Particulate characteristics data for the management of PM2.5 emissions from stationary combustion sources

Introduction of the limits for particles smaller than 2.5 μm or PM2.5 in the new ambient air quality standards in North America necessitates a reliable method to measure these very fine particles from different contributing sources. Canada recently developed such a method that offers credible emission characteristic data from stationary combustion systems that can be used in source apportionment modeling. The technique applies dilution sampling, cooling and humidification of stack gas to promote plume simulation, followed by comprehensive particulate analysis to provide secondary particulate concentrations that normally form under cooler ambient-like conditions. By adapting the size and chemical characterization techniques used in ambient particulate monitoring, the method enables derivation of emission source signature profiles from various combustion systems that are fingerprints of the fuel burned and the combustion equipment. Several source signature profiles for PM2.5 as well as PM10 (10 μm diameter) and total particulate matter have been developed using this methodology for several types of petroleum oils, bitumen emulsions, biofuels and pulverized coal blends using research and pilot-scale boilers and field sampling at Canadian industrial plants. Laboratory results and limited field data suggest that the particulate characteristics can be related to combustion unit configuration, fuel properties and operational conditions. PM 2.5 emissions from petroleum based fuel oils are most affected by fuel sulphur content whereas by blending with biodiesels reduces particulate emissions and sulphate content of particulate matter. Data from pulverized coal combustion showed a strong influence of mineral ash and sulphur content on particulate emissions and the efficiency of the particulate control device. The combustion equipment configuration also plays a critical role in combustion performance of the fuel, hence pollution emissions.Experimental results and field data are being examined for developing PM2.5 management strategies for industrial plant emissions, based on fuel modifications alone. For example, burning low sulphur and low asphaltene fuels or biofuel/petroleum blends and employing advanced burner designs could reduce emissions from oil combustion. For pulverized coal, burning of low sulphur and low ash coal blends combined with advanced particulate control devices would offer the best abatement options. The use of promising fuels such as bitumen emulsions and biodiesel blends would provide additional energy security as well as beneficial options for greenhouse gas reductions. PM 2.5 management options based on the fuel modification approach alone are given and overall plant emission reduction strategies could be further developed by incorporating additional economic and operational aspects.

Computational fluid dynamics (cfd)-simulations were carried out that focus on fine particle dynamics at high temperatures. A model was developed that includes particle transport due to electrophoresis as well as charging kinetics with respect to interaction of electrically charged fine particles and different ceramic collector materials at temperatures up to 1600–1700 K.Figure optionsDownload as PowerPoint slide