AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Emission Characterization of a Large Scale Wood Pellet Combined Heat and Power System
KUI WANG, Philip K. Hopke, Devraj Thimmaiah, Clarkson University
Abstract Number: 191 Working Group: Combustion
Abstract SUNY_ESF has installed an 8 MMBTU wood pellet combined heat and power (CHP) system. Premium wood pellets were supplied by New England Wood Pellet (GHV=8500 btu/lb, 3~5% moisture, 0.4~0.6% ash). The present study focused on the efficiency determination of an electrostatic precipitator (ESP) that was installed to control PM emissions given its location in an urban area. Emissions (including particulate and gaseous emissions) of the boiler were characterized at 3 different loads: low, medium and high.
The tests were performed during a typical winter heating season using both EPA Method 5/202 and CTM-039 sampling trains operating at both upstream and downstream of the ESP. Particle mass concentrations were measured using a TEOM 1400a series and size distributions were obtained using a Fast Mobility Particle Sizer (TSI model 3091). Concentrations of gaseous species including CO, SO2 and NO were measured using Thermo gas analyzers. For each test, multiple filters were collected: 47 mm quartz, 47 mm Teflon, a 142 mm quartz, with PUF back-up.
Studies have shown that wood pellet boilers tend to have increasing thermal efficiency with increasing load. The boiler thermal efficiency determined in this case for 3 different loads are: 89.8%, 90.7% and 90.7%. The PM collection efficiencies of the ESP determined with the method 5/202 for the three loads were as: 96.3%, 92.6% and 85.1%. The PM2.5 emission rate at full load was determined at 0.114 lbs/MMBTU or 0.861 lbs/hr. Total particle number concentration was at the magnitude of 107/cm3 at high load. The NO emissions followed the steam production rate quite well with peak concentration at around 135 ppm at high load. CO emissions determined at about 150 ppm for high load with peak concentration at over 300 ppm.
The collected PM samples have been analyzed for their chemical constituents and these results will be presented.