollutant control devices (APCDs) on the emission concentrations and emission factors (EFs) of these pollutants and elements, as well as on their removal efficiencies, was analyzed. The average release ratios for Hg, Cr, Pb and As from the coal were 96.28%, 59.95%, 65.34% and 84.85%, respectively, whereas the average overall removal efficiencies for PM, SO2, NO x , Hg, Cr, Pb and As with the APCD configurations of the ULE coal-fired industrial boilers were 99.5%, 95.9%, 81.0%, 95.6%, 95.6%, 99.3% and 96.0%, respectively. Using selective non-catalytic reduction (SNCR), and a hybrid of selective non-catalytic reduction and selective catalytic reduction (SNCR-SCR) in the ULE boilers, the EFs of the NO x were 5.5 × 10 -1 kg t -1 and 4.9 × 10 -1 kg t -1 , respectively. Overall, the removal efficiencies for NO x and Hg were 2.1 and 2.8 times higher, respectively, with the ULE than the non-ULE coal-fired industrial boilers, which was mainly attributable to the higher denitrification efficiency, higher dedusting efficiency and higher liquid/gas (L/G) desulfurization ratio of the ULE boilers.

Partitioning and Emission Characteristics of Hg, Cr, Pb, and As Among Air Pollution Control Devices in Chinese Coal-Fired Industrial Boilers

“…The information of the tested CFIBs is listed in Table . Based on our previous research, grate furnace (GF) boilers and circulating fluidized bed (CFB) boilers are the two primary existing boiler types of CFIBs in China . The APCDs of six tested CFIBs in this study can cover the current main control technologies .…”

“…Based on our previous research, grate furnace (GF) boilers and circulating fluidized bed (CFB) boilers are the two primary existing boiler types of CFIBs in China . The APCDs of six tested CFIBs in this study can cover the current main control technologies . Meanwhile, six investigated CFIBs are located in Shandong, Hubei, Zhejiang, and Hebei province, covering main regions with a large number of CFIBs in China.…”

“…Currently, highly efficient air pollution control devices (APCDs) have been developed and applied in coal-fired power plants (CFPPs) to achieve ultralow emission (ULE). Coal-fired industrial boilers (CFIBs) are distributed in densely populated cities and suburban industrial regions. , Compared with CFPPs, the capacity and flue gas emissions of CFIBs are much smaller, APCDs of most CFIBs are relatively backward, and the operation and management level of these APCDs are poor, which results in high pollutant emissions and more harm to human health and environment. Hence, the TE emission from the coal combustion process in the industrial sector has aroused wide concern.…”

Computational modeling of flow field in boiler before and after urea injection under different conditions

“…With the improvement of environment protection requirements, the emission standards of NO x in coal-fired power plants are becoming more and more stringent [1]. At present the deep NO x emission reduction technologies of coal-fired power plants include flue gas circulation, reburning technology, air staging, low nitrogen burners, selective catalytic reduction and selective non-catalytic reduction (SNCR).…”

Characteristics of Chemical Composition and Particle Size Distribution from Real Coal-fired Circulating Fluidised Bed (CFB) Boiler

“…PM emissions from coal-fired boilers are an important source of atmospheric pollution (Xu et al, 2017;Yue et al, 2020). The size distribution of particulate matter (PM) is a significant PM attribute and has previously been investigated (Linak et al, 2002;Zhang et al, 2012).…”